A high deposition rate sputter method is utilized to produce bulk,
single-crystal, low-defect density Group III nitride materials suitable
for microelectronic and optoelectronic devices and as substrates for
subsequent epitaxy, and to produce highly oriented polycrystalline
windows. A template material having an epitaxial-initiating growth surface
is provided. A Group III metal target is sputtered in a plasma-enhanced
environment using a sputtering apparatus comprising a non-thermionic
electron/plasma injector assembly, thereby to producing a Group III metal
source vapor. The Group III metal source vapor is combined with a
nitrogen-containing gas to produce a reactant vapor species comprising
Group III metal and nitrogen. The reactant vapor species is deposited on
the growth surface to produce a single-crystal M.sup.III N layer thereon.
The template material is removed, thereby providing a free-standing,
single-crystal M.sup.III N article having a diameter of approximately 0.5
inch or greater and a thickness of approximately 50 microns or greater.
