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Keysight Technologies B1500A Self-Paced Training Manual
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Keysight Technologies B1500A Self-Paced Training Manual

Semiconductor device analyzer
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Keysight Technologies B1500A
Semiconductor Device Analyzer
Self-paced
Training Manual

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Summary of Contents for Keysight Technologies B1500A

  • Page 1 Keysight Technologies B1500A Semiconductor Device Analyzer Self-paced Training Manual...
  • Page 2 Notices Manual Part Number © Keysight Technologies 2005-2014 If software is for use in the performance of a U.S. Government prime contract or subcon- No part of this manual may be reproduced in B1500-90040 tract, Software is delivered and licensed as any form or by any means (including elec- “Commercial computer software”...

  • Page 5: In This Manual

    In This Manual This document is the self-paced training manual to help you to understand what is Keysight B1500A, what functions the B1500A has, how to use the B1500A, and what applications the B1500A contributes to. • Module 1. Introduction This module explains the product concept and the key features of the B1500A/ EasyEXPERT.

  • Page 6: Class Exercises

    Class Exercises Class exercises use the test setup listed below. The test setup data are only examples and included in the Demo.xpg file stored in Keysight B1500 Series Product Reference CD-ROM. Module Exercise Device Test setup/definition/data Page Module 1 no exercise Module 2 Id-Vd measurement MOSFET...
  • Page 7 NOTE .xtd files The \data folder stores some .xtd files. They are the application test definitions used by some class exercises. To use the definition file, import the file by using the Test Definition Import dialog box opened by clicking Library > Import Test Definition. The test definition data are only examples for the class exercises.

  • Page 8: Required Devices For Class Exercises

    Required Devices for Class Exercises To perform the class exercises, you need the device set (Keysight part number 04156-87001) which contains the following devices. Description Quantity N-channel MOSFET 2 ea. NPN Bipolar Transistor 1 ea. Red Miniature LED 1 ea. 0.1 F Capacitor 50 V 1 ea.

  • Page 9: Required Accessories For Class Exercises

    Designation Description Model No. Qty. Test Fixture 1 ea. 16442A or 16442B 28 pin socket module 1 ea. (B1500A-A5F) Connection wire 6 ea. Triaxial Cable 16494A 4 ea. Interlock Cable 16493J 1 ea. Kelvin Triaxial Cable, for Module 2 16493K 1 ea.
  • Page 10 To perform the flash memory class exercise in Module 5 and if you use the selector, you need the following accessories. Description Model No. Qty. SMU/PG selector with control cable 16440A 2 sets (B1500A-A04) Selector adapter with control cable 16445A 1 set Triaxial Cable 16494A or Total equivalent 7ea.
  • Page 11 Contents Module 1. Introduction • New Features • EasyEXPERT • To Perform Easy Application Test • User Interface • Modular Mainframe • SCUU/GSWU • • SMU/Pulse Generator Selector • B2200/E5250 Switch Control • Desktop EasyEXPERTagi Module 2. Basic Measurement • SMU Fundamentals •...
  • Page 12 Contents Module 3. Low Current Measurement • Low-Current Measurement Challenges • Calibration and Zero Cancel • Effect of Cable Movement • ASU for Ultra Low-Current Measurement • Low-Current Subthreshold • Trade-Off Speed Vs Accuracy • Low-Current Gummel Plot • Low-Current Gate Oxide Leakage Module 4.
  • Page 13 Contents Module 5. SPGU Control and Applications • High Voltage SPGU • SPGU Control • Pulse Generator Mode • Charge Pumping • Flash Memory Test • ALWG Mode Contents-3...
  • Page 15 Introduction...
  • Page 16 Module 1 Introduction Note:...
  • Page 17 Module 1 Introduction Note:...
  • Page 18 •Touch screen operation (with optional stylus pen) •Contextual softkeys & knob control •Optional USB keyboard & mouse Desktop EasyEXPERT software •Controlling B1500A, B1505A, 4155B/C, or 4156B/C by an external computer •Offline test development and data analysis 415x Setup File Converter •...
  • Page 19 Module 1 Introduction Instead of setting up the instrument hardware, the EasyEXPERT software focuses on the real task at hand for the engineer ---device characterization. All that you need to do is to connect the instrument to the device terminals as shown in the EasyEXPERT test parameters area. The EasyEXPERT software also provides the classic test mode that allows the 4155/4156 like measurement setup operation and the tracer test mode that suggests the new concept curve tracer operation.
  • Page 20 Step 3: Change the setup parameters (Device parameters and Test parameters) if you want. Step 4: Connect DUT, and click the Start button. The B1500A starts the selected test. Step 5: Analyze the measurement result data displayed on the Data Display window automatically opened after the test.
  • Page 21 Module 1 Introduction...
  • Page 22 Module 1 Introduction The following modules and accessories are available for the B1500A: •MFCMU: 1 kHz to 5 MHz CV capability (1 slot) •MPSMU: 100 mA/100 V force capability, 10 fA/0.5 uV measurement resolution (1 slot) •HRSMU: 100 mA/100 V force capability, 1 fA/0.5 uV measurement resolution (1 slot) •HPSMU: 1 A/200 V force capability, 10 fA/2 uV measurement resolution (2 slots)
  • Page 23 The SCUU removes all of these worries and makes connection simple and easy. In addition, the B1500A software automatically takes care of the multiplexing based upon the type of algorithm selected from the front panel.
  • Page 24 Module 1 Introduction The GSWU must be connected to the outer conductors of the manipulators/positioners connected to the Force1/CMUH and Force2/CMUL connectors of the SCUU. And the GSWU control cable must be connected between the GSWU and the SCUU. When the SMU paths are available for the manipulators/positioners, the GSWU opens between the outer conductors.
  • Page 25 Module 1 Introduction The high-resolution SMU (HRSMU) has an innate 1 fA & 0.5 uV measurement resolution. The optional ASU extends the HRSMU measurement resolution to 0.1 fA. The ASU has another feature, built-in switching capability. It can switch between the SMU and an auxiliary input (AUX input, two BNC).
  • Page 26 CONTROL Input connector of the second selector. Switching can be controlled by the B1500A/EasyEXPERT via the 16445A selector adapter. And the switching status is known by the status indicator. When the SMU indicator lights up, the SMU Input to Output path is made.
  • Page 27 In the classic test, the switch setup is sent to B2200/E5250 when a measurement start button is clicked. B1500A/EasyEXPERT also provides the semi-auto prober control script. The semi-auto prober can be controlled without programming. The prober control script supports the die move operation by using the following first three procedures in the repeat measurement setup and adds the subsite move operation by using the Subsite procedure in the quick test setup.
  • Page 28 Introduction The Desktop EasyEXPERT software provides the following additional advantages to the B1500A, allowing you to minimize the amount of offline tasks performed on B1500A and increase the working ratio for measurements. •Allows B1500A/B1505A/4155B/4155C/4156B/4156C to be controlled from an external computer via GPIB while online.

