Patent ID: 11859311
Assignee: PANASONIC HOLDINGS CORPORATION
Field: Surface technology, coating (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A manufacturing method for a group-III nitride crystal, the manufacturing method comprising:
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 that is 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 (L/min) 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*10−4*(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,
wherein Ts (° C.) represents a temperature of the raw material chamber,
wherein Tg (° C.) represents a temperature of the nurturing chamber,
wherein H(Ts) (atm) represents a saturated vapor pressure of the group-III element at the temperature Ts in the raw material chamber,
wherein H(Tg) (atm) represents a saturated vapor pressure of the group-III element at the temperature Tg in the nurturing chamber,
wherein j represents a corrective coefficient,
wherein t (L/min) represents a sum of gas flow amounts flowing into the nurturing chamber from those other than the raw material chamber,
wherein S (mm2) represents a cross-sectional area of the connecting pipe,
wherein F(N) (L/min) represents a volumetric flow amount of the nitrogen element-containing gas supplied into the nurturing chamber, and
wherein F(T) (L/min) represents a sum of volumetric flow amounts of gases supplied into the nurturing chamber from those other than the raw material chamber, and

wherein a flow amount z (L/min) of a group-III element vapor supplied into the raw material chamber satisfies following equation (IV),

z=(x*y)/(1−x)  (IV)

wherein x (atm) represents a partial pressure of the group-III element vapor in the raw material chamber, and
wherein y (L/min) represents the flow amount y (L/min) of the carrier gas supplied into the raw material chamber at the temperature increase step that satisfies the two relational equations (I) and (II), and

wherein a flow amount T (L/min) of those other than the group-III element vapor supplied into the nurturing chamber satisfies following equation (V),

T=y+t  (V),

wherein t (L/min) represents the sum of gas flow amounts flowing into the nurturing chamber from those other than the raw material chamber, and
wherein y (L/min) represents the flow amount y (L/min) of a carrier gas supplied into the raw material chamber at the temperature increase step that satisfies the two relational equations (I) and (II).