Formation and thermal stability of contacts based on titanium borides and titanium nitrides with gallium arsenide

The formation mechanisms and thermal stability of contacts, fabricated by i on-plasma sputtering of titanium borides and nitrides on gallium arsenide, are investigated by structural, secondary-emission, photoluminescence, and electrical methods. A physical model, according to which the solid solution s BxGa1-xAs and GaNxAs1-x are formed in the process of deposition on the ph ase boundary, is proposed on the basis of the data obtained. It is shown th at the correlation between the physicochemical interactions at the phase bo undaries of the contacts and their electrical parameters is due to defects that arise in the contact layers of the semiconductor during the formation of the heterostructures and subsequent treatments. It is established that t he high thermal stability of the experimental objects is due to their bilay er structure, which sharply decreases interdiffusion processes at the phase boundary. (C) 1999 American Institute of Physics. [S1063-7826(99)01308-3].