Manufacturing method for a group-iii nitride crystal that requires a flow amount of a carrier gas supplied into a raw material chamber at a temperature increase step satisfies two relational equations (i) and (ii)

Abstract

A manufacturing method for a group-III nitride crystal, the manufacturing method includes: preparing a seed substrate; increasing temperature of the seed substrate placed in a nurturing chamber; and supplying a group-III element oxide gas produced in a raw material chamber connected to the nurturing chamber by a connecting pipe and a nitrogen element-containing gas into the nurturing chamber to grow a group-III nitride crystal on the seed substrate, wherein a flow amount y of a carrier gas supplied into the raw material chamber at the temperature increase step satisfies following two relational equations (I) and (II), y<[1−k*H(Ts)]/[k*H(Ts)−j*H(Tg)]*j*H(Tg)*t (I), y≥1.58*10*(22.4/28)S*F(N)/F(T) (II), wherein k represents an arrival rate to a saturated vapor pressure of a group-III element in the raw material chamber, Ts represents a temperature of the raw material chamber, Tg represents a temperature of the nurturing chamber, H(Ts) represents a saturated vapor pressure of the group-III element at the temperature Ts in the raw material chamber, H(Tg) represents a saturated vapor pressure of the group-III element at the temperature Tg in the nurturing chamber, j represents a corrective coefficient, t represents a sum of gas flow amounts flowing into the nurturing chamber from those other than the raw material chamber, S represents a cross-sectional area of the connecting pipe, F(N) represents a volumetric flow amount of the nitrogen element-containing gas supplied into the nurturing chamber, and F(T) represents a sum of volumetric flow amounts of gases supplied into the nurturing chamber from those other than the raw material chamber.