Method for setting specification limit of measurement machine monitoring chart

Abstract

The invention relates to a method for setting specification limit of a measurement machine monitoring chart. The method sets the specification limit of a machine according to the characteristic parameters of the machine, actual conditions of the machine during running and measurement requirement of the machine under inline condition so as to meet measurement performance and production measurement demand of the machine. The method disclosed by the invention has the advantages that: (1) reasonable specifications are set in each monitoring chart, and an abnormal condition of the machine can be sensitively detected; (2) the process capability index and the actual engineering capability index (Cpk) of the machine can be controlled within reasonable ranges, and the approval on the process capability index (Cpk) of the machine is facilitated; (3) combined with statistic and engineering judgment, each control chart is classified, so that each type of control chart can find acorresponding treatment method; and (4) automatic control can be achieved by means of complete process, and different problems of the machine can be recognized and classified.

Description

technical field [0001] The present invention relates to the field of semiconductor technology, in particular, the present invention relates to a method for setting the specification limit of a monitoring chart of a measuring machine. Background technique [0002] With the continuous development of semiconductor technology, the size of semiconductor devices has been continuously reduced, and the development of micro-devices. At the same time, with the continuous updating of technology, the requirements for measurement accuracy are getting higher and higher. Among them, the performance of the measuring machine plays a vital role in the production measurement, and its error will directly affect the production results. Therefore, the control method for the measuring machine is particularly important. [0003] At present, the industry mainly uses two methods to set the specification limit of the monitoring chart of the measuring machine: 1) 10% of the specification limit of the ...

AI Technical Summary

Problems solved by technology

It is not perfect to define the specification limit by a single element: taking the accuracy spec in the machine characteristic parameters as the specification limit only considers the condition of the machine leaving the factory, ignoring the actual status and production needs of the machine; If the actual condition n×sigma in the operation of the machine is used as the specification limit, it is impossible to know the improvement limit of the machine, and the measurement requirements that the machine should meet are also ignored; while only using inline measurement requirements as the specification limit ignores the machine itself performance and current conditions, may result in setting too wide or too tight

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