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:
Nov. 29, 2011
Filed:
Dec. 18, 2009
Josef Boeck, Munich, DE;
Wolfgang Liebl, Bad Abbach, DE;
Thomas Meister, Taufkirchen, DE;
Herbert Schaefer, Hoehenkirchen-Siegertsbrunn, DE;
Josef Boeck, Munich, DE;
Wolfgang Liebl, Bad Abbach, DE;
Thomas Meister, Taufkirchen, DE;
Herbert Schaefer, Hoehenkirchen-Siegertsbrunn, DE;
Infineon Technologies AG, Neubiberg, DE;
Abstract
The disclosed invention provides a method for the fabrication of a bipolar transistor having a collector region comprised within a semiconductor body separated from an overlying base region by one or more isolation cavities (e.g., air gaps) filled with low permittivity gas. In particular, a multilayer base-collector dielectric film is deposited over the collector region. A base region is formed onto the multilayer dielectric film and is patterned to form one or more base connection regions. The multilayer dielectric film is selectively etched during a plurality of isotropic etch processes to allow for the formation of one or more isolation region between the base connection regions and the collector region, wherein the one or more isolation regions comprise cavities filled with a gas having a low dielectric constant (e.g., air). The resultant bipolar transistor has a reduced base-collector capacitance, thereby allowing for improved frequency properties (e.g., higher maximum frequency operation).