Method for making a charge transfer semiconductor device having an oblong trench

摘要

In making trench type semiconductor CCD by using oblique ion-injections into an oblong trench groove in a semiconductor substrate region for injecting impurity atoms, an injection angle alpha for injecting a first conductivity type impurity to form isolation region into the side walls and also for injecting a second conductivity type impurity to form a charge transfer region thereon is selected less than pi /4, and another injection angle beta for injecting the same impurity into the end wall to form the end part of the isolation region and a third injection angle gamma for injecting the second conductivity type impurity thereon into the end wall to form the end part of the charge transfer region are selected: <IMAGE>