Surface Morphology And Sputtering Mechanism Of Etched Areas Of Metallic Target By Magnetron Sputtering

In recent ten years,the domestic electronic semiconductor industry has developed rapidly,and the demand for target materials is expanding.The production of excellent performance target materials has become an important industry to support the development of China's semiconductor industry.The utilization rate of magnetron sputtering target material and the sputtering yield have always been a problem that researchers have been paying attention to and focused on solving.The utilization and sputtering rate of target are mainly affected by plasma on the target surface.The plasma distribution on the target surface is determined by the magnetic field produced by the magnet on the back of the target.Therefore,optimizing the magnetic field structure is the key to improving the uniformity of target surface etching,but in actual experiments and production,it is difficult to achieve uniform etching of the target surface to increase the utilization rate of the target.The non-uniformity of the horizontal magnetic field on the target surface causes the plasma distribution on the target surface to be non-uniform,and areas with high plasma density are severely etched.In this paper,the area of the metal target after etching is studied.The plasma etching lines in different regions and the surface morphology of Ti target after etching,as well as the effects of initial surface roughness and grain size of Cu target on the surface morphology and sputtering performance after sputtering were studied.These studies not only provide new research ideas for target etching,but also have certain experimental and theoretical guiding significance for target manufacturing and quality monitoring.The etching of titanium target by magnetron sputtering shifts from the preferential sputtering of the defect areas such as scratches in the edge area to the local selective sputtering of the surface,then to the sputtering of the grain boundary,and finally to the deepest part of the sputtering crystal.In the sputtering of densely packed surfaces,different areas of the target surface show the selectivity of sputtering etching.After forging and rolling,the different sputtering areas of the Ti target have different degrees of incomplete recrystallization,and the crystal grains gradually increase with the increase of the sputtering depth;the cross-sectional grain size of the target material and the surface roughness after sputtering The degree is highly correlated,and the grain size seriously affects the surface roughness.Samples with different roughness seriously affect the surface morphology after sputtering.In the deepest area of sputter etching,there are continuous distribution of pits and protrusions,while in the incompletely etched area and scratched area.Sputter etch pits and "bright spots" formed by incompletely etched crystal grains appear in the trace area;the surface of crystal grains with different orientations will form different step-like morphologies after sputter etching;the larger the initial surface roughness of the test After 10 h of sputtering,the surface roughness of the deepest area of the sputtering etch is larger,and the sputtering yield is smaller.The grain size obviously affects the surface morphology of the target after sputtering etching.The target sample with small grain size has high grain density in the sputter etching edge area,but the grain size has nothing to do with the grain size;in the deepest area of sputter etching,the two kinds of grain size targets show relatively flat sputtering Morphology,the flat sputtering morphology of the sample surface with a smaller grain size is smaller and more uniform.The sputtering yield of the target material during the first 7.5 hours of sputtering etching of the target material increased slightly,and then it was in a downward trend.The sputtering yield of samples with 10?20 ?m grain size is larger than that of samples with120?150 ?m grain size at each stage.The Cu target sputtering voltage at each stage of the target's life cycle showed a decrease first and then gradually stabilized,while the cavity pressure showed an increase first and then gradually stabilized;the target sputtering in the constant current mode During the etching process,the target sputtering voltage keeps dropping continuously during the life of the target material,which is consistent with the increase of the target surface magnetic field intensity caused by the continuous decrease of the target material thickness.