Method of photolithographic exposure dose control as a function of resist sensitivity
US6856378B2 · kind B2 · utility
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11Claims
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Key dates
| Filing date | Oct 23, 2003 |
| Grant date | Feb 15, 2005 |
| Priority date | — |
| Expiry date | Oct 23, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70608
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A predictive method is used to compensate for intermediate batch sensitivities which inevitably occur during resist batch changeover. The compensation is applied to historical dose levels to arrive at a new dose level estimating an optimum dose. When the system discovers that a new batch of resist is loaded to a tool, historical data is used to calculate a reference dose for each tool. A batch factor is continuously calculated and using historical data along with the batch factor, a dose adjustment is made to maintain proper image size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.