The use of indium for the formation of low-resistance microcontacts to the contact layers of gallium arsenide heteroepitaxial QWIP structures
Consideration is given to the possibility of using indium in low-resistance contacts building on heteroepitaxial QWIP-structures for IR focal plane arrays detectors. The prevalent technology for forming contacts uses vacuum evaporating of Ni-Au with subsequent annealing at 450 ºC in H2 ambience. It includes a row of difficult operations, namely, preparation of photo masks, photolithography, etching mesa elements, metal deposition on two levels, which are difficult to attain in such small test samples. This paper presents an investigation of alternative methods to form the low-resistance contacts to contact layers of the QWIP GaAs/AlGaAs structures.