The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 05, 1993
Filed:
Aug. 06, 1991
William G Easter, Reading, PA (US);
Richard H Shanaman, III, Myerstown, PA (US);
American Telephone and Telegraph Company, New York, NY (US);
Abstract
A process for forming a dielectrically isolated wafer is disclosed. In particular, the conventional process is altered to replace the step of growing the thick polysilicon handle layer with the steps of growing a relatively thin conformal coating layer and bonding a single crystal wafer thereto. The wafer will become the substrate of the final device structure. The process of bonding is considered to be more efficient and economical than the prior art polysilicon growth process. Additionally, the tub structures of the wafer bonding process may be exposed to a somewhat lower temperature (for bonding) for shorter period of time than the tub regions of the conventional thick polysilicon DI structures. Therefore, the tub regions will exhibit superior qualities (e.g., less stress, fewer crystal defects) when compared with those formed with the conventional polysilicon growth technique. The wafer bonding process may be utilized with virtually any tub structure since the bonding step occurs subsequent to any tub fabrication processes.