| 摘要 |
PURPOSE:To obtain a semiconductor device which has high integration and high reliability by forming a deep groove of narrow width in contact with a shallow thermally oxidized film at the periphery of the film of wide width formed selectively, filling an isolating material in the groove, and employing the side face of the integrated groove of wide width for an element isolating region. CONSTITUTION:An n type epitaxial layer 603 is superposed on a p type Si substrate 601, in which an n<+> type layer 602 is buried, a window is opened at an SiO2 film 604 with an Si3N4 mask 605, the layer 603 is anisotropically etched to form a shallow groove 607 of wide width, and buried in a thermally oxidized thick film 608. An Si3N4 film 609 is newly covered, a resist mask 610 is formed, and a window 611 is particularly formed at the periphery of the film 608. The mask 610 is removed, and a groove 612 of high depth is formed with narrow width reaching the substrate 601. After the CVD SiO2 film 613 is accumulated sufficiently as compared with a half of the width of the opening of the groove 512, it is etched to the film 609, and when SiO2 614 is allowed to remain in the groove, element isolating regions 615, 615' of wide and narrow widths are obtained. Subsequently, an n-p-n type element is, for example, formed on an insular layer 603. According to tis configuration, a field oxidized film of wide width without step and ultrafine isolating layer are obtained, thereby gaining a semiconductor device which has high integration and high reliability. |