  • Page 29: Basic Measurement

    Basic Measurement...
  • Page 30 Module 2 Basic Measurement Note:...
  • Page 31 - Current source while monitoring current (force side measurement) - Current source while monitoring voltage (compliance side measurement) The force side measurement is available when the B1500A is in the GPIB remote mode, and is not available when EasyEXPERT is used.
  • Page 32 Module 2 Basic Measurement The SMUs can now sweep up to a value and then back down (double sweep). This feature is useful when the device must be tested without abruptly removing the forcing condition. Log sweeps are required any time the measurement results span many decades, such as a MOS subthreshold curve.
  • Page 33 Module 2 Basic Measurement A subordinate sweep variable (VAR2) may be combined with the basic sweep variable (VAR1). This corresponds to the step knob and sweep knob of a curve tracer. This produces a family of curves. VAR2 may be called the secondary sweep. Another useful combination is a synchronous sweep.
  • Page 34 Module 2 Basic Measurement The basic semiconductor device is the 4-terminal MOS transistor. By assigning an SMU to each terminal, you have complete flexibility to make any measurement without having to change the device hookup. No relays are required to switch any connection; this is all done by changing the mode of the SMU from the front panel.
  • Page 35 Module 2 Basic Measurement Note:...
  • Page 36 Connect corresponding numbers. On the 16442A/B fixture use the numbers labeled 1 - 6, not 1 - 3. Your B1500A may not match the SMU configuration shown in this figure. Note that SMU1 is the module top of the GNDU (ground unit). The SMU number become large from bottom to top as shown.
  • Page 37 Module 2 Basic Measurement This picture shows the triax cables connected to the right set of connectors which is wrong. The 4 triax cables must be connected to the left set of connectors (FORCE). You will likely see this type of erroneous response with clamping at 10 mA (no trace above 10 mA even though compliance is set much higher).
  • Page 38 Module 2 Basic Measurement Tracer Test is the best way for performing I-V measurement easily and quickly. Display the Tracer Test screen and set the measurement condition. You can finish the setup by the following five steps. 1. Click Add button and add SMU1, SMU2, SMU3, and SMU4. 2.
  • Page 39 Module 2 Basic Measurement Note: 2-11...
  • Page 40 Module 2 Basic Measurement With the 16442A/B fixture, note that there are two SMU numbering schemes..3 SMUs with force and sense, or six SMUs with force only. For this class example we will use the six (6) SMU scheme. On older fixtures, this scheme is shown in light blue lettering. In newer fixtures, this scheme is shown in white reverse background lettering.
  • Page 41 Module 2 Basic Measurement Note: 2-13...
  • Page 42 Module 2 Basic Measurement Note: 2-14...
  • Page 43 Module 2 Basic Measurement In the Tracer Test mode, the tracer test setup will be recalled as the tracer test setup. However, the setup will be recalled as the Multi Channel I/V Sweep setup in the Classic Test mode as shown in the next page.
  • Page 44 Module 2 Basic Measurement Change the test mode to Classic Test, and perform the procedure as shown. Display the Measurement Setup, Display Setup, and so on. And check the conversion result of the setup data. Also change the setup as you desire. You can set the details of measurement conditions which are not supported by the Tracer Test mode.
  • Page 45 Module 2 Basic Measurement Note: 2-17...
  • Page 46 Module 2 Basic Measurement Note: 2-18...
  • Page 47 Module 2 Basic Measurement After you get the IDVD setup data, you will see the Classic Test setup screen as shown. The Channel Setup screen allows the user to assign a meaningful name to the force/meas functions of each SMU. These names may be used in the Function Setup screen to define algebraic expressions. The Mode column is used to determine whether a particular SMU is to be used to 1) force current and measure voltage (I mode), or 2) force voltage and measure current (V mode).
  • Page 48 Module 2 Basic Measurement The Measurement Setup screen is shown here. The variables VAR1 and VAR2 define the sweep parameters. In a case where two sweep parameters are defined, the second parameter (VAR2) is called the subordinate (secondary) sweep parameter. This means that the primary parameter will be swept once for each discrete value of the subordinate parameter.
  • Page 49 Module 2 Basic Measurement The Display Setup screen allows you to set the X-Y graph axes. The display setup is divorced from the measurement setup to allow the user to tailor the view to a particular region of interest. This screen also allows you to set data variable names to be displayed in the List Display and Parameters areas on the Data Display window which is opened when the measurement is started.
  • Page 50 Module 2 Basic Measurement This window displays measurement result graph, list, and parameter values. Markers are used to traverse the actual measurement data. Markers cannot be placed anywhere on the screen except on an actual measurement trace. They are denoted with a small circle. One moves the markers with the front panel rotary pulse generator (RPG) knob, mouse, or touch screen.
  • Page 51 Module 2 Basic Measurement The List Display corresponds exactly with the Graph Plot. Even the highlighted line of data corresponds to the marker position on the Graph Plot. Up to twenty columns of data can be set on the List Display. Note that the Graph Plot can only plot nine columns (X, Y1 to Y8).
  • Page 52 Module 2 Basic Measurement Note: 2-24...
  • Page 53 Module 2 Basic Measurement Recall Id-Vd application test setup data. After you get the Id-Vd setup data, you will see the Application Test setup screen as shown. Test Parameters area shows the device connection information and allows the user to set the SMU outputs.
  • Page 54 Module 2 Basic Measurement The Extended Setup dialog box allows the user to set the additional test setup parameters. In the Id- Vd setup, the additional parameters are source voltage, maximum gate current, maximum substrate current, integration time, hold time, and delay time. 2-26...
  • Page 55 Module 2 Basic Measurement You can double the voltage or current output by combining SMUs. The VAR1’ mode allows a second SMU to be swept in tandem with the first. 2-27...
  • Page 56 Module 2 Basic Measurement Higher voltages are necessary to observe breakdown conditions, such as BVceo. In the case of BVceo the base must be open (no SMU) or the SMU must be set as a current source with I=0. One SMU must sweep in a positive direction while the other sweeps in a negative direction. The result is a floating measurement with double the differential voltage.
  • Page 57 Module 2 Basic Measurement The voltage across the resistor (VR) is the difference between V1 and V2. A simple user function can be used to plot VR. 2-29...
  • Page 58 Module 2 Basic Measurement The VAR1’ mode is used to synchronously sweep two SMUs. Setting Ratio = -1 forces one SMU to sweep in the opposite direction of the other. 2-30...
  • Page 59 Module 2 Basic Measurement The result is a clean 200 V sweep. Remember that there is a serious shocking hazard. The interlock cable is necessary for any voltage sweep greater than 42 V. 2-31...
  • Page 60 Module 2 Basic Measurement Two SMUs can be operated in parallel. The trick is to not use any SMU as COMMON. HRSMU and MPSMU can only sink 100 mA. Use GNDU (ground unit) or the chassis to sink the 200 mA of current. Chassis noise level will not affect the measurement.
  • Page 61 Module 2 Basic Measurement A user function totals the current in both SMUs. 2-33...
  • Page 62 Module 2 Basic Measurement The VAR1’ mode with Ratio = 1 forces two SMUs to sweep the same voltage. 2-34...
