A method for determining the boundaries of wafer test data specifications and a method for marking die

Abstract

The invention provides a method of determining a boundary of wafer test data standard and a crystal grain marking method, and relates to the technical field of semiconductors. The method of determining the boundary of wafer test data standard can determine corresponding wafer test data standard boundaries in view of different wafers respectively. The crystal grain marking method comprises steps: S101, the boundary of wafer test data standard is determined, wherein the method of determining the boundary of wafer test data standard is realized by adopting the above method; and S102, crystal grains when the wafer test data falls out of the boundary of the corresponding wafer test data standard are marked to be unqualified products. According to the method of determining the boundary of wafer test data standard, as a dynamic method is adopted to determine the boundary of wafer test data standard, the yield of crystal grains on the wafer can be improved. According to the crystal grain marking method, the above method is adopted to determine the boundary of wafer test data standard, and the crystal grain marking method is also provided with the above advantages.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for determining the limit of wafer test data specifications and a method for marking crystal grains. Background technique [0002] In the field of semiconductor technology, wafer sorting (wafer sort, WS for short) is the first process for distinguishing qualified products from unqualified products in the back-end of semiconductors. Wafer testing is mainly a test process in which a series of electrical tests are performed on each die on the wafer to determine whether the die is good or bad after the semiconductor device is manufactured and before dicing and packaging. Typically, the customer will provide a test plan for wafer testing, and each electrical test will generate corresponding electrical test data (called "wafer test data" or "WS" data). Moreover, customers will also provide static wafer test data specifications (specifications), also known as wafer test...

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Problems solved by technology

[0006] It can be seen that, in the prior art, the above-mentioned method of marking the die by tightening the scope of the wafer test specification, because all the wafers use the same wafer test specification limit (generally the best wafer is the benchmark), that is, using the static wafer test specification boundaries, so it is impossible to distinguish the "baseline (baseline) grains" and "critical tails (marginal tails) grains" of each wafer in a targeted manner, resulting in common die Many baseline (baseline) dies that were originally "qualified products" on the circle are marked as "non-conforming products" and discarded, which is not conducive to the improvement of product yield, and is not conducive to reducing the cost of the fab

That is to say, the method for determining the limit of the wafer test data specification in the prior art is not conducive to the improvement of the product yield, and has been unable to meet actual needs; correspondingly, using the method for determining the wafer test data specification in the prior art The method of determining the boundary of the wafer test data specification and the grain marking method of the boundary can no longer meet the actual needs.

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