p-GaN surface treatments for metal contacts
p-GaN surface treatments for metal contacts
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DOI：
10.1063/1.125772
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发表时间：
2000-01
影响因子：
4
通讯作者：
Jingxi Sun;Kimberly Anne Rickert;J. Redwing;A. Ellis;F. Himpsel;T. Kuech
中科院分区：
文献类型：
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作者：
Jingxi Sun;Kimberly Anne Rickert;J. Redwing;A. Ellis;F. Himpsel;T. Kuech
利用同步辐射光电子能谱研究了湿法化学处理的p-GaN表面的化学键合和电子性质。氯基化学键被确定在常规的盐酸处理的p-GaN表面，这是与表面费米能级向导带边缘的位移为0.9 eV相对于热清洁的表面。与HCl处理的表面相比，KOH处理的表面上的表面费米能级位于更靠近价带边缘约1.0eV处，导致对p型材料的表面势垒高度比HCl处理的表面小得多。KOH处理后对p-GaN的较小的表面势垒高度可以导致较低的接触电阻率，并且可以在降低对p-GaN的金属接触电阻率方面发挥重要作用。
The chemical bonding and electronic properties of wet, chemically treated p-GaN surfaces were studied using synchrotron radiation photoemission spectroscopy. Chlorine-based chemical bonding was identified on the conventional HCl-treated p-GaN surface, which is associated with a shift of the surface Fermi level toward the conduction band edge by ∼0.9 eV with respect to the thermally cleaned surface. Compared to the HCl-treated surface, the surface Fermi level on the KOH-treated surface lies about ∼1.0 eV closer to the valence band edge, resulting in a much smaller surface barrier height to p-type materials than the HCl-treated surface. The smaller surface barrier height to p-GaN after KOH treatment can lead to a lower contact resistivity and can play an important role in lowering the metal contact resistivity to p-GaN.