Pressure modulation method to obtain improved step coverage of seed layer

摘要

A multi-step process for the deposition of a material into high aspect ratio features on a substrate surface is provided. The process involves depositing a material on the substrate at a first pressure for a first period of time and then depositing the material on the substrate at a second pressure for a second period of time. Modulation of the pressure influences the ionization and trajectory of the particles, which are ionized in a plasma environment. The method of the invention in one aspect allows for optimum deposition at the bottom of a high aspect ratio feature during a high pressure step and increased deposition on the sidewalls of the feature during at least a low pressure step.