CMP Composition for SiC and SiN Selective Polishing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current chemical mechanical polishing (CMP) technologies face challenges in achieving high removal rates while maintaining selectivity for silicon carbide (SiC), silicon nitride (SiN), and SiC x N y films without significantly removing other dielectric materials like silicon oxide (SiO2), which is crucial for next-generation semiconductor development.
Innovation Solution
A CMP composition comprising 0.05 weight % to 30 weight % abrasive, 0.025 weight % to 5 weight % of specific chemical additives such as 4-morpholine derivatives, and a liquid carrier, with a pH range of 2 to 8, is used to selectively polish semiconductor substrates, enhancing removal rates and selectivity by altering the chemical additives and pH levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP compositions are used to polish SiC and SiN films, then polishing can be performed, but the removal rate is insufficient and selectivity against SiO2 cannot be maintained
Solution Approach 1:
The patent applies parameter changes by adjusting the pH of the CMP composition to a specific range (2-8) and incorporating chemical additives with pKa values between 1-5. These parameter modifications enable the composition to achieve both high removal rates for SiC/SiN films and maintain selectivity against SiO2, resolving the contradiction between productivity and manufacturing precision
Solution Approach 2:
The patent uses composite materials by combining colloidal silica abrasive particles with specific chemical additives (organic acids or amines) in an aqueous carrier. This composite formulation creates a synergistic effect where the abrasive provides mechanical removal while the chemical additives enhance etching of SiC and SiN selectively, achieving both high removal rate and selectivity
2Productivity
If higher removal rates are achieved for SiC and SiN, then polishing efficiency improves, but selectivity against other dielectric materials deteriorates
Solution Approach 1:
The patent utilizes parameter changes by optimizing the pH range (2-8) and pKa values (1-5) of chemical additives to create a chemical environment that selectively accelerates SiC and SiN removal while leaving other dielectric materials like SiO2 relatively unaffected. This enables high polishing efficiency without sacrificing selectivity
Solution Approach 2:
The chemical additives act as intermediaries that mediate between the abrasive and the substrate materials. These additives selectively interact with SiC and SiN surfaces, enhancing their removal rates through chemical etching while being less reactive toward other dielectric materials, thus maintaining selectivity at high polishing speeds
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 CMP composition effectively enhances removal rates and provides tunable selectivity for SiC, SiN, and SiC x N y films relative to SiO2, maintaining desirable removal rates and selectivity, thereby addressing the challenges of multi-material polishing in semiconductor substrates.
Implementation Method 1
The CMP process accomplishes the polishing (or planarization) by chemically and mechanically interacting with the substrate, that is, concurrent chemical and mechanical abrasion of the surface of the substrate
Implementation Method 2
The CMP process accomplishes the polishing (or planarization) by chemically and mechanically interacting with the substrate, that is, concurrent chemical and mechanical abrasion of the surface of the substrate
Implementation Method 3
wherein the chemical additive is selected from the group consisting of 4-morpholine derivatives... and the pH of the chemical mechanical polishing composition is from 2 to 8
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Chemical-mechanical polishing (CMP) compositions containing chemical additives and methods of using the CMP compositions are disclosed. The CMP composition comprises an abrasive; a chemical additive selected from i) piperazine derivatives, ii) 4-morpholine derivatives, iii) organic amino sulfonic acid derivatives and their salts, iv) substituted amine compounds and their salts, v) bis-amine compounds and their salts and a liquid carrier and having a pH of 2-8. The CMP compositions and the methods provide enhanced removing rate for "SiC" , SiN" and "SiCxNy" films; and tunable removal selectivity for "SiC" with respect to SiO2, "SiN" with respect to SiO2 , "SiC" with respect to "SiN", or "SiCxNy" with respect to SiO2; wherein x ranges from 0.1wt% to 55wt%, y ranges from 0.1 wt % to 32 wt %.