| 摘要 |
PURPOSE:To facilitate control of the thickness of an oxide film on the side wall of a trench by a method wherein the azimuth of the main surface of an Si substrate is selected to by equivalent to the azimuth of an orientation flat (OF) and the direction of the OF and the directions of the side surfaces of chips are so arranged as to be parallel or vertical to each other. CONSTITUTION:An azimuth 100 is employed as the azimuth A of the main surface of a substrate 1 and the azimuth B of an OF is also equivalent to the azimuth 100. If, under these conditions, the directions of the end surfaces of chips are formed so as to be parallel or vertical to the direction of the OF in a pattern formation process, the crystal azimuth of the side surfaces of the chips 2 are also made to be equivalent to the azimuth 100. As one of trench structures formed in the chip, a trench 3 is so formed as to make its side walls parallel or vertical to the end surfaces of the chip and the inside walls of the trench are subjected to hot oxidation to form an oxide film 4 which is to be the dielectric of a capacitor. An upper electrode 5 is formed by filling the trench 3 with polycrystalline silicon. With this constitution, as the azimuth D of the side wall of the trench 3 is equivalent to the azimuth 100 and the speed of oxidation in a region where the oxide film 4 is thin is low, the controllability of the thickness of the oxide film can be improved. |
