Semiconductor device element-isolation by oxidation of polysilicon in trench

Claim 1

A method of manufacturing a semiconductor apparatus, which comprises the steps of: forming a groove in a semiconductor substrate, said substrate having a region in which a plurality of active elements are formed, said groove being formed in an area other than said region; forming a first continuous insulation layer on the inner periphery of the groove and on the surface of the semiconductor substrate; forming a first polycrystalline silicon layer on the first insulation layer, said first polycrystalline silicon layer having such thickness that the groove is not completely filled; coating the first polycrystalline silicon layer with a second insulation layer; forming a second polycrystalline silicon layer on the second insulation layer, with a thickness sufficient to fill the groove; retaining the second polycrystalline silicon layer only in the groove; removing that portion of the first polycrystalline silicon layer which is positioned above that region of the semiconductor substrate and the first insulation layer in which active elements are formed; and oxidizing that portion of the first polycrystalline silicon layer which is formed over the semiconductor substrate and the first insulation layer in which no active elements are formed and the portions of the first and second polycrystalline silicon layers formed in the groove, thereby forming a field oxide layer.

Claim 2

A method of manufacturing a semiconductor apparatus, which comprises the steps of: forming a groove in a semiconductor substrate, said substrate having a region in which a plurality of active elements are formed, said groove being formed in an area other than said region; forming a first continuous insulation layer on the inner periphery of the groove and on the surface of the semiconductor substrate; forming a first polycrystalline silicon layer on the first insulation layer, said first polycrystalline silicon layer having such thickness that the groove is not completely filled; coating the first polycrystalline silicon layer with a second insulation layer; forming a second polycrystalline silicon layer on the second insulation layer, with a thickness sufficient to fill the groove; retaining the second polycrystalline silicon layer only in the groove; removing that portion of the first polycrystalline silicon layer which is positioned above that region of the semiconductor substrate and the first insulation layer in which active elements are formed; and oxidizing that portion of the first polycrystalline silicon layer which is formed over the semiconductor substrate and the first insulation layer in which no active elements are formed and the portions of the first and second polycrystalline silicon layers formed in the groove, thereby forming a field oxide layer.

Claim 13

A method of manufacturing a semiconductor apparatus, which comprises the steps of: depositing a first silicon oxide layer, a first silicon nitride layer, and a second silicon oxide layer, in the order stated, on the surface of a semiconductor substrate, said semiconductor substrate having a region in which a plurality of active elements are formed; forming a photoresist layer over all of said first silicon oxide layer, said first silicon nitride layer and said second silicon oxide layer; patterning said photoeresist layer; etching the portions of said first silicon oxide layer, said first silicon nitride layer and said second silicon oxide layer not covered by said patterned photoresist layer; removing said photoresist layer; forming a groove in the semiconductor substrate in a portion of said substrate other than said region, said second silicon oxide layer being used as an etching mask for the formation of the groove; forming a first continuous insulation layer on the inner periphery of the groove and on the surface of the semiconductor substrate, the second silicon oxide layer is removed before the first insulation layer is formed on the inner peripheral wall of the groove, as well as over the surface of the semiconductor substrate; forming a third silicon oxide layer on the inner peripheral wall of the groove; removing the first silicon nitride layer and first silicon oxide layer; forming a first polycrystalline silicon layer on the first insulation layer, said first polycrystalline silicon layer having such thickness that the groove is not completely filled; coating the first polycrystalline silicon layer with a second insulation layer; forming a second polycrystalline silicon layer on the second insulation layer, with a thickness sufficient to fill the groove; retaining the second polycrystalline silicon layer only in the groove; removing that portion of the first polycrystalline silicon layer which is positioned above that region of the semiconductor substrate and the first insulation layer in which active elements are formed; and oxidizing that portion of the first polycrystalline silicon layer positioned above that region of the semiconductor substrate and the first insulation layer in which no active elements are formed and the portions of the first and second polycrystalline silicon layers formed in the groove, thereby forming a field oxide layer.

Claim 14

A method of manufacturing a semiconductor apparatus, which comprises the steps of: depositing a first silicon oxide layer, a first silicon nitride layer, and a second silicon oxide layer, in the order stated, on the surface of a semiconductor substrate, said semiconductor substrate having a region in which a plurality of active elements are formed; forming a photoresist layer over all of said first silicon oxide layer, said first silicon nitride layer and said second silicon oxide layer; patterning said photoeresist layer; etching the portions of said first silicon oxide layer, said first silicon nitride layer and said second silicon oxide layer not covered by said patterned photoresist layer; removing said photoresist layer; forming a groove in the semiconductor substrate in a portion of said substrate other than said region, said second silicon oxide layer being used as an etching mask for the formation of the groove; forming a first continuous insulation layer on the inner periphery of the groove and on the surface of the semiconductor substrate, the second silicon oxide layer is removed before the first insulation layer is formed on the inner peripheral wall of the groove, as well as over the surface of the semiconductor substrate; forming a third silicon oxide layer on the inner peripheral wall of the groove; removing the first silicon nitride layer and first silicon oxide layer; forming a first polycrystalline silicon layer on the first insulation layer, said first polycrystalline silicon layer having such thickness that the groove is not completely filled; coating the first polycrystalline silicon layer with a second insulation layer; forming a second polycrystalline silicon layer on the second insulation layer, with a thickness sufficient to fill the groove; retaining the second polycrystalline silicon layer only in the groove; removing that portion of the first polycrystalline silicon layer which is positioned above that region of the semiconductor substrate and the first insulation layer in which active elements are formed; and oxidizing that portion of the first polycrystalline silicon layer positioned above that region of the semiconductor substrate and the first insulation layer in which no active elements are formed and the portions of the first and second polycrystalline silicon layers formed in the groove, thereby forming a field oxide layer.