Patent ID: 8409350

Claim:
A method of growing silicon-doped gallium nitride crystal by HVPE, the growth method comprising: (a) preparing carrier gasses for carrying gallium nitride precursors; (b) preparing a gas containing silicon as a dopant; (c) purifying the prepared carrier gasses so that the carrier gasses have a dew point of not greater than −60° C.; (d) preparing a gallium source and an undersubstrate suitable for gallium nitride growth and placing the gallium source and the undersubstrate within an HVPE reactor; (e) supplying the gallium nitride precursors via the carrier gasses, at a predetermined total partial pressure, into the HVPE reactor and thereby to the gallium source, supplying the doping gas into the HVPE reactor, and heating the HVPE reactor interior to vapor-phase epitaxially grow gallium nitride crystal onto the undersubstrate; (f) growing the gallium nitride crystal to a thickness of at least 200 μm; and (g) repeating (a) through (f) a plurality of times to yield a production run of silicon-doped gallium nitride crystals, wherein said total partial pressure of the carrier gasses is predetermined together with said carrier-gas dew point in such a way as to impart to the grown gallium nitride crystal a silicon dopant concentration of not less than 2.2×10 18 cm −3 correlating to a cracking frequency of not greater than 7% in the production run, given that an occurrence of cracking is taken to be 30 or more crack lines of 100 μm or greater length appearing over the entirety of a 45.8 mm-diameter area of each of the crystals grown in the production run.