Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
153 words
A method of producing an SOI semiconductor device comprising the steps of: joining a semiconductor substrate serving as a base and having a main surface and a junction surface opposite said main surface to a semiconductor layer, wherein an inner insulation film is sandwiched between said junction surface of said semiconductor substrate and said semiconductor layer and an outer insulation film is provided on said main surface of said semiconductor substrate; forming a first nitride film as a mask for trench formation over an exposed surface of said semiconductor layer; removing a second nitride film which has accumulated on said outer insulation film and which accumulated on said outer insulation film during said first nitride film forming step; using said first nitride film over said semiconductor layer as said mask in forming a trench in said semiconductor layer; and filling in said trench with a filler material to form an island semiconductor region.
Claim 2
Independent Claim
153 words
A method of producing an SOI semiconductor device comprising the steps of: joining a semiconductor substrate serving as a base and having a main surface and a junction surface opposite said main surface to a semiconductor layer, wherein an inner insulation film is sandwiched between said junction surface of said semiconductor substrate and said semiconductor layer and an outer insulation film is provided on said main surface of said semiconductor substrate; forming a first nitride film as a mask for trench formation over an exposed surface of said semiconductor layer; removing a second nitride film which has accumulated on said outer insulation film and which accumulated on said outer insulation film during said first nitride film forming step; using said first nitride film over said semiconductor layer as said mask in forming a trench in said semiconductor layer; and filling in said trench with a filler material to form an island semiconductor region.
Claim 3
Dependent Claim
45 words
The method of producing an SOI semiconductor device according to claim 1, further comprising the steps of: removing said filler material which has accumulated over said outer insulation film and which accumulated during said filling in step; and forming elements in said island semiconductor region.
Claim 4
Dependent Claim
45 words
The method of producing an SOI semiconductor device according to claim 1, further including the step of: forming said outer insulation film and said inner insulation film from silicon oxide and so that said outer insulation film and said inner insulation film have identical thicknesses.
Claim 5
Dependent Claim
67 words
The method of producing an SOI semiconductor device according to claim 3, wherein the forming of the output and inner insulation films from silicon oxide includes the step, prior to said joining step, of simultaneously forming silicon oxide films over said main surface and said junction surface of said semiconductor substrate, said silicon oxide films serving as said outer insulation film and said inner insulation film, respectively.
Claim 6
Dependent Claim
51 words
The method of producing and SOI semiconductor device according to claim 1, further comprising the steps of: forming a field oxide film over a surface of said semiconductor layer, while simultaneously oxidizing a surface of said filler material which has accumulated on said outer insulation film during said filling in step.
Claim 7
Independent Claim
149 words
A method of forming an SOI semiconductor device, said method comprising the steps of: forming a first insulation film on a first side of a substrate and a second insulation film on a second side of said substrate; bonding a semiconductor layer to said substrate so as to sandwich said first insulation film therebetween; forming a first nitride film over a surface of said semiconductor layer opposite said first insulation film; removing a second nitride film which has been deposited on said second insulation film and which has been deposited during said first nitride film forming step; forming a trench in said semiconductor layer using said first nitride film disposed over said surface of semiconductor layer opposite said first insulation film as a mask; filling in said trench with a filler material; and forming in said semiconductor layer an island-like semiconductor region in which a semiconductor element is formed.
Claim 8
Independent Claim
149 words
A method of forming an SOI semiconductor device, said method comprising the steps of: forming a first insulation film on a first side of a substrate and a second insulation film on a second side of said substrate; bonding a semiconductor layer to said substrate so as to sandwich said first insulation film therebetween; forming a first nitride film over a surface of said semiconductor layer opposite said first insulation film; removing a second nitride film which has been deposited on said second insulation film and which has been deposited during said first nitride film forming step; forming a trench in said semiconductor layer using said first nitride film disposed over said surface of semiconductor layer opposite said first insulation film as a mask; filling in said trench with a filler material; and forming in said semiconductor layer an island-like semiconductor region in which a semiconductor element is formed.