Mask overlay control
US9017903B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2013 |
| Grant date | Apr 28, 2015 |
| Priority date | — |
| Expiry date | Jul 22, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/22
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Some embodiments of the present disclosure relate to a method of patterning a workpiece with a mask, wherein a scale factor between a geometry of the mask and a corresponding target shape of the mask is determined. The scale factor results from thermal expansion of the mask and geometry due to heating of the mask during exposure to radiation by an electron beam (e-beam) in the mask manufacturing process. A number of radiation pulses necessary to dispose the geometry on the mask is determined. A scale factor for the mask is then determined from the number of pulses. The target shape is then generated on the mask by re-scaling the geometry according to the scale factor prior to mask manufacturing. This method compensates for thermal deformation due to e-beam heating to improve OVL variability in advanced technology nodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.