An amorphous silicon integrated inverter

Integration of hydrogenated amorphous silicon field effect transistors (a-Si FET's) has been investigated. It is shown that the new inverter which consists of an n-channel enhancement mode driver FET and a p-channel "depletion" mode load FET has excellent steplike transfer characteristics. With this integrated inverter, a small-signal gain of more than ten was measured and an integrated ring-oscillator of nine-stages operated for the first time. The power delay product and the minimum propagation delay time were about 480 pJ and 110 µs, respectively.