Gate orientation dependence of InGaAs/AlGaAs high electron mobility transistors formed by wet recess etching

The gate orientation dependence of InGaAs/AlGaAs high electron mobility tra nsistors (HEMTs) formed by the wet-chemical recess etching has been evaluat ed. The short channel effect strongly depends on the gate orientation and i s significant in the order of [00(1) over bar], [001] and [0 (1) over bar ( 1) over bar] oriented devices. Such orientation dependence results from a d ifference of the side-etching lengths, which are 0.01 mu m, 0.03 mu m and 0 .06 mu m for the [0(1) over bar 1], [001] and [0 (1) over bar (1) over bar] oriented devices, respectively. The other characteristics of HEMTs such BV gd, g(m) and f(T) also depend on the gate orientation because of a differen ce of the recessed shape.