Yield Estimation and Prediction

Due to inherent fluctuations in any integrated circuit manufacturing process, the yield (which is nominally viewed as the ratio of the number of chips that perform correctly, i.e., meet all performance specifications, to the number of chips manufactured) is always less than 100%. As the complexity of VLSI chips increases, and the dimensions of VLSI devices decrease, the sensitivity of performance to process fluctuations increases, thus further reducing the manufacturing yield. Since profitability of a manufacturing process is directly related to yield, the search for computer-aided methods for maximizing yield through improved design methods and control of the manufacturing process has intensified dramatically.