摘要 |
The necessary information such as chip area A, number of elements, and defect density D is inputted to calculate element density TD and mean element density TDM. The inverse operation chip area A' is calculated from the estimation equation: Y = f(A) such as Stapper's equation showing the dependence of the yield on the defect density D and chip area A. Next, for various kinds of integrated circuit devices in a diffusion process, the functional relation g (TD/TDM) which is considered to be most correct is determined from the data of the relationship between the ratio (A'/A) and the ratio (TD/TDM), and from the relational expression g (TD/TDM), the correction factor K is calculated. Finally, the values of the correction factor K and the chip area A are substituted into Y = f (A xK) to calculate the expected yield Y. <IMAGE> |