Study On Macroparticles Reduction For Multi-Arc Ion Plating And Influence Of Pulsed Bias On Properties Of Thin Film

Multi-arc ion plating is a kind of ion plating method using the evaporation source of cathodic arc,with the advantages of high ionization rate,high ion energy,rapid deposition rate,excellent film properties.However the arc from cathode arc source have high current density(up to the maximum of 105~108 A/cm2)and power density(up to the maximum of 109 W/cm2),which leads to the transmission of neutral cluster on the surface of cathodic target.The transmission could bring many big particles with different sizes from 0.1 to several hundreds of micrometers,and the size of most particles exceeds the thickness of film.These big particles could decrease the surface finish,impact the properties of film and even restrict the ability to produce highqualified film.In this article,we analyzed the production,transport and sedimentation of big particles.We combined the method of magnetic filter and baffle with the method of pulsed bias to eliminate big particles via optimizing the parameters of cathodic arc source.Also,we studied the impact of pulsed bias on the properties of film.The results indicate that:(1)Deceasing the arc current can reduce the power density on the target surface,further reduce the quantity of transmission of big particles.When the arc current decreases from 80 A to 60 A,the number of big particles is reduced by a half.(2)The poroid mechanical baffler which has the same axis with the bend of filter can decrease the deposition rate,but can enhance the ability of filtering big particles.(3)The bend bias can improve the transmission efficiency of ions availably.When bias was applied to bend,the transmission efficiency can be increased by 70% than the case without bias.(4)The pulsed bias has impact on the deposition rate of the amorphic carbon film(taC)produced by the method of magnetic filtered cathodic arc,while the range of influence is less than 10 %.As the bias voltage increases,the deposition rate increases first and then decreases,and reaches the maximum when the pulsed bias is about 1200 V.Higher bias can inhibit the formation of sp3 bond in film,reduce the content of sp3 bond,and decrease the hardness of film,yet it can be beneficial to enhance the adhesive force of film.(5)The pulsed bias can make the plasma sheath fluctuate and prevent the big particles in lower speed from reaching the substrate surface.Simultaneously,the sputtering effect of the pulsed bias can inhibit the growth of big particles on film,thus improve the surface topography of film.(6)The 90° bend magnetic filter can interdict the transport of big particles effectively and can eliminate most of particles.Combined with the pulsed bias,the filter was used to produce the tetrahedral amorphic carbon film(ta-C)which achieve the higher standard of surface particles.Thereinto,the particle density can be decreased below 0.55/100 ?m2,the average diameter can be less than 0.29 ?m and the carbon film can achieve the generic surface finishment of film produced by magnetron sputtering.