Design and Fabrication of InSb Infrared Photodiode

In this article the infrared photodiode was made by using epitaxially grown layers of p–InSb on n-type InSb substrate using liquid phase epitaxy. Finally by improving growth parameters such as growth temperature, prior cleaning of B-face (Sb) of n-InSb(111) substrate and cooling rate, the p-n junction photodiode was made. The effect of increasing cadmium atomic weight percent on p-type carrier concentration, mobility and detectivity at 77 K is also discussed. In the design of InSb photodiode ,it is important that as many as possible of the photo excited carriers reach the p-n junction and in this epitaxial layer has an average thickness about 20μm,so that free carrier absorption necessitates some thinning of the epitaxial layer to 5μm thick which is enough to make a photodiode. For making photodiode some processes such as photo engraving, mesa etching and passivation have been carried out. A high detectivity diode using opto electronic tests was calculated 5.4 × 1010 Cm Hz1/2 /w. Several other tests such as Hall Effect, thickness measurements and I–V curve were also performed and morphology images of epitaxial layers of InSb photodiode will be presented in this paper.

کلیدواژه ها:

InSb epitaxial layer ، LPE ، InSb photodiode ، Growth temperature