High-Purity 1H-Heptafluorocyclopentene for Stable Dry Etching
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Solution Overview
Problem
The etching rate in semiconductor production using 1H-heptafluorocyclopentene as a dry etching gas decreases over time due to trace amounts of organochlorine-based compounds, which concentrate in the container, reducing the gas's purity and leading to unstable dry etching processes.
Innovation Solution
Producing and using 1H-heptafluorocyclopentene with a purity of 99.9 wt% or more, limiting organochlorine-based compounds to 350 ppm by weight or less, and ensuring nitrogen and oxygen contents are 100 ppm by volume or less, achieved through purification methods involving rectification and adsorption, to maintain a stable etching rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If 1H-heptafluorocyclopentene is continuously fed to a dry etching device from a filled container, then the etching process can be maintained for extended periods, but the etching rate gradually decreases and may stop due to concentration of organochlorine-based compound impurities
Solution Approach 1:
The patent applies preliminary action by strictly controlling the purity of 1H-heptafluorocyclopentene before it is filled into the container, specifically limiting organochlorine-based compound content to 350 ppm by weight or less and nitrogen content to 100 ppm by volume or less. This pre-purification step prevents impurity concentration issues that would otherwise occur during continuous feeding, thereby maintaining stable etching rates throughout the entire duration of gas consumption from the container.
2Ease of manufacture
If standard purification methods are used to produce 1H-heptafluorocyclopentene, then production cost and complexity are reduced, but trace amounts of organochlorine-based compounds remain that cause etching rate degradation over time
Solution Approach 1:
The patent applies parameter changes by establishing specific quantitative thresholds for impurity content (organochlorine-based compounds ≤350 ppm by weight, nitrogen ≤100 ppm by volume) that must be achieved during the purification process. These parameter specifications transform the vague goal of 'high purity' into measurable, controllable targets that can be systematically achieved through standardized purification operations, balancing manufacturing feasibility with the required precision for stable dry etching performance.
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
High-purity 1H-heptafluorocyclopentene ensures a stable dry etching process and plasma CVD deposition, preventing decreases in etching rate and yield, even when the gas is nearly depleted in the container.
Implementation Method 1
brings the resulting 1H,2H-octafluorocyclopentane into contact with a basic compound (e.g., potassium carbonate) to effect dehydrofluorination
Implementation Method 2
3H-heptafluorocyclopentene and/or 4H-heptafluorocyclopentene can be isomerized into 1H-heptafluorocyclopentene by causing the same to contact a metal fluoride
Implementation Method 3
subsequently distilling the reaction product to obtain highly pure 1H-heptafluorocyclopentene
Implementation Method 4
purification methods involving rectification and adsorption
Data Source
AI summary
The present invention is a 1H-Heptafluorocyclopentene having a purity of 99.9 wt% or more and an organochlorine-based compound content of 350 ppm by weight or less. The present invention provides a high-purity 1H-Heptafluorocyclopentene that may be useful as a plasma reaction gas for semiconductors.