| 摘要 |
PURPOSE:To enable high integration of an IC by a method wherein after island regions surrounded with recess type grooves are formed on a silicon substrate and an SiO2 film is formed on the surface thereof, a polycrystalline silicon film is grown, and the silicon substrate is removed by a prescribed quantity, the surface of the remaining silicon substrate is selectively etched again to provide grooves, and SiO2 films are formed again in the grooves thereof. CONSTITUTION:An n-type silicon substrate 12 is etched selectively using SiO2 films 11 as masks to form island regions 14 surrounded with V-type grooves 13, 13'. The whole surface containing the V-type grooves is thermally oxidized to generate an SiO2 film 15, the SiO2 film of a part of the V-type grooves is removed, and only the part of the V-type groove 13' at which the SiO2 film is removed is etched moreover. Si3N4 films 18 are formed selectively on the silicon substrate 12, the silicon substrate is etched using the Si3N4 films thereof as masks to form grooves 19, and arsenic is diffused or implanted into the grooves 19 to form n<+> type buried layers 20. Thermal oxidation is performed again to form SiO2 films 20 in the grooves 19, and after the grooves are buried, by removing the Si3N4 films, element regions T1, T2 surrounded with the SiO2 films 16, 20 and provided inside with the n<+> type buried layers B, 20 are formed.
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