| 摘要 |
PROBLEM TO BE SOLVED: To obtain a group III nitride compound semiconductor substrate having a thick film and a large area. SOLUTION: A metal nitride layer 20 having a high melting point and consisting of TiN is formed on a sapphire substrate 10 as shown in Fig.(1.A). A buffer layer 30 consisting of AlN and having a thickness of 70 nm at 400°C is formed by an MOCVD method as shown in Fig.(1.B). A first semiconductor layer 40 consisting of GaN and having a thickness of 10μm at 1,150°C is formed as shown in Fig.(1.C). A second semiconductor layer 50 consisting of GaN and having a thickness of 300μm is formed by an HVPE method as shown in Fig.(1.D). The cooled second semiconductor layer 50 is soaked in an etching liquid E which is a mixture of concentrated nitric acid and a hydrogen peroxide solution as shown in Fig.(1.E). The metal nitride layer 20 having the high melting point and consisting of TiN is decomposed to titanium ions and nitrogen molecules and that the sapphire substrate 10 is exfoliated from a laminate 100 consisting of the buffer layer 30 consisting of AlN, the first semiconductor layer 40 consisting of GaN and the second semiconductor layer 50 consisting of GaN as shown in Fig.(1.F). And then the group III nitride compound semiconductor substrate 100 as shown in Fig.(1.G) is obtained. COPYRIGHT: (C)2009,JPO&INPIT
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