METHOD FOR FORMATION OF BURIED GATE ELECTRODE

摘要

PURPOSE: A method for formation of a buried gate electrode is provided to prevent the deterioration of a gate oxide film by using a silicon germanium layer as the gate electrode layer contacting with the gate oxide film. CONSTITUTION: A trench is formed inside a semiconductor substrate. A gate oxidation film(114) is formed on the semiconductor substrate having the trench. A first gate electrode layer(122) is formed on the gate oxidation film. A silicon layer is formed on the first gate electrode layer in order to fill up the trench. A part of the first gate electrode layer is selectively recessed in order to expose a part of the side of the silicon layer. A metal layer is formed on the semiconductor substrate having the part of the first gate electrode layer. A metal silicide layer(127) is formed on the top of the silicon layer by heat-treating the semiconductor substrate having a metal layer.