  • Page 63 Module 2 Basic Measurement The result is a clean sweep to 200 mV. It shows the current measurement data near 200 mA. 2-35...
  • Page 64 Module 2 Basic Measurement The series resistor (approx. 1 Mohm) is mounted on each SMU. The series resistor may be used for the device protection, negative resistance measurement, and so on. It depends on the characteristics of test device and measurement environment. Note that the series resistor may not effective for device protection.
  • Page 65 Module 2 Basic Measurement 2-37...
  • Page 66 Module 2 Basic Measurement 2-38...
  • Page 67 Module 2 Basic Measurement The measurement result without the SMU series resistor shows about 0.5 M ohm I-V characteristics. By setting the SMU series resistor, the measurement result shows about 1.5 M ohm characteristics. The IV-res setup uses the analysis function and auto analysis function to draw the regression line and get the slope of the line.
  • Page 68 Module 2 Basic Measurement To change the SMU series resistor setup, open the Advanced Setup window by clicking the Advanced button on the Measurement Setup screen. And specify NONE or 1MOHM by using the Series R pull down menu. In the power on state, the Classic Test sets the Series R to NONE. 2-40...
  • Page 69 Module 2 Basic Measurement The analysis function and the auto analysis function are used to calculate the resistance value. This auto analysis setup will draw the regression line for the X-Y1 curve. And the analysis function @L1G is used to pass the slope of the line to the R1 variable. 2-41...
  • Page 70 Module 2 Basic Measurement If you use the SMU series resistor, you will need to compensate the measurement data to eliminate the effects of the series resistor (1 M ohm). This is a compensation example by using the following user function. Vcalc = V1 –...
  • Page 71 Module 2 Basic Measurement The B1500A is a precision instrument. However, the ability to make precise and reliable measurements may be compromised by your fixturing to the device. The following section provides some theory and hints for making sense out of cabling and fixturing issues.
  • Page 72 Module 2 Basic Measurement The guard connection is needed for measurement < 1 nA. Below 1 nA a regular coax cable's capacitance dominates over the DUT (device under test) capacitance. What you see is cable charging current. I = C(dv/dt) where dv/dt is the rate of change of SMU voltage from one step to the next of a coax cable with no guard.
  • Page 73 Module 2 Basic Measurement Shown above are typical capacitance and series resistance of the force line. If cables are too long, high capacitance may cause the SMU to oscillate. Keep the force-guard cable capacitance less than 600 pF. Similarly, the guard-shield capacitance must be less than 5000 pF. Note the rather high force resistance.
  • Page 74 Module 2 Basic Measurement The triax cable is a special low dielectric loss, high impedance cable. This cable may be used down to fA levels when properly used with a guarded probe. The guard voltage tracks the force voltage exactly, so that no voltage drop can exist between guard and force. This eliminates the capacitive loading that would otherwise limit low current measurements.
  • Page 75 The internal sensing resistor Rs is the only feedback path without the Kelvin connection. Note that the B1500A operates just fine without the sense cable. This is important to know because in general you do not need the sensing Kelvin connection. Most MOS measurements are high impedance and the residual cable loss is insignificant.
  • Page 76 The triaxial cables are good for low current measurements. However, two cables are necessary for low resistance Kelvin measurements. Keysight Technologies designed a special Kelvin triaxial cable for the precision semiconductor parameter analyzers. This cable is optimized for both low current and low resistance measurement.
  • Page 77 Module 2 Basic Measurement In the example above, the device is connected with a SMU on the base sweeping current, a voltmeter on the collector, and the emitter is grounded with a Kelvin SMU. The base SMU does not have to be Kelvin since we are only forcing current and do not care about measuring the cable loss in the base.
  • Page 78 Module 2 Basic Measurement The purpose of this class exercise is to familiarize yourself with making a Kelvin measurement. Low resistance measurements such as Re, Rc (bipolar) or Rs, Rd (MOS) are excellent examples because the resistances are of the same approximate magnitude as cable resistances. Kelvin techniques must be used, or your error can be as much as 100 %.
  • Page 79 Module 2 Basic Measurement This class example requires a Kelvin triaxial cable. If the Kelvin cable is not available, substitute two standard triax cables. SMUs 1,2,3 can all be connected with Kelvin triaxial cables, but only SMU3 requires the Kelvin connection.
  • Page 80 Module 2 Basic Measurement Connect jumper leads as shown. Where, the SMU4 F terminal is connected to the B1500A’s SMU3 Sense connector. So the couple of the SMU3 F and SMU4 F terminals makes a Kelvin terminal. Locate the bipolar transistor in the corner of the socket as shown, with the flat side of the device facing toward you.
  • Page 81 Module 2 Basic Measurement Click the Single button to make a new measurement. You should see a response similar to this, will the analysis line correctly overlaying the curve. 2-53...
  • Page 82 Module 2 Basic Measurement Remove the jumper lead connected between the terminal 17 and the SMU4 F terminal. And click the Append button to add another measurement to the graph. Now you see the very large difference between Kelvin and non-Kelvin measurements when the resistance is low.
  • Page 83 Module 2 Basic Measurement Photo of SMU cable connection to a Cascade Microtech Summit probe station. The Kelvin triaxial cables mate directly to the probe station. 2-55...
  • Page 84 Module 2 Basic Measurement This is a "hybrid" Kelvin connection. Cable resistance from SMU is eliminated by shorting FORCE and SENSE lines inside the prober. A short line to the probe makes the non-Kelvin connection, simplifying hookup. 2-56...
  • Page 85 Module 2 Basic Measurement The next section sheds light on the confusing topic of connection to the device under test. Without proper considerations, noise, capacitance, sense resistance, or inductance will result in unacceptable measurement error. 2-57...
  • Page 86 Module 2 Basic Measurement These probes are guarded within 2mm of the probe tip, ideal for low current applications. The Kelvin triax probe is the ideal mate for the Kelvin triax cable. A third variation of these probes is a Kelvin triax probe with only one probe.
  • Page 87 Above 1 nA guarding is of little use. Cable capacitance has a negligible effect on the bias port. Use the floating guard triax(m) to BNC(f) adapter at the B1500A rear panel. Then use standard coax BNC cables. Use sense to minimize series resistance error. 100 mV errors can occur in bias voltages if remote sensing is not used.
  • Page 88 Module 2 Basic Measurement To prevent shock hazard, the B1500A will not operate above 42 V, unless you connect the interlock circuit. The interlock connection is required when the voltage exceeds 42 V or when the program memory is used in a control program.
  • Page 89 Module 2 Basic Measurement The 16493J interlock cable is designed to be connected directly between the B1500A’s interlock connector and the 16442A/B. If the fixture lid is closed, internal switch is closed, and then the B1500A can perform measurement up to 100 volts; 200 V with the HPSMU.
  • Page 90 This mates directly with the 16435A Interlock Cable Adapter mentioned on the previous page. Note You will notice that the socket modules for Keysight Technologies entire DC parametric product line are interchangeable. So socket modules that came with the 4142, 4145, 4155, or 4156 will work with the 16058A, 16088A/B, and 16442A/B fixtures.

