Effects of process changes on double-diffused most characteristics

This paper is concerned with showing the effects of process and structural variations on the characteristics of the double-diffused MOST(DMOST). Processing details, including boron diffusion in the absence of an oxidizing ambient, are presented for three structures, viz., etched self-aligned gate DMOST, symmetrical DMOST, and conventional non-symmetrical DMOST. Processes are varied to give different channel lengths, peak dopings and, different thresholds (to give both enhancement and depletion mode devices). The symmetrical device is shown to be a lower-frequency, lower voltage device than the non-symmetrical.