The surface roughness seriously affects the performance of devices after barrier CMP. Due to the high surface roughness of copper line, the local resistance of a device will be high when working, then the copper line ...The surface roughness seriously affects the performance of devices after barrier CMP. Due to the high surface roughness of copper line, the local resistance of a device will be high when working, then the copper line will overheat prompting the generation of electro-migration and the circuit will lose efficacy. Reducing the surface roughness of the copper line in barrier CMP is still an important research topic. The main factors influencing the surface roughness of copper line in alkaline barrier slurry are analyzed in the paper. Aimed at influencing the law on the surface roughness of copper line, using a new type of alkaline barrier slurry with a different p H of the chelating agent and changing the content of non-ionic surfactant, we then analyze the influencing law both on the surface roughness of copper line, and the influence mechanism. The experimental results show that with a chelating agent with a low p H value in the barrier slurry, the surface roughness of the copper line is 1.03 nm and it is the lowest in all of the barrier slurries, and with the increase of non-ionic surfactant concentration, the surface roughness of copper line is reduced to 0.43 nm, meeting the demand of further development of integrated circuits.展开更多
To strengthen the device performance with the pattern wafer by enhancing the Cu polishing rate and improve the surface roughness with the Cu lines, a new weakly alkaline chelating agent with a barrier slurry is develo...To strengthen the device performance with the pattern wafer by enhancing the Cu polishing rate and improve the surface roughness with the Cu lines, a new weakly alkaline chelating agent with a barrier slurry is developed to meet the process demand of the advanced barrier chemical mechanical planarization（CMP）. This new chelating agent has a stronger chelating ability and a lower p H value than the previous generation-FA/O I chelating agent researched before. Without an unstable oxidant agent added in the polishing slurry, it is difficult to enhance the copper polishing rate during the barrier CMP. The stronger chelating ability of the new chelating agent could increase the copper polishing rate along with controlling the Cu/Ta/TEOS removal rate selectivity to meet the requirements of the IC fabrication process. Thus it has solved the problem of excessive roughness due to the lower polishing rate, avoiding reducing the device performance with the pattern wafer. The new chelating agent with its lower p H value could make it possible to protect the low-k dielectric under the barrier layer from structurally breaking. The CMP experiment was performed on the 12 inch MIT 854 pattern wafers with the barrier slurry containing the new weakly alkaline chelating agent. By the DOE optimization, the results indicate that as the new chelating agent concentration in the slurry was up to 2.5 m L/L, the copper polishing rate is about 31.082 nm/min.Meanwhile, the wafer surface has a rather low roughness value of 0.693 nm（10×10 μm）, the correction ability with the above slurry is adapted to the next generation barrier CMP and the k value of the low-k dielectric seems to have no k-shift. All the results presented show that the new weakly alkaline chelating agent with its superior performance can be used for the advanced barrier CMP.展开更多
We propose an alkaline barrier slurry containing guanidine hydrochloride（GH） and hydrogen peroxide.The slurry does not contain any corrosion inhibitors, such as benzotriazole（BTA）. 3-inch samples of tantalum coppe...We propose an alkaline barrier slurry containing guanidine hydrochloride（GH） and hydrogen peroxide.The slurry does not contain any corrosion inhibitors, such as benzotriazole（BTA）. 3-inch samples of tantalum copper and oxide were polished to observe the removal rate. The effect of GH on removal rate selectivity along withhydrogenperoxidewasinvestigatedbycomparingslurrycontainingGHandH2O2withslurrycontainingonly GH. Details about the tantalum polishing mechanism in an alkaline guanidine-based slurry and the electrochemical reactions are discussed. The results show that guanidine hydrochloride can increase the tantalum polishing rate and the selectivity of copper and barrier materials. The variation of the dishing and wire line resistance with the polishing time was measured. The dishing value after a 300 mm pattern wafer polishing suggests that the slurry has an effective performance in topography modification. The result obtained from the copper wire line resistance test reveals that the wire line in the trench has a low copper loss.展开更多
文摘The surface roughness seriously affects the performance of devices after barrier CMP. Due to the high surface roughness of copper line, the local resistance of a device will be high when working, then the copper line will overheat prompting the generation of electro-migration and the circuit will lose efficacy. Reducing the surface roughness of the copper line in barrier CMP is still an important research topic. The main factors influencing the surface roughness of copper line in alkaline barrier slurry are analyzed in the paper. Aimed at influencing the law on the surface roughness of copper line, using a new type of alkaline barrier slurry with a different p H of the chelating agent and changing the content of non-ionic surfactant, we then analyze the influencing law both on the surface roughness of copper line, and the influence mechanism. The experimental results show that with a chelating agent with a low p H value in the barrier slurry, the surface roughness of the copper line is 1.03 nm and it is the lowest in all of the barrier slurries, and with the increase of non-ionic surfactant concentration, the surface roughness of copper line is reduced to 0.43 nm, meeting the demand of further development of integrated circuits.
