Fabrication method and fabrication apparatus of group III nitride crystal substance
A fabrication method of a group III nitride crystal substance includes the steps of cleaning the interior of a reaction chamber by introducing HCl gas into the reaction chamber, and vapor deposition of a group III nitride crystal substance in the cleaned reaction chamber. A fabrication apparatus of a group III nitride crystal substance includes a configuration to introduce HCl gas into the reaction chamber, and a configuration to grow a group III nitride crystal substance by HVPE. Thus, a fabrication method of a group III nitride crystal substance including the method of effectively cleaning deposits adhering inside the reaction chamber during crystal growth, and a fabrication apparatus employed in the fabrication method are provided.
1. A fabrication method of a group III nitride crystal substance, comprising the step of cleaning an interior of a reaction chamber by introducing HCl gas into said reaction chamber, and the step of vapor deposition of a group III nitride crystal substance in said cleaned reaction chamber, wherein
said reaction chamber is formed by a reactor tube containing oxygen atoms and silicon atoms,
in said step of vapor deposition of a group III nitride crystal substance, at least ammonia as and hydrogen gas are brought into contact with said reactor tube to generate moisture and Si type gas such that said oxygen atoms in said moisture and said silicon atoms in said Si type gas enter said group III nitride crystal substance.
2. The fabrication method of a group III nitride crystal substance according to claim 1 , wherein
said group III nitride crystal substance includes one of a GaN crystal substance and an AlN crystal substance.
3. The fabrication method of a group III nitride crystal substance according to claim 1 , wherein
said group III nitride crystal substance is a GaN crystal substance, and includes a facet growth domain and a C-plane growth domain, and
a concentration of said silicon atoms at said facet growth domain is lower than 1.0×10 17 cm −3 , and a concentration of said oxygen atoms at said C-plane growth domain is lower than 1.0×10 17 cm −3 .
4. The fabrication method of a group III nitride crystal substance according to claim 1 , wherein
said group III nitride crystal substance is a GaN crystal substance, and is formed at a C-plane growth domain, and
said silicon atoms enter said C-plane growth domain.
5. The fabrication method of a group III nitride crystal substance according to claim 4 , wherein
a carrier concentration of said group III nitride crystal substance is set to at least 0.8×10 18 cm −3 using doping gas of silicon atoms, in addition to said Si type gas.
6. The fabrication method of a group III nitride crystal substance according to claim 5 , wherein
employing any of SiH 4 gas, SiH 2 Cl 2 gas and SiCl 4 gas as said doping gas.