Patent ID: 6323104
Filing Date: 2001-11-27
Classification: H01L

Abstract:
A method of forming integrated circuitry comprising:forming a pad oxide layer over a bulk semiconductor substrate and a masking layer over the pad oxide layer;after forming the pad oxide layer and the masking layer, etching a first portion of an isolation trench into the semiconductor substrate, the first portion being received entirely within the semiconductor substrate and having laterally opposing sidewalls and a trench base extending therebetween;depositing a first insulative trench isolation material over the substrate and into the trench first portion to a depth insufficient to fill said first portion received entirely within the semiconductor substrate, the first insulative trench material comprising a material selected from the group consisting of Si.sub.x N.sub.y O.sub.z, Al.sub.2 O.sub.3 and Ta.sub.2 O.sub.5 ;anisotropically etching the insulative trench isolation material effective to leave a pair of opposing anisotropically ethced sidewall spacers over at least a portion of the first portion sidewalls and over laterally opposed portions the first portion trench base;with the pair of sidewall spacers in place, etching a second portion of the isolation trench into the semiconductor substrate through the first portion trench base laterally inward of the spacers;depositing a second insulative trench isolation material within the first and second portions of the isolation trench and forming an isolation trench region comprising the first and second portions;planarize polishing the second insulative trench isolation material, the opposing anisotropically etched spacers and the masking material, and leaving an uppermost surface of the anisotropically etched spacers elevationally flush with an uppermost surface of the bulk semiconductor substrate immediately thereadjacent;after depositing the second insulative trench isolation material, forming a shallow junction region within the semiconductor substrate adjacent the first trench portion;forming a covering insulative material over the trench isolation region and the shallow junction region; andetching a contact opening through the covering insulative material to the shallow junction region and the trench isolation region substantially selective to etch the covering insulative material relative to the first insulative trench isolation material within the trench isolation region.