CMP Polishing Composition for Low-LPD Silicon Wafer Smoothing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in the semiconductor industry is to reduce micro defects, known as light point defects (LPDs), while achieving high smoothness of silicon wafers during the chemical mechanical polishing (CMP) process, as existing polishing compositions with water-soluble polymers do not effectively minimize these defects.
Innovation Solution
A polishing composition containing a water-soluble polymer, abrasive, and a basic compound is developed, with a reaction product of polymerization initiator and inhibitor limited to 0.1 ppb or less, which prevents the adsorption of defects on the wafer surface, thereby reducing LPDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a polishing composition containing water-soluble polymer is used, then high smoothness is obtained, but light point defects (LPDs) are generated due to adsorption of reaction product
Solution Approach 1:
The patent applies parameter changes by strictly controlling the concentration of reaction product (polymerization initiator-inhibitor complex) to 0.1 ppb or less. This quantitative parameter control eliminates the harmful adsorption effect while preserving the beneficial smoothing effect of the water-soluble polymer in the polishing composition.
Solution Approach 2:
The patent extracts and removes the harmful reaction product (polymerization initiator-inhibitor complex) from the polishing composition system. By eliminating this specific component through purification processes and strict content control, the patent prevents LPD generation while maintaining the functional benefits of the water-soluble polymer.
2Manufacturing precision
If polishing is performed to reduce micro defects, then surface quality improves, but polishing time increases
Solution Approach 1:
The patent applies preliminary action by pre-controlling the reaction product content to 0.1 ppb or less before the polishing process begins. This preventive measure eliminates the need for extended polishing time to remove defects, as the harmful substances that would require additional processing are already absent from the composition.
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 effectively minimizes LPDs by limiting the reaction product content, resulting in a higher quality polished surface with reduced micro defects, enhancing the smoothness and precision of the CMP process.
Implementation Method 1
a water-soluble polymer, wherein a content of a reaction product of a polymerization initiator and a polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis
Implementation Method 2
A polishing composition containing fine abrasive particles and a basic compound is used in CMP. In the CMP process, mechanical polishing with such an abrasive and chemical polishing with a basic compound proceed simultaneously
Implementation Method 3
chemical polishing with a basic compound proceed simultaneously
Data Source
AI summary
Provided is a polishing composition which contains a water-soluble polymer and is suitable for reducing LPDs. The polishing composition provided in this application includes an abrasive, a water-soluble polymer, and a basic compound. In the polishing composition, the content of a reaction product of a polymerization initiator and a polymerization inhibitor is 0.1 ppb or less of the polishing composition on a weight basis.