Shift register in the sub-ns range - An example of circuit integration with Gunn devices

A description is given of the basic-technological conditions for a monolithic integration in epitaxial GaAs layers grown from the liquid phase on semi-insulating buffer layers or substrates. The shaping of the small devices required and of their metallizations was achieved by microprojection photomasking. A projection in two planes leads to very small dimensions of structure, even on mesa-shaped substrates. The advantage of utilizing the Gunn effect in a subnanosecond pulse technique is analyzed with respect to the necessary minimum dimensions of the devices. A dynamic shift register is realized with Gunn devices of 50 micron length. While Schottky double gates for domain triggering perform the logic AND function, the pulse delay is obtained in the active domain region between cathode and anode.