1. Restricted hydrolysis reaction of Si3N4 via nonionic polymer adsorption in advanced shallow trench isolation chemical mechanical planarization.
- Author
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Bae, Kiho and Lee, Kangchun
- Subjects
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ADSORPTION (Chemistry) , *POLYVINYL alcohol , *TRENCHES , *HYDROGEN bonding , *PARTICLE interactions , *POLYMERS , *HYDROLYSIS - Abstract
The adoption of ultra-fine nanoparticles as an abrasive has garnered notable attention in shallow trench isolation (STI) chemical mechanical planarization (CMP) due to its potential in scratch reduction. However, the poor removal rate, attributed to the physicochemical interaction between abrasive and conventional organic passivation agent, limits the introduction of ultra-fine nanoparticles. Here, a nonionic polymer polyvinyl alcohol (PVA), without particle interaction, is proposed as a novel passivation agent to restrict the hydrolysis reaction of Si 3 N 4 film in the advanced STI CMP process. The selective adsorption of PVA onto the Si 3 N 4 film lowers its removal rate by suppressing the hydrolysis reaction via hydrogen bonding while the removal rate of SiO 2 film remains constant. Moreover, the uniformity of SiO 2 removal is improved due to the enhanced fluidity of slurry, resulting from increased wettability between pad and slurry. As a result, the removal selectivity between both films has been improved to 113.4:1 and the in-wafer-uniformity (IWU) of SiO 2 film is supplemented by 96.8 % simultaneously. [Display omitted] • Polyvinyl alcohol (PVA), a nonionic polymer, was proposed as a passivation agent for Si 3 N 4 film during advanced STI CMP. • PVA adsorption onto the Si 3 N 4 via hydrogen bonding suppresses hydrolysis of Si 3 N 4 , resulting in drastic removal reduction. • The uniformity of SiO 2 removal was improved due to the increase in wettability. • The removal selectivity between SiO 2 and Si 3 N 4 films has been improved to 113.4:1. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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