GaN Epitaxy With Migration Enhancement and Surface Energy Modification

Abstract

Methods and apparatus for depositing thin films incorporating the use of a surfactant are described. Methods and apparatuses include a deposition process and system comprising multiple isolated processing regions which enables rapid repetition of sub-monolayer deposition of thin films. The use of surfactants allows the deposition of high quality epitaxial films at lower temperatures having low values of surface roughness. The deposition of Group III-V thin films such as GaN is used as an example.

What is claimed is: 
     
         1 . A Group III-V film comprising one or more Group III elements and a Group V element, wherein the film further comprises a surfactant layer with thickness between one and five monolayers. 
     
     
         2 . The Group III-V film of  claim 1  wherein the thickness of the surfactant layer is between one and two monolayers. 
     
     
         3 . The Group III-V film of  claim 1  wherein the surfactant comprises hydrogen, chlorine, bromine, iodine, arsenic, phosphorus, bismuth, indium, antimony, lead, tin, germanium, selenium, tellurium, magnesium, cadmium, zinc, mercury, or combinations thereof. 
     
     
         4 . The Group III-V film of  claim 1  wherein the surfactant comprises indium, antimony, or combinations thereof. 
     
     
         5 . The Group III-V film of  claim 1  wherein the Group III element comprises Al, Ga, In, or combinations thereof. 
     
     
         6 . The Group III-V film of  claim 1  wherein the Group V element comprises nitrogen. 
     
     
         7 . A semiconductor device comprising the Group III-V film of  claim 1 . 
     
     
         8 . A Group III-V thin film prepared by a method comprising:
 a) providing a deposition chamber comprising a plurality of processing regions wherein the processing regions are not in fluid contact with one another;   b) exposing a substrate to one or more Group III precursors and one or more surfactant precursors in a first processing region, wherein the exposure to one or more surfactant precursors forms a surfactant layer with thickness between one and five monolayers;   c) exposing the substrate to one or more Group V precursors in a second processing region;   d) exposing the substrate to one or more Group III precursors in a third processing region;   e) exposing the substrate to one or more Group V precursors in the second processing region; and   repeating any sequence of steps b) through e) until a desired thickness of the film is reached.   
     
     
         9 . The Group III-V film of  claim 8 , wherein the thickness of the surfactant layer is more than one monolayer and less than two monolayers. 
     
     
         10 . The Group III-V film of  claim 8 , wherein less than one monolayer of the Group III metal is deposited when the substrate is exposed to the one or more Group III precursors in the first or third processing region. 
     
     
         11 . The Group III-V film of  claim 8 , wherein the surfactant precursor comprises hydrogen, chlorine, bromine, iodine, arsenic, phosphorus, bismuth, indium, antimony, lead, tin, germanium, selenium, tellurium, magnesium, cadmium, zinc, mercury, or combinations thereof. 
     
     
         12 . The Group III-V film of  claim 8 , wherein the surfactant precursor comprises indium, antimony, or combinations thereof. 
     
     
         13 . The Group III-V film of  claim 8 , wherein the Group III precursor gases include one or more of Al-containing gases, Ga-containing gases, In-containing gases, or combinations thereof. 
     
     
         14 . The Group III-V film of  claim 8 , wherein the Group V precursor comprises a nitrogen-containing species. 
     
     
         15 . The Group III-V film of  claim 14 , wherein the nitrogen-containing species comprises active neutral species of nitrogen. 
     
     
         16 . The Group III-V film of  claim 15 , wherein the active neutral species of nitrogen comprises nitrogen species having the lowest excited state of molecular nitrogen (A 3 Σ u   + ). 
     
     
         17 . The Group III-V film of  claim 8 , wherein the substrate is exposed to the one or more Group V precursors for a time period no longer than that required to form a Group III-V thin film at sub-monolayer coverage. 
     
     
         18 . The Group III-V film of  claim 8 , wherein the growth of the film occurs at a temperature between about 500° C. and about 800° C. 
     
     
         19 . The Group III-V film of  claim 8 , wherein the film is one of AlN, GaN, InN, AlGaN, AlInN, InGaN, or InGaAlN. 
     
     
         20 . The Group III-V film of  claim 8 , further comprising contacting the substrate with a hydrogen-containing species before the substrate is exposed to the one or more Group V precursors.