Post-CMP Cleaning Composition for Silicon Residue Removal
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Solution Overview
Problem
Existing cleaning compositions are inadequate in removing residues from semiconductor substrates after chemical mechanical polishing (CMP), particularly those containing silicon-containing materials, leading to adverse effects on electrical characteristics and device reliability.
Innovation Solution
A post-CMP cleaning composition comprising a nitrogen-containing nonionic polymer and an anionic polymer with a sulfonic acid group, where the nitrogen-containing nonionic polymer content is between 0.1% to 1.0% by mass and the pH is less than 7.0, effectively removes residues by adsorption and desorption mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning compositions are used after CMP, then the cleaning process is simple, but residues remain on the semiconductor substrate surface
Solution Approach 1:
The patent changes the chemical parameters of the cleaning composition by specifying a pH range of 2.0-6.0 and particular polymer combinations (nitrogen-containing nonionic polymer at 0.01-1.0% and anionic polymer with sulfonic acid group at 0.01-0.5%). These parameter changes enable effective removal of residues including silicon-containing materials and organic substances from the semiconductor substrate surface after CMP, resolving the contradiction between maintaining simple cleaning processes and achieving high surface cleanliness
Solution Approach 2:
The patent employs a composite cleaning system combining multiple polymer types (nitrogen-containing nonionic polymer and anionic polymer with sulfonic acid group) in specific ratios. This composite approach leverages the synergistic effects of different polymers to remove various types of residues (abrasive particles, metal particles, organic substances) simultaneously, thereby improving surface cleanliness without complicating the cleaning process
2Reliability
If existing cleaning compositions are used, then the composition formulation is simple, but electrical characteristics of the semiconductor are adversely affected
Solution Approach 1:
The patent specifies precise parameter ranges for the cleaning composition including pH (2.0-6.0), nitrogen-containing nonionic polymer content (0.01-1.0%), and anionic polymer content (0.01-0.5%). These controlled parameter changes ensure effective residue removal that protects electrical characteristics without requiring overly complex formulation procedures
Solution Approach 2:
The patent references existing cleaning composition structures (as seen in JP 2020-167237A) but modifies them by incorporating specific polymer combinations and pH ranges. This approach adapts proven cleaning concepts while making targeted improvements to protect electrical characteristics, avoiding the need to develop entirely new complex formulations
3Manufacturing precision
If polymers with higher content are used to improve cleaning effectiveness, then residue removal improves, but the composition becomes less stable and may leave new residues
Solution Approach 1:
The patent identifies optimal concentration ranges for each polymer component: nitrogen-containing nonionic polymer at 0.01-1.0% and anionic polymer with sulfonic acid group at 0.01-0.5%, with pH controlled at 2.0-6.0. These parameter optimizations ensure sufficient residue removal effectiveness while preventing composition instability and new residue formation that would occur at higher concentrations
Solution Approach 2:
The patent assigns different functional roles to different polymer components at different concentrations. The nitrogen-containing nonionic polymer primarily targets silicon-containing residues, while the anionic polymer with sulfonic acid group addresses organic residues. This localized functional assignment within the composite system achieves comprehensive residue removal without requiring excessive polymer content, thereby maintaining composition stability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition efficiently removes abrasive and organic residues from semiconductor substrates, particularly those with silicon nitride, silicon oxide, and polysilicon films, thereby improving the electrical characteristics and reliability of the devices.
Implementation Method 1
effectively removes residues by adsorption and desorption mechanisms
Data Source
AI summary
An object of the present invention is to provide a means capable of sufficiently removing residues remaining on the surface of a polished object to be polished containing a silicon-containing material.The present invention is a post-chemical mechanical polishing cleaning composition containing a nitrogen-containing nonionic polymer and an anionic polymer containing a sulfonic acid group, in which the content of the nitrogen-containing nonionic polymer is more than 0.1% by mass and less than 1.0% by mass with respect to the entire post-chemical mechanical polishing cleaning composition, and the pH is less than 7.0.