| 摘要 |
A new control wafer configuration and method allows for the earlier detection of processing problems and resulting striations, localized high concentrations of phosphorous, in product wafers as compared to the standard control wafer configuration currently being used. By increasing the thickness of a phosphorus doped silicate glass (PSG) layer in a film stack from about 1500 Å in the standard control wafer to a thickness greater than about 2500 Å, preferably a thickness in the range between about 3000 Å to about 4000 Å, any localized high concentration phosphorus striations are consistently found within the PSG layer during testing. As a result, the PSG layer in the control wafer accurately represents potential defects in the product wafers. If there is a problem on the production line, the striations are detected in the control wafer before mass production of product wafers continues.
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