Abstract: A method for analyzing a process output and a method for creating an equipment parameter model are provided. The method for analyzing the process output includes the following steps: A plurality of process steps are obtained. A processor obtains a step model set including a plurality of first step regression models, each of which represents a relationship between N of the process steps and a process output. The processor calculates a correlation of each of the first step regression models. The processor picks up at least two of the first step regression models to be a plurality of second step regression models whose correlations are ranked at top among the correlations of the first step regression models. The processor updates the step model set by a plurality of third step regression models, each of which represents a relationship between M of the process steps and the process output.

Abstract: A method for analyzing a process output and a method for creating an equipment parameter model are provided. The method for analyzing the process output includes the following steps: A plurality of process steps are obtained. A processor obtains a step model set including a plurality of first step regression models, each of which represents a relationship between N of the process steps and a process output. The processor calculates a correlation of each of the first step regression models. The processor picks up at least two of the first step regression models to be a plurality of second step regression models whose correlations are ranked at top among the correlations of the first step regression models. The processor updates the step model set by a plurality of third step regression models, each of which represents a relationship between M of the process steps and the process output.

Abstract: A method for predicting tolerable contact-to-gate spacing is provided. At first, a wafer with a plurality of source/drain contacts are provided. Then, a plurality of testing gate lines are formed on the wafer by using a photomask. In one die, there are different contact-to-gate distances ranging from d+?d to d??d wherein d is the standard spacing and ?d<d. Then, the wafer is inspected to find failure counts corresponding to each contact-to-gate distance. The tolerable spacing is determined according to the failure counts and the contact-to-gate distances based on a statistical method.

Abstract: A method for predicting tolerable contact-to-gate spacing is provided. At first, a wafer with a plurality of source/drain contacts are provided. Then, a plurality of testing gate lines are formed on the wafer by using a photomask. In one die, there are different contact-to-gate distances ranging from d+?d to d??d wherein d is the standard spacing and ?d<d. Then, the wafer is inspected to find failure counts corresponding to each contact-to-gate distance. The tolerable spacing is determined according to the failure counts and the contact-to-gate distances based on a statistical method.

Abstract: An operating voltage tuning method for a static random access memory is disclosed. The static random access memory receives a periphery voltage and a memory cell voltage. The steps of the method mentioned above are shown as follows. First, perform a shmoo test on the static random access memory to obtain a shmoo test plot and a minimum operating voltage. Compare the minimum operating voltage with a preset specification. Position a specification position point on the line which the periphery voltage is equal to the memory cell voltage in the shmoo test plot corresponding to the preset specification. Fix one of the memory cell voltage and the periphery voltage and gradually decrease the other to test the static random access memory and obtain a failure bits distribution. Finally, tune process parameters of the static random access memory according to the specification position point and the failure bits distribution.

Abstract: An operating voltage tuning method for a static random access memory is disclosed. The static random access memory receives a periphery voltage and a memory cell voltage. The steps of the method mentioned above are shown as follows. First, perform a shmoo test on the static random access memory to obtain a shmoo test plot and a minimum operating voltage. Compare the minimum operating voltage with a preset specification. Position a specification position point on the line which the periphery voltage is equal to the memory cell voltage in the shmoo test plot corresponding to the preset specification. Fix one of the memory cell voltage and the periphery voltage and gradually decrease the other to test the static random access memory and obtain a failure bits distribution. Finally, tune process parameters of the static random access memory according to the specification position point and the failure bits distribution.