In-line method for extracting the temperature coefficient of resistance of surface-micromachined polysilicon thin films

A method to in-line extract the temperature coefficient of resistance of polysilicon thin films is proposed. It is composed of two polysilicon microbeams with the same width and thickness but different lengths. The effects of all heat exchange by convection, radiation and heat transfer through the air gap and into substrates are considered in the electrothermal model of the polysilicon microbeams. In our measurements, by using parameter best fitting analysis of the theoretical curves with the experiment I–V curves of the two beams and its transient state cooling characteristics, the surface-micromachined polysilicon thin films with p+ doped and a sheet resistance 116.25 Ω/sq., the linear temperature coefficient, −5.4354 × 10−4 K−1, and the quadratic temperature coefficient, −4.7312 × 10−6 K−2, can be obtained. The proposed method is suitable for the in-line extraction of the temperature coefficient of resistance for the surface-micromachined polysilicon thin films.