| 摘要 |
PROBLEM TO BE SOLVED: To prevent cracking by forming a first layer of GaN based semiconductor having a specified thickness, a second layer of Ti and a GaN based semiconductor layer sequentially on an Si substrate. SOLUTION: A first buffer layer 3 and a second GaN layer 4 are grown at growth temperature of 1000-122 deg.C and 1000-1150 deg.C, respectively, on the (111) face of an Si substrate by MOCVD. The Si substrate 2 is then heated up to 150 deg.C by means of a lamp heater and a bulk of Ti is melted by irradiating with an electron beam to form a signal crystal Ti layer of 3000 Å thick on the GaN layer 4. Thereafter the chamber is evacuated to 2×10<4> Torr or below and sustained in that state for 5 min at 600 deg.C before the surface of the Ti layer 5 is cleaned. A second buffer layer 6 of Al0.9 Ga0.1 N is then grown at growth temperature of 300 deg.C and the temperature is raised up to 1000 deg.C before forming an n clad layer 7 and subsequent layers by an ordinary method. According to the method, the GaN based semiconductor layer can be protected against cracking. |
