Vertical control method for use in lithography machine
US11042101B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2018 |
| Grant date | Jun 22, 2021 |
| Priority date | — |
| Expiry date | Mar 14, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7034
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for vertical control of a lithography machine includes step 1, prior to a scanning exposure, controlling vertical measurement sensors to measure workpiece to obtain overall surface profile data of the workpiece; step 2, performing a global leveling based on the overall surface profile data of the workpiece; and step 3, during the scanning exposure of each exposure field, measuring a local surface profile of the workpiece in real time by the vertical measurement sensors and controlling at least one of a mask stage, a workpiece stage and a projection objective to move vertically according to a Z-directional height value, an Rx-directional tilt value and an Ry-directional tilt value corresponding to the local surface profile of the workpiece, to compensate for the local surface profile of the workpiece in real time, so that an upper surface of each exposure field coincides with a reference focal plane for the exposure field. This method enables flexible vertical control with high accuracy by providing multiple control options.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.