Materials and their Properties Used in Semiconductors
Most semiconductor material originates from the United States, in Silicon Valley, California. Different materials and their properties are used in creating semiconductors. There are two primary types of materials used in creating semiconductors, intrinsic and extrinsic material. Intrinsic material is chemically very pure, possesses low conductivity, and has a fewer number of charge carriers. Extrinsic material has a small amount of purity, uses doping to create an excess or a shortage of electrons. N-type semiconductors have an excess of electrons. P-type have a shortage of electrons. Many elements are crystalline inorganic solids and have different positions on the periodic table.
Material | Symbol/ Formula | Group | Properties |
Cadmium Sulphide
|
CdS |
II-VI
|
Used in solar cells
Used in photo resistors |
Gallium Arsenide
|
GaAs |
III-V |
Second widely used
Used in high performance RF devices
|
Gallium Nitride
|
GaN |
III-V |
Used in Microwave ICs
Used in microwave transistors Insensitive to ion radiation |
Gallium Phosphide
|
GaP |
III-V |
Used in LED technology
Early forms low –medium brightness Colors vary by dopats
|
Germanium
|
Ge |
IV
|
Used in early devices
Used for some RF devices Offers a better charge carrier mobility Not widely used |
Lead Sulphide
|
PbS |
IV-VI
|
Used in early radio detectors
|
Silicon
|
S |
IV
|
Most widely used
Used for integrated circuits Easy to fabricate Good electrical and mechanical properties
|
Silicon Carbide
|
SiC |
IV
|
Used in power devices
Operating temperatures are higher Breakdown capability is greater that silicon Used in early forms of yellow and blue LEDS
|