Method and appararus for real-time analysis of complex thin-film multi-layer growth processes

摘要

A method for real-time analysis of complex thin-film multi-layer growth processes, the method comprising: repetitively irradiating a growing thin-film structure (8); measuring the reflectance R exp,1 (t) values received from the growing thin-film structure (8) for a set of wavelength and for each deposited layer L; calculating the virtual back surface complex reflectance r vbs according to the virtual interface approximation (VIA) method; determining the growth rate g L of layer L and providing the obtained growth rate g L to an optical feed-back control system (1) for comparing the obtained growth rate g L with the expected growth rate and finally adjusting the growing parameters according to the difference between the obtained growth rate g L and the expected growth rate. This method allows for quantitative optical in-situ analysis (spectroscopic or multi-wavelength) and related feed-back control of multi-layer thin-film growth under extreme conditions: growth performed on large area semiconductor substrates and at high growth rate, with a total number of layers in the stack reaching up to 100 layers or more.