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:
Mar. 25, 1997
Filed:
Jun. 29, 1995
Joseph P Ellul, Nepean, CA;
John M Boyd, Woodlawn, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A buried layer contact for a integrated circuit structure is provided, with particular application for a contact for a buried collector of a bipolar transistor. The buried layer contact takes the form of a sinker comprising a fully recessed trench isolated structure having dielectric lined sidewalls and filled with conductive material, e.g. doped polysilicon which contacts the buried layer. The trench isolated contact is more compact than a conventional diffused sinker structure, and thus beneficially allows for reduced transistor area. Advantageously, a reduced area sinker reduces the parasitic capacitance and power dissipation. In a practical implementation, the structure provides for an annular collector contact structure to reduce collector resistance.