A MODEL FOR LOW-TEMPERATURE OPERATION OF MINORITY-CARRIER WELL-TYPE GUARD RINGS IN EPITAXIAL CMOS STRUCTURES

As temperature is lowered, behaviors of well-type guard rings in an ep itaxial substrate are quite different from those at RT so that the pre vious formulation is unable to reflect these discrepancies precisely. This leads to a new escape-current model suitable for low-temperature applications. In addition to the structural parameters, the new model is also functions of other physical quantities such as temperature, hi gh-level injection, surface recombination velocity at the high/low jun ction and minority-carrier transport parameters, which are also import ant at low temperature. (C) 1997 Elsevier Science Ltd.