Field effect transistor mfr., e.g. for MESFET or HEMT prodn. - applying mask on gate region active semiconductor layer and forming ohmic contact in second step between semiconductor layer and metallising material

摘要

The mask (2) has apertures in source gate, and drain regions. The ohmic contact between the semiconductor layer (4) and the suitable metallising material is formed in anisotropic manner in oblique impingement direction. In the two mfg. steps, the mask thickness and the impingement angle are chosen such that the ohmic contact material does not reach the mask gate aperture. In a third step, a metallisation (5) is applied in anisotropic manner over the entire surface orthogonally to the semiconductor layer. In the fourth step, the parts of the metallisation between source and gate, and between gate and chain are removed. In the fifth step the metallisation is sintered by heat treatment. ADVANTAGE - Ohmic metal-semiconductor regions are self-adjusting for gate region formation.