Single step ohmic contact for heavily doped n-type silicon
Single step ohmic contact for heavily doped n-type silicon
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DOI：
10.1016/j.apsusc.2019.144686
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发表时间：
2020-03
影响因子：
6.7
通讯作者：
Febin Paul;Krishna Nama Manjunatha;S. Govindarajan;S. Paul
中科院分区：
文献类型：
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作者：
Febin Paul;Krishna Nama Manjunatha;S. Govindarajan;S. Paul
本工作的重点是在n型c-Si晶片上的金属-半导体接触，并探索使用镁（Mg）来形成电子选择性接触的可能性，而不是使用传统的Au-Sb膜，其需要在350和500 °C之间的高温退火。在镁触点上添加铝（Al）覆盖层以防止镁的氧化。在热蒸发Mg/Al接触上进行各种电学测量以研究p型和n型硅上的导电特性，其中p型掺杂硅观察到肖特基行为，而n型掺杂的c-Si样品观察到欧姆行为（V_（？）I）。在研究了Mg中间层的各种厚度后，结果进一步优化，发现10 nm的Mg中间层具有最小的电阻。计算优化结构（n-Si/Mg-10 nm/Al）的电阻率，并且根据传输线法（TLM）的测量显示接触电阻率为462 mΩ cm 2 ± 20 mΩ cm 2。还对镁接触的高温退火的效果进行了进一步的研究，其显示电阻随着退火温度的增加而增加，其中在没有退火的情况下获得最低的电阻。另外的调查集中在沉积镁的形态分析及其对电特性的影响。
This work focusses on the metal-semiconductor contact onn-type c-Si wafers and explore the possibility of using magnesium (Mg) to form electron–selective contacts instead of using the conventional Au-Sb films which requires high temperature annealing between 350 and 500 °C. Aluminium (Al) capping layer was added over the magnesium contacts to prevent oxidation of magnesium. Various electrical measurements were performed over thermally evaporated Mg/Al contacts to investigate the conduction properties on both p-type and n-type silicon, where a Schottky behaviour was observed for thepdoped silicon, but an ohmic behaviour (V ∝ I) for then-type doped c-Si samples. The results were further optimised after investigating various thicknesses of the Mg interlayer, with 10 nm of Mg interlayer found to have the least resistance. The resistivity of the optimised structure (n-Si/Mg-10 nm/Al) was calculated, and measurements according to the Transmission Line Method (TLM) showed a contact resistivity of 462 mΩ cm2± 20 mΩ cm2. Further investigations were also conducted on the effect of high temperature annealing of the magnesium contact, which showed an increase in resistance with increase in annealing temperature, with the lowest resistance obtained without annealing. Additional investigations focussed on the morphological analysis of the deposited magnesium and its impact on the electrical characteristics.