Patent ID: 6127734
Filing Date: 2000-10-03
Classification: H01L

Abstract:
A semiconductor device, comprising:a semiconductor substrate having a main surface;a conductive region formed at the main surface of said semiconductor substrate;a first insulating layer formed on the main surface of said semiconductor substrate;a second insulating layer formed of a material having an etch rate different from that of said first insulating layer, formed on said first insulating layer;a third insulating layer formed of a material having approximately same etch rate as said first insulating layer, on said second insulating layer; anda fourth insulating layer formed of a material having approximately same etch rate as said first insulating layer, formed on said third insulating layer; whereina hole opened by anisotropic etching is formed in said first, second, third and fourth insulating layers reaching said conductive region formed at the main surface of said semiconductor substrate through these insulating layers,said hole having a first opening diameter smaller than a minimum possible dimension formable by conventional photolithography in a portion formed in said first and second insulating layers and having a second opening diameter larger than said first opening diameter and substantially equal to a minimum possible dimension formable by conventional photolithography in a portion formed in said fourth insulating layer the second opening diameter being approximately constant in its depth direction;said device further comprising:a conductive layer electrically connected to said conductive region through said hole and extending over said fourth insulating layer.