Semiconductor substrate and process for its production

Abstract

The present invention provides a semiconductor substrate comprising a semiconductor layer 3 formed on a supporting substrate 1 with interposition of an insulating layer 3 therebetween, wherein a mark is formed in a region other than a surface region of the semiconductor layer; and a process for producing the semiconductor substrate.

What is claimed is:  
     
         1 . A semiconductor substrate comprising a semiconductor layer formed on a supporting substrate with interposition of an insulating layer therebetween, wherein a mark is formed in a region other than the surface region of the semiconductor layer.  
     
     
         2 . The semiconductor substrate according to    claim 1   , wherein the mark is at least one selected from the group consisting of numerals, characters, symbols, and bar codes.  
     
     
         3 . The semiconductor substrate according to    claim 1   , wherein the region to be marked is a peripheral region of the supporting substrate where the semiconductor layer is not present.  
     
     
         4 . The semiconductor substrate according to    claim 3   , wherein an outside border line of the peripheral region is an outer peripheral edge of the supporting substrate, and an inside border line of the peripheral region is at a position of 1 mm or more inside from the outer peripheral edge of the supporting substrate.  
     
     
         5 . The semiconductor substrate according to    claim 1   , wherein the region to be marked is in an internal region of the supporting substrate, where the semiconductor layer is not locally present.  
     
     
         6 . The semiconductor substrate according to    claim 1   , wherein the region to be marked is on the back surface side of the supporting substrate.  
     
     
         7 . The semiconductor substrate according to    claim 1   , wherein the mark is formed near a notch or an orientation flat.  
     
     
         8 . The semiconductor substrate according to    claim 1   , wherein the mark is formed by making a recessed portion and/or a protruded portion.  
     
     
         9 . The semiconductor substrate according to    claim 1   , wherein the mark is formed by laser.  
     
     
         10 . The semiconductor substrate according to    claim 1   , wherein the mark is formed by engraving a surface.  
     
     
         11 . The semiconductor substrate according to    claim 1   , wherein the semiconductor substrate is an SOI substrate.  
     
     
         12 . The semiconductor substrate according to    claim 11   , wherein the SOI substrate is a bonding SOI substrate.  
     
     
         13 . The semiconductor substrate according to    claim 12   , wherein the bonding SOI substrate has the semiconductor layer separated at an ion-implanted layer formed by implantation of hydrogen and/or an inert gas.  
     
     
         14 . The semiconductor substrate according to    claim 12   , wherein the bonding SOI substrate has the semiconductor layer formed by transferring a nonporous semiconductor layer formed on a porous material onto the supporting substrate.  
     
     
         15 . The semiconductor substrate according to    claim 11   , wherein the SOI substrate has the insulating layer formed by implantation of oxygen and/or nitrogen ions and teat treatment.  
     
     
         16 . A process for producing a semiconductor substrate comprising a semiconductor layer formed on a supporting substrate with interposition of an insulating layer therebetween, the process comprising a step of forming a mark in a region other than a surface region of the semiconductor layer.  
     
     
         17 . The process for producing a semiconductor substrate according to    claim 16   , wherein at least one selected from the group consisting of numerals, characters, symbols, and bar codes is engraved as the mark.  
     
     
         18 . The process for producing a semiconductor substrate according to    claim 16   , wherein the region to be marked is a peripheral region of the supporting substrate where the semiconductor layer is not present.  
     
     
         19 . The process for producing a semiconductor substrate according to    claim 18   , wherein an outside border line of the peripheral region is an outer peripheral edge of the supporting substrate, and an inside border line of the peripheral region is at a position of 1 mm or more inside from the outer peripheral edge of the supporting substrate.  
     
     
         20 . The process for producing a semiconductor substrate according to    claim 16   , wherein the region to be marked is an internal region of the supporting substrate where the semiconductor layer is not locally present.  
     
     
         21 . The process for producing a semiconductor substrate according to    claim 16   , wherein the region to be marked is a back surface side of the supporting substrate.  
     
