Processing of Indium Phosphide (InP)

Indium Phosphide (InP)

Indium (In), Phosphorus (P)
Substance Type
Compound material

Elements, Chemical Composition and Structure

Indium Phosphide (InP) is a material with a zincblende crystal structure and composed of the elements indium (In) and phosphorus (P). It has a blue-gray metallic appearance. It is a III-V gap semiconductor and it has higher electron mobility and band gap than the more common semiconductor silicon, and is therefore suitable for high-speed applications.

Chemical Formula InP
Crystal Structure Zincblende
Melting Point 1062 ℃
Electron Mobility 5,400 cm2/Vs
Band Gap 1.35 eV


The electron mobility of indium phosphide is 4 times as high as that of the common semiconductor silicon, and therefore used in High Electron Mobility Transistors (HEMT). Because they are also direct band gap semiconductors, they are also used in infrared emitting devices.
It is possible to epitaxially grow a thin layer of another substrate with the same lattice constants on a single crystal indium phosphate wafer. Because of its higher lattice constant than gallium arsenide (GaAs) and gallium phosphide (GaP), substrates such as indium gallium arsenide (InGaAs) and indium gallium arsenide phosphide (InGaAsP) are grown on indium phosphide wafers.


Single crystal indium phosphide is grown using Liquid-Encapsulated Czochralski (LEC) method, which involves pulling a crytal rod that is sealed within a liquid. Because it has lower thermal conductivity than gallium arsenide, controlling its temperature during the process is difficult; therefore it is more challenging to grow high quality single crystal ingots.


Being a direct band gap semiconductor with its epitaxial growth substrate, they can be found in laser diodes, photonic integrated circuits and optical telecommunications. They are also used in high-frequency with oscillations over 90 GHz.

DISCO's processing solutions

DISCO's grinders, polishers, dicing and laser saws can be used for processing indium phosphide substrate wafers.