Deep Plasma Etching Gas Mix for Lower Warming Impact
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Solution Overview
Problem
Existing plasma processing methods for deep etching face challenges in suppressing global warming impacts and achieving high throughput, primarily due to the use of C4F8, which exacerbates global warming, and HFO-1234yf, which leads to contamination and prolonged cleaning times.
Innovation Solution
A plasma processing method using a mixed gas of C4F8 and 2,3,3,3-tetrafluoropropene (HFO-1234yf) as a protective film deposition gas, with a flow rate ratio of HFO-1234yf between 5% and 60%, to balance global warming suppression and high-throughput processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If C4F8 is used as a protective film deposition gas, then deep etching can be performed, but global warming impacts are exacerbated
Solution Approach 1:
The patent changes the chemical composition parameters of the protective film deposition gas from pure C4F8 to a mixed gas containing HFO-1234yf (2,3,3,3-tetrafluoropropene) at specific flow rate ratios (5-60%). This parameter change reduces the global warming impact while maintaining the protective film deposition functionality needed for deep etching.
2Object-affected harmful factors
If HFO-1234yf is used as a protective film deposition gas, then global warming impacts are suppressed, but CF polymer contamination increases in the chamber
Solution Approach 1:
The patent optimizes the flow rate ratio parameter of HFO-1234yf in the mixed gas to be between 5-60%. This parameter optimization balances the reduction of global warming impact with the control of CF polymer contamination, achieving an acceptable compromise between environmental benefits and process stability.
3Object-affected harmful factors
If HFO-1234yf is used as a protective film deposition gas, then global warming impacts are reduced, but cleaning time increases
Solution Approach 1:
By controlling the HFO-1234yf flow rate ratio between 5-60% in the mixed gas, the patent reduces CF polymer accumulation on chamber walls during protective film deposition. This parameter optimization shortens the required cleaning time between substrates, thereby reducing time loss while still achieving global warming suppression.
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 effectively reduces global warming impacts and increases throughput by minimizing cleaning time and gas usage, while maintaining the quality of deep etching processes.
Implementation Method 1
a protective film deposition process of depositing a protective film in a recess formed through the etching process by using plasma of a protective film deposition gas
Implementation Method 2
an etching process of etching the substrate by using plasma of an etching gas such as SF6
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
[Problem to be Solved] Provided is a plasma processing apparatus or the like, with which impacts on global warming can be suppressed and high-throughput plasma processing can be achieved. [Solution] A plasma processing apparatus 100 according to the present invention includes a chamber 1 in which plasma is generated, a mounting table 2 disposed in the chamber, wherein a substrate S is mounted on the mounting table 2, and a gas supply source 3 (3a to 3d) for supplying gas for generating plasma in the chamber, wherein the substrate is subjected to deep etching by executing alternately and repeatedly an etching process S2 of etching the substrate by using plasma and a protective film deposition process S3 of depositing a protective film in a recess formed through the etching process by using plasma. It is characterized in that, in the protective film deposition process S3, a mixed gas of C4F8 and 2,3,3,3-tetrafluoropropene is supplied from the gas supply sources 3b, 3c into the chamber as gas supplied for generating plasma.