Parametric Semiconductor Analyzer
As new semiconductor materials are investigated, fabrication techniques are used to form semiconductor devices. Although many different types of real devices can be fabricated, we can often consider these to be types (or combinations of) the following basic categories:
Figure 1: Circuit element symbols for transistors, diodes, resistors, and capacitors
We can then consider the parameters of these devices – typically these will be measured using current-voltage (IV) or capacitance-voltage (CV) measurements. This is useful for fabrication process development, extracting parameters for device modelling, and checking materials and processes do not change over time (process control).
As devices are developed into mature technologies, they can be produced reliably and reproducibly. At this point, we may consider making circuits from these devices for useful applications. Knowing the parameters of these devices, we can consider them as ‘lumped’ objects, which is much more convenient for circuit design. This would mark the transition of semiconductor technologies from the realm of device physics to electronic/optoelectronic engineering.
We use a Keysight B1500A semiconductor device analyser for the routine test of electronic and optoelectronic devices. This system houses four separate source/measure channels: two high voltage (40V), and two high precision channels.
Figure 2: Keysight B1500A system
The built-in software from Keysight can be totally user-programmed, but also has a number of application-specific tests which are useful for most common device types. as well as the capability to quickly plots the results from tests. This means that routine test measurements can be set up and analyzed rapidly.
Figure 3: Example output after a measurement
Manual probe setup
The semiconductor device analyser is often used in combination with a manual probe station for maximum flexibility. Four probes are available to perform a variety of tests, including sheet resistance measurements, diode measurements, and transistor transfer characteristics (IDS/VGS) and output characteristics (IDS/VDS)
Figure 4; Manual probing of an organic light-emitting diode (OLED) device