Method for manufacturing semiconductor substrate

Abstract

Hydrogen ions are implanted to a surface (main surface) of the single crystal Si substrate 10 at a dosage of 1.5×10 17 atoms/cm 2 or higher to form the hydrogen ion implanted layer (ion-implanted damage layer) 11 . As a result of the hydrogen ion implantation, the hydrogen ion implanted boundary 12 is formed. The single crystal Si substrate 10 and the low melting glass substrate 20 are bonded together. The bonded substrate is heated at relatively low temperature, 120° C. or higher and 250° C. or lower (below a melting point of the support substrate). Further, an external shock is applied to delaminate the Si crystal film along the hydrogen ion implanted boundary 12 of the single crystal Si substrate 10 out of the heat-treated bonded substrate. Then, the surface of the resultant silicon thin film 13 is polished to remove a damaged portion, so that a semiconductor substrate can be fabricated. There can be provided a semiconductor substrate in which a high-quality silicon thin film is transferred onto a substrate made of a low melting point material.

1 . A method for manufacturing a semiconductor substrate, comprising:
 a first step of implanting hydrogen ions to a main surface side of a silicon substrate at a dosage of 1.5×10 17  atoms/cm 2  or higher;   a second step of bonding a main surface of the silicon substrate and a main surface of a support substrate made of a low melting point material;   a third step of performing heat treatment on the bonded substrate at a temperature of 120° C. or higher and 250° C. or lower below a melting point of the support substrate; and   a fourth step of delaminating a silicon crystal film along a hydrogen ion implanted boundary of the silicon substrate out of the bonded substrate after the heat treatment to form a silicon thin film on a surface of the support substrate.   
   
   
       2 . The method for manufacturing a semiconductor substrate according to  claim 1 , wherein the support substrate is made of an inorganic material, and the second step of bonding the substrates is carried out by applying surface activation through plasma treatment or ozone treatment to at least one of the main surface of the silicon substrate and the main surface of the support substrate. 
   
   
       3 . The method for manufacturing a semiconductor substrate according to  claim 2 , wherein the support substrate is low melting glass having a melting point of 500° C. or lower. 
   
   
       4 . The method for manufacturing a semiconductor substrate according to  claim 1 , wherein the support substrate is made of an organic material, and the second step of bonding the substrates is carried out by applying an adhesive to the main surface of the silicon substrate and the main surface of the support substrate. 
   
   
       5 . The method for manufacturing a semiconductor substrate according to  claim 4 , wherein the support substrate is made of plastics. 
   
   
       6 . The method for manufacturing a semiconductor substrate according to  claim 4 , wherein the adhesive is silicon oil. 
   
   
       7 . The method for manufacturing a semiconductor substrate according to  claim 5 , wherein the adhesive is silicon oil. 
   
   
       8 . The method for manufacturing a semiconductor substrate according to  claim 1 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       9 . The method for manufacturing a semiconductor substrate according to  claim 2 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       10 . The method for manufacturing a semiconductor substrate according to  claim 3 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       11 . The method for manufacturing a semiconductor substrate according to  claim 4 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       12 . The method for manufacturing a semiconductor substrate according to  claim 5 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       13 . The method for manufacturing a semiconductor substrate according to  claim 6 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate. 
   
   
       14 . The method for manufacturing a semiconductor substrate according to  claim 7 , wherein the fourth step is carried out by applying a mechanical shock onto a hydrogen ion implanted region at an edge of the silicon substrate.