VIPMOS, a Buried Local Injector for EPROMs

A highly effective substrate hot electron injection EPROM device can be made using a buried injector, which operates in punch-through mode. The buried injector is formed by a local overlap of the N-well and P-well of a retrograde twin-well CMOS-process. As the VIPMOS-EPROM is compatible with VLSI-processing and the danger of latch-up doesn't exist, the VIPMOS-structure may be used in VLSI-applications. Due to an efficient electron supply mechanism as well as a high injection probability, programming rates of 1V/μs can be obtained.