CMP Polishing Composition for High Oxide Removal Without Scratching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current chemical mechanical polishing (CMP) processes face challenges in achieving high removal rates for silicon oxide (TEOS), tantalum (Ta), and copper (Cu) while maintaining stability and avoiding surface scratching.
Innovation Solution
A polishing composition comprising a silica abrasive with specific particle size ranges, an inorganic base, a zwitterion silicon oxide removal rate controller, and a peroxide oxidizer, which collectively enhance the removal rates of TEOS, Ta, and Cu while ensuring high stability and preventing surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP compositions are used to remove silicon oxide, then removal rate is achieved, but stability is compromised and surface scratching occurs
Solution Approach 1:
The patent modifies the chemical composition parameters by introducing a zwitterionic silicon oxide removal rate controller with specific pKa characteristics (pKa between 7-11), combining it with peroxide oxidizer and silica abrasive in controlled concentrations. This parameter optimization enables high silicon oxide removal rates while maintaining composition stability and preventing surface scratching during CMP processing.
Solution Approach 2:
The invention creates a composite polishing composition integrating multiple functional components: silica abrasive particles, peroxide oxidizer, zwitterionic removal rate controller, and buffer agents. This composite formulation synergistically combines mechanical abrasion with chemical oxidation, achieving enhanced silicon oxide removal while maintaining stability and surface integrity.
2Productivity
If high removal rates for TEOS, Ta, and Cu are achieved, then polishing efficiency improves, but surface scratching increases
Solution Approach 1:
The patent optimizes chemical parameters by controlling pH buffer ranges (using borate, phosphate, or silicate buffers) and maintaining specific concentrations of peroxide and zwitterionic additives. These parameter controls enable aggressive material removal while regulating the chemical-mechanical interaction to prevent surface scratching during high-speed polishing of TEOS, Ta, and Cu layers.
Solution Approach 2:
The zwitterionic silicon oxide removal rate controller acts as a mediator between the abrasive particles and the substrate surface. It modulates the chemical reaction intensity and abrasive interaction, enabling high removal rates while preventing direct mechanical damage that causes scratching. The peroxide oxidizer also serves as an intermediary, chemically softening the silicon oxide surface before abrasive contact.
3Productivity
If silicon oxide removal rate is increased, then polishing efficiency improves, but composition stability deteriorates
Solution Approach 1:
The patent carefully balances chemical parameters by selecting zwitterionic compounds with specific pKa values (7-11) that provide effective silicon oxide removal while maintaining pH stability. Buffer agents (borate, phosphate, or silicate) are incorporated to stabilize the composition pH during storage and use, preventing premature reaction or degradation while enabling high removal rates during polishing.
Solution Approach 2:
The peroxide oxidizer is used at controlled concentrations to provide fresh oxidative capability during polishing without requiring long-term compositional stability. The peroxide acts as a consumable reactive component that is replenished during the polishing process, allowing high silicon oxide removal rates without compromising the overall composition stability during storage.
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 proposed composition achieves increased removal rates for silicon oxide, tantalum, and copper, along with high stability and reduced risk of surface scratching, thereby improving the efficiency and quality of the CMP process.
Implementation Method 1
CMP involves applying a polishing composition to the surface of the substrate or a polishing pad that polishes the substrate. This process achieves both the removal of unwanted material and planarization of the surface of the substrate.
Implementation Method 2
CMP is a process in which material is removed from the surface of a substrate (such as a semiconductor wafer), and the surface is polished (planarized) by coupling a physical process, such as abrasion, with a chemical process, such as oxidation or chelation.
Implementation Method 3
the silicon oxide removal rate controller being a zwitterion
Implementation Method 4
the base compound being an inorganic base
Data Source
AI summary
The present disclosure relates to a polishing compositions that increase a silicon oxide removal rate without impairing the stability of an abrasive. The present disclosure relates to a polishing composition comprising an abrasive, a base compound, a silicon oxide removal rate controller, and an oxidizer, wherein the abrasive is a silica abrasive with a primary particle size ranging from about 30 nm to about 70 nm and a secondary particle size ranging from about 50 nm to about 130 nm; the base compound is an inorganic base; the silicon oxide removal rate controller is a zwitterion; and the oxidizer is a peroxide.