Dual-port end point window for plasma etcher

An end point detection window for a process chamber, comprising:

• a window plate having a primary window recess and a secondary window recess for mounting in the process chamber;
• a partition separating said primary window recess from said secondary window recess;
• a primary window provided in said primary window recess and a secondary window provided in said secondary window recess;
• a primary sensor port provided adjacent to said at primary window and a secondary sensor port provided adjacent to said secondary window;
• and
• a cover provided adjacent to said secondary window recess for selectively covering and uncovering said secondary window.

A process chamber comprising:

• a chamber wall defining a chamber interior;
• at least two windows provided in said chamber wall;
• at least two sensor ports provided in said chamber wall adjacent to said at least two windows, respectively;
• and
• a cover provided adjacent to one of said at least two windows for selectively covering and uncovering said one of said at least two windows.