Wafer bonding technique for dielectric isolation processing

USH1137H · kind H · statutory invention registration

Assignee

• American Telephone and Telegraph, Co. · US

Inventors

• William Easter · Oviedo, US
• Richard Shanaman · Myerstown, US

Key dates

• Grant date: Feb 2, 1993

Classification

• Technology area (CPC —): General

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 and tub structure since the bonding step occurs subsequent to any tub fabrication processes.