A Temperature Control Stage for Deposition of Thin Metal Films

Abstract

Because the properties of the films are significantly affected by a deposition temperature change of only several degrees Celsius, it is vital that the substrate temperature be uniform across the entire substrate and constant throughout the deposition process, even while it is being radiatively heated by the evaporant metal. A temperature control substrate stage is being developed at Houghton University for thin metal films produced on 10 cm Si substrates via physical vapor deposition, with a base pressure of 10-6 Torr. To test possible substrate-stage adhesion materials, a test chamber was set up containing a substrate fixed to a 10 cm diameter aluminum heat sink. Resistive wire was epoxied to the substrate surface to simulate the ~6.5 W of radiative heating that would occur during deposition. Using double-sided copper tape, the minimum temperature change was 18°C in 10 minutes. Adding clamps decreased this to 13°C in 10 minutes. Using Ag paste as an adhesive resulted in a temperature change of only 3°C in 10 minutes.