Bevel Polymer Removal via Mechanical Brushing and Thermal Peeling
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Solution Overview
Problem
Existing methods fail to reliably remove multi-layered bevel/backside polymers from semiconductor wafers, which are formed during plasma etching and can cause defects, contamination, and wafer damage due to their complex organic and inorganic layers.
Innovation Solution
A method and device that mechanically destroy and thermally peel off multi-layered bevel/backside polymers using a combination of brushing and localized heating, specifically employing a brushing mechanism and a heating mechanism that applies temperatures between 200° C to 300° C to effectively remove both organic and inorganic layers without using wet chemicals or sputtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single-step cleaning methods are used, then the process is simple, but multi-layered bevel/backside polymers cannot be reliably removed
Solution Approach 1:
The cleaning process is divided into two distinct steps: a first step for mechanical destruction of the polymer layers, and a second step for heating residues. This segmentation allows each step to target specific aspects of the multi-layered polymer structure, achieving reliable removal while maintaining manageable process complexity through systematic decomposition of the cleaning task.
Solution Approach 2:
The invention changes the physical parameters of the cleaning process by applying controlled heating in the second step after mechanical destruction in the first step. This parameter change (from mechanical to thermal) enables effective removal of different types of polymer residues that cannot be removed by a single method, thereby improving removal reliability.
2Reliability
If heating temperature is increased to remove polymer residues, then removal effectiveness improves, but wafer damage risk increases
Solution Approach 1:
The first step of mechanical destruction is performed before heating in the second step. This preliminary action reduces the polymer layers to smaller residues, which then require lower heating temperatures and shorter heating times for complete removal. This sequence prevents direct high-temperature exposure of the wafer to bulky polymer masses, thereby reducing wafer damage risk while maintaining removal effectiveness.
Solution Approach 2:
The cleaning process uses periodic action with two distinct phases: mechanical destruction followed by heating. This periodic approach allows the system to alternate between mechanical and thermal methods, preventing the need for continuously high temperatures that would damage the wafer, while still achieving complete polymer removal through the combined effect of both phases.
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
This approach allows for the reliable removal of bevel/backside polymers, preventing defects and contamination, maintaining wafer integrity, and being applicable in the back-end of line wafer processing without damaging the semiconductor wafers.
Implementation Method 1
a second step of heating residues of the multi-layered bevel/backside polymers mechanically destroyed
Data Source
AI summary
A bevel/backside polymer removing method removes multi-layered bevel/backside polymers adhering to a bevel surface and a backside of a target substrate. The multi-layered bevel/backside polymers include an inorganic layer and an organic layer. The bevel/backside polymer removing method includes mechanically destroying the multi-layered bevel/backside polymers and heating residues of the multi-layered bevel/backside polymers mechanically destroyed.