Wafer Backside Cleaning Roller with Abrasive Periphery
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Solution Overview
Problem
The post-chemical mechanical polishing (CMP) process for semiconductor wafers faces challenges in effectively removing slurry residues from the backside periphery region, leading to contamination and potential loss in die yield and device performance.
Innovation Solution
A roller with an abrasive bottom element, made of materials such as abrasive pads, sand papers, or asbestos, is designed to contact the backside of the wafer, allowing for mechanical removal of particles from the periphery region without additional chemical cleaning processes, utilizing its abrasive portion to polish and clean the wafer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional post-CMP cleaning processes are used, then chemical cleaning is performed, but slurry residues remain on the backside periphery region causing contamination
Solution Approach 1:
The roller is divided into distinct functional zones: a polishing pad section for general cleaning and an abrasive section specifically positioned to target the backside periphery region. This segmentation allows different parts of the roller to address different cleaning needs, with the abrasive portion specifically removing slurry residues from the problematic periphery area that conventional processes miss
Solution Approach 2:
The roller incorporates an abrasive portion with different material properties (abrasive materials) localized to the specific area needed for removing slurry residues from the backside periphery. This local quality enhancement targets the harmful slurry residues precisely where they accumulate, without affecting other areas of the wafer
2Reliability
If additional chemical cleaning processes are implemented, then more thorough cleaning is achieved, but process complexity and time increase
Solution Approach 1:
The roller merges multiple cleaning functions into a single component: the polishing pad provides general cleaning while the integrated abrasive portion simultaneously performs mechanical removal of slurry residues from the periphery. This combination eliminates the need for separate additional chemical cleaning processes, reducing both process complexity and time while maintaining cleaning completeness
Solution Approach 2:
The roller serves multiple cleaning functions in one operation: it cleans the general wafer surface through the polishing pad and specifically removes slurry residues from the backside periphery through the abrasive portion. This multi-functionality allows a single device to replace what would otherwise require multiple specialized cleaning steps
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 roller effectively removes particles from the backside periphery of the wafer during rotation, enhancing the post-CMP cleaning process performance by eliminating the need for additional chemical cleaning or bevel CMP processes, thereby preventing contamination and improving yield and device performance.
Implementation Method 1
The abrasive portion of the bottom element is configured to remove particles on the periphery region of the backside of the wafer
Data Source
AI summary
The present disclosure provides a roller for cleaning a backside of a wafer. The backside of the wafer has a central region and a periphery region surrounding the central region. The roller includes an upper element, a bottom element, and an axis element for connecting the upper element and the bottom element. The upper element of the roller is configured to contact with a frontside of the wafer. The bottom element is configured to contact with the backside of the wafer and remove particles from the periphery region of the backside of the wafer. The bottom element is made of materials selected from a group comprising abrasive pads, sand papers, and asbestos.