Bevel Edge Etching Gas Modulation for Plasma Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The edge exclusion zone in substrate processing, where no dies are present near the substrate edge, leads to accumulation and flaking of deposited films and etch byproducts, reducing usable area and impacting device yield.
Innovation Solution
A plasma etching processing chamber with center and edge gas feeds and tuning gases is used to selectively control the etching process, confining the plasma treatment and adjusting the etching profile to remove unwanted deposits near the bevel edge, thereby expanding the usable area and reducing the edge exclusion zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional plasma etching is used without edge gas feeds, then the etching process is simple and easy to control, but deposits accumulate on the bevel edge and flake off, reducing device yield
Solution Approach 1:
The gas delivery system is segmented into center gas feeds and edge gas feeds, allowing independent control of plasma distribution in different regions. The edge gas feeds are specifically positioned to target the bevel edge area where deposits accumulate, enabling localized cleaning without affecting the entire substrate
Solution Approach 2:
Different gas flows are applied to different regions: center gas feeds maintain the main etching process while edge gas feeds specifically address the bevel edge deposition problem. This local differentiation allows the edge exclusion zone to be minimized without compromising overall process stability
2Area of stationary object
If the edge exclusion zone is large, then deposits have space to accumulate without affecting dies, but the usable substrate area is reduced
Solution Approach 1:
The edge gas feeds are activated during the etching process to prevent deposit accumulation before it can flake off and contaminate dies. By continuously removing deposits at the bevel edge throughout processing, the system maintains a clean edge region that can be safely reduced to a minimal exclusion zone
Solution Approach 2:
The edge gas feeds, which create additional plasma activity at the bevel edge, are used to convert the harmful deposit accumulation into beneficial continuous cleaning. The same region where deposits form becomes the target of active removal, transforming the problem area into a controlled cleaning zone
3Manufacturing precision
If tuning gases are added to control etching profile, then etching precision is improved, but process complexity increases
Solution Approach 1:
Tuning gases are introduced to modify plasma chemistry and control the etching profile at the bevel edge. By adjusting gas composition and flow rates, the system achieves precise control over etch rate and anisotropy, enabling the edge exclusion zone to be minimized while maintaining manufacturing precision
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 effectively removes unwanted deposits and extends the usable substrate area closer to the edge, improving process yield by confining the plasma treatment and adjusting the etching profile to minimize flaking and enhance device performance.
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 top edge electrode and the bottom edge electrode are configured to generate an etching plasma near the bevel edge to remove the thin film on the bevel edge of the substrate
Implementation Method 3
A plasma etching processing chamber with center and edge gas feeds and tuning gases is used to selectively control the etching process
Implementation Method 4
the top edge electrode and the bottom edge electrode are configured to generate an etching plasma near the bevel edge
Data Source
AI summary
The various embodiments provide apparatus and methods of removal of unwanted deposits near the bevel edge of substrates to improve process yield. The embodiments provide apparatus and methods with center and edge gas feeds as additional process knobs for selecting a most suitable bevel edge etching processes to push the edge exclusion zone further outward towards the edge of substrates. Further the embodiments provide apparatus and methods with tuning gas(es) to change the etching profile at the bevel edge and using a combination of center and edge gas feeds to flow process and tuning gases into the chamber. Both the usage of tuning gas and location of gas feed(s) affect the etching characteristics at bevel edge. Total gas flow, gap distance between the gas delivery plate and substrate surface, pressure, and types of process gas(es) are also found to affect bevel edge etching profiles.