US 11,942,330 B2
Methods for selective dry etching gallium oxide
Feng Q. Liu, San Jose, CA (US); Lisa J. Enman, Sunnyvale, CA (US); Lakmal C. Kalutarage, San Jose, CA (US); and Mark J. Saly, Santa Clara, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jun. 9, 2022, as Appl. No. 17/836,694.
Application 17/836,694 is a continuation of application No. 17/014,251, filed on Sep. 8, 2020, granted, now 11,398,388.
Prior Publication US 2022/0301883 A1, Sep. 22, 2022
Int. Cl. H01L 21/311 (2006.01); H01L 21/02 (2006.01)
CPC H01L 21/31122 (2013.01) [H01L 21/02175 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of etching gallium oxide from a semiconductor substrate, the method comprising:
flowing a first reagent in a substrate processing region housing the semiconductor substrate, wherein the first reagent comprises HX, wherein H is hydrogen, wherein X is at least one of fluorine, chlorine, and bromine, and wherein the semiconductor substrate comprises an exposed region of gallium oxide overlying gallium nitride, and fluorinating the exposed region of gallium oxide to form a gallium halide and H2O;
flowing a second reagent in the substrate processing region, wherein the second reagent is at least one of trimethylgallium, tin acetylacetonate, tetramethylsilane, and trimethyltin chloride, the second reagent promoting a ligand exchange wherein a methyl group is transferred to the gallium halide to form a volatile Me2GaY or Me3Ga, wherein Me is methyl, and wherein Y is at least one of fluorine, chlorine, and bromine from the second reagent;
flowing a third reagent in the substrate processing region, wherein the third reagent is at least one of chlorine, bromine, boron trichloride, and boron tribromide; and
recessing a surface of the gallium oxide.