     
         22 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed near a notch or an orientation flat.  
     
     
         23 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed by making a recessed portion and a protruded portion.  
     
     
         24 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed by laser light.  
     
     
         25 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed by engraving a surface.  
     
     
         26 . The process for producing a semiconductor substrate according to    claim 16   , wherein the semiconductor substrate is an SOI substrate.  
     
     
         27 . The process for producing a semiconductor substrate according to    claim 26   , wherein the SOI substrate is a bonding SOI substrate.  
     
     
         28 . The process for producing a semiconductor substrate according to    claim 27   , wherein the bonding SOI substrate is formed by implanting hydrogen and/or inert gas ions into a first substrate, bonding the first substrate to a second substrate as the supporting substrate, and separating the first substrate from the second substrate at a separation layer formed by the implantation of the ions.  
     
     
         29 . The process for producing a semiconductor substrate according to    claim 28   , wherein the first substrate has a semiconductor layer formed by epitaxial growth.  
     
     
         30 . The process for producing a semiconductor substrate according to    claim 28   , further comprising a step of smoothening a surface of the separated substrate by hydrogen annealing and/or polishing.  
     
     
         31 . The process for producing a semiconductor substrate according to    claim 27   , wherein the bonding SOI substrate has the semiconductor layer formed by transferring a nonporous semiconductor layer formed on a porous material onto the supporting substrate.  
     
     
         32 . The process for producing a semiconductor substrate according to    claim 31   , wherein the formation of the bonding SOI substrate is further conducted by removing the porous layer and subsequently smoothening a surface of the semiconductor layer by hydrogen annealing and/or polishing.  
     
     
         33 . The process for producing a semiconductor substrate according to    claim 31   , further comprising a step of removing a peripheral portion of the transferred semiconductor layer.  
     
     
         34 . The process for producing a semiconductor substrate according to    claim 31   , wherein the removal of the porous material includes a step of separating the bonding SOI substrate at a layer of the porous material, and a step of etching the porous material remaining on a separation surface of the nonporous semiconductor layer.  
     
     
         35 . The process for producing a semiconductor substrate according to    claim 27   , wherein the bonding SOI substrate having the semiconductor layer is formed by preparing a first substrate constituted of a nonporous substrate and a nonporous semiconductor formed thereon with interposition of a layer of a porous material therebetween, bonding the first substrate to a second substrate as the supporting substrate, and separating the first and the second substrates at the layer of the porous material to transfer the nonporous semiconductor layer to the supporting substrate.  
     
     
         36 . The process for producing a semiconductor substrate according to    claim 35   , wherein the bonding SOI substrate having the semiconductor layer is formed by forming a layer of a porous material on a nonporous substrate by anodization, forming a protective film on inside walls of pores in the porous material, conducting hydrogen baking, growing epitaxially a nonporous semiconductor layer on the layer of the porous material, forming an insulating layer on the surface thereof to provide a first substrate, bonding the first substrate to a second substrate as the supporting substrate, separating the first and the second substrate at the layer of the porous material, removing the porous material remaining the separation surface of the second substrate, and smoothening an exposed surface of the nonporous semiconductor layer.  
     
     
         37 . The process for producing a semiconductor substrate according'to    claim 35   , wherein the bonded substrates are separated by inserting a solid and/or fluid wedge.  
     
     
         38 . The process for producing a semiconductor substrate according to    claim 35   , wherein the bonded substrates are separated by applying at least one of pressure, pulling force, shearing force, and ultrasonic vibration.  
     
     
         39 . The process for producing a semiconductor substrate according to    claim 27   , wherein the bonding SOI substrate having the semiconductor layer is formed by preparing a first substrate constituted of a nonporous substrate and a nonporous semiconductor layer formed thereon with interposition of a layer of a porous material therebetween, bonding the first substrate to a second substrate as the supporting substrate, and removing the nonporous substrate and the porous material by at least one of grinding, polishing and etching to transfer the nonporous semiconductor layer to the supporting substrate.  
     
