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:
Apr. 24, 2007
Filed:
Jul. 08, 2002
Albert Birner, Dresden, DE;
Joern Luetzen, Dresden, DE;
Albert Birner, Dresden, DE;
Joern Luetzen, Dresden, DE;
Infineon Technologies AG, Munich, DE;
Abstract
To fabricate a vertical transistor, a trench is provided, the side wall of which is formed by a semiconductor substrate in single crystal form and the base of which is formed by a polycrystalline semiconductor substrate. A transition region is arranged between the side wall and the base. A semiconductor layer is deposited so that an epitaxial semiconductor layer grows on the side wall and a semiconductor layer grows on the base, with a space remaining between these layers. The semiconductor layers are covered with a thin dielectric, which partially limits a flow of current, and the space is filled. During a subsequent heat treatment, dopants diffuse out of the conductive material into the epitaxial semiconductor layer, where they form a doping region. The thin dielectric limits the diffusion of the dopants into the semiconductor substrate and prevents the propagation of crystal lattice defects into the epitaxial semiconductor layer.