Title :
Comparison of novel cleaning solutions with various chelating agents for post-CMP cleaning on poly-Si film
Author :
Pan, Tung Ming ; Lei, Tan Fu ; Ko, Fu Hsiang ; Chao, Tien Sheng ; Chiu, Tzu Huan ; Lee, Ying Hao ; Lu, Chih Peng
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
11/1/2001 12:00:00 AM
Abstract :
In this study, various cleaning solutions containing chelating agents with carboxyl acid group (-COOH), such as ethylenediaminetetraacetic acid, citric acid and oxalic acid, were developed for post-poly-Si CMP cleaning. The chelating agent and tetramethylammonium hydroxide (TMAH) were simultaneously added into 2% ammonium hydroxide alkaline solution to promote the removal efficiency on particles and metallic impurities. The effectiveness of various cleaning recipes and their interaction mechanism with the poly-Si surface were studied. We could explain the surface behavior of various cleaning solutions by the different molecular size and charge of chelating agents. Based on the mechanism, the behavior of surface particle and metallic impurity can be realized. The co-existence of TMAH with citric acid or oxalic acid in the alkaline cleaning solutions can significantly enhance the electrical properties of capacitors
Keywords :
chemical mechanical polishing; elemental semiconductors; impurities; integrated circuit manufacture; rough surfaces; semiconductor technology; semiconductor thin films; silicon; substrates; surface cleaning; NH4OH; NH4OH alkaline solution; Si; alkaline cleaning solutions; carboxyl acid group; chelating agents; citric acid; cleaning recipes; cleaning solutions comparison; ethylenediaminetetraacetic acid; metallic impurities; molecular size; oxalic acid; particle removal; poly-Si surface; polysilicon film; post-CMP cleaning; removal efficiency; surface behavior; tetramethylammonium hydroxide; Chaos; Chemicals; Cleaning; EPROM; Impurities; Planarization; Rough surfaces; Slurries; Surface contamination; Surface roughness;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
