Method of manufacturing a passivating composite comprising a silicon nitride (SI1 3N4) layer and a phosphosilicate glass (PSG) layer for a semiconductor device layer

Claim 1

An improved method of passivating an integrated circuit device of the type comprising a substrate of semiconductor material having semiconductor devices formed therein, said semiconductor devices being covered by a first layer of insulating material, the improvement comprising the steps of: (a) forming contact openings through said first layer of insulating material; (b) covering said first layer of insulating material .[.which.]. .Iadd.with .Iaddend.an impervious layer of silicon nitride; then (c) covering said impervious layer with a phosphosilicate glass layer .Iadd.that contains less than about 7% phosphorus by weight.Iaddend.; then (d) forming contact openings through said phosphosilicate glass layer which align with said contact openings formed through said first layer of insulating material; then (e) heating said phosphosilicate glass layer in the presence of steam at a temperature sufficient to cause the edges of said contact openings formed in said phosphosilicate glass layer to become rounded, said temperature not being sufficient to affect said impervious layer; then (f) extending said contact openings through those portions of said impervious layer which are exposed through the contact openings formed in the phosphosilicate glass layer; and (g) applying a metal over the surface of said phosphosilicate glass layer, whereby said metal will extend through said contact openings to make electrical contact to underlying portions of the semiconductor material which are exposed through said contact openings.