  • Page 91: Low Current Measurement

    Low Current Measurement...
  • Page 92 Module 3 Low Current Measurement This module is primarily written for the B1500A installed with the HRSMU (high resolution SMU) and covers sub pA measurement techniques. Course exercises are included which fully explore speed vs. accuracy issues to the fA level.
  • Page 93 Module 3 Low Current Measurement Making wafer level measurements to fA levels is easy and routine using proper measurement procedures on a low noise probe station. This module explains how.
  • Page 94 The probes themselves must be guarded. The B1500A defaults at bootup to setup conditions which are not optimized for ultra low current. This is desirable because there is a large trade-off between speed and ultra-low current accuracy.
  • Page 95 Module 3 Low Current Measurement This check list covers most sources of noise or stray capacitance. In a "clean" probing environment the B1500A can be used with short integration time and no delay time between steps.
  • Page 96 Module 3 Low Current Measurement This is a systematic strategy for focusing in on the sources of noise and error. You can be very surprised. Some prober cable is not low loss. You may see popping noise due to relaxing of PTFE fiber in the cables, high current level due to poor dielectric loss, etc.
  • Page 97 Use the Calibration window to perform the SMU calibration and zero cancel. See the next page. NOTE: The B1500A provides the auto calibration function which automatically starts calibration for all modules every 30 minutes if the output switches of all modules are off for 30 minutes. You can enable or disable this function on the Calibration window.
  • Page 98 Module 3 Low Current Measurement Click Calibration button to open the Calibration window. SMU calibration is performed on the SMU Calibration tab screen. Specify the modules for calibration by checking the left check box and click Start Calibration button to start calibration. If ASU (atto sense/switch unit) is connected and 1 pA range is used for measurement, check Full Range Calibration check box before clicking Start Calibration button.
  • Page 99 Module 3 Low Current Measurement The following pages lead you step-by-step through the "ZERO CHECK" class exercise. This is the logical place to start if you are debugging a "noisy" test environment. You will create an algorithm to look at the low level measurement capability of a SMU. On the next page you will see the expected curve when looking into an open at the rear panel.
  • Page 100 Module 3 Low Current Measurement With slight modification of the default SMU settings of Classic Test I/V Sweep, you can check the conditions of your measurement system. This is a typical plot when no cable is attached to the SMU port.
  • Page 101 Module 3 Low Current Measurement Click the Classic Test tab, I/V Sweep, and Select to display the Channel Setup screen. On this display, delete the rows of SMU1 and SMU2. Change the Mode of SMU4 to V. Change the Function of SMU4 to VAR1. This setup will be used for checking the zero measurement on SMU4.
  • Page 102 Module 3 Low Current Measurement This default sweep setup is enough for the Zero Check measurement. The sweep steps are small (10 mV) and that is ideal for checking current at fA levels. Also the sweep starts at 0, so no big discontinuities on the first step of the sweep. There is no need to change anything on the Measurement Setup screen.
  • Page 103 Module 3 Low Current Measurement You must change the range setting from the default of LIMITED 1 nA to LIMITED 10 pA or to AUTO. Otherwise you will have 100 fA resolution instead of the best 1 fA resolution possible. Also change the High Resolution ADC Mode to PLC and Factor to 16.
  • Page 104 Module 3 Low Current Measurement The best check is done with a LINEAR scale which brackets either side of ZERO by 100 fA or less. A log scale is particularly unacceptable, Log plots of zero are not possible, and all readings of a log plot must be either all positive or all negative.
  • Page 105 Here we see the effect of connecting a cable to the open SMU port of the B1500A. The discontinuity lasted for 50 seconds of a 2 minute sweep from 0 to 1 volt in 10 mV steps.
  • Page 106 Module 3 Low Current Measurement As you can see, your fixturing must be free from vibration. Bending cables during a test is another NO NO. The above measurements were made on a single triax cable for classic parameter analyzers. The Kelvin triax cable is less sensitive to movement (triboelectric effects). However, either cable works fine to fA level if the cables are reasonably still...i.e.
  • Page 107 For ultra low current measurement, use ASU (atto sense/switch unit). The HRSMU has an innate 1 fA measurement resolution. And the ASU extends it to 0.1 fA. Note that the ASU must be connected to the HRSMU before turning on the B1500A. 3-17...
  • Page 108 If the ASU Serial Number field shows its serial number, the HRSMU-ASU combination is correct. If the ASU Serial Number field shows *s/n mismatch, the combination is wrong. The B1500A can work with this wrong combination however it cannot satisfy its specifications. The specifications are guaranteed for the correct combination of HRSMU and ASU.
  • Page 109 Module 3 Low Current Measurement This slide shows the open measurement results with ASU and without ASU. The ASU provides the 1 pA measurement range and the stable measurement results as shown. The 1 pA range is disabled with the default setting. To enable the 1 pA range, set the ranging mode to LIMITED 1 pA (1 pA limited auto ranging) or FIXED 1 pA (1 pA fixed range).
