Method and apparatus for separating composite member using fluid

Abstract

To separate a composite member consisting of a plurality of bonded members without destructing or damaging it, a fluid is jetted against the composite member from a nozzle to separate it into a plurality of members at a position different from a bonding position.

What is claimed is:  
     
         1 . A method of separating a composite member having a plurality of members as mutually bonded, at a position different from the bonding position of the plurality of members, comprising jetting a fluid against a side surface of the composite member to separate the composite member.  
     
     
         2 . The method according to  claim 1  wherein the composite member has inside one of the members a separation region containing microcavities and the fluid is jetted against the neighborhood of the separation region to separate it into the plurality of members around the separation region.  
     
     
         3 . The method according to  claim 2  wherein a recessed portion is formed near the separation region, the recessed portion receiving the fluid to extend the separation region.  
     
     
         4 . The method according to  claim 2  wherein the separation region has a lower mechanical strength than the bonding position.  
     
     
         5 . The method according to  claim 2  wherein the separation region comprises a porous layer formed by anodization.  
     
     
         6 . The method according to  claim 2  wherein the separation region can provide microcavities formed by ion implantation.  
     
     
         7 . The method according to  claim 1  wherein as the method of jetting the fluid a water jet method that jets a flow of high-pressure water from a nozzle is used.  
     
     
         8 . Members obtained by the separation method according to  claim 1 .  
     
     
         9 . A method of producing a semiconductor substrate comprising the steps of: 
 preparing on a substrate a first substrate having a porous single crystal semiconductor layer and a nonporous single crystal semiconductor layer provided on the porous single crystal semiconductor layer;    bonding the first substrate to a second substrate to form a composite member; and    jetting a fluid to the vicinity of the porous single crystal semiconductor layer of the composite member to separate the composite member at the porous single crystal semiconductor layer.    
     
     
         10 . The method according to  claim 9  wherein a recessed portion is formed near the porous single crystal semiconductor layer of the composite member, the recessed portion receiving the fluid to extend the porous single crystal semiconductor layer.  
     
     
         11 . The method according to  claim 9  wherein the porous single crystal semiconductor layer has a lower mechanical strength than the bonding surface between the first and second substrates.  
     
     
         12 . The method according to  claim 9  wherein the porous single crystal semiconductor layer is formed by anodization.  
     
     
         13 . The method according to  claim 9  wherein as the method of jetting the fluid a water jet method that jets a flow of high-pressure water from a nozzle is used.  
     
     
         14 . The method according to  claim 9  wherein the first substrate is formed by partly making a single crystal silicon substrate porous to form a porous single crystal silicon layer and allowing a nonporous single crystal silicon layer to grow epitaxially on the porous single crystal silicon layer.  
     
     
         15 . The method according to  claim 14  wherein the first and second substrates are bonded mutually via at least one insulating layer and the insulating layer is formed by oxidizing the surface of the nonporous single crystal silicon layer.  
     
     
         16 . The method according to  claim 9  wherein the second substrate comprises a light-transmissive substrate.  
     
     
         17 . The method according to  claim 9  wherein the second substrate comprises a silicon substrate.  
     
     
         18 . A method of producing a semiconductor substrate comprising the steps of: 
 implanting ions into a first substrate comprising a single crystal semiconductor at a predetermined depth to form an ion-implanted layer such that a microcavity layer can be obtained;    bonding the first substrate and a second substrate to each other via an insulating layer therebetween to form a composite member; and    jetting a fluid against the vicinity of the ion-implanted layer of the composite member to separate the composite member at the ion-implanted layer.    
     
     
         19 . The method according to  claim 18  wherein a recessed portion is formed near the ion-implanted layer in the composite member, the recessed portion receiving the fluid to extend the ion-implanted layer.  
     
     
         20 . The method according to  claim 18  wherein the ion-implanted layer has a lower mechanical strength than the bonding surface between the first and second substrates.  
     
     
         21 . The method according to  claim 18  wherein as the method of jetting the fluid a water jet method that jets a flow of high-pressure water from a nozzle is used.  
     
     
         22 . A semiconductor substrate produced by using the method according to  claim 9 .  
     
     
         23 . A separation apparatus executing the separation method according to  claim 1 .  
     
     
         24 . The separation apparatus according to  claim 23  wherein a flow of the fluid is jetted by using the water jet method for jetting a flow of high-pressure water from a nozzle.  
     
     
         25 . The separation apparatus according to  claim 24  wherein the composite member and the nozzle are moved relatively to scan the flow of water.  
     
     
         26 . The separation apparatus according to  claim 25  wherein the composite member is fixed while the nozzle is scanned in order to scan the flow of water.  
     
     
         27 . The separation apparatus according to  claim 26  having a holder for holding the composite member; a nozzle horizontal movement mechanism for moving the nozzle in the horizontal direction along the bonding position of the composite material; and a nozzle vertical movement mechanism for adjusting the vertical distance between the composite member and the nozzle.  
     
     
         28 . The separation apparatus according to  claim 26  having a mechanism for scanning the nozzle in such a way as to draw a fan around a supporting point.  
     
     
         29 . The separation apparatus according to  claim 26  wherein the nozzle rotates around the composite member.  
     
     
         30 . The separation apparatus according to  claim 26  including a plurality of the nozzles.  
     
     
         31 . The separation apparatus according to  claim 25  wherein the composite member is scanned while the nozzle is fixed in order to scan the flow of water.  
     
     
         32 . The separation apparatus according to  claim 31  having a rotation mechanism for rotating the composite member.  
     
     
         33 . The separation apparatus according to  claim 32  wherein the nozzle is located so as to be directed toward the rotational center of the composite member.  
     
     
         34 . The separation apparatus according to  claim 32  having a rotation holding member for holding the rotational center of the composite member.  
     
     
         35 . A separation method comprising the steps of: 
 rotatably holding a first surface of a composite member having a plurality of members as mutually bonded by using a first holder;    rotatably holding a second surface of the disc-like composite member by using a second holder;    rotating the first and second holders in synchronism; jetting a fluid against the end surface of the composite member, which is rotating; and    separating the composite member into a plurality of members using as a starting point the portion on which the fluid has been jetted.    
     
     
         36 . The separation method according to  claim 35  wherein the fluid is jetted against a separation position different from the bonding position of the composite member.  
     
     
         37 . The separation method according to  claim 35  wherein a recessed portion is provided in the end surface of the composite member and the fluid is jetted against the bottom of the recessed portion.  
     
     
         38 . A separation apparatus comprising a first holder for rotatably holding a first surface of a disc-like composite member having a plurality of members as bonded mutually; a second holder for rotatably holding a second surface of the disc-like composite member; synchronizing means for allowing the first and second holders during rotation to synchronize mutually; and a nozzle that jets a fluid against the end surface of the composite member, which is rotating, in order to separate the composite member into a plurality of members using as a starting point the position on which the fluid has been jetted.  
     
     
         39 . The separation apparatus according to  claim 38  having means for setting the position of the nozzle so that the fluid is jetted against a separation position different from the bonding position of the composite member.  
     
     
         40 . The separation apparatus according to  claim 38  wherein a recessed portion is provided in the end surface of the composite member and the apparatus has means for setting the position of said nozzle so that the fluid is jetted against the bottom of the recessed portion.  
     
     
         41 . A method of separating a composite member having a plurality of members, at a region including cavities or pores, comprising jetting a fluid consisting essentially of an abrasive particle-free liquid against a side surface of the composite member to separate the composite member.