Introduction
General Features
Biploar Diode JFET
Each menu has one or more submenus to run the specific characterization for the chosen device.
The input parameter for voltages and currents to use for the chosen segment are read in from
a file "input", which resides in the folder "ProgramC:TransTest:PROJECT". The data files are
stored in
the folder "ProgramC:TransTest:data" and are appended with a suffix indicating the
characterization which created it. An example input file is
available.
This input files contain parameter for general settings and the settings for the individual
characterizations, which will be listed in the corresponding sections of this manual.
The general options to choose from are the following:
- file: JAMES:ProgramC:TransTest:data:test
- Specifies the filename (including the abolute path) to use for the output files. The program will append a suffix to "test" identifying the routine, which created the file. The suffixes are described in the section corresponding to the performed measurement.
- intTime: m
- Specifies the integration time of the HP analyser:
"l", "L" - long integration time
"m", "M" - medium integration time
"s", "S" - short integration time - I_compliance: 1.0e-3
- Current compliance (in A) for the voltage sources, here 1 mA. The same value is used for all voltage sources and characterizations, but for bipolar transistors it is rescaled according to the size of the transistor. The value given here should be the maximum current for the largest transistor size (here 32).
- V_compliance: 2.0
- Voltage compliance (in V) for current sources, here 2.0 V. The same value is used for all voltage sources and characterizations.
The program uses a maximum of all four SMU's and two voltage sources. The voltage sources supply the potentials for the substrate (VS1) and for the epi-pads (VS2). Their value is hard wired in the program to 0.0 V for the substrate and 5.0 V for the epi-pad and can therefore not be changed using the input file. All lines in the input file preceded by a # are treated as comments.
Each special option section of the input file contains lines specifying the range of the HP display. Values are always set in Ampere or Volts. "min_x" and "max_x" indicate the minimum and maximum value for the variable used as the x-axis, while "min_y1"/"min_y2" and "max_y2"/"max_y2" set the range for the two possible y-axises available on the HP diplay. If only "min_y" and "max_y" are specified only one y-axis is needed. These settings don't effect the value range used in the output files where only absolute values for voltages and currents are noted. Here only the compliance values will set a limit.
Biploar Transistor Characterization
Transistor Type Common Emitter Forward Gummel Matching
The base of the transistor needs to be connected to SMU1, the collector to SMU2, the
emitter to SMU3 and the n-well to SMU4 (for PNP transistors) while the substrate is biased via VS1
and the epi-pad via VS2. All values are set as positive voltages and
currents besides the voltage for the n-well, which needs to be set to the right polarity.
For each bipolar transistor testing program, the size of the transistor needs to be entered as
a integer number. According to this number, the current compliance and the display range
for the currents is rescaled. The size will be included in the output file name.
1. Transitor Type
This option will set the type of the bipolar transistor to NPN or PNP. The defaults setting
in NPN. As long as the program is running, the last setting is valid until it is overwritten
by a new type selection. The suffix "_NPNsize" or "_PNPsize" will be appended to the filename
for the chosen transistor type, where "size" is the number as the transistor size.
All voltage and current values for the parameter analyzer (including the display settings)
will be calculated to the correct polarity for the choosen transistor type.
2. Common Emitter Characteristic
The common emitter characteristic sweeps the collector-emitter bias voltage (V_collector swept
and V_emitter held constant) and measures the collector current for different, constant base
currents. The output file contains the step number, the collector-emitter bias voltage,
the collector current and current gain beta (beta=I_c/I_b) for all applied base currents.
In the input file, the options for the forward emitter characteristics are labeled with the
keyword emitter_char:. Use for all voltages and currents positive values.
The collector voltage V_c is displayed on the x-axis, while the collector current and the
base voltage are displayed on the y-axis in linear scale.
3. Forward Gummel Plot
For the forward gummel plot the base-emitter voltage is swept, while the collector and the base
current are measured. The collector-base voltage is held at 0.0 V.
In the input file, the options for the forward gummel plot are labeled with the
keyword forward_gummel:. Use for all voltages and currents positive values.
The emitter voltage V_c is displayed on the x-axis, while the collector current and the
base voltage are displayed on the y-axis in logarithmic scale. The output file contains the
step number,
the base-emitter bias voltage, the collector current and current
gain beta (beta=I_c/I_b).
4. Matching Transistors
To characterize the matching of two bipolar transistors a forward gummel plot is performed and
the collector currents of the two transistors are compared. The bases of both transistors are
connected together to SMU1, while the second collector is measured with SMU4.
On the HP4145B display only the two collector currents vs the base emitter bias are displayed.
The output file contains the step number, the base-emitter voltage, the collector current
for transistor 1 and 2 and the difference between these two currents.
Diodes
1. Forward Diode Characteristic
For the forward characteristic the bias voltage, which is applied to the cathode of the
diode is swept, while the current is measured. The settings for this measurement are labeled
by the keyword forward_diode: in the input file:
The output file contains the step number, bias voltage, an empty current row and the diode current.
2. Reverse Diode Characteristic
For the reverse characteristic the bias voltage, which is applied to the cathode of the
diode is swept, while the current is measured. The settings for this measurement are labeled
by the keyword reverse_diode: in the input file:
The output file contains the step number, bias voltage, an empty current row and the diode current.
