Target thickness measurements with quartz crystal sensors of the third generation
1985; Elsevier BV; Volume: 236; Issue: 3 Linguagem: Inglês
10.1016/0168-9002(85)90973-8
ISSN1872-9576
Autores Tópico(s)Mechanical and Optical Resonators
ResumoThe new generation of quartz crystal thickness monitors uses 6 MHz AT-cut plano convex quartz crystals vibrating in the thickness shear mode. Contrary to industrial applications, which require only thickness monitors measuring film thicknesses with relative accuracy to their substrate, the isotope target preparation needs absolute thicknesses. Carefully selected quartz crystals can fulfill this demand. A smaller aperture area in front of the crystal is sufficient for the new plano convex crystals compared to the crystals with both faces in a plano shape. The accuracy and the calibration of the following thickness monitors was controlled: Model FDC-8000 Airco Temescal; Model FTM 4 Edwards; Model XTM Inficon; Models IL 001 and IL 002 Intellemetrics; Model QM 321 Kronos; Model TM 100 Mathis and Model Omni III Sloan.
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