  • Page 110 Module 3 Low Current Measurement The following pages show a typical plot of the subthreshold curves for this class exercise, device connections, and setup changes with comments. 3-20...
  • Page 111 On older fixtures, this scheme is shown in light blue lettering. In newer fixtures, this scheme is shown in white reverse background lettering. Connect the cables between the B1500A and test fixture as follows. SMU1 : SMU1 SMU2 : SMU2...
  • Page 112 Module 3 Low Current Measurement With lid closed, you should see this typical response using the IDVG setup data. If the subthreshold region is much higher, at the pA or nA level, the MOS device may be statically damaged. Replace the device using the handling procedure detailed on the previous page.
  • Page 113 Module 3 Low Current Measurement You can trade off speed vs accuracy by varying the LIMITED range setting or the integration time setting. The 100 nA range will speed up the test but you will lose low-end resolution. Try setting LIMITED to 10 pA range or 100 pA range.
  • Page 114 Module 3 Low Current Measurement The "Gummel Plot" is an excellent low current measurement to make on a bipolar transistor. It plots log base current and log collector current against the same bias voltage. A good bipolar device has constant gain over a wide bias range (both curves are linear and parallel). Low level base and collector currents can be measured to the fA level on small signal devices.
  • Page 115 Module 3 Low Current Measurement The following pages will lead you through the setup and measurement procedure for a low current Gummel measurement. Single triaxial cable connections to the force lines of SMUs 2, 3, and 4 are fine for this test. Kelvin triaxial cables are not necessary. 3-25...
  • Page 116 With the 16442A/B fixture, note that there are two SMU numbering schemes..3 SMUs with force and sense, or six SMUs with force only. For this class example we will use the six (6) SMU scheme. Connect the cables between the B1500A and test fixture as follows. SMU1 : SMU1...
  • Page 117 Module 3 Low Current Measurement Ve is swept below ground level to keep positive bias on the NPN device. 3-27...
  • Page 118 Module 3 Low Current Measurement Medium integration smoothes the plot at the ultra low levels. Make sure the range is set to AUTO or LIMITED to lowest current range: HRSMU: 10 pA MPSMU: 1 nA HPSMU: 1 nA 3-28...
  • Page 119 Module 3 Low Current Measurement This curve shows a normal gummel characteristic of the bipolar transistor. The collector current is linear when plotted on log scale from 10 mA down to fA levels. Keep the fixture lid closed and do not bump any part of the setup during the measurement. (End of This Class Exercise) 3-29...
  • Page 120 Module 3 Low Current Measurement This is a common occurrence when high frequency bipolar transistors are tested with jumper lead connections. When RF couples in the air to the base lead, there can be enough DC rectification to increase the base current bias. This causes positive feedback. At some point along the curve, there will be enough feedback to abruptly turn on the transistor (steep increase in base and collector current).
  • Page 121 Module 3 Low Current Measurement This curve shows the high quality measurement that you would typically expect with the B1500A and a well guarded probe station. The MARKER is sitting at 5.3 fA near the subthreshold region. To get best ultra low current accuracy, zero the SMU offset error just prior to taking the measurement by using the Calibration window.
  • Page 122 To prevent charging current due to residual cable or probe capacitance, you should limit the STEP size to 100 mV. The B1500A has a built-in delay time on the low current ranges, and you do not need to add extra time.
  • Page 123 Module 3 Low Current Measurement You can see an initial high current that drops off after a few measurements. This is the effect when delay time is set to zero. Any residual capacitance due to un-guarded probes is the cause. This effect is minimal in this case due to the use of fully guarded probes to within 2 mm of the probe tip.
  • Page 124 (1 fA resolution). The factory default of LIMITED 1 nA gives 100 fA resolution and is adequate for most measurements. Since the B1500A can trade off speed for resolution, you get better speed performance by limiting current ranging.
  • Page 125 Module 3 Low Current Measurement Gate oxide leakage tests are complicated by the fact that there is an electrical connection to the back of the wafer. The chuck must be insulated and guarded to get meaningful low current results. The huge capacitance of the chuck surface would cause charging currents which would swamp out the low level currents you are trying to measure through the oxide.
  • Page 126 MOS FET. The MARKER is set to -27.590 mA. This is the point at which rupture of the gate oxide occurred. The B1500A has the sweep abort function which automatically aborts sweep measurement when any abnormal occurs.
  • Page 127 Module 3 Low Current Measurement A 3 second delay at the beginning of the measurement will be required. The SMU must initially step from 0 to -5 V, a very large step. Fully guarded probes to within 2 mm of probe tip and fully guarded chuck eliminated the need for delays at every measurement point.
  • Page 128 Module 3 Low Current Measurement This is a simplified block diagram of the prober requirements for a guarded chuck connection. When implemented properly, very fast low level sweeps are possible due to the elimination of stray capacitance at the probes (wafer top side) as well as in the chuck (wafer bottom side). 3-38...

