Silicon Grinding Fluid Additives for Flatness and Removal Rate
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in planarizing substrates with irregular topographies, as conventional grinding methods risk excessive material removal and damage, while chemical mechanical polishing (CMP) has low throughput and particle removal rates.
Innovation Solution
A grinding method using a grinding fluid with pH adjusters, viscosity additives, and surfactants, combined with diamond-impregnated polishing pads, to enhance particle removal rates and control substrate flatness during the grinding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional grinding methods are used to planarize substrates with irregular topography, then material removal is achieved, but excessive material removal and surface damage occur
Solution Approach 1:
The patent changes the chemical parameters of the grinding fluid by incorporating pH adjusters (ammonium hydroxide, hydrogen peroxide), viscosity additives (polymer suspensions, colloidal silica), and surfactants. These chemical modifications enable controlled material removal at lower pressures, preventing excessive material removal and surface damage while maintaining productivity
Solution Approach 2:
The enhanced grinding fluid acts as an intermediary between the grinding pad and substrate. The slurry contains abrasive particles suspended in a chemically modified fluid that mediates the material removal process, enabling gentler contact pressures and preventing direct mechanical damage to the substrate surface
2Manufacturing precision
If chemical mechanical polishing (CMP) is used to planarize substrates, then surface flatness is improved, but particle removal rate is low and throughput is limited
Solution Approach 1:
The patent merges the advantages of grinding (high material removal rate) and CMP (surface flatness) by using a grinding pad with abrasive particles combined with chemically modified grinding fluid. This hybrid approach achieves both high throughput and excellent surface flatness by integrating the material removal capability of grinding with the surface quality control of CMP
Solution Approach 2:
The patent modifies the chemical parameters of the grinding fluid to enhance its CMP-like characteristics. By adjusting pH, viscosity, and surfactant content, the fluid achieves better dispersion of abrasive particles and controlled material removal, enabling high particle removal rates while maintaining surface flatness comparable to CMP
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 method enhances substrate removal and control of substrate flatness during the grinding process.
Implementation Method 1
Grinding processes use a hard grinding surface to remove from the substrate surface all materials in substantially an absolute geometrical reference plane
Implementation Method 2
the grinding fluid comprises a pH adjuster, viscosity additives, a surfactant, or combinations thereof
Data Source
AI summary
A method and apparatus for grinding a surface of a substrate is presented. The method includes positioning a substrate proximate a grinding surface using a carrier head, providing a pressure on the substrate to press an unpolished surface of the substrate to the grinding surface, flowing a grinding fluid onto the unpolished surface, the grinding fluid comprising a pH adjuster, viscosity additives, a surfactant, or combinations thereof, and grinding the unpolished surface using the grinding surface to create a polished surface on the substrate.