METHOD FOR PRODUCING ALUMINUM NITRIDE SINGLE CRYSTAL

PROBLEM TO BE SOLVED: To provide a method for producing an aluminum nitride single crystal where yield is enhanced by effectively suppressing the occurrence of cracks at the neighborhood of the boundary surface to a seed substrate in a temperature falling step after the aluminum nitride single crystal is formed on the seed crystal substrate. SOLUTION: In an apparatus for producing the aluminum nitride single crystal provided with a heating furnace body comprising a reaction chamber having an opening part at an upper part and housing a raw material at the bottom side of an inner space and a susceptor to plug the opening part, a temperature regulating means placed at the outside of the heating furnace body and a gas supplying means to introduce a process gas from outside to the inner space, the raw material is heated and sublimed and the single crystal having a predetermined film thickness is grown on the seed substrate and then the occurrence of cracks is suppressed by performing such steps in this order as a first temperature falling step A to fall the temperature of the seed substrate, an isothermal holding step B to hold the temperature and a second temperature falling step C to further fall the temperature. It is favorable that the isothermal holding step is performed when the temperature of the seed substrate becomes 1,350°C or higher and 1,500°C or lower. COPYRIGHT: (C)2010,JPO&INPIT