Electron energy distributions and plasma parameters in high-power pulsed magnetron sputtering discharges
Electron energy distributions and plasma parameters in high-power pulsed magnetron sputtering discharges
复制标题
高功率脉冲磁控溅射放电中的电子能量分布和等离子体参数
DOI：
10.1088/0963-0252/18/2/025008
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发表时间：
2009
影响因子：
3.8
通讯作者：
J. Lukas
中科院分区：
文献类型：
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作者：
A. D. Pajdarová;J. Vlček;P. Kudlacek;J. Lukas
我们报道了在高功率脉冲直流磁控溅射放电中使用时间分辨朗缪尔探针测量所获得的结果。以直径为100 mm的平面靶为衬底，研究了铜膜高速沉积过程中电子能量分布和局域等离子体参数随时间的变化规律。脉冲的平均靶功率密度为5 0 0 W cm−2，重复频率为1 kHz，脉冲宽度为2 0 0 ×S，气压为1 pa。在脉冲过程中，观察到了具有两个能团和截断高能尾部的电子能量分布。在50 的S脉冲的初始阶段快速上升之后，电子的运动温度(使用平均电子能量定义)保持在10 500到12 200 K的范围内，直到脉冲终止。在脉冲初始阶段，弱布居超热电子的温度迅速下降，在脉冲启动后接近动力学温度约100 微米S。在建立了脉冲期间目标功率密度为6 5 0~6 80 W−2的稳态放电机制后，在衬底位置获得了高密度的等离子体，对于10 0 的S，等离子体密度范围为1×10 12~2×10 12 cm−3，延迟时间为5 0 S。脉冲期间等离子体电位缓慢上升至3.5 V，终止后缓慢上升至25 µS。
We report on the results obtained using time-resolved Langmuir probe measurements in high-power pulsed dc magnetron sputtering discharges. Time evolutions of the electron energy distribution and the local plasma parameters were investigated at a substrate position of 100 mm from a planar target of 100 mm diameter during a high-rate deposition of copper films. The average target power density in a pulse was 500 W cm−2 at a repetition frequency of 1 kHz, a voltage pulse duration of 200 µs and an argon pressure of 1 Pa. The electron energy distributions with two energy groups and sharply truncated high-energy tails were observed during a pulse. After a fast rise in a 50 µs initial stage of the pulse, the kinetic temperature of electrons, defined using the mean electron energy, remained in the range from 10 500 to 12 200 K till the pulse termination. The temperature of weakly populated hot electrons decreased rapidly in the initial stage of the pulse approaching the kinetic temperature approximately 100 µs after a pulse initiation. High plasma densities, being in the range 1 × 1012–2 × 1012 cm−3 for 100 µs, were achieved at the substrate position with a 50 µs delay after establishing the 125 µs steady-state discharge regime with the target power density of 650–680 W cm−2 during a pulse. The plasma potential slowly increased from 0.5 to 3.5 V during the pulse and 25 µs after its termination.