Gallium trichloride injection scheme
View Patent ↗The invention relates to a method and system for epitaxial deposition of a Group III-V semiconductor material that includes gallium. The method includes reacting an amount of a gaseous Group III precursor having one or more gaseous gallium precursors as one reactant with an amount of a gaseous Group V component as another reactant in a reaction chamber; and supplying sufficient energy to the gaseous gallium precursor(s) prior to their reacting so that substantially all such precursors are in their monomer forms. The system includes sources of the reactants, a reaction chamber wherein the reactants combine to deposit Group III-V semiconductor material, and one or more heating structures for heating the gaseous Group III precursors prior to reacting to a temperature to decompose substantially all dimers, trimers or other molecular variations of such precursors into their component monomers.
1. A method for epitaxial deposition of a Group III-V semiconductor material comprising gallium, which method comprises:
reacting an amount of a gaseous Group III precursor comprising one or more gaseous gallium precursors as one reactant with an amount of a gaseous Group V component as another reactant in a reaction chamber; and
supplying sufficient energy to the gaseous gallium precursor(s) prior to their reacting so that substantially all such precursors are in their monomer forms.
2. The method of claim 1 wherein the gaseous gallium precursors comprise one or more chlorogallanes.
3. The method of claim 1 wherein the gaseous Group V component comprises a nitrogen containing gas provided in a substantially greater amount than that of the gaseous Group III precursor so that a Group III nitride is deposited.
4. The method of claim 3 wherein the nitrogen containing gas is activated by thermal energy or by RF energy prior to reacting.
5. The method of claim 1 wherein the energy is supplied by heating the gaseous gallium precursors to a temperature such that substantially all dimers, trimers or other molecular variations of such precursors are decomposed into their component monomers.
6. The method of claim 5 wherein the gaseous gallium precursors comprise gaseous gallium trichloride.
7. The method of claim 6 wherein the gaseous gallium trichloride is heated to at least 700° C. prior to reacting.
8. The method of claim 6 wherein the gaseous gallium trichloride is continuously provided into the reaction chamber at a mass flow of at least 50 g gallium/hour to facilitate high volume manufacture of the semiconductor material.
9. The method of claim 5 wherein the heating occurs, at least in part, prior to entry of the gaseous gallium precursors into the reaction chamber.
10. The method of claim 9 wherein the heating prior to entry further comprises flowing the gaseous gallium precursors over and/or around one or more radiation absorbent heat-transfer materials that are heated by a radiant energy source.
11. The method of claim 5 wherein the reacting occurs over a susceptor within the chamber, and wherein the heating occurs upstream of the susceptor.
12. The method of claim 11 wherein the heating occurs, at least in part, subsequent to entry of the gaseous gallium precursors into the reaction chamber but upstream of the susceptor.
13. The method of claim 11 wherein the heating subsequent to entry further comprises flowing the gaseous gallium precursors over and/or around one or more radiation absorbent heat-transfer materials.
14. The method of claim 1 wherein the reaction chamber is in communication with a source of the gaseous Group III precursor(s) and a source of the gaseous Group V component, and includes one or more substrates supported on one or more susceptors therein which substrate(s) receive a deposit of the Group III-V semiconductor material.
15. The method of claim 14 wherein the heating is conducted by flowing the gaseous reactant over or around a radiation absorbent plate.
16. The method of claim 14 wherein the reaction chamber includes a slot-shaped inlet for one of the reactants and a funnel-shaped nozzle subjacent the slot, and wherein the heating comprises passing the gaseous reactant through the funnel-shaped nozzle and slot-shaped inlet before entering the reaction chamber.
17. The method of claim 15 which further comprises providing radiation absorbent heat-transfer beads within the funnel-shaped nozzle that, when heated, also heat the gaseous reactant flowing around and/or through the beads, and wherein heat is provided by a radiant energy source operatively associated with the radiation absorbent heat-transfer beads.