EE324 Fall 2002

Lab 1 Some physical properties of silicon crystal wafers

The purpose of this lab is to work with some wafers and become
familiar with some basic measurements and properties.  Your sample is
brittle, so don't drop it, but before the end of the lab it will be in
many pieces.  

Your sample will have a polished side and a unpolished side; call
these the front and back.

Record the results of all measurements.  Discuss each of the tests,
the results of the measurement, and the usefulness of the measurement.

1.  Use a ohm meter to measure the resistance of both sides of your
sample.  Use sand paper (600 grit) to remove any surface coatings and
repeat.  Record all your measurements.  Discuss the results and the
usefulness of this measurement.

2.  Use the hot probe technique to determine if your sample is n of p.
Do this on the front and back of a clean section.  Record and discuss.

3.  Use the 4-point probe setup to measure the sample resistivity.
Draw the circuits used.  Repeat this measurement 3 times on each side
and estimate the accuracy.  Record and discuss.

4.  Use your resistivity to find the doping concentration.  Do it now.

5.  Cleave off small pieces of your sample.  Estimate the angles of
the crystal planes.  Use this information along with the web crystal
viewer to determine crystal plane of the surface of your sample.  
Record and discuss.

6.  Compare your results with others in the class.  There should be
several of you with samples from the same wafer of batch.  
  a. Once you have found others with the same sample, compare all the
test results.
  b. Repeat any tests that are significantly different until there is
agreement or you decide the samples are not the same.