Benzotriazole(BTA), an anticorrosion agent of slurry, is the main organic pollutant remaining after CMP of multilayer copper wiring, and also the main removal object of post CMP cleaning. The adsorption of BTA onto th...Benzotriazole(BTA), an anticorrosion agent of slurry, is the main organic pollutant remaining after CMP of multilayer copper wiring, and also the main removal object of post CMP cleaning. The adsorption of BTA onto the copper could form a dense Cu-BTA film, which makes the copper surface strongly passivated. According to this characteristic, quantitative analysis of BTA residue after cleaning is carried out by contact angle measurement and electrochemical measurement in this paper. A scanning electron microscope(SEM) with EDX was used to observe and analyze the BTA shape and elements. The efficiencies of organic alkali and inorganic alkali on the removal of BTA were studied. The corresponding reaction mechanism was also analyzed. The results show that the adsorption structure of Cu(I)-BTA cannot be destroyed in an alkaline environment with a pH less than 10; the effect of BTA removal by inorganic alkali is worse than that of the organic amine alkali with the coordination structure under the same pH environment; the FA/O Ⅱ chelating agent with the fraction of 200 ppm can effectively remove BTA residue on the surface of copper wafer.展开更多
Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dime...Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dimensions of less than 32 nm,a comprehensive understanding of the physical,chemical,and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential.During the CMP process,some issues such as film delamination,scratching,dishing,erosion,and corrosion can generate defects which can adversely affect the yield and reliability.In this article,an overview of material removal mechanism of CMP process,investigation of the scratch formation behavior based on polishing process conditions and consumables,scratch formation mechanism and the scratch inspection tools were extensively reviewed.The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed.The current research trends in the scratch formation,based on modeling perspective were also discussed.展开更多
The effect of a non-ionic surfactant on particles removal in post-CMP cleaning was investigated. By changing the concentration of the non-ionic surfactant, a series of experiments were performed on the 12 inch Cu patt...The effect of a non-ionic surfactant on particles removal in post-CMP cleaning was investigated. By changing the concentration of the non-ionic surfactant, a series of experiments were performed on the 12 inch Cu pattern wafers in order to determine the best cleaning results. Then the effect of the surfactant on the reduction of defects and the removal of particles was discussed in this paper. What is more, the negative effect of a non-ionic surfactant was also discussed. Based on the experiment results, it is concluded that the non-ionic surfactant could cause good and ill effects at different concentrations in the post-CMP cleaning process. This understanding will serve as a guide to how much surfactant should be added in order to achieve excellent cleaning performance.展开更多
The cleaning of copper interconnects after chemical mechanical planarization （CMP） process is a crit- ical step in integrated circuits （ICs） fabrication. Benzotriazole （BTA）, which is used as corrosion inhibitor...The cleaning of copper interconnects after chemical mechanical planarization （CMP） process is a crit- ical step in integrated circuits （ICs） fabrication. Benzotriazole （BTA）, which is used as corrosion inhibitor in the copper CMP slurry, is the primary source for the formation of organic contaminants. The presence of BTA can degrade the electrical properties and reliability of ICs which needs to be removed by using an effective cleaning solution. In this paper, an alkaline cleaning solution was proposed. The alkaline cleaning solution studied in this work consists of a chelating agent and a nonionic surfactant. The removal of BTA was characterized by contact angle measurements and potentiodynamic polarization studies. The cleaning properties of the proposed cleaning solution on a 300 mm copper patterned wafer were also quantified, total defect counts after cleaning was studied, scanning electron microscopy （SEM） review was used to identify types of BTA to confirm the ability of cleaning solution for BTA removal. All the results reveal that the chelating agent can effectively remove the BTA residual, nonionic surfactant can further improve the performance.展开更多
基金Project supported by the Major National Science and Technology Special Projects(No.2016ZX02301003-004-007)the Natural Science Foundation,China(No.61704046)the Hebei Natural Science Foundation Project(No.F2018202174)
文摘Benzotriazole(BTA), an anticorrosion agent of slurry, is the main organic pollutant remaining after CMP of multilayer copper wiring, and also the main removal object of post CMP cleaning. The adsorption of BTA onto the copper could form a dense Cu-BTA film, which makes the copper surface strongly passivated. According to this characteristic, quantitative analysis of BTA residue after cleaning is carried out by contact angle measurement and electrochemical measurement in this paper. A scanning electron microscope(SEM) with EDX was used to observe and analyze the BTA shape and elements. The efficiencies of organic alkali and inorganic alkali on the removal of BTA were studied. The corresponding reaction mechanism was also analyzed. The results show that the adsorption structure of Cu(I)-BTA cannot be destroyed in an alkaline environment with a pH less than 10; the effect of BTA removal by inorganic alkali is worse than that of the organic amine alkali with the coordination structure under the same pH environment; the FA/O Ⅱ chelating agent with the fraction of 200 ppm can effectively remove BTA residue on the surface of copper wafer.
文摘Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dimensions of less than 32 nm,a comprehensive understanding of the physical,chemical,and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential.During the CMP process,some issues such as film delamination,scratching,dishing,erosion,and corrosion can generate defects which can adversely affect the yield and reliability.In this article,an overview of material removal mechanism of CMP process,investigation of the scratch formation behavior based on polishing process conditions and consumables,scratch formation mechanism and the scratch inspection tools were extensively reviewed.The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed.The current research trends in the scratch formation,based on modeling perspective were also discussed.
基金Project supported by the Specific Project Items No.2 in National Long-Term Technology Development Plan(No.2009zx02308-003)
文摘The effect of a non-ionic surfactant on particles removal in post-CMP cleaning was investigated. By changing the concentration of the non-ionic surfactant, a series of experiments were performed on the 12 inch Cu pattern wafers in order to determine the best cleaning results. Then the effect of the surfactant on the reduction of defects and the removal of particles was discussed in this paper. What is more, the negative effect of a non-ionic surfactant was also discussed. Based on the experiment results, it is concluded that the non-ionic surfactant could cause good and ill effects at different concentrations in the post-CMP cleaning process. This understanding will serve as a guide to how much surfactant should be added in order to achieve excellent cleaning performance.
基金supported by the Natural Science Foundation of Hebei Province,China(No.F2015202267)the Scientific Innovation Grant for Excellent Young Scientists of Hebei University of Technology(No.2015007)
文摘The cleaning of copper interconnects after chemical mechanical planarization （CMP） process is a crit- ical step in integrated circuits （ICs） fabrication. Benzotriazole （BTA）, which is used as corrosion inhibitor in the copper CMP slurry, is the primary source for the formation of organic contaminants. The presence of BTA can degrade the electrical properties and reliability of ICs which needs to be removed by using an effective cleaning solution. In this paper, an alkaline cleaning solution was proposed. The alkaline cleaning solution studied in this work consists of a chelating agent and a nonionic surfactant. The removal of BTA was characterized by contact angle measurements and potentiodynamic polarization studies. The cleaning properties of the proposed cleaning solution on a 300 mm copper patterned wafer were also quantified, total defect counts after cleaning was studied, scanning electron microscopy （SEM） review was used to identify types of BTA to confirm the ability of cleaning solution for BTA removal. All the results reveal that the chelating agent can effectively remove the BTA residual, nonionic surfactant can further improve the performance.
