ETCHING TECHNIQUE FOR THE FABRICATION OF THIN (Al, In, Ga)N LAYERS

Abstract

An etching technique for the fabrication of thin (Al, In, Ga)N layers. A suitable template or substrate is selected and implanted with foreign ions over a desired area to create ion implanted material. A regrowth of a device structure is then performed on the implanted template or substrate. The top growth surface of the template is bonded to a carrier wafer to created a bonded template/carrier wafer structure. The substrate is removed, as is any residual material, to expose the ion implanted material. The ion implanted material on the bonded template/carrier wafer structure is then exposed to a suitable etchant for a sufficient time to remove the ion implanted material.

1 . A device, comprising:
 a template having a growth surface;   a carrier wafer; and   one or more nitride layers grown on the growth surface of the template and then bonded to the carrier wafer;   wherein the nitride layers do not contain knock-on ion damage;   wherein the nitride layers are positioned between the template and the carrier wafer; and   wherein a surface of the template opposite the growth surface and the nitride layers is planar to a nanometer scale.   
     
     
         2 . The device of  claim 1 , wherein the device comprises an entire wafer. 
     
     
         3 . The device of  claim 1 , wherein the template is a portion of a gallium nitride template having a thickness of  2  micrometers or less, and the growth surface of the template is a crystalline surface suitable for the growth of the nitride layers. 
     
     
         4 . The device of  claim 1 , wherein the device is etched from a surface different from a growth surface of the nitride layers, thereby minimizing damage to the nitride layers. 
     
     
         5 . The device of  claim 1 , wherein the device comprises an optoelectronic microcavity, non linear optical waveguide, transistor, or free-standing substrate including the nitride layers. 
     
     
         6 . A semiconductor structure of etched, thin, epitaxially-grown nitride layers, comprising:
 (a) a suitable template or substrate implanted with foreign ions over a desired area, resulting ion implanted material;   (b) a nitride device structure grown on the ion implanted material; and   (c) a carrier wafer bonded to an exposed growth surface of the nitride device structure, so that the nitride device structure is positioned between the carrier wafer and the ion implanted material, resulting in a bonded nitride device structure/carrier wafer structure;   (d) wherein the ion implanted material on the bonded nitride device structure/carrier wafer structure is removed from a surface of the template or substrate opposite the nitride device structure, so that the surface of the template or substrate is planar on a nanometer scale.   
     
     
         7 . The structure of  claim 6 , wherein a portion of the template or substrate is removed from the nitride device structure/carrier wafer structure. 
     
     
         8 . The structure of  claim 7 , wherein any residual material is removed to expose the ion implanted material after the portion of the template or substrate is removed. 
     
     
         9 . The structure of  claim 6 , wherein the desired area is an entire wafer. 
     
     
         10 . The structure of  claim 6 , wherein the ion implanted material forms a damage layer, leaving the template's surface unaffected, and the damage layer etches more readily and without regard to crystal orientation as compared to non-implanted material. 
     
     
         11 . The structure of  claim 6 , wherein the ion implanted material is etched to an etch stop below the template or substrate surface and defined by an implantation profile or damage layer. 
     
     
         12 . The structure of  claim 6 , wherein the template or substrate is removed either over at least one selected area or completely to form at least one nitride membrane structure or at least one thick nitride wafer. 
     
     
         13 . The structure of  claim 6 , wherein the implantation profile or damage layer extends from a few tens of nanometers below the template or substrate surface through a thickness of the template or substrate. 
     
     
         14 . The structure of  claim 6 , wherein:
 (1) the ion implanted material is below the surface of the template or substrate such that the surface of the template or substrate remains intact, thereby providing a crystalline surface suitable for regrowth on the surface of the template or substrate; and   (2) the nitride structure/carrier wafer structure is etched from a surface different from a growth surface of the nitride device structure regrowth, thereby minimizing damage to the nitride device structure regrowth.   
     
     
         15 . The structure of  claim 14 , wherein the nitride structure/carrier wafer structure is etched from a backside opposite the growth surface, thereby minimizing damage to the nitride device structure regrowth.