Plasma Edge Cleaning via Segmented Dielectric Electrodes
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Solution Overview
Problem
In substrate manufacturing, etch byproducts accumulate on the bevel edge and backside of substrates, leading to particle contamination and yield issues due to the inability to effectively remove polymer layers and deposited films during processing.
Innovation Solution
A plasma etch processing chamber with top and bottom edge electrodes and a remote plasma source is used to generate a cleaning plasma, which is confined by dielectric rings to clean the bevel edge and backside of substrates, and a cover plate mechanism to protect the main substrate surface during cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma etching is performed on substrate, then material removal and deposition are achieved, but etch byproducts accumulate on bevel edge and backside surfaces
Solution Approach 1:
The patent applies oxygen plasma treatment to convert the harmful polymer byproducts into volatile compounds that can be removed. The oxygen plasma reacts with the carbon-containing polymer deposits, oxidizing them into CO and CO2 gases that desorb from the surface, thereby converting the harmful accumulation into a removable gaseous state
Solution Approach 2:
The patent segments the plasma treatment into two distinct phases: first performing the etching process with fluorocarbon-based plasma to remove material and form patterns, then performing a separate oxygen plasma cleaning step to remove byproducts. This segmentation allows each process to be optimized independently without interference
2Reliability
If polymer layers are deposited on bevel edge during etching, then etch byproducts accumulate, but these layers eventually weaken and peel off causing particle contamination
Solution Approach 1:
The patent performs oxygen plasma treatment as a preliminary action after etching to remove polymer deposits before they can accumulate and peel off. By proactively cleaning the bevel edge and backside surfaces immediately after etching, the system prevents the formation of thick polymer layers that would eventually weaken and contaminate subsequent substrates
Solution Approach 2:
The patent implements a feedback mechanism where the presence of polymer byproducts on bevel edges and backside surfaces triggers an oxygen plasma cleaning step. The system monitors the etching process and automatically initiates the cleaning phase to maintain surface cleanliness and prevent particle generation
3Ease of manufacture
If substrate backside is not exposed to etching plasma, then byproduct polymer layer accumulates on backside, but this accumulation is not removed during subsequent etch processing
Solution Approach 1:
The patent uses oxygen plasma as an intermediary cleaning mechanism that can access and clean the substrate backside without requiring complex mechanical intervention. The plasma species diffuse through the chamber and deposit on the backside surface, where they react with and remove polymer accumulations that would otherwise be inaccessible during normal etching operations
4Duration of action of stationary object
If chamber interior accumulates etch byproduct polymers, then byproducts accumulation and chamber particle issues occur, but periodic removal is required
Solution Approach 1:
The patent implements continuous chamber cleaning through oxygen plasma treatment that maintains the chamber interior free of polymer accumulations throughout extended operational periods. Rather than periodic maintenance, the system continuously activates oxygen plasma to prevent polymer deposition on chamber walls, extending the duration between maintenance cycles
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 solution effectively reduces the accumulation of polymer byproducts and deposited films, enhancing process yield by ensuring thorough removal of contaminants from the substrate edges and chamber interior.
Implementation Method 1
An appropriate set of plasma gases is then introduced into the chamber and a plasma is generated to etch exposed areas of the substrate
Implementation Method 2
The substrate is then processed in a series of steps in which materials are selectively removed (or etched) and deposited
Implementation Method 3
a plasma is generated to etch exposed areas of the substrate... a cleaning plasma, which is confined by dielectric rings to clean the bevel edge and backside of substrates
Data Source
AI summary
Improved mechanisms of removal of etch byproducts, dielectric films and metal films near the substrate bevel edge, and etch byproducts on substrate backside and chamber interior is provided to avoid the accumulation of polymer byproduct and deposited films and to improve process yield. An exemplary plasma etch processing chamber configured to clean a bevel edge of a substrate is provided. The chamber includes a bottom edge electrode surrounding a substrate support in the plasma processing chamber, wherein the substrate support is configured to receive the substrate and the bottom edge electrode and the substrate support are electrically isolated from each other by a bottom dielectric ring. The chamber also includes a top edge electrode surrounding a gas distribution plate opposing the substrate support, wherein the top edge electrode and the gas distribution plate are electrically isolated from each other by a top dielectric ring, and the top edge electrode and the bottom edge electrode are configured to generate a cleaning plasma to clean the bevel edge of the substrate.