| 摘要 |
PURPOSE:To simplify a manufacturing process while improving the degree of integration and increasing operating speed by forming the oxide film of a peripheral circuit region and an oxide film required for shaping the recessed section of a storage cell region through one-time oxidation and selectively removing only the oxide film required for forming the recessed section. CONSTITUTION:An N<+> type layer 2 is formed onto a P<-> type silicon substrate 1 and an N<-> type epitaxial layer 3 onto the layer 2. The in ter-element region of a peripheral circuit region S and a storage cell region M are oxidized by using a LOCOS method, and thick oxide films 4a, 4b are shaped only the oxide film 4a of the storage cell region M is removed selectively, and the indentation 5 of the N<-> type epitaxial layer is formed. Groove type isolation regions 8 are shaped by a grooving isolation method, P<+> type base diffusion regions 6 are formed into the N<-> type epitaxial layer 3, and N<+> type emitter regions 7 are shaped into the base diffusion regions 6. Since sections among elements are isolated by deep grooves, the degree of integration is improved and operation at high speed is acquired, an inter-element oxide film is unnecessitated, and a semiconductor storage device can be formed through one time oxidation process and a manufacturing process can be shortened.
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