不同氩气气压下钒靶HIPIMS放电特性的演变

目的以V靶为例,研究高功率脉冲磁控溅射(HIPIMS)放电时不同工作气压下靶脉冲电流及等离子体发射光谱的表现形式和演变规律,为HIPIMS技术的进一步广泛应用提供理论依据。方法利用数字示波器采集HIPIMS脉冲放电电流波形,并利用发射光谱仪记录不同放电状态下的光谱谱线,分析不同气压下V靶HIPIMS放电特性的演变规律。同时,利用HIPIMS技术成功制备了V膜,并利用扫描电子显微镜观察了V膜的截面形貌。结果不同氩气气压下,随着靶脉冲电压的增加,靶电流峰值、靶电流平台值及靶电流平均值均单调增加,而且增加的速度越来越快,但靶电流峰值的增加速度明显高于平台值,这是由于脉冲峰值电流由气体放电决定所致。不同气压下,Ar0、Ar+、V0和V+四种谱线峰的光谱强度均随靶电压的增加而增加,相同靶电压时,其光谱强度随着气压的增加而增加。当气压为0.9 Pa、靶电压为610 V时,Ar和V的离化率分别为78%和35%。此外,利用HIPIMS技术制备的V膜光滑、致密,无柱状晶生长形貌特征。结论较高的工作气压和靶脉冲电压有利于获得较高的系统粒子离化率,但HIPIMS放电存在不稳定性。合适的工作气压是获得优质膜层的关键。

Evolution of Discharge Characteristics of High Power Impulse Magnetron Sputtering Vanadium Target under Various Argon Pressures

Objective As a new technology with high ionization rate of sputtered materials, High Power Impulse Magnetron Sputtering (HIPIMS) has widely received more and more attention home and abroad. The form and evolution of target pulse current and plasma emission spectrum of HIPIMS discharge with V target as an example under different working pressures have been investigated, which provide theoretical basis for the further application of HIPIMS technology. Methods HIPIMS pulse discharge current waveforms were acquired by digital oscilloscope and the spectral lines were recorded by emission spectrometer. The evolution law of V target HIPIMS discharge characteristics under different pressures was analyzed. At the same time, the V film was prepared by HIPIMS technique and the morphology of the V film was observed by scanning electron microscope. Results Under different argon pressures, the peak of discharge current, the platform of discharge current and the mean discharge current all monotonicly increased with target voltage. And they increased faster and faster. However, the peak value of the target current was significantly higher than that of the platform, which was due to the pulse peak current determined by gas discharge. Ar0, Ar+, V0 and V+ intensity increased with the increase of target voltage under different pressures. The spectral intensity increased with the increase of the pressure at the same target voltage. The ionizations of Ar and V were 78% and 35% at target voltage of 610 V and Ar pressure of 0.9 Pa. In addition, the V films prepared by HIPIMS technique were smooth and dense, and had no columnar crystal growth morphology. Conclusion Higher working pressure and target pulse voltage are beneficial to obtain higher system particle ionization rate, but the HIPIMS discharge is not stable. Suitable working pressure is the key to obtain high quality film.