Method for manufacturing soi substrate

Abstract

A heating plate having a smooth surface is placed on a hot plate which constitutes a heating section, and the smooth surface of the heating plate is closely adhered on the rear surface of a single-crystal Si substrate bonded to a transparent insulating substrate. The temperature of the heating plate is kept at 200° C. or higher but not higher than 350° C. When the rear surface of the single-crystal Si substrate bonded to the insulating substrate is closely adhered on the heating plate, the single-crystal Si substrate is heated by thermal conduction, and a temperature difference is generated between the single-crystal Si substrate and the transparent insulating substrate. A large stress is generated between the both substrates due to rapid expansion of the single-crystal Si substrate, thus separation takes place at a hydrogen ion-implanted interface.

1 . A method for manufacturing an SOI substrate, characterized by:
 a first step of forming a hydrogen ion-implanted layer on the surface side of a first substrate which is a single-crystal silicon substrate;   a second step of applying a surface activation treatment to at least one of the surface of a second substrate which is a transparent insulating substrate and the surface of said first substrate;   a third step of bonding together the surface of said first substrate and the surface of said second substrate; and   a fourth step of forming an SOI layer on the surface of said second substrate by closely adhering the rear surface of said first substrate of said bonded substrates on a heating plate kept at a temperature of 200° C. or higher but not higher than 350° C. to heat said first substrate and thereby peel off a silicon layer from said first substrate.   
     
     
         2 . The method for manufacturing an SOI substrate according to  claim 1 , characterized in that said second substrate is one of a quartz substrate, a sapphire (alumina) substrate, a borosilicate glass substrate, and a crystallized glass substrate. 
     
     
         3 . The method for manufacturing an SOI substrate according to  claim 1 , characterized in that the amount of hydrogen ion implantation (dose amount) in said first step is 1×10 16  to 5×10 17  atoms/cm 2 . 
     
     
         4 . The method for manufacturing an SOI substrate according to  claim 1 , characterized in that said surface activation treatment in said second step is carried out by means of at least one of plasma treatment and ozone treatment. 
     
     
         5 . (canceled) 
     
     
         6 . The method for manufacturing an SOI substrate according to  claim 1 , characterized in that said heating plate used in said fourth step is one of a semiconductor substrate and a ceramic substrate having a smooth surface. 
     
     
         7 . The method for manufacturing an SOI substrate according to  claim 1 , characterized in that said fourth step includes a sub-step of applying separation-accelerating external impact from an edge of said hydrogen ion-implanted layer before or after the heating of said first substrate.