External Heating of Substrate Tubes in Plasma Chemical Vapor Deposition Processes

Abstract

A PCVD apparatus including an insulative covering disposed to surround at least a portion of the substrate tube and provide external heating of the substrate tube during the deposition process. The insulative covering functions to capture and retain the external thermal energy created by the plasma process. As a result, the areas of the substrate tube that are removed from the current location of the plasma absorb this captured thermal energy and remain at an essentially constant temperature until the next pass of the work coil.

Dependencies are inferred from the claim text.