Method of adaptive interactive learning control and a lithographic manufacturing process and apparatus employing such a method
US7181296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 2004 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Sep 14, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/20
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
By applying time-frequency analysis to a given standard iterative learning control or ILC an adaptive filter for the learned feed-forward loop is designed. This time varying filter varies according to the momentary frequency content of the error signal and allows to discriminate between areas of deterministic and stochastic error. Its application results in selective application of ILC to those intervals where error signals of high level are concentrated and allows application of a single ILC acquisition to different setpoint trajectories. The adaptive filter finds particular use in lithographic scanning systems where it is used for varying scan length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.