| 摘要 |
PURPOSE:To obtain perfect insulated and isolated structure by forming the trench surrounding each discrete semiconductor element forming regions to an Si substrate where the epitaxial layer is formed by the epitaxial growth method, forming the trench also to the rear surface corresponding to said trench, depositing the insulating polycrystalline Si layer to the front and rear surfaces filling said treaches and removing the polycrystalline Si layer while only the polycrystalline Si layer on the front surface is left within the trench of the front surface. CONSTITUTION:An N<-> type layer 5 is formed by the epitaxial growth method on an N<+> type Si substrate 4, a trench 7 for insulating isolation is formed on the layer 5 surrounding each discrete semiconductor element forming regions and the SiO2 films 8 and 9 are respectively deposited on all exposed surfaces of front and rear surfaces. An isulating first polycrystalline Si layer 10 is deposited on the surface filling the trench 7 and a trench 11 which corresponds to the trench 7 and is also wider than it is formed on the rear surface of substrate 4. Thereafter, an insulating second polycrystalline layer 15 is deposited on the rear surface of substrate 4 through the SiO2 film 13, filling the trench 11 and the first polycrystalline Si layer 10 on the surface is removed by executing the etching until the film 8 is exposed. Thereby, the region isolated by the upper and lower trenches consisting of films 8 and 13 and polycrystalline layers 10 and 15 can be obtained.
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