As a key material driving progress in information technology and energy transformation, electronic-grade silane plays a vital role in core industries such as semiconductors, photovoltaics (PV), and new energy. With intensifying global technological competition, this "hidden champion" is accelerating towards high-end, diversified, and localized development.

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Properties and Quality Standards of Electronic Grade Silane

Silane refers to a class of compounds composed of silicon and hydrogen, with the general formula Si _nH _2n+2. The simplest is monosilane (SiH ₄). As a representative of high-purity gases, the physical and chemical properties of electronic-grade silane, along with its strict purity standards, form the basis of its industrial application.

Main Properties

Type	Property Description	Key Points
Physical	Colorless gas at room temperature; boiling point of -111.9°C; density under standard conditions is lower than air (approx. 1.00 g/mL), making it easy to diffuse; slightly soluble in water, easily soluble in organic solvents.	Easy diffusion, low boiling point
Chemical	Flammable and explosive; can form explosive mixtures with air; strong reducing agent, reacts violently with oxidizers; Hydrolysis: reacts with water to generate silicon dioxide and hydrogen; Thermal stability: decomposes into silicon and hydrogen at high temperatures.	High reactivity, hydrolysis
Toxicity	Irritating to the respiratory tract; high concentrations may cause suffocation.	Requires safe operation

Quality Requirements and Standards

The production and application of electronic-grade silane must follow the national standard "GB/T 15909-2017 Gas for Electronic Industry — Silane".

• Purity Index: Requires silane (SiH ₄) purity to reach ≥ 99.9999%.
• Impurity Control: Key impurities (such as chlorosilanes, disilane, etc.) must be controlled at the ppb level.
• Application Process: Mainly used for high-purity polysilicon deposition, silicon nitride chemical vapor deposition (CVD), semiconductor epitaxial growth, etc.

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Core Applications of Electronic Grade Silane

Silane plays a central role in semiconductor manufacturing through two major processes: doping and deposition.

1. Doping Process (Regulating Electrical Performance)

Doping is the process of introducing a small amount of specific impurity atoms to change the electrical properties of semiconductor materials.

• Main Role: Silane (SiH ₄), as a silicon source gas, provides silicon atoms through thermal decomposition to form silicon thin films or layers that serve as the substrate for doping.
• Synergistic Mechanism: Silane participates in reactions alongside dopant gases (such as arsine AsH ₃, phosphine PH ₃, diborane B ₂H ₆, etc.).
• Specific Methods: Doping mechanisms involve epitaxial growth doping, diffusion doping, and ion implantation doping.

2. Deposition Process (Preparation of Functional Thin Films)

Silane (SiH ₄) is the core precursor gas for thin-film deposition in semiconductor manufacturing:

Advantageous Feature	Description
Low-Temperature Deposition	Silane achieves film deposition at 300-600°C, significantly lower than other silicon sources (e.g., SiCl 4 requires >800°C), reducing thermal damage to the substrate.
High Purity and Uniformity	Decomposition products are only silicon and hydrogen, with no byproduct pollution; film thickness uniformity error can be controlled to < 2%.
Large-Area Applicability	Achieves over 99% coverage in uniform deposition on 12-inch wafers and larger.

Silane plays an irreplaceable role in epitaxial layers, polysilicon/silicon nitride deposition, and low-dielectric film preparation:

• Epitaxial Silicon Layer Growth:
  SiH ₄ → Si + 2H ₂ ↑ (High Temp)
• Polysilicon/Silicon Nitride Deposition:
  • Polysilicon: Used for gate materials, capacitor electrodes, and interconnect layers.
  • Silicon Nitride (SiN):
    3SiH ₄ + 4NH ₃ → Si ₃N ₄ + 12H ₂ ↑ (RF Plasma)
• Low-Dielectric Constant (Low-κ) Film Preparation:
  4MS + O ₂ + NH ₃ → SiCOH + volatile byproducts (Plasma)

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Future Development Trends of Electronic Grade Silane

1. High-end: Disilane (Si ₂H ₆) Replacing Monosilane (SiH ₄)

• Technical Advantages: Disilane offers higher film density and faster film-forming rates, improving yield in 14nm and 7nm processes.
• Market Potential: Global disilane market size is expected to grow continuously.

2. Diversification: Emerging Applications

• Photovoltaics: Domestic demand for silane is expected to reach 24,500 tons by 2025.
• New Energy Vehicles: China's demand for silicon-carbon anodes is expected to reach 500,000 tons by 2026, driving massive silane demand.

3. Localization: Import Substitution

• Progress: Domestic enterprises have achieved breakthroughs in high-purity (6N and above) silane gas.
• Policy: National policies prioritize breakthroughs in electronic specialty gases.

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