US Patent 7867921 Reduction of etch-rate drift in HDP processes

A processing chamber is seasoned by providing a flow of season precursors to the processing chamber. A high-density plasma is formed from the season precursors by applying at least 7500 W of source power distributed with greater than 70% of the source power at a top of the processing chamber. A season layer having a thickness of at least 5000 Å is deposited at one point using the high-density plasma. Each of multiple substrates is transferred sequentially into the processing chamber to perform a process that includes etching. The processing chamber is cleaned between sequential transfers of the substrates.