Method for manufacturing a substrate comprising a relaxed ingan layer

Abstract

A method for manufacturing a substrate comprising the following steps of: providing a stack comprising an initial substrate, a GaN layer, a doped InGaN layer and an unintentionally doped InGaN layer, transferring the doped InGaN layer and the unintentionally doped InGaN layer to an anodising support, so as to form a second stack, dipping the second stack and the counter-electrode into an electrolyte solution, and applying a voltage or current between the doped InGaN layer and a counter electrode, to porosify the doped InGaN layer, and relaxing the unintentionally doped InGaN layer, transferring the doped InGaN layer and the unintentionally doped InGaN layer to a support of interest, forming an InGaN layer by epitaxy on the unintentionally doped InGaN layer, whereby a relaxed epitaxially grown InGaN layer is obtained.

What is claimed is: 
     
         1 - 19 . (canceled) 
     
     
         20 . A substrate successively comprising a support of interest, a porous doped InGaN layer, and an unintentionally doped InGaN layer. 
     
     
         21 . The substrate according to  claim 20 , wherein the unintentionally doped InGaN layer has a thickness of less than 3 nm. 
     
     
         22 . The substrate according to  claim 20 , wherein the support of interest comprises a support layer and a buried oxide layer. 
     
     
         23 . The substrate according to  claim 22 , wherein the support layer is made of sapphire, SiC or silicon. 
     
     
         24 . The substrate according to  claim 20 , wherein the porous doped InGaN layer has a thickness ranging from 10 nm to 200 nm. 
     
     
         25 . The substrate according to  claim 20 , wherein the porous doped InGaN layer has a porosity ranging from 5% to 70%. 
     
     
         26 . The substrate according to  claim 20  wherein the porous doped InGaN layer comprises pores having diameters ranging from 10 nm to 70 nm. 
     
     
         27 . The substrate according to  claim 20 , wherein the porous doped InGaN layer has an electron concentration ranging from 2 ╳ 10 18  cm 3  and 2 ╳ 10 19  cm 3 . 
     
     
         28 . The substrate according to  claim 20 , wherein the unintentionally doped InGaN layer has a doping concentration of less than 5 ╳ 10 17  atoms/cm 3 . 
     
     
         29 . A light emitting diode successively comprising: the substrate of  claim 20  and an epitaxially regrown stack,
 wherein the epitaxially regrown stack successively comprises from the unintentionally doped InGaN layer:
 a relaxed epitaxially grown InGaN layer doped with a first conductivity type, 
 an active zone with one or more red or green emitting InGaN/(Ga,ln)N quantum wells, 
 a doped InGaN layer of a second conductivity type, different from the first conductivity type. 
 
 
     
     
         30 . The light emitting diode according to  claim 29 , wherein the epitaxially regrown stack further comprises an electron barrier comprising AlGaN or GaN between the active zone and the doped InGaN layer of the second conductivity type. 
     
     
         31 . The light emitting diode according to  claim 29 , wherein the light emitting diode further comprises a passivation layer deposited on flanks of the epitaxially regrown stack. 
     
     
         32 . The light emitting diode according to  claim 31 , wherein the passivation layer comprises aluminum. 
     
     
         33 . The light emitting diode according to  claim 32 , wherein the passivation layer has a thickness ranging from 2 nm to 5 nm. 
     
     
         34 . The light emitting diode according to  claim 29 , wherein the relaxed epitaxially grown InGaN layer has the same In concentration as the doped and porous InGaN layer.