1. ECE 874: Physical Electronics
Prof. Virginia Ayres
Electrical & Computer Engineering
Michigan State University

2. Lecture 01, 30 Aug 12
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3. Chp. 01: Basic Semiconductor Properties Crystal structures Motivation
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4. Motivation:
nanoFET with large current density J
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5. Motivation: C and D: selected area electron diffraction
A, B, and E: High resolution transmission electron microscopy
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6. Figure 1.1:
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7. Top way might seem easier
Figure 1.1:
Bottom way
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8. In a real problem where you don’t know a and b distances or how to set the lines “in-between”, bottom way would be easier
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9. Another point: This is a 2D plane view of a 3D crystal
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10. Figure 1.2: When describing crystals, we do it this way.
These lines and even points describe symmetries not bonds.
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11. Figure 1.3: describes symmetries
Figure 1.5: Shows real atoms and bonds
2 X’s
Note: Si and GaAs really do have spatially well defined covalent bonds. Not every crystal does
Table 1.4  energy band diagrams
Chp. 03 / ECE 931C
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12. Cubic System Symmetries Standard unit cells
Note: Most metals belong to fcc and bcc crystal systems. Metals do not have well defined covalent bonds. They have ‘fuzzy’ metallic bonds.
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13. Problem 1.1:
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14. Problem 1.1a:
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15. Problem 1.1a: ½ atom top and bottom ¼ atom sides 2 x ½ = 1 4 x ¼ = 1
Equivalent of 2 atoms inside
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16. Problem 1.1b: I used white boxes to cut off the outsides of the atoms,
and then used group to create a few unit cells
that I could move around and stack to create a crystal.
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17. Problem 1.1b: Three parallel planes of atoms.
Try moving them into position.
Pattern is:
1 atom
4 atoms
1 atom
4 atoms
1 atom
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18. Compare to standard unit cells:
Problem 1.1c:
I put the three parallel planes in place and then used more white boxes to hide everything else.
Compare to standard unit cells:
bcc
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19. Problem 1.1c:
Another choice for three parallel planes of atoms. But it would be harder to identify the bcc structure from this choice
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20. Problem 1.1c:
Another choice for three parallel planes of atoms. But it would be harder to identify the bcc structure from this choice
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