  • Page 129: Capacitance Measurement

    Capacitance Measurement...
  • Page 130 Module 4 Capacitance Measurement...
  • Page 131 Capacitance Measurement The multi frequency CMU (capacitance measurement unit) adds the CV measurement capability to the B1500A. You can now perform both IV and CV measurements by using the B1500A one box without an external capacitance meter. Key features of the CMU are listed above.
  • Page 132 Module 4 Capacitance Measurement Generally, any mutual inductance, interference of the measurement signals, and unwanted residual factors in the connection method incidental to ordinary termination methods will have significant effects on the measurements, especially at a high frequency. The CMU employs the four-terminal pair (4TP) measurement configuration which permits easy, stable, and accurate measurements and avoids the measurement limitations inherent to such factors.
  • Page 133 Module 4 Capacitance Measurement CMU supports the linear single sweep and the linear double sweep. The CMU can sweep up to a value and then back down (double sweep). This feature is useful when the device must be tested without abruptly removing the forcing condition. The CMU can force up to 25 V DC bias.
  • Page 134 Module 4 Capacitance Measurement...
  • Page 135 One side of the CMU cable forms the attachment used to join and fix it to the CMU. And the other side provides four BNC connectors used to connect the fixture as shown. Connect the cables between the B1500A and the test fixture as follows. SMU1 : SMU1...
  • Page 136 Module 4 Capacitance Measurement With the 16442A/B fixture, note that there are two SMU numbering schemes..3 SMUs with force and sense, or six SMUs with force only. For this class example we will use the six (6) SMU scheme. On older fixtures, this scheme is shown in light blue lettering. In newer fixtures, this scheme is shown in white reverse background lettering.
  • Page 137 Module 4 Capacitance Measurement This is the measurement example of the MOS FET Cgs-Vg characteristics. To make the measurement, set SMU1 and SMU2 to COMMON. And set the CMU as shown in the next page.
  • Page 138 Module 4 Capacitance Measurement 1. Select the Cp-G mode, and enter the C Name and G Name. 2. Set the Start, Stop, and Step to specify the DC bias sweep condition. 3. Set the Frequency List to specify the measurement frequency. 4.
  • Page 139 Module 4 Capacitance Measurement CMU is equipped with the error correction function used to realize accurate impedance measurements. The correction function minimizes the effects of the error elements in the extension cables and the DUT interface such as manipulator and probe card. At least perform the phase compensation and the open correction.
  • Page 140 Module 4 Capacitance Measurement Open the Calibration window and click the CMU Calibration tab to perform the CMU calibration. At first, open the measurement terminals for CMUH and CMUL, and perform the Phase Compensation by clicking the Measure… button. After the phase compensation, perform the Open Correction by clicking the Measure… button. If you can make the short condition, short the measurement terminals, and perform the Short Correction.
  • Page 141 The SCUU removes all of these worries and makes connection simple and easy. In addition, the B1500A software automatically takes care of the multiplexing based upon the type of algorithm selected from the front panel. 4-13...
  • Page 142 Module 4 Capacitance Measurement Before connecting the SCUU, turn the B1500A off. And restart the B1500A after connection is completed. The B1500A cannot recognize the SCUU without restart after connection. Use normal triaxial cables or Kelvin triaxial cables to connect between the SCUU and the test fixture.
  • Page 143 Module 4 Capacitance Measurement To install the SCUU near the manipulators/positioners, use the N1301A-102 SCUU cable. To realize accurate capacitance measurement, use the N1301A-200/201/202 GSWU & cable. See the next section. 4-15...
  • Page 144 The residual inductance will be roughly 1/10 to 1/30 compared with no return path. To make the return path, use the GSWU (Guard Switch Unit) which was developed to make the setup easily. The GSWU is the accessory available only for the B1500A equipped with the CMU and the SCUU.
  • Page 145 Module 4 Capacitance Measurement 1. Place the GSWU at the appropriate location near the manipulators/positioners. 2. Connect the GSWU control cable between the GSWU and the SCUU. 3. Connect a clip wire between the GSWU and the outer conductor of the manipulator/positioner connected to Force1/CMUH.
  • Page 146 Module 4 Capacitance Measurement The ASU (Atto Sense and Switch Unit) is available for the B1500A installed with the HRSMU. Using the ASU permits use of the 1 pA range. Also the ASU can switch the measurement resources, HRSMU or an instrument connected to the AUX input connectors.
  • Page 147 The triax cable and the D-sub cable are connected between ASU and HRSMU. Before starting the ASU connection, turn the B1500A off. And restart the B1500A after the connection is completed. The B1500A cannot recognize the ASUs without restart after the connection.
  • Page 148 If the ASU Serial Number field shows its serial number, the HRSMU-ASU combination is correct. If the ASU Serial Number field shows *s/n mismatch, the combination is wrong. The B1500A can work with this wrong combination however it cannot satisfy its specifications. The specifications are guaranteed for the correct combination of HRSMU and ASU.

