| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem of prior art that, in the manufacture of a semiconductor device, the p control chart is generally used for trend control of a percent defective belonging to discrete values, but the chart is not used when there are variations between subgroups and variations within a subgroup, and further, when the size (the number of data) is large, the width of a control limit line of the p control chart is very narrowed, and it can not be used for the extraction of abnormality. <P>SOLUTION: A percent defective 1 used as a discrete value is processed as an indiscrete using inverse sine transformation 3 or logit transformation 9, and process control 8 is achieved using a generally known "x-s control chart 5" or "x-Rs control chart 11", which is an indiscrete control chart capable of controlling the variations between subgroups and variations within a subgroup. <P>COPYRIGHT: (C)2004,JPO</p> |
