Patterned Polishing Sheet Structure for Uniform CMP Pore Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CMP processes face limitations in forming fine and uniform pore structures in polishing pads, leading to impaired polishing performance and shortened pad lifespan, which restricts the production of high-quality semiconductor devices.
Innovation Solution
A process involving the preparation of a polymer sheet with a patterned surface, wound into a cylindrical shape, and cut perpendicular to the center line, allowing for controlled size and distribution of patterns, enabling adjustable physical properties and extended pad lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods (solid phase foaming agent, liquid substance, or inert gas) are used to form pores in polishing pad, then pores can be formed, but the pore structure becomes non-uniform with poor size distribution control
Solution Approach 1:
The patent uses a porous polymer sheet as the base material for the polishing pad, which inherently provides a uniform pore structure. This eliminates the need for complex foaming processes while maintaining excellent pore uniformity and size distribution control.
Solution Approach 2:
The invention combines a porous polymer sheet with a polishing layer to create a composite polishing pad structure. This composite approach leverages the uniform pore structure of the porous material while adding the necessary polishing functionality, achieving both manufacturing ease and precision.
2Reliability
If polishing pad surface is conditioned using diamond disk to restore surface state, then surface deterioration can be addressed, but the process is time-consuming and reduces productivity
Solution Approach 1:
The polishing pad is designed with a self-restoring surface structure from the outset, where the porous polymer sheet maintains its pore structure integrity during use. This preliminary design eliminates the need for frequent conditioning interventions, maintaining both reliability and productivity.
Solution Approach 2:
The polishing pad structure is designed to automatically maintain its surface state through its inherent porous structure that resists deformation and contamination accumulation, reducing the need for external conditioning processes and thereby maintaining high productivity.
3Duration of action of stationary object
If polishing pad pores are deformed by compressive force and shear force during CMP process, then pore structure deteriorates, but this leads to shortened pad lifespan
Solution Approach 1:
The use of a porous polymer sheet with specifically engineered pore structure provides inherent resistance to compressive and shear forces. The porous structure is designed to maintain its geometry under CMP process loads, preventing deformation and extending pad lifespan while maintaining composition stability.
4Manufacturing precision
If patterned polymer sheet is wound and cut to form polishing sheets, then fine and uniform patterns can be controlled at desired locations, but the process complexity increases
Solution Approach 1:
The polishing pad is divided into distinct functional layers: a porous polymer sheet base layer and a polishing layer. This segmentation allows independent optimization of each layer's properties while simplifying the overall manufacturing process through standardized assembly procedures.
Solution Approach 2:
The patent controls pattern characteristics by adjusting parameters of the porous polymer sheet such as pore size, porosity, and distribution during the sheet manufacturing process, rather than through complex post-processing of the polishing pad itself. This approach maintains manufacturing precision while reducing process complexity.
Data Source
AI summary
The embodiments provide a process for preparing a polishing sheet, a polishing pad using the same, and a process for preparing a semiconductor device using the same. The process for preparing a polishing sheet comprises forming a pattern on the surface of a polymer sheet and winding the patterned polymer sheet to form a wound roll in a cylindrical shape. Thus, there are great advantages in that it is possible to control the size and distribution ratio of a fine and uniform pattern at a desired location in an economical and efficient way and to freely design the type, size, structure, physical properties, and the like of the polishing sheet according to the purpose, whereby the application field can be expanded, and a bulk structure can be manufactured.