Temperature Drift of Silicon Photodiode Spectral Sensitivity

Abstract

The spectral sensitivity change of a silicon photodiode with its temperature is analyzed in the article. This research area is relevant because silicon photodiodes are used as sensitive elements in temperature control systems of the vapour-phase epitaxy process. Technical characteristics of the obtained semiconductor devices are mostly determined by the quality of heterostructures used for their manufacture. The optical pyrometry method is used for the surface temperature precise control of the A3B5 solid solutions active layers during metalorganic chemical vapour deposition (MOCVD). Since the surface relief and parameters during deposition change significantly, classical pyrometry leads to significant measurement errors, so the pyrometry method with radiation compensation is used. This method combines the wafer surface radiation measurement and its reflectivity. This allows to determine the surface temperature true value, the layer thickness and the heat distribution uniformity on the wafer in real time.

However, for high precision, it is necessary to take into account the temperature coefficient of the silicon photodiode ampere-watt sensitivity change. The basics of MOCVD technology are discussed in this article. The features of the epitaxy process in the reactor with high-precision temperature control are highlighted.

The analytical and empirical study of change in silicon photodiode ampere-watt sensitivity and its effect on measurement accuracy are given. The research results improve the accuracy of real temperature measurement using pyrometric parameter control systems in MOCVD technology and help to understand and to take into account the influence of temperature factors on measurement accuracy to improve this technology.