Synergetic effect of chelating agent and nonionic surfactant for benzotriazole removal on post Cu-CMP cleaning

The cleaning of copper interconnects after chemical mechanical planarization (CMP) process is a critical 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.

[1]  Y. Ein‐Eli,et al.  Copper corrosion mitigation by binary inhibitor compositions of potassium sorbate and benzotriazole , 2014 .

[2]  Chenwei Wang,et al.  Non-ionic surfactant on particles removal in post-CMP cleaning , 2015 .

[3]  Dinesh Koli,et al.  Study of the cross contamination effect on post CMP in situ cleaning process , 2015 .

[4]  Yi Hu,et al.  The optimization of FA/O barrier slurry with respect to removal rate selectivity on patterned Cu wafers , 2016 .

[5]  A. West,et al.  Evaluation of post-Cu CMP cleaning of organic residues using microfluidic device , 2008 .

[6]  Yuling Liu,et al.  Effect of chelating agent on benzotriazole removal during post copper chemical mechanical polishing cleaning , 2014 .

[7]  W. Tseng,et al.  Post Cu CMP Cleaning of Polyurethane Pad Debris , 2014 .

[8]  Youn-Jin Oh,et al.  Planarization of Copper Layer for Damascene Interconnection by Electrochemical Polishing in Alkali-Based Solution , 2006 .

[9]  Jun Wang,et al.  Chemical mechanical planarization of copper using transition alumina nanoparticles , 2008 .

[10]  T. Mukherjee,et al.  Study of Pyrazole as Copper Corrosion Inhibitor in Alkaline Post Chemical Mechanical Polishing Cleaning Solution , 2014 .

[11]  S. Cho,et al.  Local Corrosion of the Oxide Passivation Layer during Cu Chemical Mechanical Polishing , 2009 .

[12]  T. Kwon,et al.  Characterization of TMAH based cleaning solution for post Cu-CMP application , 2013 .

[13]  Hyunseop Lee,et al.  Mechanical effect of colloidal silica in copper chemical mechanical planarization , 2009 .

[14]  Y. Ein‐Eli,et al.  Potassium sorbate as an inhibitor in copper chemical mechanical planarization slurries. Part II: Effects of sorbate on chemical mechanical planarization performance , 2010 .

[15]  Liu Yuling,et al.  Defectivity control of aluminum chemical mechanical planarization in replacement metal gate process of MOSFET , 2016 .

[16]  W. Shuai,et al.  Investigation of aluminum gate CMP in a novel alkaline solution , 2016 .

[17]  L. Borucki,et al.  A three-step copper chemical mechanical planarization model including the dissolution effects of a commercial slurry , 2010 .

[18]  D. Roy,et al.  Achievement of high planarization efficiency in CMP of copper at a reduced down pressure , 2009 .

[19]  Zhang Baoguo,et al.  A new kind of chelating agent with low pH value applied in the TSV CMP slurry , 2015 .

[20]  Wei Sun,et al.  Ablation behavior of HfC protective coatings for carbon/carbon composites in an oxyacetylene combustion flame , 2012 .

[21]  S. Yen,et al.  Acetic acid and phosphoric acid adding to improve tantalum chemical mechanical polishing in hydrogen peroxide-based slurry , 2010 .

[22]  David Starosvetsky,et al.  Review on copper chemical–mechanical polishing (CMP) and post-CMP cleaning in ultra large system integrated (ULSI)—An electrochemical perspective , 2007 .

[23]  Jin-Goo Park,et al.  Characterization of non-amine-based post-copper chemical mechanical planarization cleaning solution ☆ , 2014 .

[24]  I. Milošev,et al.  Inhibition of copper corrosion by 1,2,3-benzotriazole: A review , 2010 .

[25]  Soo‐Kil Kim,et al.  Effects of nitrogen atoms of benzotriazole and its derivatives on the properties of electrodeposited Cu films , 2014 .

[26]  G. Ingo,et al.  Investigation of the benzotriazole inhibition mechanism of bronze disease , 2012 .

[27]  Jianbin Luo,et al.  Electrochemical investigation of copper passivation kinetics and its application to low-pressure CMP modeling , 2013 .