A vertical channel JFET fabricated using silicon planar technology

A vertical channel JFET with a new structure was fabricated using a self-aligned process and doped polysilicon technology. This structure is suitable for a high power device, since many channels are easily integrated on a single chip. It is also suitable for a high frequency device, because two essential conditions for high frequency operation, sufficiently low gate resistance and small channel length, can be realized without difficulty. This device shows triode-like I-V characteristics, which are determined by the channel impurity concentration and gate diffusion profile. Typical performances of an n-channel, 4 mm/spl times/4 mm, 5520 channel power FET, designed for an audio amplifier, are a voltage amplification factor of 5, a source-to-gate breakdown voltage of 60 V, a drain-to-gate breakdown voltage of 200 V, and I/SUB DSS/=4 A at V/SUB DS/=7 V.