Method for high temperature thermal processing with reduced convective heat loss
US5002630A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1989 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Jun 6, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B25/10
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for inducing a reaction in a reaction chamber of a reactive carrier having a first specific heat, on a reaction surface of a substrate. The method comprises the steps of supporting the substrate in the reaction chamber. Next, the substrate is heated to a reaction temperature, so that the reaction surface has an essentially balanced temperature distribution. The reactive carrier is mixed with an inert gas having a second specific heat to form a reaction mixture, wherein the second specific heat is lower than the first specific heat. Finally, the reaction mixture is supplied into the chamber so that it flows over the surface of the substrate. Because the inert gas has a lower specific heat than the carrier, the overall specific heat of the reaction mixture is reduced. With a lower specific heat, less heat is transferred from the wafer into the reaction mixture. This reduces convective heat loss and thermal gradients in the substrate. The technique is particularly applicable to rapid thermal processing of semiconductor wafers for epitaxial growth of silicon. According to this aspect, hydrogen is the reactive carrier, mixed with a chlorinated silicon source. The inert gas may …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.