Real-time monitoring and control of epitaxial semiconductor growth in a production environment by in situ spectroscopic ellipsometry

To manufacture the next generation of epitaxially grown semiconductor device structures, real-time monitoring and control of the growth is considered a necessity to achieve acceptable yields. In situ spectroscopic ellipsometry (SE) has demonstrated sensitivity to important growth parameters, such as substrate temperature, layer thickness and composition; the literature also contains some examples of growth control by in situ SE. However, applying this characterization technique in a production environment presents a number of challenges. This article discusses these challenges and solutions which have been implemented on production-ready growth chambers. Real-time in situ SE composition monitoring results which were obtained on such chambers are in excellent agreement with ex situ characterization techniques. Preliminary composition control experiments, using in situ SE as the feedback sensor, are also presented.