Cerium Oxide CMP Slurry With High Ce3+ for STI Selectivity
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Solution Overview
Problem
Conventional cerium oxide slurries face challenges in achieving high oxide film removal rates with small particle sizes, leading to increased polishing scratches and reduced mechanical action, while also failing to optimize the Ce3+ to Ce4+ ratio and additive components for improved polishing efficiency and selectivity.
Innovation Solution
A chemical mechanical polishing (CMP) slurry composition comprising cerium oxide particles with a high Ce3+ content on the surface, combined with a cationic polymer and passivation regulator, to enhance oxide film polishing rate and minimize polysilicon film polishing, maintaining a transparent and monodispersed state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the average particle diameter of cerium oxide particles is reduced to minimize polishing scratches, then polishing scratch occurrence is reduced, but mechanical action is reduced and polishing rate decreases
Solution Approach 1:
The patent changes the chemical composition parameters of cerium oxide particles by controlling the Ce3+ to Ce4+ ratio through specific synthesis conditions (pH control during precipitation). This chemical parameter change enables small particles (5-50 nm) to achieve high oxide film removal rates without requiring larger particle sizes, thus resolving the contradiction between small particle size and polishing rate
Solution Approach 2:
The patent creates a composite slurry system combining cerium oxide particles with specific additives (anionic surfactants, chelating agents) to enhance the polishing performance of fine particles. The additive components work synergistically with small cerium oxide particles to maintain high polishing rates while minimizing scratches
2Object-affected harmful factors
If the average particle diameter of cerium oxide particles is reduced to minimize polishing scratches, then polishing scratch occurrence is reduced, but mechanical action is reduced
Solution Approach 1:
The patent replaces mechanical polishing action with chemical polishing action by increasing the Ce3+ content on the cerium oxide particle surface. The chemical reaction between Ce3+ and oxide films provides the primary polishing mechanism, eliminating the need for mechanical force from larger particles, thus resolving the contradiction between small particle size and mechanical action
3Object-affected harmful factors
If conventional cerium oxide slurries are used with small particle sizes, then polishing scratches are reduced, but oxide film removal rate is insufficient
Solution Approach 1:
The patent optimizes the Ce3+ to Ce4+ ratio parameter by controlling precipitation pH during synthesis. This chemical composition optimization enables small particles (5-50 nm) to achieve high oxide film removal rates through enhanced chemical reactivity, resolving the contradiction between particle size and removal rate
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 achieves a high oxide film removal rate with minimal surface defects, optimizing polishing rates and selectivity, and reducing scratches, thereby improving semiconductor device manufacturing precision.
Implementation Method 1
the proportion of Ce3+ on the surface of cerium oxide increases to have a high oxide film removal rate
Implementation Method 2
through an appropriate additive component, to reduce polysilicon film polishing rate for passivation
Data Source
AI summary
Cerium oxide particles for chemical-mechanical polishing and a slurry composition for chemical-mechanical polishing including same are described. By means of a combination of cerium oxide particles with a cationic polymer and a passivation regulator, it is possible to provide a slurry composition for chemical-mechanical polishing which can improve oxide film polishing speed while maximizing a silicon oxide film/polysilicon film selection ratio during a STI polishing process, and a method for manufacturing a semiconductor device using same.