Sputter yield amplification by tungsten doping of Al₂O₃ employing reactive serial co-sputtering: process characteristics and resulting film properties

Abstract

The deposition rate of reactively sputtered Al 2 O 3 coatings is demonstrated to increase by 80% upon Tungsten doping of the Aluminum target utilized. This effect is based on the recoil of the sputtering species at implanted dopants below the target surface and is termed Sputter Yield Amplification. For the investigation of this effect, a novel type of magnetron sputter deposition system has been employed that facilitates serial co-sputtering. In this technique doping of the elementary target is enabled by a dynamic sputtering process from an auxiliary cathode. In our case, the rotating Aluminum target has been dynamically coated with Tungsten from this auxiliary cathode. Since the primary target rotates, the auxiliary cathode is placed in series with the primary erosion zone. The deposition rate of Al 2 O 3 can be considerably increased in this process already for very low concentrations of approximately 1% of Tungsten in the resulting film. A characterization of the dynamics of reactive sputtering as a function of target rotation speed has been performed.

Enhanced resputtering and asymmetric interface mixing in W/Si multilayers

“…W) to the target material [8]. This effect originates in a reduction of the implantation depth of the light element due to an increased stopping power and is known as "sputter yield amplification" (SYA) [9].…”

41.3: Invited Paper: Molybdenum Titanium based Sputter Targets for TFT Application

“…2 shows the dependency of the deposition rate on Ti content of MoTi alloys with high Ti contents. The deposition rate of MoTi90 is almost 40% higher compared to pure Ti which can be explained by the sputter yield amplification effect [1].…”

Serial cosputtering for aluminum doping manipulated zinc oxide as front contact for Cu(In,Ga)Se2 solar cells

“…Here, TCO can be doped with an additional element to manipulate the device properties. [17][18][19] In particular, the serial cosputtering technique introduced by Belkind 20) showed benefits such as the sputter amplification yield effect, 21,22) and an advanced concept was shown by Fraunhofer-Institut für Schicht-und Oberflächentechnik IST. 23) Serial cosputtering in an in-line setup has until now not been shown to be applicable to the production of window layers for CIGS solar cells.…”