FET useful in microwave region - with hetero structure and pref. gallium arsenide and gallium aluminium arsenide layers

摘要

FET has a layer of n- or p-conductive material (I) on a semiconductor substrate (II) with source, drain and gate contacts and another layer between (I) and (II), which consists of a different material (III) from (I), so that the FET has a hetero-structure. These FETs are esp. useful in the microwave region. The hetero-structure improves the properties of the potential threshold. Pref. the lattice constants of (I) and (III) are so close that the number of holes and additional electrons at the boundary is minimised. Pref. (I) and (II) consist of GaAs and (III) of the ternary alloy Ga1-xAlxAs (0 x =1). (III) can be n- or p-doped and is so thin that it is kept in depletion in operating and gives no bridging affected with resistance to the rest of the transistor.