Method of fabricating a high reliable SOI substrate

Claim 1

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } surface; forming an oxide layer in the single semiconductor substrate; forming a hydrogen-containing layer at a predetermined depth in the single crystal semiconductor substrate by adding hydrogen into the single semiconductor substrate from a side of the main surface through the oxide layer; bonding the single crystal semiconductor substrate and a supporting substrate to each other; separating the single crystal semiconductor substrate by a first heat treatment along the hydrogen-containing layer; carrying out a second heat treatment at a temperature of 900 to 1200° C.; polishing a single crystal semiconductor layer remaining on the supporting substrate and having a main surface of a { 110 } plane; and forming at least one thin film transistor using the single crystal semiconductor layer as an active layer thereof.

Claim 2

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } surface; forming an oxide layer in the single semiconductor substrate; forming a hydrogen-containing layer at a predetermined depth in the single crystal semiconductor substrate by adding hydrogen into the single semiconductor substrate from a side of the main surface through the oxide layer; bonding the single crystal semiconductor substrate and a supporting substrate to each other; separating the single crystal semiconductor substrate by a first heat treatment along the hydrogen-containing layer; carrying out a second heat treatment at a temperature of 900 to 1200° C.; polishing a single crystal semiconductor layer remaining on the supporting substrate and having a main surface of a { 110 } plane; and forming at least one thin film transistor using the single crystal semiconductor layer as an active layer thereof.

Claim 3

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } surface; forming a porous semiconductor layer by anodic oxidation of the single crystal semiconductor substrate; carrying out a first heat treatment on the porous semiconductor layer in a reducing atmosphere; carrying out an epitaxial growth of a first single crystal semiconductor layer having a main surface of a { 110 } plane on the porous semiconductor layer; oxidizing the first single crystal semiconductor layer to form an oxide layer, wherein a remaining portion in the first single crystal semiconductor layer which is not oxidized in the oxidizing step is defined as a second single crystal semiconductor layer; bonding the single crystal semiconductor substrate and a supporting substrate to each other; carrying out a second heat treatment at a temperature of 900 to 1200° C.; polishing the single crystal semiconductor substrate until the porous semiconductor layer is exposed; removing the porous semiconductor layer to expose the second single crystal semiconductor layer; and forming at least a thin film transistor using the second single crystal semiconductor layer over the supporting substrate as an active layer thereof (Embodiment 2).

Claim 4

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } surface; forming a porous semiconductor layer by anodic oxidation of the single crystal semiconductor substrate; carrying out a first heat treatment on the porous semiconductor layer in a reducing atmosphere; carrying out an epitaxial growth of a first single crystal semiconductor layer having a main surface of a { 110 } plane on the porous semiconductor layer; oxidizing the first single crystal semiconductor layer to form an oxide layer, wherein a remaining portion in the first single crystal semiconductor layer which is not oxidized in the oxidizing step is defined as a second single crystal semiconductor layer; bonding the single crystal semiconductor substrate and a supporting substrate to each other; carrying out a second heat treatment at a temperature of 900 to 1200° C.; polishing the single crystal semiconductor substrate until the porous semiconductor layer is exposed; removing the porous semiconductor layer to expose the second single crystal semiconductor layer; and forming at least a thin film transistor using the second single crystal semiconductor layer over the supporting substrate as an active layer thereof (Embodiment 2).

Claim 5

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } plane; forming an oxygen-containing layer at a predetermined depth in the single crystal semiconductor substrate by adding oxygen ions into the single semiconductor substrate from a side of the main surface; converting the oxygen-containing layer into a buried oxide layer by a heat treatment, wherein a single crystal layer having a main surface of a { 110 } plane remains on the buried oxide layer; and forming at least one thin film transistor using the single crystal semiconductor layer as an active layer thereof.

Claim 6

A method of fabricating a semiconductor device, said method comprising the steps of: preparing a single crystal semiconductor substrate having a main surface of a { 110 } plane; forming an oxygen-containing layer at a predetermined depth in the single crystal semiconductor substrate by adding oxygen ions into the single semiconductor substrate from a side of the main surface; converting the oxygen-containing layer into a buried oxide layer by a heat treatment, wherein a single crystal layer having a main surface of a { 110 } plane remains on the buried oxide layer; and forming at least one thin film transistor using the single crystal semiconductor layer as an active layer thereof.