Intellectual Property Office

Non-Confidential Disclosures

"Selective Area, Low Temperature Crystallization of Amorphous Silicon Films by Metal Induced Rapid Thermal Annealing"

PSU Invention Disclosure Number 897 & 1073

Field of the Invention:

Amorphous Silicon Films

Inventors:

S.J. Fonash, et al.

Patent status:

Issued U.S. Patent Nos. 5,147,826 & 5,275,851

Background:

Thin film poly-Si is of considerable interest today for microelectronics, flat panel displays, and photovoltaics. A well established technique for obtaining poly-Si is to solid phase crystallize (SPC) an a-Si precursor film. SPC of low pressure chemical vapor deposition or plasma enhanced chemical vapor deposition a-Si films may be achieved in less than 5 min at 700 ° C. However, in all areas of poly-Si use there is still a considerable need to lower processing temperatures even further while maintaining the advantages of annealing rapidly and of forming large grain sizes. The present invention significantly advances semiconductor processing technology in this direction.

Invention description:

The patented invention is a technique for reducing the thermal budget of rapid thermal annealing (RTA) for converting a-Si to poly-Si. This new technique reduces the temperature range to 550 ° C - 650 ° C. This is accomplished by deposition of a ultra thin discontinuous film of a nucleating site forming material prior to RTA or furnace annealing. Furthermore, by selectively using the surface modification material in a pattern, only the a-Si beneath this pattern is caused to crystallize during annealing, while the remaining areas of a-Si remain in the amorphous state.

Advantages:

• Major benefits of this technology include the following: Reduction of temperature during rapid thermal annealing (RTA)
  
• Use of substrates which can not be used in higher temperature RTA
  
• A simple and inexpensive method for achieving patterned high quality poly-Si by selective crystallization of a-Si thus making poly-Si circuits and a-Si pixel switches possible
  
• Proven technology already licensed non-exclusively

Contact:

Richard M. Weyer
Sr. Technology Licensing Officer
Intellectual Property Office
The Pennsylvania State University
113 Technology Center
University Park, PA 16802-7000
Phone: (814) 865-6279
Fax: (814) 865-3591
E-mail: rmw4@psu.edu