基金Project supported by the Special Project Items No.2 in National Long-Term Technology Development Plan,China(No.2009ZX02308)the Natural Science Foundation of Hebei Province,China(No.E2014202147)
文摘To strengthen the device performance with the pattern wafer by enhancing the Cu polishing rate and improve the surface roughness with the Cu lines, a new weakly alkaline chelating agent with a barrier slurry is developed to meet the process demand of the advanced barrier chemical mechanical planarization（CMP）. This new chelating agent has a stronger chelating ability and a lower p H value than the previous generation-FA/O I chelating agent researched before. Without an unstable oxidant agent added in the polishing slurry, it is difficult to enhance the copper polishing rate during the barrier CMP. The stronger chelating ability of the new chelating agent could increase the copper polishing rate along with controlling the Cu/Ta/TEOS removal rate selectivity to meet the requirements of the IC fabrication process. Thus it has solved the problem of excessive roughness due to the lower polishing rate, avoiding reducing the device performance with the pattern wafer. The new chelating agent with its lower p H value could make it possible to protect the low-k dielectric under the barrier layer from structurally breaking. The CMP experiment was performed on the 12 inch MIT 854 pattern wafers with the barrier slurry containing the new weakly alkaline chelating agent. By the DOE optimization, the results indicate that as the new chelating agent concentration in the slurry was up to 2.5 m L/L, the copper polishing rate is about 31.082 nm/min.Meanwhile, the wafer surface has a rather low roughness value of 0.693 nm（10×10 μm）, the correction ability with the above slurry is adapted to the next generation barrier CMP and the k value of the low-k dielectric seems to have no k-shift. All the results presented show that the new weakly alkaline chelating agent with its superior performance can be used for the advanced barrier CMP.
基金Project supported by the Major National Science and Technology Special Projects(No.2009ZX02308)Tianjin Natural Science Foundation of China(No.10JCZDJC15500)the Fund Project of Hebei Provincial Department of Education,China(No.2011128)
文摘We propose an alkaline barrier slurry containing guanidine hydrochloride（GH） and hydrogen peroxide.The slurry does not contain any corrosion inhibitors, such as benzotriazole（BTA）. 3-inch samples of tantalum copper and oxide were polished to observe the removal rate. The effect of GH on removal rate selectivity along withhydrogenperoxidewasinvestigatedbycomparingslurrycontainingGHandH2O2withslurrycontainingonly GH. Details about the tantalum polishing mechanism in an alkaline guanidine-based slurry and the electrochemical reactions are discussed. The results show that guanidine hydrochloride can increase the tantalum polishing rate and the selectivity of copper and barrier materials. The variation of the dishing and wire line resistance with the polishing time was measured. The dishing value after a 300 mm pattern wafer polishing suggests that the slurry has an effective performance in topography modification. The result obtained from the copper wire line resistance test reveals that the wire line in the trench has a low copper loss.
