Effect of organic amine alkali and inorganic alkali on benzotriazole removal during post Cu-CMP cleaning

Abstract

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.

Unraveling the Mechanism of Removing NA Contamination by TMAH-Based Cleaning Solution During Post Co-CMP Cleaning

“…Tetramethylammonium hydroxide (TMAH) has been widely used to clean several kinds of surfaces after CMP process. 17,18 It would not generate a quick corrosion on Co surface because it could not form a complex with Co. 19 Hence, complexing agents should be added to obtain better effect of NA removal. 20 Triethylenetetramine (TETA), Ethylene diamine tetra acetic acid (EDTA) and Glycine (Gly) are common complexing agents used in Co or Cu CMP process.…”

Utilizing an α,β-Unsaturated Dicarboxylic Acid for a Defect Initiated Residue Removal During Cu post-Chemical Mechanical Planarization Cleaning

“…17 To reduce the aforementioned defectivity, post-CMP (p-CMP) cleaning methods are used as a critical processing step for contaminant remediation. [18][19][20][21][22]23,24,25 A leading strategy in p-CMP is through the implementation of Polyvinyl alcohol (PVA) brushes coupled with cleaning chemistries to aid in the removal of contamination however, their reliance on shear and compressive forces results in the culmination of secondary defectivity (i.e., scratching, galvanic corrosion, etc.) that are detrimental to the performance of IC devices.…”