Patent ID: 7501023

Claim:
A hydride vapor phase epitaxy (HVPE) method of fabricating and controlling a shape of a crack-free AlN layer, the method comprising: locating at least one substrate within a growth zone of a multi-temperature zone HVPE reactor; locating a first Al source within a first source channel; flushing the reactor with an inert gas; heating said at least one substrate; heating said first Al source; introducing a halide gas flow into said first source channel wherein said halide gas and said first Al source react to form at least an aluminum chloride gas; introducing an ammonia gas flow into said growth zone; delivering said aluminum chloride gas to said growth zone with a transport gas, wherein said aluminum chloride gas and said ammonia gas react to form a layer consisting of AlN that is crack-free as verified by transmission and reflection microscopy while controlling a curvature of the crack-free AlN layer by controlling a position of the at least one substrate within sub-zones of said growth zone that are defined, in part, by their respective temperatures; continuing said process until said crack-free AlN layer is at least 10 microns thick; terminating said halide gas flow; terminating said ammonia gas flow; and cooling said crack-free AlN layer.