Focusing and leveling device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- RAINBOW SOURCE LASER RSLASER
- Publication Date
- 2015-05-20
Smart Images
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Abstract
Description
technical field
[0001] The invention relates to a focusing and leveling device for a projection photolithography machine, in particular to a focusing and leveling device with a grating and a reference grating. Background technique
[0002] The focus and leveling device of the projection lithography machine has a large incident angle of light, and it is difficult to ensure that each measurement point is clearly imaged on the silicon wafer, which in turn affects the measurement accuracy. For this reason, in CANON company US 5414515 patent, the method of compensation optics is used to realize clear imaging of each measurement point; in NIKON company US5602399 patent, the method of using inclined prism; in CN 101477319A of SMEE company, the design of inclined mask plate is adopted; in CN 100559278C, reflective stepped prism is used The method; Beijing Institute of Technology CN 100592214C adopts the method of microlens array to realize. Although these methods can achieve clear ...