ELEC321, LAB#2
LAB #2
THE Si AND GaAs CRYSTALLOGRAPHY
The Objectives:
1. To study the crystal structures of the Si and GaAs using the simulation package.
The Theory:
Among the semiconductor materials Si and GaAs are the most popular. These
crystals particularly play an important role in the development of the solid state devices,
which have changed the quality of our life. A good knowledge of their crystal structure
leads to a better understanding the physical properties of these materials. In this lab
experiment, as oppose to the first lab, you will be expected to use your knowledge of CaR
Ine Crystallography simulation package to interrogate the crystal structures of the Si and
GaAs. And in your lab report, for this lab experiment, you should provide an adequate
answer to all the questions listed in the procedure section.
The Procedure:
1- Build the unit cell of Si using a = 5.43 Å, and then answer the following questions:
a) What is the minimum distance between any two adjacent atoms? Is it the same as the
Si atom radius?
b) What is the maximum distance between any two adjacent atoms?
c) What is the maximum distance between any two atoms inside the unit cell?
d) What is the number of atoms inside the Si unit cell?
e) What is the density of the Si unit cell?
f) What is the number of atoms of the Si unit cell that the (100) plane cuts through?
g) What is the surface density of the (100) plane?
h) What is the number of atoms of the Si unit cell that the (111) plane cuts through?
i) What is the surface density of the (111) plane?
2- Build the Unit Cell of the GaAs using a = 5.65 Å, then answer the following
questions:
a) What is the minimum distance between any two adjacent atoms? Is it same as the
GaAs atom radius?
b) What is the maximum distance between any two adjacent atoms?
c) What is the maximum distance between any two atoms inside the unit cell?
d) What is the number of atoms inside the GaAs unit cell?
e) What is the surface density of the GaAs crystal?
f) What is the number of atoms of the GaAs unit cell that the (100) plane cuts through?
g) What is the surface density of the (100) plane?
h) What is the number of atoms of the GaAs unit cell that the (111) plane cuts through?
i) What is the surface density of the (111) plane?
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ELEC321, LAB#2
Emergency Procedures
1.
Emergency Evacuation
 Stop your work
 Proceed to the nearest Fire Exit (Don't Use Elevators or Escalators)
 General alarm - bells ring continuously
You must evacuate
2. Emergency Procedure in the Event of Fire
 Sound the nearest Fire Alarm


Call Security 811
Phones are located at all stairwell exits
Public phones can be used to call security (no charge)
General alarm - bells ring continuously
You must evacuate
3. What to do in case of Medical Emergency
Serious/Life Threatening Emergency
 Call 9-911 to alert Urgences Santé and provide the address of the Hall Building
1455 de Maisonneuve Blvd. W.
(They will not follow other directions)


Call Security 811
Give your location and that you have called Urgences Santé
Provide first aid assistance if you can or call 848-3100 for an emergency responder
Non Life-Threatening Situations (not requiring Urgences Santé)


Call Security 811
Provide first aid assistance if you can or call 848-3100 for an emergency responder
Phones are located at all stairwell exits
Public phones can be used to call security (no charge)
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