Defect density calculation method

Abstract

The invention discloses a defect density calculating method. The defect density calculating method comprises the steps that S1, the wafer yield of chips on a wafer production line is calculated; S2, the die area of a single chip of products is calculated; S3, the complexity coefficient N of the products in a chip manufacturing process is calculated according to the device test bin coefficient, the litho coefficient and the technology coefficient; S4, the defect density D0 is calculated according to the wafer yield, the die area and the complexity coefficient N of the chips. According to the defect density calculating method, the complexity coefficient N is calculated according to the device test bin coefficient B, the litho coefficient L and the technology coefficient T, the defect density is calculated through the modified N, and the deviation of the defect density and actual wafer processing ability is reduced. Meanwhile, the calculating method and the technological process will not produce additional cost.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a defect density calculation method. Background technique [0002] At present, the semiconductor manufacturing process is to grow hundreds of thousands of identical chips on a wafer at the same time, and the wafer after all the processes are completed is also called a bare chip. Qualified chips are selected by testing the bare chips, and cut and packaged into products. Usually, the calculation method of WaferYield for a certain product yield rate of a wafer production line is to first randomly select a number of dies of this product produced by the same wafer production line (the number can vary according to the production situation), and then test all the selected dies. For all chips on the bare chip, use the calculation formula of WaferYield: [0003] WaferYield=Number of qualified chips / total number of chips [0004] Get the product yield WaferYield of a certain prod...

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Problems solved by technology

[0011] In the above model calculation formula, N represents the complexity coefficient. In the existing algorithm, only the number of photolithography layers is used to calculate the value of the complexity coefficient N, but it does not take into account the different device test item coefficients and different process technologies. Density 0 caused by the influence, so the calculated defect density D 0 there is a big error

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