Patent ID: 6452224
Filing Date: 2002-09-17
Classification: H01L

Abstract:
A method of forming a deep trench capacitor formed in an open top trench with sidewalls, and a bottom in a substrate doped with a dopant of a first polarity, comprising:forming a counterdoped plate electrode region in the substrate surrounding the trench near the bottom by doping through sidewalls of the trench, forming a node dielectric for the capacitor on trench sidewalls, forming a counterdoped conductive buffer covering the node dielectric, forming a conductive, lower diffusion barrier layer over the buffer, forming a node conductor on the surface of the lower diffusion barrier layer, the node conductor being doped with a dopant of the first polarity, forming a conductive, upper diffusion barrier layer over the node conductor, forming a counterdoped conductive cap on the surface of the upper diffusion barrier layer doped with a dopant of the opposite polarity, and forming a counterdoped strap region by outdiffusion of dopant of the opposite polarity into a region in the substrate.