Keithley Series 2600 User Manual

4-2
SECTION 4
FET Tests
Install an N-channel FET such as an SD210 in the appropriate 6.
transistor socket of the test fixture.
Now, we must send the code to the instrument. The simplest 7.
method is to right-click in the open script window of TSB,
and select ‘Run as TSP file’. This will compile the code and
place it in the volatile run-time memory of the instrument.
To store the program in non-volatile memory, see the “TSP
Programming Fundamentals” section of the Series 2600 Refer-
ence Manual.
Once the code has been placed in the instrument run-time 8.
memory, we can run it at any time simply by calling the func-
tion ‘ FET _ Comm _ Source() ’. This can be done by typing
the text ‘ FET _ Comm _ Source() ’ after the active prompt
in the Instrument Console line of TSB.
In the program ‘9. FET_Comm_Source.tsp’, the function FET _
Comm _ Source(vgsstart, vgsstop, vgssteps,
vdsstart, vdsstop, vdssteps) is created.
vgsstart • represents the initial voltage value in the
gate-source V
GS
sweep
vgsstop • represents the final voltage value in the gate-
source V
GS
sweep
vgssteps • represents the number of steps in the sweep
vdsstart • represents the initial voltage value in the
drain-source V
DS
sweep
vdsstop • represents the final voltage value in the drain-
source V
DS
sweep
vdssteps • represents the number of steps in the sweep
If these values are left blank, the function will use the default
values given to the variables, but you can specify each vari-
able value by simply sending a number that is in-range in
the function call. As an example, if you wanted to have the
start voltages for V
GS
and V
DS
sweeps be 1V, the stop value
be 11V, and the number of steps be 20, you would send
FET _ Comm _ Source(1, 11, 20, 1, 11, 20) to
the instrument.
The sources will be zeroed and then enabled. The program 10.
will execute a sweep of V
GS
values between 0V and 10V using
2V steps. At each V
GS
step, V
DS
will be stepped between 0V
and 10V at 0.1V increments. At each increment, I
D
will be
measured.
Once the measurements have been completed, the data (V11.
GS
,
V
DS
, and I
DS
) will be presented in the Instrument Console
window of TSB.
4.3.3 Typical Program 9 Results
Figure 4-2 shows a typical plot generated by example Program 9.
A 2N4392 N-channel JFET was used to generate these curves.
4.3.4 Program 9 Description
The unit is returned to default conditions. Next, SMUB, which
sweeps V
GS
, is programmed as follows:
Source V•
1mA compliance, 1mA range•
Local sense•
vgsstart • : 0V
vgsstop • : 10V
vgssteps • : 5
SMUA, which sweeps V
DS
and measures I
D
, is configured as
follows:
I
V
I
V
Series 2600
System
SourceMeter
Channel A
Sweeps V
DS
,
Measures I
D
Series 2600
System
SourceMeter
Channel B
Sweeps V
GS
V
DS
V
GS
Test
Fixture
FET
Under Test
Output HI
Output HI
Output LO
Output LO
I
D
Figure 4-1. Test configuration for common-source tests

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.