High rate silicon nitride deposition method at low pressures
US6506691B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1999 |
| Grant date | Jan 14, 2003 |
| Priority date | — |
| Expiry date | Sep 15, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67115
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for high rate silicon nitride deposition at low pressures, including a method of operating a CVD reactor providing a novel combination of wafer temperature, gas flow and chamber pressure resulting in both rapid deposition and a uniform, smooth film surface. According to the method, a wafer is placed in a vacuum chamber wherein a reactant gas flow of silane and ammonia is directed in parallel with the wafer surface via a plurality of temperature controlled gas injectors, the gas being confined to a narrow region above the wafer. The gas is injected at a high velocity, causing the deposition rate to be limited only by the rate of delivery of unreacted gas to the wafer surface and the rate of removal of reaction byproducts. The high velocity gas stream passing across the wafer has the effect of thinning the layer adjacent the wafer surface containing reaction by-products, known as the “boundary layer,” resulting in faster delivery of the desired reactant gas to the wafer surface. The rapid gas flow also reduces the gas residence time above the substrate surface, and sweeps out unwanted reaction by-products resulting in a further increase in the relative concentrat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.