Applications of microphotolithography to millimeter and infrared devices

The skin effect loss mechanism is a predominant factor which contributes to the deterioration in the performance of millimeter wave devices. Microphotolithography permits the definition of conductive waveguide boundaries in close proximity to extremely small semiconductor junctions thus removing lossy material. This concept has been implemented in a planar annular diode structure to confine a diode entirely within a diameter of 11 microns with a thickness of four microns. Microphotolithographic art permits the fabrication of semiconductor junctions and transmission line structures with dimensions approaching one micron. These techniques have been used to define single-mode rectangular dielectric image-line waveguide and depletion layer waveguide structures useful in the millimeter and infrared region.