| 摘要 |
PURPOSE:To obtain a CMOS semiconductor device having a high-integration degree by a method wherein the number of times of the use of the photo masks is lessened than ever, an element isolation is executed by providing the trench type region, which is superior in isolating property, and moreover, the self-matching of each photo mask is enhanced. CONSTITUTION:An SiO2 film 12 is formed on a P-type Si substrate 11 and an Si3N4 film 14 is deposited thereon, and is opened in such a way as to be left part of the film 12a on the bottom of the trench. The trench is filled with a polycrystalline Si layer 15a, an n<-> im purity implanted layer 18 is provided in the substrate 11 using an Si3N4 film 17 and a resist 16 as masks and the end parts of them are made to position on the nearly center of the width part of the trench. The resist 16 is removed and an opening 19 is formed in such a way as to occupy half of the trench width, an n<+> channel cut region 20 is formed in the n<-> well 18 by performing an ion-implantation and an SiO2 film 12b is formed in the opening 19 by performing a thermal oxidation. The film 17 and the layer 15a are removed and a p<+> channel cut region 21 is provided in an opening 19a. The film 13 is removed, a CVD-SiO2 film 22 is superposed on the whole surface as the fifth mask and an opening 23 is formed by an RIE method in such a way as to leave CVD-SiO2 films 22a and 22b on the opening edges thereof. The internal surface of the trench is covered with an SiO2 film 12c, a p<+> channel cut region 24 is formed by performing an ion-implantation, and the interior of the trench is filled with a polycrystalline Si film 25. The resulting flat surface is thermally oxidized 26. After that, electrodes 31a-31d are adhered and the insulation-isolated and high-integration degree CMOS semiconductor device is completed. |
