Patent ID: 8878263
Filing Date: 2014-11-04
Classification: H01L

Abstract:
1. A semiconductor device comprising: a semiconductor substrate having a trench, wherein the trench has a sidewall portion and a bottom portion; an impurity region formed at the sidewall portion and the bottom portion of the trench of the semiconductor substrate, thereby forming a buried channel in association with the impurity region wherein the impurity region is in contact with a photodiode impurity region having a high concentration region and a low concentration region, wherein the high concentration region is in direct contact with the impurity region and the high concentration region is above the low concentration region; a gate insulating film formed, by one of a radical oxidation process and a plasma oxidation process, on an internal surface of the sidewall and the bottom portion of the trench and on surfaces of the semiconductor substrate; and a gate electrode formed as buried in the trench, wherein, the gate insulating film and the gate electrode form a vertical metal oxide semiconductor transistor, the gate insulating film is formed in a uniform thickness irrespective of a face orientation of and an impurity concentration in the semiconductor substrate, and the gate insulating film is in contact with the impurity region and the impurity region is in contact with the photodiode impurity region.