Method of forming an electronic device using a separation technique

Abstract

A method of forming an electronic device can include forming a metallic layer by an electrochemical process over a side of a substrate that includes a semiconductor material. The method can also include introducing a separation-enhancing species into the substrate at a distance from the side, and separating a semiconductor layer and the metallic layer from the substrate, wherein the semiconductor layer is a portion of the substrate. In a particular embodiment, the separation-enhancing species can be incorporated into a metallic layer and moved into the substrate, and in particular embodiment, the separation-enhancing species can be implanted into the substrate. In still another embodiment, both the techniques can be used. In a further embodiment, a dual-sided process can be performed.

1 . A method of forming an electronic device comprising:
 forming a first metallic layer by a first electrochemical process over a first side of a substrate that includes a semiconductor material;   annealing the substrate and first metallic layer;   cooling the substrate and the first metallic layer after annealing the substrate and the first metallic layer, wherein after cooling the substrate and the first metallic layer, stress within the substrate is higher than it was before annealing; and   separating a first semiconductor layer and the first metallic layer from the substrate, wherein the first semiconductor layer is a first portion of the substrate.   
     
     
         2 . The method of  claim 1 , wherein during annealing, stress develops within the substrate. 
     
     
         3 . The method of  claim 1 , wherein during cooling, stress develops within the substrate. 
     
     
         4 . The method of  claim 1 , further comprising forming a doped region adjacent to first side of a substrate that includes a semiconductor material before forming the first metallic layer, wherein the doped region has a conductivity type opposite that of the substrate. 
     
     
         5 . The method of  claim 1 , wherein forming the first metallic layer further comprises forming an adhesion film, a barrier film, a seed film, or any combination thereof before initiating the first electrochemical process. 
     
     
         6 . The method of  claim 1 , wherein the first electrochemical process comprises plating. 
     
     
         7 . The method of  claim 1 , wherein:
 the introducing a first separation-enhancing species into the substrate at a first distance from the first side; and   the separation-enhancing species includes hydrogen, helium, boron, silicon, fluorine, or chlorine.   
     
     
         8 . The'method of  claim 7 , wherein introducing the first separation-enhancing species comprises:
 incorporating hydrogen into the first metallic layer; and   moving the hydrogen from the first metallic layer into the substrate.   
     
     
         9 . The method of  claim 8 , wherein forming the first metallic layer is performed using an acidic solution as a source of hydrogen. 
     
     
         10 . The method of  claim 8 , wherein forming the first metallic layer and incorporating hydrogen into the first metallic layer occur substantially simultaneously during a particular time period. 
     
     
         11 . The method of  claim 1 , wherein separating the first semiconductor layer and the first metallic layer from the substrate comprises mechanically separating the first semiconductor layer and the first metallic layer from the substrate. 
     
     
         12 . The method of  claim 11 , wherein mechanically separating the first semiconductor layer and the first metallic layer from the substrate is performed using a wedge, a wire, or a saw. 
     
     
         13 . The method of  claim 1 , wherein separating the first semiconductor layer and the first metallic layer from the substrate comprises fracturing or cleaving the substrate at substantially the first distance from the first side of the substrate. 
     
     
         14 . The method of  claim 1 , wherein after separating the first semiconductor layer and the first metallic layer from the substrate, the first metallic layer is thicker than the first semiconductor layer. 
     
     
         15 . The method of  claim 1 , wherein forming the first metallic layer to a thickness, such that by itself, the first metallic layer provides sufficient mechanical support to the first semiconductor layer. 
     
     
         16 . The method of  claim 1 , further comprising adding contacts to the first semiconductor layer after separating the first semiconductor layer and the first metallic layer from the substrate. 
     
     
         17 . The method of  claim 1 , wherein the electronic device comprises a photovoltaic cell that includes the first semiconductor layer and the first metallic layer. 
     
     
         18 . The method of  claim 1 , further comprising:
 forming a second metallic layer by a second electrochemical process over a second side of the substrate, wherein the second side is opposite the first side;   introducing a separation-enhancing species into the substrate at a distance from the second side; and   separating a second semiconductor layer and the second metallic layer from the substrate, wherein the second semiconductor layer is a second portion of the substrate.   
     
     
         19 . The method of  claim 18 , wherein:
 forming the first metallic film and forming the second metallic layer are performed substantially simultaneously during a first time period; and   annealing the substrate and introducing the separation-enhancing species are performed substantially simultaneously during a second time period.   
     
     
         20 . A method of forming an electronic device comprising:
 forming a first film over a first side of a substrate that includes a semiconductor material, wherein the first film includes an adhesion film, a barrier film, a seed film, or any combination thereof;   plating a metallic film over the first film by a first electrochemical process, wherein plating is performed using an acidic solution;   incorporating hydrogen into the metallic film during plating;   annealing the substrate, the first film, and metallic film, wherein hydrogen moves from the metallic film into the substrate during annealing;   cooling the substrate, the first film, and the metallic film after annealing the substrate, the first film, and the metallic film, wherein after cooling, stress within the substrate is higher than it was before annealing; and   separating a semiconductor layer, the first film, and the metallic film from the substrate using a wire, wherein the semiconductor layer is a first portion of the substrate, wherein after separating the metallic film is thicker than the semiconductor layer.   
     
     
         21 . The method of  claim 20 , further comprising:
 forming a doped region adjacent to the first side of the substrate before plating the metallic film, wherein after separating the semiconductor layer, the first film, and the metallic film from the substrate, the doped region is disposed within the semiconductor layer; and   forming a patterned interconnect layer along a second side of the semiconductor layer opposite the first side.