New Bird's Beak‐Free Device Isolation Technology

Abstract

A selective epitaxial layer is grown in field regions rather than active device areas and is completely converted to thermal silicon-sioxide film to form the field oxide. This new technology results in a 'bird's beak'-free device. Called selective epitaxial-layer field oxidation (SELFOX), the technology offers several unique features: (i) uniform field oxide (1000 nm thickness) independent of the field area which can range from one micron to hundreds of microns, (ii)no bird's beak encroachment even for 1 ~m-thick field oxide, (iii) no dislocations in active device areas as small as 1 ~m. Reverse leakage ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 155.69.4.4 Downloaded on 2015-05-23 to IP Vol. 135, No. 10 ABSTRACT Fluorinated silicon nitride films were deposited by plasma-CVD from SiF4-N2-H2 or Si2F6-N2-H2 gas mixture. The deposition rate was increased by using the latter gas system, typically as high as 50 rim/rain, which was comparable to that of the conventional hydrogenated silicon nitride deposited from Sill4. The fluorinated silicon nitride exhibited (i) lower hydrogen content, (ii) higher stability against hydrogen outdiffusion, and (iii) higher thermal endurance. Successful applica-

Selective epitaxial growth of silicon and some potential applications

“…• Replacement of local silicon oxidation [15] and filling of deep trench structures [16,17] in order to achieve device and circuit isolation. • Refilling and planarization of contact holes [18].…”