本實驗研究以矽化鎢(WSix)於氮化鎵(GaN)之蕭特基接觸特性。利用共同濺鍍法成長矽化鎢薄膜於氮化鎵上。由I-V之量測得到，於未加熱之蕭特基能障大小約為0.5eV。而以RTA及爐管各30秒以及1小時，550、750、950℃熱處理後，發現矽化鎢薄膜可承受至950℃，1小時之處理，能障大小約上升至0.6eV。經由X-ray分析，在950℃溫度時，矽化鎢薄膜形成了四方柱體之結構。而由化學分析電子能譜儀之縱深分析，於950℃熱處理前後，矽化鎢與氮化鎵之界面保持良好。 矽化鎢於有低溫成長氮化鎵覆蓋層(LT-GaN)上，熱處理前後蕭特基能障大小約為1eV。而比較Ni/Au，Cr，Ti金屬於低溫成長氮化鎵覆蓋層上，仍發現其比理論值高，約為1eV。這有可能為低溫成長氮化鎵覆蓋層材料內部缺陷太高導致費米能階被固定住。 The Schottky barrier heights of WSix contact s onto GaN are about 0.54eV,and they exhibited good thermal stability after 750℃ for 1 hour alloying. After 950℃for 1 hour alloying, SBH increases up to 0.65 eV. The Schottky barrier heights of WSix contact s onto LT-GaN are about 1eV,and they exhibited good thermal stability even a one-hour thermal alloying at 950 ℃.The Fermi level of LT-GaN might be pinned at 0.9~1 eV because of hightly defect density in LT-GaN. Compared to conventional Schottky barrier diodes, it was found that we could significantly reduce the leakage current in Schottky barrier diodes by introducing a LT-GaN cap layer on top GaN.