  • Page 149: Spgu Control And Applications

    SPGU Control and Applications...
  • Page 150 Module 5 SPGU Control and Applications...
  • Page 151 Module 5 SPGU Control and Applications High Voltage Semiconductor Pulse Generator Unit (HVSPGU) is specially designed for semiconductor test. Most pulse generators' output voltage is less than 10 V with 50 ohm impedance. However, in semiconductor test (especially reliability test) 30 to 40 V capability is required for the flash memory write/erase cycle test.
  • Page 152 SPGU Control and Applications The B1500A can install the maximum of five SPGUs. The SPGUs must be installed in the contiguous slots from the slot 1. Where the SPGU installed in the slot 1 is the master SPGU. The channel number PG1 is assigned for the Output 1 of the master SPGU.
  • Page 153 Module 5 SPGU Control and Applications The pulse switch is the built-in high speed analog switch to open/close the SPGU output for each channel. This switch is used in the write/erase cycle of the NOR type flash memory cell test. This dramatically improves throughput of the endurance test (write/erase lifetime reliability test).
  • Page 154 Module 5 SPGU Control and Applications The voltage actually applied to the DUT depends on it’s impedance. This behavior is very common among the instrumentations like DC power supply and pulse generators. In this meaning, SMU is very special because the output of SMU is controlled by the feedback loop from the voltage monitored by the sense terminal.
  • Page 155 Module 5 SPGU Control and Applications Here is the example of the voltage error due to the mismatch of the load impedance setting. If the load impedance is set to 50 ohm when the actual load impedance is 1 Mohm, the voltage actually applied to the DUT is about double the setting value.
  • Page 156 Module 5 SPGU Control and Applications Keysight 16493P is the connection cable for the SPGU outputs.
  • Page 157 The SPGU provides two output mode, VPULSE (pulse generator mode) and ALWG (arbitrary linear waveform generator mode). And the same mode must be set to the all output channels. The B1500A can have the maximum of ten SPGU output channels.
  • Page 158 Module 5 SPGU Control and Applications If the SPGU output mode is set to VPULSE, the Pulse/ALWG button opens the SPGU Pulse Setup window. This window is used to define the voltage pulses applied by the specified SPGU channels. For the setup parameters, see later page titled Pulse Setup Parameters of Pulse Generator Mode. In the other classic test, this window is opened by the SPGU Pulse Setup button on the Measurement Setup screen.
  • Page 159 Module 5 SPGU Control and Applications You can set the pulse switch operation on the Pulse Switch Setup dialog box. Set the SW Sync to ENABLE to use the pulse switch. The delay time is the time from start of pulse output to changeover of pulse switch.
  • Page 160 Module 5 SPGU Control and Applications You can specify the load impedance of DUT on the Load Z Setup dialog box. By setting the load impedance value accurately, the SPGU can apply the voltage near the setting value to the DUT. 5-12...
  • Page 161 Module 5 SPGU Control and Applications If the SPGU output mode is set to ALWG, the Pulse/ALWG button opens the SPGU ALWG Setup window. This window is used to define the arbitrary linear waveform voltage applied by the specified SPGU channels. In the other classic test, this window is opened by the SPGU ALWG Setup button on the Measurement Setup screen.
  • Page 162 Module 5 SPGU Control and Applications The pulse setup parameters are defined as shown above. The pulse leading time and trailing time are defined as the voltage transition time between 10 % and 90 % of the amplitude. Programmable range is 8 ns to 400 ms. 5-14...
  • Page 163 Module 5 SPGU Control and Applications To apply the SPGU pulse output, set the pulse setup parameters, specify the Operation, and click the Single button. The following operations are available. PULSE COUNT: SPGU outputs the specified number of pulses. Specify a number within the range of 1 to 1000000.
  • Page 164 Module 5 SPGU Control and Applications Up to 10 output channels can be installed in one B1500A and each channel can output 3-level pulse with a maximum output voltage. The channels are independent. So the channels can apply the different pulses. However, the pulse period value is common for all channels.
  • Page 165 Module 5 SPGU Control and Applications Charge pumping is a type of hot carrier measurement. It provides direct measurement of interface states and an indication of electron and hole trapping. The gate of the MOS transistor is connected to a pulse generator. The current (Icp) is caused by the repetitive recombination of minority carriers with majority carriers at the silicon-silicon oxide interface.
  • Page 166 Module 5 SPGU Control and Applications Square Pulse The base of the pulse is stepped from well below gate threshold to well above. At each step, the substrate leakage current is monitored. The flat part of the resultant curve is proportional to interface-state density.
