Keithley Series 2600 User Manual

3-3
SECTION 3
Bipolar Transistor Tests
3.3.4 Typical Program 4 Results
Figure 3-2 shows typical results generated by Example Program 4.
A 2N5089 NPN transistor was used to generate these test results.
3.3.5 Program 4 Description
For the following program description, refer to the program
listing below.
Source I•
IV compliance, 1.1V range•
Local sense•
istart • current: 10M
istop • current: 50µA
isteps • : 5
Following SMUB setup, SMUA, which sweeps VCE and measures
IC, is programmed as follows:
Source V•
Local sensing•
100mA compliance, autorange measure•
1 NPLC Line cycle integration (to reduce noise)•
vstart • : 0V
vstop • : 10V
vsteps • : 100
Once the two units are configured, the SMUB sources istart ,
SMUA sources vstart , and the voltage (V
CE
) and current (I
CE
)
for SMUA are measured. The source value for SMUA is then
incremented by l _ vstep , and the sweep is continued until
the source value reaches vstop . Then, SMUB is incremented by
l_istep and SMUA begins another sweep from vstart to
vstop in vsteps . This nested sweeping process continues until
SMUB reaches istop .
The instrument output is then turned off and the function
Print _ Data() is run to print the data to the TSB window. To
graph the results, simply copy and paste the data into a spread-
sheet such as Microsoft Excel and chart.
3.4 Gummel Plot
A Gummel plot is often used to determine current gain variations
of a transistor. Data for a Gummel plot is obtained by sweeping
the base-emitter voltage (V
BE
) across the desired range of values at
specific increments. At each V
BE
value, both the base current (I
B
)
and collector current (I
C
) are measured.
Once the data are taken, the data for I
B
, I
C
, and V
BE
is returned to
the screen. If using TSB, a plot can be generated using the “copy-
and-paste” method in a spreadsheet program such as Microsoft
Excel. Because of the large differences in magnitude between I
B
and I
C
, the Y axis is usually plotted logarithmically.
3.4.1 Test Configuration
Figure 3-3 shows the test configuration for Gummel plot tests.
SMUB is used to sweep V
BE
across the desired range, and it also
Common-Emitter Characteristics (2N5089)
V
BE
(Volts)
I
B
= 10µA
I
B
= 20µA
I
B
= 30µA
I
B
= 40µA
I
B
= 50µA
I
C
(Amps)
5.00E–02
4.00E–02
3.00E–02
2.00E–02
1.00E–02
0.00E+00
0 1 2 3 4 5 6 7 8 9 10
Figure 3-2. Program 4 results: Common-emitter characteristics

Keithley Series 2600 Specifications

General

Model	Series 2600
Measurement Functions	Voltage, Current, Resistance, Power
Resolution	Up to 6.5 digits
Current Source Range	Up to 10A
Communication Interfaces	GPIB, USB
Applications	Semiconductor testing
Category	Source Measure Unit (SMU)
Channels	Single or Dual Channel (varies by model)

Summary

Section 1 General Information

1.1 Introduction

Discusses system configurations for application programs.

1.2 Hardware Configuration

Details system hardware configuration.

1.2.1 System Configuration

Describes the overall hardware configuration of a test system.

1.2.2 Remote/Local Sensing Considerations

Discusses sensing methods for optimizing accuracy.

1.3 Graphing

Explains how to visualize data using graphing.

Section 2 Two-terminal Device Tests

2.1 Introduction

Introduces tests for two-terminal devices.

2.2 Instrument Connections

Details instrument connections for two-terminal device tests.

2.3 Voltage Coefficient Tests of Resistors

Explains testing voltage coefficient of resistors.

2.4 Capacitor Leakage Test

Details testing capacitor leakage current.

2.5 Diode Characterization

Explains diode characterization tests.

Section 3 Bipolar Transistor Tests

3.1 Introduction

Introduces bipolar transistor tests.

3.2 Instrument Connections

Details instrument connections for bipolar transistor tests.

3.3 Common-Emitter Characteristics

Explains testing common-emitter characteristics for transistors.

3.4 Gummel Plot

Explains generating Gummel plots for transistors.

3.5 Current Gain

Discusses methods for measuring DC and AC current gain.

3.6 Transistor Leakage Current

Explains testing transistor leakage current.

Section 4 FET Tests

4.1 Introduction

Introduces FET testing.

4.2 Instrument Connections

Details instrument connections for FET tests.

4.3 Common-Source Characteristics

Explains common-source characteristics for FETs.

4.4 Transconductance Tests

Details transconductance testing for FETs.

4.5 Threshold Tests

Explains methods for determining FET threshold voltage.

Section 5 Using Substrate Bias

5.1 Introduction

Introduces substrate bias concepts.

5.2 Substrate Bias Instrument Connections

Details instrument connections for substrate bias.

5.3 Source-Measure Unit Substrate Biasing

Discusses SMU substrate biasing methods.

5.4 BJT Substrate Biasing

Explains substrate bias for BJTs.

Section 6 High Power Tests

6.1 Introduction

Introduces high power testing challenges.

6.1.1 Program 15 Test Configuration

Details test setup for high current tests.

6.1.2 Example Program 15: High Current Source and Voltage Measure

Shows high current sourcing with voltage measurement.

6.2 Instrument Connections

Details instrument connections for high power tests.

6.2.1 Program 16 Test Configuration

Details test setup for high voltage tests.

6.2.2 Example Program 16: High Voltage Source and Current Measure

Shows high voltage sourcing with current measurement.

Appendix A Scripts

Two-Terminal Device Scripts

Contains scripts for two-terminal device tests.

Bipolar Transistor Scripts

Contains scripts for bipolar transistor tests.

High Power Test Scripts

Contains scripts for high power tests.

FET Test Scripts

Contains scripts for FET tests.

Substrate Bias Scripts

Contains scripts for substrate bias tests.