Silicon Oxide Recess Etching with Hydrogen Flow Shaping
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Solution Overview
Problem
Existing substrate-processing methods face challenges in controlling the etching shape of films formed in recesses, particularly in achieving uniform etching and preventing excessive etching or voids in high-aspect-ratio recesses.
Innovation Solution
A substrate-processing method involving a plasma generated from a gas mixture of trifluoromethane, oxygen, and hydrogen is used to etch silicon oxide films, with the hydrogen flow rate adjusted to control the etching amount and shape, ensuring gradual reduction from the top to the bottom of the recess, thereby preventing excessive etching and voids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma etching methods are used, then etching can be performed, but the etching shape cannot be precisely controlled and excessive etching or voids occur in high-aspect-ratio recesses
Solution Approach 1:
The patent applies parameter changes by adjusting the hydrogen flow rate during plasma etching to control the etching amount and shape. Specifically, the hydrogen flow rate is increased in stages or maintained at a high level to suppress excessive etching and prevent void formation in high-aspect-ratio recesses, thereby achieving precise control over the etching profile and improving both manufacturing precision and reliability
Solution Approach 2:
The patent employs periodic action by changing the hydrogen flow rate in stages during the etching process. The hydrogen flow rate is adjusted at different time points to control the etching progression, allowing for precise shape control in high-aspect-ratio recesses while maintaining etching uniformity throughout the process
2Shape
If high-aspect-ratio recesses are etched, then fine structures can be formed, but voids and excessive etching occur making filling difficult
Solution Approach 1:
The patent uses parameter changes by controlling the hydrogen flow rate to achieve the desired recess shape with appropriate aspect ratio. The hydrogen flow rate adjustment suppresses excessive etching and prevents void formation, creating a filling-friendly recess geometry that maintains both the required aspect ratio and high manufacturing precision for subsequent filling operations
3Productivity
If etching amount is increased to remove film completely, then film removal is efficient, but excessive etching occurs causing shape control loss
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the hydrogen flow rate during etching to maintain optimal etching conditions. This allows efficient film removal while preventing excessive etching, as the hydrogen flow rate modulation controls the etching speed and profile, ensuring both high productivity and precise shape control are achieved simultaneously
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 precise control of the etching shape and effective filling of high-aspect-ratio recesses with silicon oxide films without voids or seams, improving the productivity and reducing the cost of apparatuses.
Implementation Method 1
generating a plasma using a gas mixture to etch the silicon oxide film with the plasma
Implementation Method 2
etch the silicon oxide film with the plasma
Data Source
AI summary
A substrate-processing method includes a) providing a substrate in which a recess is formed, where the substrate has a surface where a silicon oxide film is exposed, and b) generating a plasma using a gas mixture to etch the silicon oxide film with the plasma, where the gas mixture includes a trifluoromethane gas, an oxygen-containing gas, and a hydrogen-containing gas.