Polycrystalline III-nitrides

摘要

This invention provides a process for producing high-purity dense polycrystalline III-nitride slabs. A vessel which contains a group III-metal such as gallium or an alloy of group III-metals of shallow depth is placed in a reactor. The group III-metal or alloy is heated until a molten state is reached after which a halide-containing source mixed with a carrier gas and a nitrogen-containing source is flowed through the reactor vessel. An initial porous crust of III-nitride forms on the surface of the molten III-metal or alloy which reacts with the nitrogen-containing source and the halide-containing source. The flow rate of the nitrogen-containing source is then increased and flowed into contact with the molten metal to produce a dense polycrystalline III-nitride. The products produced from the inventive process can be used as source material for III-nitride single crystal growth which material is not available naturally.

主权项

1. A method for making a polycrystalline III-nitride of high purity and density comprising flowing a halide-containing vapor and a nitrogen-containing vapor into contact with a molten group III-metal by:
(a) flowing the nitrogen-containing vapor having a first nitrogen flow rate and the halide-containing vapor over the molten group III-metal at a first temperature for a first duration sufficient to form a porous crust in a first flow, wherein the porous crust comprises a plurality of pores, the porous crust covering a portion of an upper surface of the molten group III-metal; and (b) increasing the first nitrogen flow rate relative to a halide flow rate to obtain a second nitrogen flow rate in a second flow to contact a remaining portion of the molten group III-metal at the porous crust at a second temperature for a second duration sufficient to convert substantially all of the remaining portion of the molten group III-metal to a high density slab comprising the polycrystalline III-nitride, wherein the first temperature and the second temperature are substantially similar, the high density slab having a density of 75 to 99% and being substantially solid throughout.