文献类型：期刊文献

英文题名：Promotion of boron diffusion and gettering by employing thin Al2O3 layer as a reaction barrier

作者：Zhang, Zhen[1];Yang, Ning[2];Lu, Minglei[1];Yuan, Xiao[1];Ye, Xiaojun[1];Liu, Cui[1];Li, Hongbo[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[2]China Aerosp Sci & Technol Corp, Shanghai Inst Space Power Sources, Shanghai 200245, Peoples R China

年份：2021

卷号：32

期号：7

起止页码：8205

外文期刊名：JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS

收录：;EI(收录号：20211010045041);WOS:【SCI-EXPANDED(收录号:WOS:000625721600004)】；

基金：This work was supported by the National Key R&D Program of China (2018YFB1500300).

语种：英文

外文关键词：Iron - Alumina - Diffusion barriers - Silicon oxides - Substrates - Aluminum oxide - Silica

摘要：The formation of a boron-rich layer (BRL) is a common phenomenon during the fabrication of boron (B) emitter due to different solubility of B in the silicon oxide layer and the silicon substrate. In our work, we employ alumina oxide (Al2O3) layers as reaction barriers to avoid the production of the silicon oxide layer and eliminate the BRL. The B diffusion in silicon becomes much more accessible that the diffusion concentration and depth are increased dramatically with the absence of BRL. The Al2O3 layer can also improve the uniformity of surface sheet resistance due to its hydrophilic, bringing superior quality of liquid boron source spin coating. We investigate the influence of Al2O3 with different thicknesses and refractive indexes on the B diffusion. The diffusion profiles of B in the silicon capped with Al2O3 become broader as the thicknesses and refractive indexes of Al2O3 increase. Besides, iron is employed as a model impurity to study the gettering effects during the B diffusion. The increase of the maximum B concentration and the total amount of B doping contribute to a superior gettering effect with the interstitial iron concentration decrease from 3.91e12 cm(-3) to a minimal value of 1.65e11 cm(-3), and the iron concentration even dropped to 7.24e10 cm(-3) after attaching a second deposition. We analyze the mechanisms of gettering systematically during the B diffusion. The present work will help deepen the understanding of B doping and the fabrication of B emitter.