| 摘要 |
PROBLEM TO BE SOLVED: To prevent an opening part from being expanded, by a method wherein a second- conductivity nitride-based semiconductor layer is grown selectively, at a temperature which is higher than the decomposition temperature of a mask material, in the opening part in which a mask is formed of a material which changes the second-conductivity nitride-based semiconductor layer into a first-conductivity nitride-based semiconductor layer, and a part of the constituent element of the mask material is made identical to a part of the constituent element of the second-conductivity nitride-based semiconductor layer. SOLUTION: A P-type gallium nitride contact layer 11 is formed by a selective growth method in which a silicon nitride film 216 is used as a mask. At this time. ammonia as a group V raw material is decomposed in an atmosphere at about 1000 deg.C or higher, and a nitrogen partial pressure in a vapor phase exists. As a result, the desorption of N from the silicon nitride film 216 and the adsorption of N to the silicon nitride film 216 are in equibrium. Even when the P-type gallium nitride contact layer 111 is formed at a high temperature of 1050 deg.C, it is possible to restrain the silicon nitride film 216 from being decomposed. Consequently, while the contact layer 11 is being formed, it is possible to prevent that the silicon nitride film 216 is retreated and that an opening part is expanded. Consequently, it is possible to prevent that the silicon which is generated by the decomposition of the silicon nitride film 216 is deposited in a regrowth interface so as to be taken into the P-type gallium nitride contact layer 111. |
