400-Picosecond monolithic current switch

Modern developments in semiconductor devices

“…The dimensions of a typical device are shown in figure 1. Such a device would give useful power gain at frequencies up to 2 GHz, and devices with even smaller dimensions are being made to give adequate gain at 5 GHz (Dhaka 1966). The problems with such small dimensions arise from the sensitivity of shallow diffusions to small amounts of surface damage and from the definition and registration of elements which are not much larger than the wavelength of light.…”