The Stress Calibrators for the Wafer Thin-Film Stress Measuring Instrument

To verify the measurement accuracy of the wafer thin-film stress measuring instrument, the development of the stress calibrator and the research of measuring algorithm are carried out. First of all, the generation and distribution pattern of the wafer thin-film are studied, and the calculation model and transformation mechanism of the wafer thin-film stress are established. Secondly, the combination of the stress measuring theory and the micro-nano optical manufacturing technology are innovatively realized. Through the precise control of multiple parameters such as Young’s modulus, Poisson’s ration, the substrate curvature radius, the film thickness, and the substrate thickness, etc., the multi-value stress calibrators with the nominal value of 10 MPa to 300 MPa are developed. Finally, a standardized measuring scheme is developed by establishing the algorithm model of the calibrator measuring algorithm with single-parameter transformation. The measuring algorithm model is used to measure the stress calibrators, and take the measurement results of the stress measuring instrument as the reference values. The results show that the magnitude uniformity of the developed stress calibrators is controlled within 2.0%, and they can be used for calibration of wafer thin-film stress measuring instrument.