Substrate pretreatment for subsequent high temperature group iii depositions

Abstract

Embodiments of the present invention relate to apparatus and method for pretreatment of substrates for manufacturing devices such as light emitting diodes (LEDs) or laser diodes (LDs). One embodiment of the present invention comprises pretreating the aluminum oxide containing substrate by exposing a surface of the aluminum oxide containing substrate to a pretreatment gas mixture, wherein the pretreatment gas mixture comprises ammonia (NH 3 ) and a halogen gas.

1 . A method for forming a device, comprising:
 pre-treating one or more aluminum oxide containing substrates in a first processing chamber, wherein pre-treating comprises:
 exposing a surface of each of the one or more aluminum oxide containing substrates to a pretreatment gas mixture to form a pretreated surface, wherein the pretreatment gas mixture comprises ammonia (NH 3 ), a group-III metal halide gas and an etchant containing gas that comprises a halogen gas in the first processing chamber; and 
   forming one or more group III metal nitride layers over the pretreated surface in a second processing chamber.   
     
     
         2 . The method of  claim 1 , wherein the first processing chamber is an HVPE (hydride vapor phase epitaxy) chamber. 
     
     
         3 . The method of  claim 2 , wherein the second processing chamber is a MOCVD (metal organic chemical vapor deposition) chamber. 
     
     
         4 . The method of  claim 1 , wherein the pretreated surface comprises aluminum oxynitride or aluminum nitride. 
     
     
         5 . The method of  claim 1 , wherein the halogen gas is chlorine (Cl 2 ). 
     
     
         6 . The method of  claim 1 , wherein forming the one or more group III metal nitride layers further comprises:
 exposing a first metal source to a first processing gas comprising chlorine (Cl 2 ) to form a metal halide gas, wherein the first metal source comprises an element selected from the group consisting of gallium, aluminum and indium; and   exposing the pretreated surface of the plurality of substrates to a nitrogen precursor gas and the metal halide gas to form the one or more group III metal nitride layers on a surface of the one or more aluminum oxide containing substrates.   
     
     
         7 . The method of  claim 1 , wherein the group III metal nitride layers comprise a material selected from the group consisting of gallium nitride, n-type doped gallium nitride (n-GaN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN) and p-type doped gallium nitride (p-GaN). 
     
     
         8 . The method of  claim 1 , wherein forming the group-III metal nitride layers comprises exposing the one or more aluminum oxide containing substrates to a nitrogen containing precursor gas, a first group-III metal halide gas and a second group-III metal halide gas, wherein the first and second group-III metal halide gases each comprise aluminum, gallium or indium. 
     
     
         9 . The method of  claim 1 , wherein forming the group-III metal nitride layers comprises exposing the one or more aluminum oxide containing substrates to a nitrogen containing precursor gas, a first group-III metal halide gas and a second group-III metal halide gas, wherein the first and second group-III metal halide gases each comprise aluminum, gallium or indium. 
     
     
         10 . The method of  claim 9 , wherein the nitrogen containing precursor gas comprises ammonia, and the group-III metal halide gas is formed by exposing a metal source to a first processing gas comprising chlorine (Cl 2 ), and the metal source comprises an element selected from the group consisting of gallium, aluminum and indium. 
     
     
         11 . A method for forming a device, comprising:
 processing one or more aluminum oxide containing substrates in a first processing chamber, wherein processing the one or more aluminum oxide containing substrates comprises:
 exposing a surface of each of the one or more aluminum oxide containing substrates to a pretreatment gas mixture to form a pretreated surface, wherein the pretreatment gas mixture comprises ammonia (NH 3 ), a group-III metal halide gas and an etchant containing gas that comprises a halogen gas in the first processing chamber; and 
 forming a first group III metal nitride layer over the pretreated surface; and 
   forming a second group III metal nitride layer over the first group III metal nitride layer in a second processing chamber.   
     
     
         12 . The method of  claim 11 , wherein forming the first group III metal nitride layer further comprises:
 exposing a first metal source to a first processing gas comprising chlorine (Cl 2 ) to form a metal halide gas, wherein the first metal source comprises an element selected from the group consisting of gallium, aluminum and indium; and   exposing the pretreated surface of the one or more aluminum oxide containing substrates to a nitrogen precursor gas and the metal halide gas to form the first group III metal nitride layer on a surface of the one or more aluminum oxide containing substrates.   
     
     
         13 . The method of  claim 11 , wherein the first group III metal nitride layer comprises a material selected from the group consisting of gallium nitride. 
     
     
         14 . The method of  claim 11 , wherein the second group III metal nitride layer comprises a material selected from the group consisting of gallium nitride, indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN) and p-type doped gallium nitride. 
     
     
         15 . The method of  claim 11 , wherein the first processing chamber is an HVPE (hydride vapor phase epitaxy) chamber. 
     
     
         16 . The method of  claim 15 , wherein the second processing chamber is a MOCVD (metal organic chemical vapor deposition) chamber. 
     
     
         17 . The method of  claim 11 , wherein the pretreated surface comprises aluminum oxynitride or aluminum nitride. 
     
     
         18 . The method of  claim 11 , wherein forming the second group III metal nitride layer comprises:
 exposing a first metal source to a first processing gas comprising chlorine (Cl 2 ) to form a metal halide gas, wherein the first metal source comprises an element selected from the group consisting of gallium, aluminum and indium; and   exposing the pretreated surface of the plurality of substrates to a nitrogen precursor gas and the metal halide gas to form the one or more group III metal nitride layers on a surface of the one or more aluminum oxide containing substrates.   
     
     
         19 . The method of  claim 11 , wherein forming the second group-III metal nitride layer comprises exposing the one or more aluminum oxide containing substrates to a nitrogen containing precursor gas, a first group-III metal halide gas and a second group-III metal halide gas, wherein the first and second group-III metal halide gases each comprise aluminum, gallium or indium. 
     
     
         20 . The method of  claim 11 , further comprising exposing a surface of the one or more aluminum oxide containing substrates to a nitriding gas mixture for a first period of time.