The application of a helicon plasma source in reactive sputter deposition of tungsten nitride thin films

【摘要】 A reactive helicon wave plasma（HWP） sputtering method is used for the deposition of tungsten nitride（WNx） thin films. N₂ is introduced downstream in the diffusion chamber. The impacts of N₂ on the Ar-HWP parameters, such as ion energy distribution functions（IEDFs）, electron energy probability functions（EEPFs）, electron temperature（Te） and density（ne）, are investigated. With the addition of N₂ , a decrease in electron density is observed due to the dissociative recombination of electrons with N₂⁺.The similar IEDF curves of Ar+and N₂⁺indicate that the majority ofN₂⁺stems from the charge transfer in the collision between Ar+and N₂ . Moreover, due to the collisions between electrons and N₂ ions, EEPFs show a relatively lower Tewith a depletion in the high-energy tail. With increasing negative bias from 50 to 200 V,a phase transition from hexagonal WN to fcc-WN0.5is observed, together with an increase in the deposition rate and roughness.更多还原

【Abstract】 A reactive helicon wave plasma（HWP） sputtering method is used for the deposition of tungsten nitride（WNx） thin films. N₂ is introduced downstream in the diffusion chamber. The impacts of N₂ on the Ar-HWP parameters, such as ion energy distribution functions（IEDFs）, electron energy probability functions（EEPFs）, electron temperature（Te） and density（ne）, are investigated. With the addition of N₂ , a decrease in electron density is observed due to the dissociative recombination of electrons with N₂⁺.The similar IEDF curves of Ar+and N₂⁺indicate that the majority ofN₂⁺stems from the charge transfer in the collision between Ar+and N₂ . Moreover, due to the collisions between electrons and N₂ ions, EEPFs show a relatively lower Tewith a depletion in the high-energy tail. With increasing negative bias from 50 to 200 V,a phase transition from hexagonal WN to fcc-WN0.5is observed, together with an increase in the deposition rate and roughness.更多还原