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. 05, 1978
Filed:
Mar. 31, 1977
Alwin E Michel, Ossining, NY (US);
Robert O Schwenker, Hopewell Junction, NY (US);
James F Ziegler, Putnam Valley, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for forming a non-epitaxial bipolar integrated circuit comprising first forming in a silicon substrate of one-type of conductivity, recessed silicon dioxide regions extending into the substrate and laterally enclosing at least one silicon substrate region of said one-type conductivity. Then, forming by ion implantation the first region of opposite-type conductivity which is fully enclosed laterally by said recessed silicon dioxide. This region is formed by directing a beam of ions of opposite-type conductivity impurity at said enclosed silicon region at such energy and dosage levels that the opposite conductivity-type impurity introduced into the substrate in said region will have a concentration peak at a point below the surface of this first region. Then, a region of said one-type conductivity is formed which extends from the surface into said first opposite-type conductivity region to a point between said concentration peak and said surface. Next, a second region of said opposite-type conductivity is formed which extends from the surface part way into said region of one-type conductivity. Preferably, the ion beam energy level is at least one MeV, and said concentration peak is at least one micron below the surface. It is further preferable that the energy and dosage levels of the beam of ions are selected so that the opposite-type conductivity impurity has a more gradual distribution gradient between the peak and the surface than between the peak and the junction of the first region with the substrate.