使用三氮化氫成長磊晶氮化銦薄膜: 成長機制之即時研究與光學特性分析

Epitaxial InN film using Hydrazoic acid: in-situ study of growth and ex-situ optical characterization

陳志泰(Jr-tai Chen)

指導教授 ： 陳貴賢 ； 林麗瓊 ； 施文欽

大同大學/電機資訊學院/光電工程研究所/碩士(2006年)

摘要

在氣態源分子束磊晶系統 (Gas-source Molecular Beam Epitaxy)下，使用三氮化氫 (Hydrazoic acid; HN3) 作為氮原子來源，氮化銦薄膜已經成功地沿 (0001) 方向磊晶成長在c軸氮化鎵樣板(c-plane GaN template)上。殘餘氣體分析儀的結果顯示，三氮化氫具有高解離及近乎線性可調控之特性。藉由即時的反射式高能電子繞射儀、場發射電子掃描顯微鏡、和X光繞射儀之分析，我們仔細地研究基板溫度與五三比 (V/III ratio) 對於氮化銦薄膜成長的影響。我們發現，經由適當地調控五三比，在550oC的基板溫度下，可以得到最佳的薄膜形貌 (morphology) 與結晶特性 ( crystallinity )。氮化銦的光學能隙 (optical band gap) 在光激發螢光光譜量測 ( photoluminescence ) 及吸收光譜量測分析下，發現位在1.5 eV左右。此結果可用自由電子引發包斯丁-摩斯位移 ( free electron induced Burstein-Moss shift) 解釋。這是由於高載子濃度存在於氮化銦薄膜當中，所造成的光譜位移。此已經由霍爾效應量測得到證實。最後，透過二次離子質譜儀的分析，氮化銦的高度簡併 ( high degeneracy) 可歸咎於碳原子與氧原子污染物的影響，並且排除氫原子在此系統中為可能的摻質 (donor)。

關鍵字

氮化銦

並列摘要

Epitaxial InN thin film has been successfully grown along (0001) direction with wurtzite structure on c-plane GaN template using hydrazoic acid as nitrogen source by gas-source molecular beam epitaxy. Residual gas analyzer (RGA) result shows that HN3 exhibits highly dissociated property and a linearly controllable behavior. The effects of growth temperature and V/III ratio on growth of InN films were carefully studied by means of in-situ Reflection of High-Energy Electron Diffraction (RHEED), field-emission scanning electron microscope (FE-SEM), and X-ray diffraction (XRD). The best quality in morphology and crystallinity was achieved at 550oC through adjusting V/III ratio ratio adequately. The optical band gap of InN films characterized by Photoluminescence (PL) spectroscope and absorption measurement was about 1.5 eV, which can be accounted for by free electron induced Burstein-Moss shift due to high carrier concentration in InN film measured by Hall measurement. Secondary-ion mass spectrometry (SIMS) results show that high degeneracy of InN films was ascribed to the effect of carbon and oxygen contaminants, and exclude that hydrogen was possible donor in our system.

並列關鍵字

indium nitride ； InN

參考文獻

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