Low temperature ohmic contacts to gallium arsenide using In and Al

A method of making ohmic contact to n-type GaAs by means of micro-alloying at 320°C for 90 s, resulting in a specific contact resistance of approximately 0.1 Ω.cm²is described. This technique involves an aluminum overlay which prevents puddling and thus maintains contact geometry. Such contacts, having a relatively high specific contact resistance, have the advantage of being formed by low temperature micro-alloying for short times.