| 摘要 |
PROBLEM TO BE SOLVED: To provide a group-III semiconductor element of a quantum well structure which can prevent the sublimation of a well layer at the time of forming a barrier layer therein, and can control its film thickness with good crystallinity and enhance luminous efficiency. SOLUTION: N2 or H2 gas is supplied at a flow rate of 20 liters/min, an NH3 gas is supplied at a flow rate of 10 liters/min and a TMG is supplied at a flow rate of 2.0×10<-4> mol./min at a substrate temperature of 900 deg.C. to form a barrier layer 51 of GaN having a thickness of about 35 Å. Next, the substrate temperature is reduced down to 600 deg.C, and the supply amount of H2 or NH3 is made constant, under which condition TMG is supplied at a flow rate of 7.2×10<-5> mol./min and TMI is supplied at a flow rate of 0.19×10<-4> mol./min to form a well layer 52 of In0.20 Ga0.80 N having a thickness of about 35 Å. Subsequently, the substrate temperature is kept at 600 deg.C, N2 or H2 is supplied at a flow rate of 20 lit./min, NH3 is supplied at a flow rate of 10 lit./min, and TMG is supplied at a flow rate of 2.0×10<-4> mol./min to form a cap layer 53. (a) Then the substrate temperature is increased from 600 deg.C to 900 deg.C, during which the cap layer 53 disappears due to pyrolysis reaction. (b) When the substrate temperature reaches 900 deg.C, the next barrier layer 51 is formed on the well layer 52 under these conditions. |
