Procedure for etch rate consistency

摘要

Methods of conditioning interior processing chamber walls of an etch chamber are described. A fluorine-containing precursor may be remotely or locally excited in a plasma to treat the interior chamber walls periodically on a preventative maintenance schedule. The treated walls promote an even etch rate when used to perform gas-phase etching of silicon regions following conditioning. Alternatively, a hydrogen-containing precursor may be remotely or locally excited in a plasma to treat the interior chamber walls in embodiments. Regions of exposed silicon may then be etched with more reproducible etch rates from wafer-to-wafer. The silicon etch may be performed using plasma effluents formed from a remotely excited fluorine-containing precursor.

主权项

1. A method of conditioning a substrate processing region, the method comprising:
exciting a hydrogen-containing precursor in a conditioning plasma to produce conditioning plasma effluents; exposing interior processing chamber walls to the conditioning plasma effluents, wherein the interior processing chamber walls border a substrate processing region, wherein the substrate processing region is essentially devoid of fluorine during the operation of exposing the interior processing chamber walls to the conditioning plasma effluents; performing multiple cycles of substrate etching, each cycle comprising:
(i) transferring a substrate into the substrate processing region following the operation of exposing the interior processing chamber walls to the conditioning plasma effluents, wherein the substrate comprises an exposed silicon portion;(ii) flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a remote plasma in the remote plasma region to produce etching plasma effluents; and(iii) selectively etching the exposed silicon portion by flowing the etching plasma effluents into the substrate processing region through through-holes in a showerhead, wherein the showerhead is disposed between the remote plasma region and the substrate processing region.