Dielectric isolation substrate

Abstract

Abstract PURPOSE:To improve the manufacturing yield by forming a supporting region of a polycrystalline Si suport layer of modified structure when forming a plurality of single crystal semiconductor insular regions separated by an insulating film on the supporting region, and forming a plurality of oxygen invasion preventive films on the surface opposed to the insular regions, thereby eliminating the warpage of a substrate. CONSTITUTION:A plurality of isolation grooves 2 are opened by selectively etching on one surface of an N type Si wafer 1, and an SiO2 film 3 is coated on the overall surface which includes the grooves. Then, a support layer 4 made of modified polycrystalline Si mixed with an ultrafine amount of CO2 gas is accumulated on the film 3, the surface is polished to the portion designated by a line A as a reference surface, and an O2 invasion preventive film 9 which does not contain O2 such as Si3N4 is coated on the surface. Then, a wafer 1 side is ground until the bottoms of the grooves 2 are presented as insular regions that the wafer 1 is isolated by the grooves 2, a plurality of holes 10 are opened at the film 9, and an SiO2 layer 11 is formed in the oxposed layer 4. Further, the layer 11 is coated on the insular regions, holes are opened, and P type regions are diffused and formed in the insular regions.

Inventors

• 👤 Hironori Inoue
• 👤 洋典 井上
• 👤 Takaya Suzuki
• 👤 誉也 鈴木

Bibliographic Details