| 摘要 |
PURPOSE:To enable formation of U-shaped grooves on a semiconductor substrate with good reproductivity and controllability for microminiaturization of element separation region by forming impurity implantation layers in the predetermined depth from a surface of a semiconductor substrate and grooves which reach the impurity implantation layers from the surface of the semiconductor substrate. CONSTITUTION:On an Si substrate 1, a necessary pattern consisting of photoresist 2 is formed and oxygen ions are implanted by ion implantation using said photoresist 2 as a mask. As a result, O<+> implantation layers 3 consisting of SiOx are formed in the region of the predetermined depth. After that, the Si substrate 1 is subjected to anisotropic etching by dry etching using a gas consisting of a chlorine group gas mainly and U-shaped grooves 4 are formed. As a ratio of etching speed of the SiOx layer and Si is larger than 10, depths of the U-shaped grooves 4 are determined by depths of the impurity layers 3 formed by ion implantation and the uniformity is improved. |
