The surface-charge transistor

The surface-charge transistor (SCT) is a new active semiconductor device that can be used to store, transport, and control the transport of nonequilibrium surface charge. In its simplest (discrete) form, it consists of two adjacent storage electrodes and an overlapping control electrode. All of these electrodes are separated from each other and the semiconductor surface by a thin insulating film. This structure will provide storage and controlled transport of mobile surface charge along the semiconductor surface. Data are presented for both the quasi-static characteristics of this device and its transient response. The quasi-static data are compared with an analysis based on the solution of Poisson's equation for the device, and the measured transient response is compared with a numerical solution of the equation of motion for surface-charge transport. The accuracy of these models is attested to by the agreement between theory and experiment. The fabrication of surface-charge transistor structures is also described.