Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors
A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet (DUV) and Extreme Ultra-Violet (EUV) wavelengths. The method results in a product with minimum feature sizes of less than 0.10 [micro]m for the shortest wavelength (13.4 nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R[sup 2] factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates. 15 figs.
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- Assignee:
- Sandia Corp., Albuquerque, NM (United States)
- Patent Number(s):
- US 5911858; A
- Application Number:
- PPN: US 8-801883
- OSTI ID:
- 6367198
- Resource Relation:
- Patent File Date: 18 Feb 1997
- Country of Publication:
- United States
- Language:
- English
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