2012 Fiscal Year Final Research Report
In situ observation of LPE growth process of aluminum nitride for understanding the dislocation formation mechanism
| Project/Area Number |
23656475
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Metal making engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2011 – 2012
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| Keywords | 窒化物半導体 / 窒化アルミニウム / 結晶成長 / その場観察 |
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| Research Abstract |
The growth process of AlN from Al-Ga flux at high temperature was observed in-situ. The dislocation formation, which leads to the formation of low quality AlN, is strongly dependent on the AlN nucleation process on the substrate. On the sapphire substrate, AlN crystals formed by heterogeneous nucleation. Each of the crystal, which has mismatched crystallographic orientation, grows by coalescence growth mechanism. This growth process resulted in low quality AlN crystal with high dislocation density. On the other hand, AlN crystals grow homo-epitaxially on the nitride sapphire substrate. And the coalescence growth was suppressed on the nitride sapphire. These growth mechanisms resulted in the high quality AlN formation on nitride sapphire substrate.
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