Patent ID: 9218944
Filing Date: 2015-12-22
Classification: C23C,H01J,H01L

Abstract:
1. A plasma reactor for processing a workpiece that is transparent at least within a range of wavelengths, comprising: a vacuum chamber having a sidewall and a ceiling; a workpiece support pedestal and having a support surface facing said ceiling and lying within said chamber for supporting a workpiece; an array of passages extending through said workplace support pedestal from a bottom thereof and forming a two-dimensional matrix of rows and columns of openings in said support surface; a plurality of optical fibers, each fiber extending through a respective one of said passages and having: (a) a viewing end with a field of view through the corresponding opening in said support surface, and (b) an output end outside of said chamber; optical sensing apparatus coupled to the output ends of said optical fibers and being responsive in said range of wavelengths; an array of gas injection ports in communication with said chamber, said gas injection ports being distributed about a full circle in a circumferential direction with respect to said sidewall, a process gas supply end a plurality of controllable valves connected between said supply and respective ones of said array of gas injection ports; and a process controller connected to receive information from said optical sensing apparatus indicative of etch rate distribution and to transmit control commands to said controllable valves to affect distribution along said circumferential direction gas flow rates in said gas injection ports.