System and method for monitoring and evaluating semiconductor wafer fabrication

摘要

A system (60) and method for monitoring, evaluating and controlling the uniformity of a semiconductor wafer fabrication process is provided for use in manufacturing integrated circuits on semiconductor wafers (40). By using in situ ellipsometry (20) in conjunction with statistical modeling methods, the spatial etch rate pattern across a semiconductor wafer (40) may be inferred as a function of the process conditions. A predicted mean etch rate may be calculated for other locations (46 and 48) on the semiconductor wafer surface (42) by using the mean etch rate measured at the selected ellipsometer site (44) and individual spatial etch rate models developed for each site (44 and 48) based on statistically designed experiments. The predicted mean etch rate at the other sites (46 and 48) is also a function of the fabrication process conditions. The method for evaluating uniformity may be used with fabrication processes such as oxidation, doping, etching or any other process which may be measured in situ at a selected location (44) on a semiconductor wafer (40) during the fabrication process.