Plasma Etching Sidewall Protection Against Necking
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Solution Overview
Problem
Conventional plasma etching methods face issues with necking and bowing of holes due to reaction product accumulation, leading to degraded hole shapes, as removing the reaction product during etching can cause sidewall narrowing.
Innovation Solution
A plasma etching method involving a hole forming process, followed by a removing process to clear reaction products, a deposition process to coat the sidewalls with a protective deposit, and an extending process to deepen the hole, with these steps repeated multiple times using CF-based and deposition gases like CHF3 and Ar, to maintain hole shape integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a deposit is deposited on the sidewall to prevent bowing, then hole shape is improved, but the process complexity increases
Solution Approach 1:
The patent merges the etching and deposition processes into a single integrated apparatus and method. Both processes are performed in the same chamber using the same equipment, eliminating the need for separate processing steps and reducing overall system complexity despite the multi-step nature of the process.
Solution Approach 2:
The patent applies universality by designing the processing apparatus to perform multiple functions - both etching and deposition - within a single system. The same chamber and basic equipment structure support both opposing processes, reducing device complexity compared to using separate specialized equipment for each function.
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 method effectively suppresses necking and bowing, improving the shape of the holes by repeatedly depositing a plasma-resistant film on the sidewalls and controlling etching processes to prevent ion collisions, resulting in better hole formation compared to conventional techniques.
Implementation Method 1
performing an etching process of etching the processing target film
Implementation Method 2
a deposit is deposited on a sidewall of the hole
Data Source
AI summary
A plasma etching method includes a first process and a second process. In the first process, a hole is formed in a processing target film formed on a substrate accommodated within a processing chamber by performing an etching process of etching the processing target film. In the second process, a removing process, a deposition process and an extending process are repeatedly performed. In the removing process, a reaction product adhering to an inlet portion of the hole which is formed through the etching process is removed. In the deposition process, a deposit is deposited on a sidewall of the hole from which the reaction product is removed through the removing process. In the extending process, the hole, in which the deposit is deposited on the sidewall thereof through the deposition process, is deeply etched by performing the etching process.