END-POINT DETECTION BY SPUTTERED NEUTRAL MASS-SPECTROMETRY IN ION MILLING OF PREPATTERNED SEMICONDUCTOR AND HIGH-T(C) SUPERCONDUCTOR FILMS

We explore the use of sputtered neutral mass spectrometry (SNMS) for s emiconductor and superconductor device processing. SNMS allows us to p recisely determine the end point at interfaces during sputter etching of prepatterned semiconductor and superconductor thin films. By postio nizing the sputtered neutrals the detection sensitivity is similar for all elements. The dynamic range of up to three orders of magnitude ma kes precise end-point detection possible even if the mask allows sputt er etching of only a small fraction of the surface of the specimen.