Influence Of Peak Current And Deposition Time By Dual Power Pulsed Electric Field On Structure And Properties Of Tin Films

According to the basic theory of gas discharge in plasma physics,when gas discharge is introduced into the strong glow and weak arc region,the plating particles will break away from the target surface in a "collision-induced heat emission" manner,and obtain higher ionization rates and higher densities.In this paper,we construct a dual power pulsed?DPP?electric fieldenvironment of target peak current presenting "step" in one pulse period was put forward,and the gas discharge is introduced into the strong glow and weak arc discharge region.At the same time,the ionization at the early stage of weak ionization can be used to reduce the interpolar field strength in the later stage of strong ionization,and increase the average deposition rate of the thin film by reducing the probability of the high ionized plating particles returning to the cathode target surface again.In this paper,in the dual power pulsed?DPP?electric field mode,TiN films were deposited on the GCrl5 substrate by changing the pulse peak current and deposition time.The microstructure,morphology,chemical composition,hardness,film-based bonding performance,and corrosin resistance of the TiN films controlled by various parameters were discussed.The results show that under the same average current conditions,the TiN films were prepared by the dual power pulsed electric field have higher effective deposition rate than the TiN films were prepared by the direct current electric field,which means that the dual power pulsed electric field can be used to introduce the gas discharge into the strong glow and weak arc discharge region.The deposited particles have higher ionization and off-target numbers than those deposited on the glow region.At the same time,in the dual power pulsed electric field mode,as the pulse peak current continues to increase,the average deposition rate of the TiN film gradually increases and gradually approaches deposition rate of TiN film in the direct current field mode,and the crystallinity of the film increases,the preferred orientation also changes,the surface roughness of the film gradually becomes smaller,the film surface is relatively flat.Through the study of the mechanical properties and corrosion resistance of the film,it is found that the dual power pulsed?DPP?electric field mode has an obvious effect on the mechanical properties of TiN films,TiN films were deposited at a peak current of 7.5A using DPP,there is the highest hardness and elastic modulus?28.5GPa and 323.7GPa?,and it was significantly higher than those of direct current mode?15.1GPa and 228.0GPa?.At the same time,it had good toughness,good film-based bonding strength,and better corrosion resistance(corrosion rate of 1.3×10^-4mm/a).Through the study of the structure and properties of TiN films prepared at different deposition times of DPP electric field,it was found that with the increase of deposition time,the crystallinity of the film increases,the average grain size gradually increases,the internal stress of the film tends to increase,but the internal stress is small.And the hardness and elastic modulus show an increasing trend,when the deposition time is 150min,the prepared TiN film has larger hardness?31.3GPa?and elastic modulus?348.2GPa?than TiN film prepared at other deposition time,at the same time,TiN films exhibited lower corrosion current density Icorr?1.1× 10-8A/cm2?and corrosion rate Vcorr(5.9×10^-5mm/a).