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:
Sep. 28, 1976
Filed:
Mar. 26, 1975
San-Mei Ku, Poughkeepsie, NY (US);
Charles A Pillus, Wappingers Falls, NY (US);
Michael R Poponiak, Newburgh, NY (US);
Robert O Schwenker, Hopewell Junction, NY (US);
IBM Corporation, Armonk, NY (US);
Abstract
In integrated circuit fabrication, a method is provided for simultaneously forming two regions of the same conductivity-type such as the base and isolation regions. In one embodiment, an epitaxial layer of one conductivity-type is formed on a substrate of opposite conductivity-type, after which dopant ions of the opposite conductivity-type are introduced into the epitaxial surface areas which are to provide the base and isolation regions, and in addition, the isolation regions are bombarded with non-dopant ions having a maximum atomic number of two, e.g., hydrogen or helium ion while the base regions are appropriately masked and remain umbombarded, said bombardment is carried out at temperatures below 300.degree. C, preferably room temperature. The bombardment is preferably carried out so that the non-dopant ions are implanted primarily in regions below the isolation regions. Next, the wafer is heated at a temperature at a range of from 600.degree. - 900.degree. C which is substantially below normal drive-in diffusion temperatures for unbombarded doped regions. The heating to be maintained for a period sufficient to drive-in diffuse the bombarded isolation regions through the epitaxial layer into contact with the substrate but is insufficient to drive-in the unbombarded base regions to such a depth.