We have proposed a TSV(through-silicon-via) alkaline barrier slurry without any inhibitors for barrier CMP(chemical mechanical planarization) and investigated its CMP performance. The characteristics of removal rate and selectivity of Ti/SiO2/Cu were investigated under the same process conditions. The results obtained from6.2 mm copper,titanium andsilica showthat copperhasalowremovalrate during barrier CMP byusingthisslurry,and Ti and SiO2 have high removal rate selectivity to Cu. Thus it may be helpful to modify the dishing. The TSV wafer results reveal that the alkaline barrier slurry has an obvious effect on surface topography correction,and can be applied in TSV barrier CMP.
This work investigates the static corrosion and removal rates of copper as functions of H2O2 and FA/OIIconcentration,and uses DC electrochemical measurements such as open circuit potential(OCP),Tafel analysis,as well as cyclic voltammetry(CV) to study H2O2 and FA/OIIdependent surface reactions of Cu coupon electrode in alkaline slurry without an inhibitor. An atomic force microscopy(AFM) technique is also used to measure the surface roughness and surface morphology of copper in static corrosion and polishing conditions. It is shown that 0.5 vol.% H2O2 should be the primary choice to achieve high material removal rate. The electrochemical results reveal that the addition of FA/O II can dissolve partial oxide film to accelerate the electrochemical anodic reactions and make the oxide layer porous,so that the structurally weak oxide film can be easily removed by mechanical abrasion. The variation of surface roughness and morphology of copper under static conditions is consistent with and provides further support for the reaction mechanisms proposed in the context of DC electrochemicalmeasurements.Inaddition,inthepresenceofH2O2,3vol.%FA/OIImaybesignificantlyeffectivefroma surfaceroughnessperspectivetoobtainarelativelyflatcoppersurfaceinchemicalmechanicalplanarization(CMP)process.
The mechanism of the FA/O chelating agent in the process of chemical mechanical polishing(CMP) is introduced. CMP is carried on a 300 mm copper film. The higher polishing rate and lower surface roughness are acquired due to the action of an FA/O chelating agent with an extremely strong chelating ability under the condition of low pressure and low abrasive concentration during the CMP process. According to the results of several kinds of additive interaction curves when the pressure is 13.78 kPa, flow rate is 150 mL/min, and the rotating speed is55/60 rpm, it can be demonstrated that the FA/O chelating agent plays important role during the CMP process.
TSV(through silicon via) is an emerging technology, which can realize micromation compared with the conventional packaging and extend Moore's law. Chemical mechanical polishing(CMP) is one of the most important steps in the process of TSV manufacture, and it is an enabling technology to extend Moore's law in the past two decades. Low pressure, low abrasive and low p H value are the main requirements for copper interconnection.In this paper, the effect of different kinds of TSV slurry with FA/OⅡ or FA/O IV type chelating agent on CMP are studied. All kinds of slurry used in this study are alkaline with no added inhibitors. From the experiment results, it can be seen that the copper removal rate and surface roughness achieved by using the FA/OⅣ type chelating agent with a low p H value is superior to using the FA/OⅡ type chelating agent.
This article introduces the removal technology of CuO particles on the post CMP wafer surface of multi-layered copper. According to the Cu film corrosion curve with different concentrations of H2O2 and the effect curve of time on the growth rate of CuO film, CuO film with the thickness of 220 nm grown on Cu a surface was successfully prepared without the interference of CuCl2 2H2O. Using the static corrosion experiment the type of chelating agent(FA/O II type chelating agent) and the concentration range(10–100 ppm) for CuO removal was determined, and the Cu removal rate was close to zero. The effect of surfactant on the cleaning solution properties was studied, and results indicated that the surfactant has the effect of reducing the surface tension and viscosity of the cleaning solution,and making the cleaning agent more stable.The influence of different concentrations of FA/O I type surfactant and the mixing of FA/O II type chelating agent and FA/O I type surfactant on the CuO removal effect and the film surface state was analyzed. The experimental results indicated that when the concentration of FA/O I type surfactant was 50 ppm, CuO particles were quickly removed, and the surface state was obviously improved. The best removal effect of CuO on the copper wiring film surface was achieved with the cleaning agent ratio of FA/O II type chelating agent 75 ppm and FA/O I type surfactant 50 ppm. Finally, the organic residue on the copper pattern film after cleaning with that cleaning agent was detected, and the results showed that the cleaning used agent did not generate organic residues on the film surface, and effectively removes the organic residue on the wafer.
The effect of a novel alkaline TSV(through-silicon-via) slurry with guanidine hydrochloride(GH) on CMP(chemical mechanical polishing) was investigated.The novel alkaline TSV slurry was free of any inhibitors.During the polishing process,the guanidine hydrochloride serves as an effective surface-complexing agent for TSV CMP applications,the removal rate of barrier(Ti) can be chemically controlled through tuned selectivity with respect to the removal rate of copper and dielectric,which is helpful to modifying the dishing and gaining an excellent topography performance in TSV manufacturing.In this paper,we mainly studied the working mechanism of the components of slurry and the skillful application guanidine hydrochloride in the TSV slurry.
