Patent ID: 8332416

Claim:
A specification establishing method for controlling semiconductor process, comprising the steps of: providing a database and choosing a population from the database; sampling a plurality of sample groups from the population, each sample group being a non-normal distribution and having a plurality of samples; filtering the sample groups; summarizing the filtered sample groups to form a non-normal distribution diagram; getting a value-at-risk and a median by calculating from the non-normal distribution diagram; getting a critical value by calculating the value-at-risk and the median with a critical formula; getting a plurality of state values by calculating the filtered sample groups with a proportion formula; and getting an index value by calculating the non-normal distribution diagram with the proportion formula; thereby the state values present the states of the sample groups are abnormal or not by comparing the state values to the index value, wherein the critical formula is VaR + M n = V cri ⁡ ( n ∈ R , n > 0 ) , VaR is the value-at-risk, M is the median and V cri is the critical value.