Patent ID: 6806138
Filing Date: 2004-10-19
Classification: H01L

Abstract:
A method for forming a deep trench capacitor structure, the method comprising the steps of:(a) forming a deep trench in a semiconductor substrate, said deep trench having an upper region and a lower region; (b) forming a collar on interior walls of said upper region of said deep trench; (c) forming a layer of hemispherical silicon grain on exposed interior walls of said lower region of said deep trench; (d) annealing said substrate in an environment comprising oxygen while simultaneously forming a doped region in said substrate, thereby oxidizing said layer of hemispherical silicon grain and oxidizing a portion of said substrate to form a roughened surface on interior walls of said deep trench; and (e) removing said oxidized layer of hemispherical silicon grain and said oxidized portion of said substrate.