Patent ID: 7897940

Claim:
An apparatus comprising: a beam generation chamber connected to an analyzer chamber connected to a pumping chamber connected to a resolving chamber connected to a wafer chamber, said analyzer, pumping and resolving chambers having interior surfaces; when in operation, a charged particle beam generated in said beam generation chamber and passing through said analyzer pumping chamber and said resolving chamber to a semiconductor substrate in said wafer chamber; an electromagnet having poles positioned within said analyzer chamber and deflecting said charged particle beam onto said substrate; one or more removable liners in contact with one or more different interior surfaces of one or more of said analyzer, pumping and resolving chambers, said liners preventing material generated by interaction of said charged beam and said substrate from coating said one or more different interior surfaces of regions of said analyzer, pumping and resolving chambers; wherein said one or more liners positioned in said analyzer chamber do not cover said poles of said electromagnet when positioned in said analyzer chamber; and a first liner, a second liner, a third liner and a fourth liner in said analyzing chamber, said analyzing chamber having opposite first and second sidewalls connecting opposite top and bottom surfaces, said first liner adjacent to said second aperture and extending along said first sidewall, said second liner adjacent to said second aperture and extending along said second sidewall, said third liner adjacent to said second aperture and extending along said top surface, said fourth liner adjacent to said second aperture and extending along said bottom surface, said third and fourth liners mechanically fastened to first and second liners, said first liner mechanically fastened to an access port cover of said analyzing chamber, said third and fourth liners not covering said first and second pole ends.