Flat Plate With Large Perimeter Design for LPCVD
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Successful attempts to obtain radial uniformity in films such as phosphorous in-situ doped polysilicon by low pressure chemical vapor deposition (LPCVD) required geometrical contrivances holding or surrounding the wafers. The wafer-support design consists primarily of the use of one or more flat plates 10 upon which the wafers 12 lie. The key design concept is that the plate width be greater than the wafer diameter. A production-oriented configuration would consist of several plates stacked vertically above each other in a tiered fashion to increase the batch size, as shown in Fig. 1 and the Fig. 2 end view of Fig. 1. Two alternative configurations are a 90Œ rotation of the above approach to allow wafers 12 on both sides of the vertical plates 14, as seen in Fig.