  • Page 167 Module 5 SPGU Control and Applications Icp is measured after each increment of the gate pulse base value. A curve of Icp vs base value is plotted. The maximum Icp value is noted. At this point: Icp = f * Qss = f * Ag * q * Dit where f: pulse frequency...
  • Page 168 Module 5 SPGU Control and Applications Note: 5-20...
  • Page 169 SMU4 : terminal 4 PGU1 : terminal 3 Then, the modules must be connected to the fixture as shown below. B1500A SMU1 -> Fixture SMU1 connector B1500A SMU2 -> Fixture SMU2 connector B1500A SMU4 -> Fixture SMU4 connector B1500A PG1 -> Fixture PGU1 connector...
  • Page 170 Module 5 SPGU Control and Applications Here we see the result of plotting Icp vs pulse base voltage. 5-22...
  • Page 171 Module 5 SPGU Control and Applications Flash memory is one type of floating gate memory. The left figure shows the structure of the floating gate memory cell. There is a metal floating node on the top of transistor channel region. Any stored charge in this floating node shifts its threshold voltage as shown in the right figure.
  • Page 172 Module 5 SPGU Control and Applications Endurance test is a kind of reliability tests. Repetitive write (program) and erase pulses are applied to the cell and the Vth of the cell is monitored after certain number of pulses are applied. This test is important because the flash memory is used for the data and file storage application.
  • Page 173 Module 5 SPGU Control and Applications Note: 5-25...
  • Page 174 Module 5 SPGU Control and Applications This is an example setup to perform the write operation of the NOR type flash memory cell. This setup uses three sets of the SMU, SPGU, and selector/ASU. This setup is used by the Demo-S- NorFlash Endurance test shown in Class Exercise.
  • Page 175 Module 5 SPGU Control and Applications This is an example setup to perform the erase operation of the NOR type flash memory cell. To perform the erase operation, all of the selector/ASU channels must make the path to the PG and the PG3 internal pulse switch must be opened.
  • Page 176 Module 5 SPGU Control and Applications Vth must be measured after writing or erasing. To perform the Vth measurement, all of the selector/ASU channels must make the path to the SMU. Vth is measured at each decade, so a mechanical relay will be used, not the solid state relay. The mechanical relay has low leakage specifications to better match the capabilities of the SMUs.
  • Page 177 B1500A installed with two SPGU modules and four SMU modules Test fixture Triaxial cable, 7 ea. BNC-SMA cable, 3 ea. B1500A installed with two SPGU modules, three pairs of HRSMU and ASU, and a SMU module Test fixture Triaxial cable, 7 ea. BNC-SMA cable, 3 ea.
  • Page 178 B1500A SMU3 -> Selector ch2 SMU input or ASU ch2 Force B1500A SMU4 -> Selector ch3 SMU input or ASU ch3 Force B1500A PG2 -> Selector ch1 PGU input or ASU ch1 AUX In B1500A PG3 -> Selector ch2 PGU input or ASU ch2 AUX In B1500A PG4 ->...
  • Page 179 Module 5 SPGU Control and Applications For the instrument connection shown in the previous pages, change the value as follows. Pgate -> SPGU3 Gate -> SMU3 Psource -> SPGU2 Source -> SMU2 Pdrain -> SPGU4 Drain -> SMU4 Subs -> SMU1 Also, set a small TotalWriteAndEraseCycles value, for example 1000.
  • Page 180 Module 5 SPGU Control and Applications This is a test result example displayed on the Data Display window. 5-32...
  • Page 181 Module 5 SPGU Control and Applications ALWG stands for Arbitrary Linear Waveform Generator. This function is similar to the AWG (Arbitrary Waveform Generator), but specialized for a semiconductor parametric test. The ALWG describes the pulse wave by the combination of the line segment described as the differential time and absolute voltage. Key features are as follows.
  • Page 182 Module 5 SPGU Control and Applications To apply the ALWG output, define the ALWG output sequence, specify the Operation, and click the Single button. The following operations are available. PULSE COUNT: SPGU outputs the specified number of sequences. Specify a number within the range of 1 to 1000000.
  • Page 183 Module 5 SPGU Control and Applications A pattern can be defined by specifying the differential time and the absolute voltage. You can define it by using the left side GUI or the right side table on the window. 5-35...
  • Page 184 Module 5 SPGU Control and Applications Channel Setup: SMU1 -> V1, I1, Mode=I SMU2 -> V2, I2, Mode=COMMON SPGU1 -> SPGUV1, Mode=ALWG Measurement Setup: Interval=2 ms No of Samples=201 SMU1 -> Source=0 A, Compliance=2 V Range: SMU1 -> Mode=FIXED, Range=2 V ADC/Integ: SMU1 ->...
  • Page 185 SMU1 : terminal 1 SMU2 : terminal 4 PGU1 : terminal 1 Then, the modules must be connected to the fixture as shown below. B1500A SMU1 -> Fixture SMU1 connector B1500A SMU2 -> Fixture SMU2 connector B1500A PG1 -> Fixture PGU1 connector 5-37...
  • Page 186 Module 5 SPGU Control and Applications This is a test result example displayed on the Data Display window for the “ALWG monitor” test setup. 5-38...
  • Page 188 This information is subject to change without notice. © Keysight Technologies 2005-2014 Edition 8, August 2014 *B1500-90040* B1500-90040 www.keysight.com...