Diagnose And Analysis Of Cr-Based Magnetron Sputtering Plasma By Different Magnetic Field Configuration

Distribution of three kinds of plasma parameter(ni, ne, Te) at different magnetic field configration(different unbalance coefficient and different closed state) was diagnosed and characteristiced by Langmuir probe. The relationship between ion density distribution feature and coating thickness distribution(radial direction) was compared, the difference and the reasons of plasma distribution effected by different unbalance coefficient and different closed state was been studeid, the influence of Cr coating micromorphology effected by plasma distribution which changed by changing magnetic parameter was analysed.The results indicate that:plasma density was decreased along the target to substrate direction at the place x=0mm(ni was decreased from 7.41 X 1016/m3 to 3.41 X 1016/m3 from 30mm to 210mm; ne was decreased from 2.58X 1016/m3to 1.09X 1016/m3 from 30mm to 210mm) which similar to coating thickness variation along this direction when single magnetron discharged(K=4.46). The plasma parameter of different unbalance coefficent magnetron discharged were obviously different near target surface area(plasma density when K was 2.78 was higher than K was 6.41), especially from 30mm to 70mm at the place x=21.5mm(innermost within etchring. ni was 8.79 X 1016/m3-4.19 X 1016/m3 within this measured interval when K=2.78, ne was 2.98 X 1016/m3-1.12X 1016/m3, Te was 5.64ev-2.44ev; ni was 4.06 X 1016/m3-4.05 X 1016/m3 within this measured interval when K=6.41, ne was 9.81 X 1015/m3-6.75X 1015/m3, Te was 1.22ev-1.03ev), so that the Cr coating surface topography was significant different near target surface and slightly different far from target surface. The substrate which was near to target surface(60mm) got warmer by high desity ion bormbard, promoted deposited particle diffuse, and coating surface particles fused more easier, enhanced compactness. Over-dense ion desity bormbard decreased compactness because of thermal stress. However, the sbustracte warmer by ion bormbard was not enough to overcome shadowing when used single magnetrom. Magnetic field closed state remarkable enhanced the plasma density in vaccum chamber than unclosed state, and the density was increased along target to substracte direction(except d= 160mm) at every measured points along axial(d=0mm,40mm, 80mm,120mm,160mm respectively). This was against to coating thickness variation along this direction(for instance when d=0mm, ni was increased from 3.04×1016/m3 to 1.09×1017/m3 from 70mm to 205mm; ne was increased from 1.07×1016/m3to 6.41 X 1016/m3 from 70mm to 205mm). Enhanced plasma density made ion bombardment more effective, so that Cr coating more compact and smooth, and no distinct topography columner ctystal structure observed in cross section.The difference of magneticline divergence was the reason for the difference of plasma parameters distribution. The introduction of closed magneticline between two adjacent magnetron was account of the increased of plasma density when magnetic field under closed state. Low target atom ionizating rate lead to ion density radial direction distribution opposite to coating thickness distribution.