Method of transferring a thin crystalline semiconductor layer

Abstract

A method for transferring a monocrystalline, thin layer from a first substrate onto a second substrate involves epitaxial growth of a sandwich structure with a strained epitaxial layer buried below a monocrystalline thin layer, and lift-off and transfer of the monocrystalline thin layer with the cleaving controlled to happen within the buried strained layer in conjunction with the introduction of hydrogen.

1 . A method for transferring a thin semiconductor layer comprising: 
 forming a first heterostructure by depositing a non-graded layer of a material of the formula Si 1-x Ge x  on a first substrate and thereafter depositing a monocrystalline epitaxial semiconductor layer on the Si 1-x Ge x  layer, wherein 0<x<1;    introducing hydrogen atoms into the first heterostructure and allowing the hydrogen atoms to diffuse into the non-graded layer of Si 1-x Ge x  layer of the first heterostructure;    bonding the semiconductor layer of the first heterostructure to a second substrate to form a second heterostructure; and    splitting the second heterostructure at said Si 1-x Ge x  layer, thereby transferring the semiconductor layer from the first heterostructure to the second substrate.    
     
     
         2 . The method of  claim 1 , wherein the region of the first heterostructure under maximum energy deposition during the step of introducing hydrogen into the first heterostructure is distant from the Si 1-x Ge x  layer.  
     
     
         3 . The method of  claim 1 , wherein the epitaxial monocrystalline layer includes at least one material selected from the consisting of a group II element, a group III element, a group V element, and a group VI element.  
     
     
         4 . The method of  claim 1 , wherein the thickness of the epitaxial monocrystalline semiconductor layer deposited on the non-graded Si 1-x Ge x  layer is less than 1000 nm.  
     
     
         5 . The method of  claim 1  wherein the thickness of the non-graded Si 1-x Ge x  layer is less than 500 nm.  
     
     
         6 . The method of  claim 1 , wherein splitting the second heterostructure comprises subjecting the second heterostructure to an externally applied force.  
     
     
         7 . The method of  claim 1  wherein the second heterostructure is split using a razor blade.  
     
     
         8 . The method of  claim 1 , wherein splitting the second heterostructure comprises inserting a gas blade into the Si 1-x Ge x  layer, the gas being selected from that group consisting of nitrogen, argon, helium, and oxygen.  
     
     
         9 . The method of  claim 1 , wherein splitting the second heterostructure comprises subjecting said second heterostructure to a transfer heat-treatment to produce cracks in the non-graded Si 1-x Ge x  layer.  
     
     
         10 . The method of  claim 1 , further comprising heating the first heterostructure to a temperature of from about 100 degrees Celsius to about 1000 Celsius for at least 1 second as hydrogen diffuses into the non-graded Si 1-x Ge x  layer.  
     
     
         11 . The method of  claim 1 , wherein the introduction of hydrogen into the first heterostructure comprises plasma hydrogenation.  
     
     
         12 . The method of  claim 11 , wherein plasma hydrogenation comprises radiofrequency plasma hydrogenation or DC plasma hydrogenation.  
     
     
         13 . The method of  claim 11 , wherein plasma hydrogenation comprises an energy of ionized hydrogen of from about 50 eV to about 100 keV.  
     
     
         14 . The method of  claim 11 , wherein plasma hydrogenation comprises an energy of ionized hydrogen of less than about 1 keV.  
     
     
         15 . The method of  claim 11 , wherein the temperature of the first heterostructure during plasma hydrogenation is low enough to minimize blistering on the surface of the first heterostructure.  
     
     
         16 . The method of  claim 11 , wherein the temperature of the first heterostructure during plasma hydrogenation is at least 100 degree Celsius.  
     
     
         17 . The method of  claim 11 , wherein the temperature of the first heterostructure during plasma hydrogenation is from about 250 degrees Celsius to about 350 degrees Celsius.  
     
     
         18 . The method of  claim 1 , wherein the introduction of hydrogen into the first substrate comprises implantation, wherein hydrogen comprises normal hydrogen, deuterium, and mixtures thereof.  
     
     
         19 . The method of  claim 18 , wherein hydrogen implantation occurs through an encapsulating silicon oxide layer.  
     
     
         20 . The method of  claim 18 , wherein the temperature of the first heterostructure during hydrogen implantation is from about minus 196 degrees Celsius to about 500 degrees Celsius.  
     
     
         21 . The method of  claim 1  wherein said the introduction of hydrogen into the first heterostructure comprises electrically connecting the first heterostructure to an electrolytic cell and exposing the first heterostructure to an electrolyte in the electrolytic cell.  
     
     
         22 . The method of  claim 21 , wherein the electrolyte dissociates to produce hydrogen atoms.  
     
     
         23 . The method of  claim 21 , wherein the electrolyte is at least one selected from the group consisting of H 3 PO 4 , HF, HCl, H 2 SO 4 , and CH 3 COOH.  
     
     
         24 . The method of  claim 1 , further comprising subjecting the first heterostructure to a thermal treatment before hydrogen is introduced into the first heterostructure.  
     
     
         25 . The method of  claim 24 , wherein the thermal treatment comprises heating the first heterostructure at a temperature from about 100 degrees Celsius to about 1000 degrees Celsius for at least 1 second.  
     
     
         26 . The method of  claim 1 , further comprising subjecting the first heterostructure to ion bombardment before hydrogen is introduced into the first heterostructure.  
     
     
         27 . The method of  claim 26 , wherein the ion bombardment comprises ions selected from the group consisting of hydrogen, deuterium, helium, and silicon.  
     
     
         28 . The method of  claim 1 , further comprising subjecting the first heterostructure to electron bombardment before hydrogen is introduced into the first heterostructure.  
     
     
         29 . The method of  claim 1 , wherein the first substrate is silicon and the semiconductor layer is silicon.  
     
     
         30 . A method for forming a semiconductor structure, the method comprising: 
 forming a first heterostructure by depositing a layer of Si 1-x C x  on a first substrate, wherein 0<x<1, and thereafter depositing a semiconductor layer on the Si 1-x C x  layer;    introducing hydrogen atoms into the Si 1-x C x  layer;    bonding the first heterostructure to a second substrate to form a second heterostructure; and    splitting said second heterostructure at the Si 1-x C x  layer.