The description of charge transfer in fast negative ions scattering on water covered Si(100) surfaces

• Published in: Applied surface science 2016-11, Vol.387, p.1174-1182
• Main Authors: Chen, Lin, Qiu, Shunli, Liu, Pinyang, Xiong, Feifei, Lu, Jianjie, Liu, Yuefeng, Li, Guopeng, Liu, Yiran, Ren, Fei, Xiao, Yunqing, Gao, Lei, Zhao, Qiushuang, Ding, Bin, Li, Yuan, Guo, Yanling, Chen, Ximeng
• Format: Article
• Language: English
• Subjects: Charge transfer; Collisions; Construction; Doping; Ion scattering; Mathematical models; Negative ion; Positive ion; Scattering; Semiconductor surface; Semiconductors
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.06.132

•We first observe that negative-ion fractions present no variation with the doping concentration, which is very different from the results of low energy Li neutralization from doped Si samples.•Our work shows that the affinity levels and collision time significantly counteract the band gap effect on negative ion formation. The work will improve our understanding on electron transfer on semiconductor surfaces associated with doping.•In addition, we build a complete theoretical framework to quantitatively calculate the negative-ion fractions.•Our work is related to charge transfer on semiconductor surfaces, which will be of interest to a broad audience due to the wide necessity of the knowledge of charge exchange on semiconductor surfaces in different fields. Doping has significantly affected the characteristics and performance of semiconductor electronic devices. In this work, we study the charge transfer processes for 8.5–22.5keV C− and F− ions scattering on H2O-terminated p-type Si(100) surfaces with two different doping concentrations. We find that doping has no influence on negative-ion formation for fast collisions in this relatively high energy range. Moreover, we build a model to calculate negative ion fractions including the contribution from positive ions. The calculations support the nonadiabatic feature of charge transfer.