Investigations on the effects of Ti target position and bias potential to the synthesis of TiN in a magnetized sheet plasma source
Abstract
In a previous study, TiN is successfully synthesized both on stainless steel samples and on actual industrial tools with the Ti disk target (9.15 cm in diameter) placed at the anode of the extraction region. The positive potential on the disk limits the sputtering yield and gives inconsistent deposition rate and film quality as the nitriding process on the surface of the Ti target could dominate the sputtering process. Here, sputtering is primarily due to electron bombardment. In this study, it is therefore aimed to increase the sputtering yield with positive argon ions. A Ti disk is placed at the production and at the extraction regions of the SPNIS and biased with negative potential (−250 V, −400 V and −900 V). The disk is water-cooled to eliminate the effect of heating on the sputtering rate. The stainless steel substrates are placed at the extraction region parallel to the sheet plasma and at 2.3 cm from the sheet's core. Because of the geometry and magnetic confinement configuration of the source, no TiN film is produced on the SS samples when the target is located at the production region. However, TiN film that exhibits good adhesion and of good optical properties is deposited on the glass tubing of the target holder. Infrared reflection of up to 50% is obtained. TiN films are successfully produced on the SS samples when the target is placed at the extraction region. The XRD patterns of the synthesized films showed TiN (200), TiN (311) and Ti2N (220) phases.
