Film uniformity by selective pressure gradient control

摘要

A system for depositing a film on a substrate in a CVD process has a second-source injection sub-system for injecting a control gas. The deposition rate of the material deposited in the CVD process is a function of the concentration of the control gas at the point that material is deposited. The second source injection sub-system provides a concentration gradient of the control gas relative to the substrate surface coated, and alters the thickness uniformity of the film. By controlling the gradient one may control the thickness uniformity profile. In another embodiment, the invention applies to dry etching with reactive gas, and the etching rate is controlled by second source provision of a control gas.