Method for fabricating a SOI type semiconductor device

Claim 3

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein the substrate is a silicon substrate.

Claim 4

A method for fabricating a SOI type semiconductor device as set forth in claim 2, wherein said step (a) includes forming the insulating layer by oxidation of the silicon substrate.

Claim 5

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein the insulating layer is composed of silicon dioxide.

Claim 6

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein said step (a) of forming a single crystalline island includes the substeps of: forming a first polycrystalline layer on the insulating layer; selectively passivating the first polycrystalline layer except for the portion in which the single crystalline island is to be formed; coating the surface of the first polycrystalline layer, after the selectively passivating substep, with a layer which is the source of the dopant for providing the island portion of the first polycrystalline layer with the one conductivity type; heating for recrystallizing the first polycrystalline layer at the island portion and for diffusing the dopant into the first polycrystalline layer at the island portion; and removing the coating layer after said heating substep.

Claim 7

A method for fabricating a SOI type semiconductor device as set forth in claim 5, wherein said heating substep is performed by the irradiation of an energy beam.

Claim 8

A method for fabricating a SOI type semiconductor device as set forth in claim 6, wherein the energy beam is a laser beam.

Claim 9

A method for fabricating a SOI type semiconductor device as set forth in claim 5, wherein the first polycrystalline layer is formed from a material which can result in the same substance as the insulating layer when passivated.

Claim 10

A method for fabricating a SOI type semiconductor device as set forth in claim 5, wherein the first polycrystalline layer is a polysilicon layer.

Claim 11

A method for fabricating a SOI type semiconductor device as set forth in claim 9, wherein said substep of selectively passivating is performed by oxidation.

Claim 12

A method for fabricating a SOI type semiconductor device as set forth in claim 5, wherein the coating layer is formed from an antimony-silicate grass (Sb-SG).

Claim 13

A method for fabricating a SOI type semiconductor device as set forth in claim 5, wherein the epitaxial layer is formed from the same material as the first polycrystalline layer.

Claim 14

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein the epitaxial layer is formed of silicon.

Claim 15

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein said step (b) of forming an epitaxial layer includes the substep of forming a first polycrystalline layer around the epitaxial layer and said step (c) of forming the tentatively-exposed side surface of the epitaxial layer includes the substeps of: forming a mask layer on the surface of the epitaxial layer; and removing the first polycrystalline layer which has been formed around the epitaxial layer during said step (b) of forming the epitaxial layer.

Claim 16

A method for fabricating a SOI type semiconductor device as set forth in claim 14, wherein said step (d) of forming the conduction path at the tentatively-exposed side surface of the epitaxial layer comprises introducing one conductivity type impurity to the side surface of the epitaxial layer having the mask layer.

Claim 17

A method for fabricating a SOI type semiconductor device as set forth in claim 14, wherein said step (d) of forming the conduction path includes the substeps of: forming a conduction path at the exposed side surface of the epitaxial layer after the substep of removing the first polycrystalline layer around the epitaxial layer; forming a second polycrystalline layer on the surface of the insulating layer and around the epitaxial layer with the conduction path; passivating the second polycrystalline layer; and exposing the upper surface of the epitaxial layer after the substep of passivating the second polycrystalline layer.

Claim 18

A method for fabricating a SOI type semiconductor device as set forth in claim 16, wherein the second polycrystalline layer is formed from the same material as that forming the single crystalline island.

Claim 19

A method for fabricating a SOI type semiconductor device as set forth in claim 16, wherein the second polycrystalline layer is a polysilicon layer.

Claim 20

A method for fabricating a SOI type semiconductor device as set forth in claim 18, wherein the substep of passivating the second polycrystalline layer comprises passivating the polysilicon layer by oxidation.

Claim 21

A method for fabricating a SOI type semiconductor device as set forth in claim 16, wherein the substep of exposing the upper surface of the epitaxial layer is performed by mechanical polishing.

Claim 22

A method for fabricating a SOI type semiconductor device as set forth in claim 16, wherein in the substep of exposing the upper surface of the epitaxial layer, the upper surface is leveled to the surface of the passivated second polycrystalline layer around the epitaxial layer.

Claim 23

A method for fabricating a SOI type semiconductor device as set forth in claim 1, wherein said step (b) of forming an epitaxial layer includes the substep of forming a first polycrystalline layer around the epitaxial layer and said step (c) of forming the tentatively-exposed side surface of the epitaxial layer includes the substeps of: forming a first mask layer on the surface of the epitaxial layer by a first resist layer; passivating the first polycrystalline layer which has been formed around the epitaxial layer during said step (b) of forming the epitaxial layer; removing the first mask layer; selectively forming a second mask layer on the surface of the epitaxial layer so that the peripheral area of the surface is exposed; and forming a groove in the peripheral area, the groove having a depth equal to or larger than the thickness of the epitaxial layer.

Claim 24

A method for fabricating a SOI type semiconductor device as set forth in claim 22, wherein said step (d) of forming the conduction path at the tentatively-exposed side surface of the epitaxial layer comprises forming a second polycrystalline layer on the surface of the first polycrystalline layer and the epitaxial layer so that the groove formed in the peripheral area of the epitaxial layer is filled with the second polycrystalline layer, the second polycrystalline layer having one conductivity type impurity.

Claim 25

A method for fabricating a SOI type semiconductor device as set forth in claim 23, wherein the second polycrystalline layer is formed from the same material as that forming the single crystalline island.

Claim 26

A method for fabricating a SOI type semiconductor device as set forth in claim 23, wherein the second polycrystalline layer is a polysilicon layer.

Claim 27

A method for fabricating a SOI type semiconductor device as set forth in claim 23, wherein said step (d) of forming the conduction path includes a substep of exposing the upper surface of the epitaxial layer after forming the second polycrystalline layer.

Claim 28

A method for fabricating a SOI type semiconductor device as set forth in claim 26, wherein said substep of exposing the upper surface of said epitaxial layer is performed by mechanical polishing.

Claim 29

A method for fabricating a SOI type semiconductor device as set forth in claim 26, wherein in said substep of exposing the upper surface of the epitaxial layer, the upper surface of the epitaxial layer is leveled to the surface of the passivated first polycrystalline layer around the epitaxial layer.