Base layer structure for covering hole in semiconductor insulation layer

摘要

The base layer structure formed in a hole (3a) in a semiconductor insulation layer (3-2) has a base layer (51) extending over at least part of the upper section of the hole and the adjacent part of the insulation layer. The effective thickness of the base layer extending over the upper section of the hole is greater than the thickness of the base layer over the insulation film and greater than a critical thickness so that part of the base layer remains over the upper section of the hole after anisotropic etching for removing the part of the base layer extending over the insulation layer.