CMOS-Compatible Surface-Micromachined Test Structure for Determination of Thermal Conductivity of Thin Film Materials based on Seebeck Effect

This paper reports the design, modeling, fabrication and measurement of a CMOS-compatible surface-micromachined test structure for the determination of the thermal conductivity of thin films based on the Seebeck effect. The Seebeck effect-based temperature sensing is more advantageous for thin film materials with a relatively large Seebeck coefficient, such as lightly doped poly-Si and poly-SiGe. In this paper, the conceptual design is first analyzed and then verified with finite element modeling. The test structure is fabricated with poly-Si_70% Ge_30%. Its functionality is demonstrated from experimental results. The sources of the measurement error are discussed and the solutions to minimize the measurement error are proposed.