METHOD FOR REDUCING ANOMALOUS NARROW CHANNEL EFFECT IN TRENCH-BOUNDED BURIED-CHANNEL P-TYPE MOSFET

摘要

PROBLEM TO BE SOLVED: To provide a method for reducing anomalous sensitivity to a sidewise width in a buried channel p-type MOSFET. ;SOLUTION: After a deep phosphorous n-type channel is doped, a low- temperature annealing step is carried out using an inert gas. A boron buried channel is doped, and a gate oxidization step is carried out. Then a low temperature annealing step is selectively carried out between the boron-buried channel doping and the gate oxidization. A deep phosphorous n-type well is doped, and a boron-buried channel is doped. In an rapid thermal oxidization(RTO) step, gate oxidization is carried out. A gate oxidization step at 850°C is selectively carried out just after the rapid thermal oxidization(RTO) step.;COPYRIGHT: (C)1996,JPO