Effects of oxygen thermal annealing treatment on formation of ohmic contacts to n-GaN
Effects of oxygen thermal annealing treatment on formation of ohmic contacts to n-GaN
复制标题
氧热退火处理对 n-GaN 欧姆接触形成的影响
DOI：
--
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
C. Wetzel
中科院分区：
文献类型：
--
作者：
W. Hou;T. Detchprohm;C. Wetzel
确定了不需要沉积后退火的未掺杂和n型GaN的接触方案。沉积态Ti/Al/Ti/Au通常形成肖特基接触。然而，我们发现，通过在金属沉积之前进行氧气快速热退火，接触将发展出欧姆行为，比接触电阻为3.8 × 10−5 Ω cm 2。在X射线光电子能谱中，我们发现Ga 3 d电子结合能随着预处理而增加，表明费米能级向导带移动。高温处理步骤的这种顺序反转允许器件制造灵活性的重要增益。
A contact scheme to undoped and n-type GaN was identified that does not require a post deposition anneal. As-deposited Ti/Al/Ti/Au usually forms a Schottky contact. However, we find that by means of an oxygen rapid thermal annealing prior to metal deposition, the contact will develop an ohmic behavior with a specific contact resistance of 3.8 × 10−5 Ω cm2. In X-ray photoelectron spectroscopy, we find that the Ga 3 d electron binding energy increases with this pre-treatment, indicating a shift of the Fermi level closer to the conduction band. This sequence reversion of high temperature processing steps allows important gain in device fabrication flexibility.