Etching Method Using Protective Film Formation
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Solution Overview
Problem
Conventional etching methods face challenges in reducing the opening width of target films without generating etching defects, particularly due to issues with protective film deposition and etching failure during the etching process.
Innovation Solution
An etching method utilizing a substrate processing apparatus with specific gas combinations and voltage applications, including the use of Ar, H2, and CF4 gases, to form a protective film and etch the target film, optimizing the timing and type of gases to prevent etching failure and reduce the opening width effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a protective film is deposited on the side wall of the opening to reduce the opening width, then the opening width is reduced, but etching defects are generated
Solution Approach 1:
The patent changes the chemical composition parameters of the etching gas by introducing a sedimentary gas (CF4, C4F6, or C4F8) that deposits protective films on side walls during etching. This allows continuous protection during the etching process rather than separate deposition steps, reducing opening width while preventing etching defects through parameter optimization of gas composition and flow rate
Solution Approach 2:
The protective film formation is made continuous throughout the etching process by using a sedimentary gas that deposits film material during etching. This continuous action maintains side wall protection without interruption, preventing etching defects while achieving the desired opening width reduction
2Manufacturing precision
If the opening width is reduced to a predetermined width, then the pattern precision is improved, but etching failure occurs
Solution Approach 1:
The patent optimizes multiple parameters simultaneously: gas composition (adding sedimentary gas CF4/C4F6/C4F8), gas flow rate (5-50 sccm), and pressure (10-100 Pa) to achieve the right balance between etching rate and protective film deposition rate, preventing etching failure while achieving precise opening width control
Solution Approach 2:
The process uses feedback control by monitoring the etching progress and adjusting gas flow rates and other parameters to maintain optimal conditions for both etching and protective film formation, preventing etching failure while achieving the target opening width
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 method successfully reduces the opening width of target films without causing etching failures, achieving precise control over the etching process and maintaining the aspect ratio of the patterned films.
Implementation Method 1
a second step of forming a protective film by introducing a second gas containing Ar gas, H2 gas, and a sedimentary gas and applying a DC voltage to the second electrode
Implementation Method 2
forming a protective film by introducing a second gas containing Ar gas, H2 gas, and a sedimentary gas and applying a DC voltage to the second electrode
Implementation Method 3
a first step of etching a target film on a substrate halfway into a pattern of a predetermined film on the target film by introducing a first gas
Implementation Method 4
etching the target film by introducing a third gas
Data Source
AI summary
Provided is an etching method performed in a substrate-processing apparatus having: a first electrode on which a substrate is placed; and a second electrode facing the first electrode, the method comprising: a first step for introducing a first gas and halfway etching a target film into a pattern of a predetermined film on the target film formed on the substrate; a second step for introducing a second gas including Ar gas, H2 gas, and deposition gas and applying DC voltage to the second electrode to form a protective film, the second step being performed after the first step; and a third step for introducing a third gas and etching the target film, the third step being performed after the step for forming the protective film.