     
         40 . The process for producing a semiconductor substrate according to    claim 26   , wherein the SOI substrate has the insulating layer formed by implantation of oxygen and/or nitrogen ions and heat treatment.  
     
     
         41 . The process for producing a semiconductor substrate according to    claim 40   , further comprising a step of partially removing the semiconductor layer.  
     
     
         42 . A process for producing a semiconductor substrate comprising a semiconductor layer formed on a supporting substrate with interposition of at least one layer therebetween, the process comprising a step of forming a mark in a region other than a surface region of the semiconductor layer.  
     
     
         43 . A semiconductor substrate having a semiconductor layer formed on a supporting substrate with interposition of at least one layer therebetween, wherein a mark is formed in a region other than a surface region of the semiconductor layer.  
     
     
         44 . The semiconductor substrate according to    claim 1   , wherein the semiconductor substrate is a bonding SOI substrate, and the mark is formed on a surface of the supporting substrate where bonding is not conducted.  
     
     
         45 . The semiconductor substrate according to    claim 1   , wherein the semiconductor substrate is a bonding SOI substrate, and the mark is formed on a surface of the supporting substrate outside a position corresponding to a contact edge.  
     
     
         46 . The semiconductor substrate according to    claim 1   , wherein the semiconductor substrate is a bonding SOI substrate, and the mark is formed on a surface of the supporting substrate outside a position corresponding to a contact edge or a bonding edge.  
     
     
         47 . The semiconductor substrate according to    claim 1   , wherein the semiconductor substrate is a bonding SOI substrate, and the mark is formed on a surface of the supporting substrate where a bonding edge is locally moved inward from an outer peripheral portion of the supporting substrate comparative to the other bonding edge.  
     
     
         48 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed in a state of covering the surface region of the semiconductor layer with a film other than the semiconductor layer.  
     
     
         49 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed in a state of covering the surface region of the semiconductor layer with a layer of a porous material.  
     
     
         50 . The process for producing a semiconductor substrate according to    claim 16   , wherein the mark is formed in a state of covering the surface region of the semiconductor layer with a mask for shaping a peripheral region.  
     
     
         51 . The process for producing a semiconductor substrate according to    claim 16   , further comprising a step of preparing a first substrate and a second substrate having the mark formed thereon, and a step of transferring a layer to be transferred of the first substrate by bonding the first substrate and the second substrate and by removing an unnecessary portion of the first substrate.  
     
     
         52 . The process for producing a semiconductor substrate according to    claim 16   , further comprising a step of preparing a first substrate, forming the mark on a peripheral portion of a second substrate, and a step of transferring a layer to be transferred of the first substrate by bonding the first substrate and the second substrate without bonding at the marked portion and by removing an unnecessary portion of the first substrate.  
     
     
         53 . The process for producing a semiconductor substrate according to    claim 16   , further comprising a step of preparing a first substrate, forming the mark on a peripheral portion of a second substrate, and a step of transferring a layer to be transferred of the first substrate by bonding the first substrate and the second substrate so as to bring a contact edge or a bonding edge to a position inside the marked portion and by removing an unnecessary portion of the first substrate.  
     
     
         54 . The process for producing a semiconductor substrate according to    claim 16   , further comprising a step of preparing a first substrate, forming the mark on a peripheral portion of a second substrate, and a step of transferring a layer to be transferred of the first substrate by bonding the first substrate and the second substrate so as to locally bring a bonding edge inside the marked portion and by removing an unnecessary portion of the first substrate.  
     
     
         55 . The process for producing a semiconductor substrate according to    claim 36   , wherein the bonded substrates are separated by inserting a solid and/or fluid wedge.  
     
     
         56 . The process for producing a semiconductor substrate according to    claim 36   , wherein the bonded substrates are separated by applying at least one of pressure, pulling force, shearing force, and ultrasonic vibration.