ZOGMOST: an improved m.o.s.t. for c.c.d. peripheral circuits

An improved formation for m.o.s. transistors fabricated with the `shadow-etch¿ c.c.d. process is reported. The narrow self-aligned gaps produced by the process are used to provide an additional screen gate, which allows the gate-drain overlap capacitance to be minimised, thereby improving the frequency characteristics of linear and digital m.o.s. circuits. Depending on the gain of the stage involved, an improvement in the frequency performance of up to 5 times is expected, and practical results for the modified m.o.s.t. agree with this prediction.