Crystal-polarity dependence of Ti/Al contacts to freestanding n-GaN substrate
Crystal-polarity dependence of Ti/Al contacts to freestanding n-GaN substrate
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DOI：
10.1063/1.1419053
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发表时间：
2001-11
影响因子：
4
通讯作者：
J. Kwak;Kyu-Pil Lee;J. Y. Han;Jaehee Cho;S. Chae;O. Nam;Young-Kwan Park
中科院分区：
文献类型：
--
作者：
J. Kwak;Kyu-Pil Lee;J. Y. Han;Jaehee Cho;S. Chae;O. Nam;Young-Kwan Park
研究了晶体极性对n-GaN衬底上Ti/Al接触电学性质的影响。在GaN面n-GaN衬底上制备的Ti/Al接触在600°C以上的温度下进行30次S处理后，其接触电阻率为2×10−5Ωcm~2，呈现出非线性的电流-电压曲线，并且在相同的热处理条件下测得了高于1 eV的高肖特基势垒高度。这些结果可以用GaN衬底的不同极性引起的GaN/AlN异质结上相反的压电场来解释。
The effect of crystal polarity on the electrical properties of Ti/Al contacts to n-GaN substrate has been investigated. The Ti/Al contacts prepared on Ga-face n-GaN substrate became ohmic with a contact resistivity of 2×10−5 Ω cm2 after annealing at temperatures higher than 600 °C for 30 s. On the contrary, the contacts on N-face n-GaN substrate exhibited nonlinear current–voltage curve and high Schottky barrier heights over 1 eV were measured at the same annealing conditions. These results could be explained by opposite piezoelectric-field at GaN/AlN heterostructure resulted from different polarity of the GaN substrate.