Temperature dependence of the reflectivity of silicon with surface oxide at wavelengths of 633 and 1047 nm

We measure the temperature coefficient of the reflectivity of Si at a red w avelength of 633 nm that is much larger than the Si band gap, and at an inf rared wavelength of 1047 nm that is close to the band gap. Our reflectivity measurement is done over a temperature range from room temperature to 200 degrees C, with an accuracy of better than 1 part in 10(5). Our results sho w that the temperature coefficient for the infrared reflection is over thre e times larger than that for the red reflection over the temperature range studied. Our results and technique can be useful for remote monitoring of t emperatures of Si or other materials. (C) 1999 American Institute of Physic s. [S0003-6951(99)00627-0].