| 摘要 |
PURPOSE:To contrive to stabilize the threshold voltage by a method wherein an insular SiN film is formed on the Si substrate and after an Si layer is selectively made to epitaxially grow outside the SiN film using tricholorosilane, the SiN film is removed and a recess is formed. CONSTITUTION:An SiO2 film 6a is formed on an Si substrate 1 and an SiN film 6b is formed thereon. Then, an etching is performed on the SiO2 film 6a and the SiN film 6b and an insular SiN mask 6c is formed. After that, the SiN mask 6c is removed by performing an etching and a recess 3a is completed. The bottom surface of the recess 3a, which is made to expose by this etching, is smooth and there exists no remaining stress in the bottom surface. A dielec tric film 4a to be formed on the inner surface of the recess 3a, wherein there is no both remaining stress and surface roughness, is more stable than a conven tional dielectric film 4 in withstand voltage and the side surface thereof is slanting. Accordingly, an electrode 5a to be formed by coating is improved its coverage more than that of a conventional electrode 5 and the characteristics of the capacitor to be formed are stabilized. |
