Increased doping depth of Al in wet-chemical laser doping of 4H-SiC by expanding laser pulse
Increased doping depth of Al in wet-chemical laser doping of 4H-SiC by expanding laser pulse
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DOI：
10.1016/j.mssp.2016.11.036
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发表时间：
2017-11
影响因子：
4.1
通讯作者：
A. Ikeda;Daichi Marui;R. Sumina;H. Ikenoue;T. Asano
中科院分区：
文献类型：
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作者：
A. Ikeda;Daichi Marui;R. Sumina;H. Ikenoue;T. Asano
用脉冲KrF准分子激光辐照浸泡在AlCl 3水溶液中的4 H-SiC，在4 H-SiC中掺杂Al。研究了扩展激光脉冲宽度对掺杂深度的影响。激光束经反射镜分束、重组后产生展宽脉冲。激光脉冲宽度由原来的55-100 ns扩展，而在相同的激光能量密度下，扩展后的脉冲峰值功率只有原来的一半。在Al浓度为1×1016/cm 3时，激光脉冲的多次发射使掺杂深度从原来的短、高峰值功率激光的单次发射的30 nm增加到100 nm。增加的掺杂深度可能是由于通过重复的激光照射产生的额外空位而增强的扩散。由于激光峰值功率较小，扩展脉冲激光可以抑制多次激光照射下的损伤产生，结果，pn结二极管的漏电流保持较低。
Al is doped into 4H-SiC by irradiating pulsed KrF excimer laser to 4H-SiC immersed in AlCl3aqueous solution. Impact on doping depth of the use of expanded laser-pulse width is investigated. Expanded laser pulse is produced by splitting and recombining the laser beam with mirrors. The laser pulse width was expanded from its original width of 55–100 ns, while the peak power of the expanded pulse is as half as that of the original pulse under the same laser fluence. Multiple shots of the expanded laser pulses increased the doping depth at the Al concentration of 1×1016/cm3to 100 nm from 30 nm of the single shot of the original short, high-peak power laser. The increased doping depth could be due to enhanced diffusion by extra vacancies generated by the repeated laser irradiations. Due to the smaller laser peak power, the expanded pulse laser can suppress damage generation under multiple laser shots and, as a result, leakage current of the pn junction diode is kept low.