摘要
提出了一种基于靶台(工件)二次加速的束线离子注入的新方法,基本原理是将传统束线离子注入和等离子体离子注入有效复合。采用二维Particle-in-cell(PIC)模型对这种注入方法进行了数值仿真研究。考察了靶台加负偏压情况下靶台表面空间电势、离子密度变化以及离子的运动状态的时空演化。统计分析了不同时刻离子注入剂量、注入能量和注入角度的分布规律。结果表明:靶台施加偏压对束流离子起到了很好的二次加速效果,束线离子复合加速离子注入这种新方法理论上是切实可行的。同时发现在靶台附近空间电场的作用下,离子束会发生小角度偏转,由柱状形逐渐变成"喇叭口"形,靶台表面有效注入范围扩大。靶台表面注入剂量分布呈中心区域高边缘区域低的趋势。这种新方法有助于减缓电源硬件加工的难度,增加了工艺的灵活性。
Abstract A novel technique was developed to improve the conventional ion implantation. In the newly-developed technique, a negative pulsed voltage, with respect to the vacuum chamber, was applied to the target so as to re-accelerate the impinging ions; and the conventional ion implantation was combined with plasma ion implantation. The various influencing factors,including the time evolutions of the field distribution above the negatively biased target surfaces, ion density distribution and ion trajectories, were modeled and simulated with 2-D software package particle-in-cell. The distributions of the implantation dosage, energy and incident angle of the ions at different times were statistically evaluated. The simulated results show that the negative bias significantly accelerates the ion for a second time,and the technique has a sold theoretical basis. Besides, the field distribution, originated from the bias, slightly bends the ion beam in such a way that its cylindrical shape changes into a bell-like one, considerably increasing the implantation area of the target. Moreover, the ion dosage decreased in radial direction because of the sheath configuration and ion deflection by the curved field. The advantages include relaxation of the power supply requirements and more flexibility of ion implantation.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2012年第6期493-498,共6页
Chinese Journal of Vacuum Science and Technology
基金
国家自然科学基金项目(10975041和10905013)
新世纪优秀人才计划资助项目
关键词
离子注入
粒子模拟
复合加速
束线离子注入
等离子体离子注入
Ion implantation, Particle-in-cell, Hybrid acceleration, Ion beam implantation, Plasma ion implantation
