Electronic-grade gas
The technical indicators and requirements of electronic grade acetylene can be divided into basic grade and ultra-high purity grade according to application scenarios. The specific standards are as follows:
1. Core purity requirements
Basic electronic grade (99.99%, 4N grade)
The acetylene volume fraction is ≥99.99%, meeting the needs of welding, atomic absorption spectrum analysis and other needs.
Ultra-high purity (99.999%, 5N level)
Advanced processes such as semiconductor photolithography carbon mask deposition and amorphous silicon growth, the purity must reach more than 99.999%.
2. Key impurity limits
|
Impurity type |
Limit requirements |
Detection method |
|
Phosphide (PH₃) |
≤0.05 |
Gas chromatography-mass spectrometry combined |
|
Hydrogen sulfide (H₂S) |
≤0.1 |
Silver nitrate test strip method |
|
Carbon monoxide (CO) |
≤1 |
Infrared absorption method |
|
Carbon dioxide (CO₂) |
≤1 |
Gas chromatography |
|
Moisture (H₂O) |
≤3 |
Karl Fischer |
|
Total hydrocarbon impurities |
≤0.1 |
Gas chromatography |
Note: The semiconductor grade (5N) requires additional control of metal ions (Fe, Na≤1 ppb) and particulate matter (≥0.1μm ≤0.1/mL).
3. Relevance of application scenarios and indicators
Lithography process (plasma deposition)
Used from the carbon mask layer, excessive phosphine will cause leakage of semiconductor devices, and the strict limit is required to be ≤0.05 ppm.
Analytical instrument gas
When atomic absorption spectral gas, moisture ≤3 ppm can avoid flame instability.
Rare metal refining
High-purity acetylene participates in the reduction reaction, and the total carbon impurities are ≤0.1 ppm to prevent product contamination.
4. Packaging and safety specifications
Packaging: Special solvent-free steel cylinder (porous filler structure), electrolytic polishing and passivation treatment of inner wall.
Storage and transportation: The storage temperature is ≤30℃ from light, and the leakage concentration alarm threshold is set to 0.5% (first-level warning).
Safety warning: The explosion limit is 2.3%-82%, and the operating area must be equipped with a real-time monitor for acetylene concentration.
5. Standard basis
Purity and impurities: Perform T/CCGA 30008-2025 "Electronic Grade Acetylene".
Trace analysis: Refer to SEMI standard (metal ion detection uses ICP-MS).
The residue of hydrogen arsenide (AsH₃) of electronic grade acetylene needs to be removed through an exclusive adsorption module. Industrial acetylene raw materials must be purified by level 5 (adsorption-desorption-compression-drying-filtration) before they can meet the standards.
