EXAM 1

Question 1

Semiconductor Materials

Answer 1

Si, Ge, GaAs
* Silicon, Germanium and Gallium Arsenide

Question 2

are special class of elements having a conductivity between insulator and conductor.

Answer 2

Semiconductor

Question 3

Classes of semiconductor material:

Answer 3

Single crystal and Compound

Question 4

Germanium and Silicon

Answer 4

Single crystal

Question 5

Cadmium Sulphide CdS), Gallium Arsenide (GaAs), Gallium Nitride (GaN), Gallium Arsenide Phosphide (GaAsP).

Answer 5

Compound

Question 6

After the discovery of diode in 1939 and the transistor in 1947 the ____ is commonly used material

Answer 6

Germanium

Question 7

What transistors suffered in low levels of reliability due to its sensitivity to temperature change?

Answer 7

Transistors constructed from Germanium

Question 8

When did scientists come up with Silicon transistor?

Answer 8

1954

Question 9

Silicon has _ orbiting electrons, Germanium has 32 electrons, Gallium has 31 electrons and Arsenic has 33 orbiting electrons.

Answer 9

14

Question 10

Silicon has 14 orbiting electrons, Germanium has __ electrons, Gallium has 31 electrons and Arsenic has 33 orbiting electrons.

Answer 10

32

Question 11

Silicon has 14 orbiting electrons, Germanium has 32 electrons, Gallium has __ electrons and Arsenic has 33 orbiting electrons.

Answer 11

31

Question 12

Silicon has 14 orbiting electrons, Germanium has 32 electrons, Gallium has 31 electrons and Arsenic has __ orbiting electrons.

Answer 12

33

Question 13

• Eg = ___ eV (Ge)
• Eg = 1.1 eV (Si)
• Eg = 1.43 eV (GaAs)

Answer 13

0.67

Question 14

• Eg = 0.67 eV (Ge)
• Eg = ___ eV (Si)
• Eg = 1.43 eV (GaAs)

Answer 14

1.1

Question 15

• Eg = 0.67 eV (Ge)
• Eg = 1.1 eV (Si)
• Eg = ___ eV (GaAs)

Answer 15

1.43

Question 16

• Extrinsic material is obtained by doping process.
• Adding impurities in semiconductor material is called “____”.

Answer 16

DOPING