利用氫化物氣相磊晶法在物理氣相沉積氮化鋁的緩衝層上成長氮化鎵厚膜之研究

Abstract

本實驗室以往是使用有機金屬化學氣相沉積法成長的氮化鎵當緩衝層，本論文則使用氫化物氣相磊晶法在物理氣相沉積的氮化鋁上成長氮化鎵厚膜，其中，氮化鋁緩衝層的厚度約為25到40奈米，用此基板成長氮化鎵厚膜可有效降低成本。本論文再藉由掃描式電子顯微鏡及穿透式電子顯微鏡觀察其表面形貌及探討其磊晶機制。 本論文已成功生產出1.5吋獨立式氮化鎵厚膜，在雷射剝離後的平均厚度可達310微米，利用X-ray繞射儀發現其晶格品質相較原本實驗室所產出的好，且用蝕刻的方式測量其缺陷密度，也發現缺陷密度和原本使用氮化鎵緩衝層的差不多，故未來基板的使用上又多了一項選擇。

In this paper, the fabrication of GaN thick film grown by HVPE with physical vapor deposition (PVD) formed aluminum nitride (AlN) buffer layer is presented. The thickness of PVD-AlN layer was 25~40 nm. The GaN thick films were grown by three-steps method using HVPE system. After laser lift-off (LLO), the thickness of free-standing GaN using PVD-AlN as buffer layer was 310µm. The diameter of sample was 1.5 inch with a smooth surface. The full width at half maximum (FWHM) of the XRD rocking curve of the (002) symmetric plane of the free-standing GaN grown on GaN template was under 100arcsec. And the etch pit density (EPD) was estimated at the level of 3×107 /cm2.