Silicon micromachined thermal profilers

Abstract

This paper presents a class of scanning thermal profilers micromachined from bulk silicon. Each device consists of an Au-polysilicon thermocouple supported by a probe shank overhanging the edge of the device substrate. The probe shank is suspended by flexural beams and can be electrostatically excited into physical motion by lateral comb drives. A polysilicon heater that can be used to provide a thermal bias during the scan lies at its base. Variations of the basic design include suspension of the thermocouple on a dielectric diaphragm, and replacing the thermocouple by a thermopile. A single-sided, IC-compatible 8 mask process has been developed to fabricate these devices. Preliminary data from test scans obtained using a simple set-up indicates that temperature resolution better than 20/spl deg/mC is possible even with basic silicon shank devices.