کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1690413 | 1518953 | 2015 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Strategy for tuning the average charge state of metal ions incident at the growing film during HIPIMS deposition Strategy for tuning the average charge state of metal ions incident at the growing film during HIPIMS deposition](/preview/png/1690413.png)
Energy and time-dependent mass spectrometry is used to determine the relative number density of singly- and multiply-charged metal-ion fluxes incident at the substrate during high-power pulsed magnetron sputtering (HIPIMS) as a function of the average noble–gas ionization potential. Ti is selected as the sputtering target since the microstructure, phase composition, properties, and stress-state of Ti-based ceramic thin films grown by HIPIMS are known to be strongly dependent on the charge state of Tin+ (n = 1, 2, …) ions incident at the film growth surface. We find that the flux of Tin+ with n > 2 is insignificant; thus, we measure the Ti2+/Ti+ integrated flux ratio JTi2+/JTi+JTi2+/JTi+ at the substrate position as a function of the choice of noble gas–Ne, Ar, Kr, Xe, as well as Ne/Ar, Kr/Ar, and Xe/Ar mixtures -- supporting the plasma. We demonstrate that by changing noble–gas mixtures, JTi2+JTi2+ varies by more than two orders of magnitude with only a small change in JTi+JTi+. This allows the ratio JTi2+/JTi+JTi2+/JTi+ to be continuously tuned from less than 0.01 with Xe, which has a low first-ionization potential IP1, to 0.62 with Ne which has a high IP1. The value for Xe, IPXe1=12.16eV, is larger than the first ionization potential of Ti, IPTi1=6.85eV, but less than the second Ti ionization potential, IPTi2=13.62eV. For Ne, however, IPNe1=21.63eV is greater than both IPTi1 and IPTi2. Therefore, the high-energy tail of the plasma-electron energy distribution can be systematically adjusted, allowing JTi2+/JTi+JTi2+/JTi+ to be controllably varied over a very wide range.
• Ti-based ceramics grown by HIPIMS are strongly dependent on the charge state of Tin+ (n = 1, 2, …).
• Ti2+/Ti+ flux ratio JTi2+/JTi+JTi2+/JTi+ is measured as a function of the choice of noble gas: Ne, Ar, Kr, Xe.
• With changing noble–gas, JTi2+JTi2+ varies by two orders of magnitude with only a small change in JTi+JTi+.
• JTi2+/JTi+JTi2+/JTi+ can be tuned from 0.01 with Xe, to 0.62 with Ne depending on gas IP.
• This strategy is applicable to wide range of metal targets that satisfy IPXe1
Journal: Vacuum - Volume 116, June 2015, Pages 36–41