Low-Pressure Chemical Vapor Deposition (LPCVD) System

Low-pressure chemical vapor deposition (LPCVD) is a deposition process. The process is used to deposit high-quality films of materials such as silicon nitride (Si₃N₄), silicon dioxide (SiO₂), polycrystalline silicon (Poly-Si), and other functional materials onto various substrates. The LPCVD system operates at relatively low pressures, allowing for high deposition uniformity, excellent film quality, and precise control over film thickness and properties. The system has 4 furnace tubes (St1, St2, St3, and St4).

Furnace St1: Si₃N₄ and SiN_x LPCVD

Applications

St₁ is used for the deposition of silicon nitride (Si₃N₄) and low-stress silicon nitride (SiN_x) films.

Technical Specifications

• Sample Size: Standard sizes are 4", 6", and 8" wafers.
• Temperature: Si₃N₄: 700°C-800°C, SiN_x: 780°C-850°C
• Process Pressure: ~200 mtorr (millitorr).
• Gas Type: DCS (disilane) and NH₃ (ammonia) are used to form Si₃N₄ and SiN_x.
• Refractive Index: Si₃N₄: 2.0 ± 0.05, SiN_x: 2.3 ± 0.05
• WTW (Wafer-to-Wafer Uniformity): Si₃N₄: ≤±4% for 150 nm thickness, SiN_x: ≤±4% for 150 nm thickness
• Processing Capability:
  6" and 4" wafers: 25 pieces per furnace.
  8" wafers: 20 pieces per furnace.

Furnace St2: SiO₂ LPCVD Using TEOS

Applications

Furnace St2 is used for the deposition of silicon dioxide (SiO₂) films, using TEOS (tetraethyl orthosilicate) as a silicon source.

Technical Specifications

• Sample Size: Standard sizes include 8", 6", and 4" wafers.
• Temperature: 630°C-750°C
• Process Pressure: ~200 mtorr
• Gas Type: TEOS (tetraethyl orthosilicate), which decomposes to form SiO₂.
• Refractive Index: 1.44 ± 0.04
• WTW: ≤±5% for 150 nm thickness
• Processing Capability:

4" and 6" wafers: 25 pieces per furnace.

8" wafers: 20 pieces per furnace.

Furnace St3: SiC Furnace for High-Temperature Annealing and Oxidation

Applications

Furnace St3 is a silicon carbide (SiC) furnace used for high-temperature annealing and oxidation processes, particularly for silicon wafer thermal oxidation (dry and wet oxidation).

Technical Specifications

• Sample Size: 6" and 8" wafers
• Temperature: 900°C-1200°C, suitable for high-temperature processes like oxidation and annealing.
• Process Pressure: Atmospheric pressure (common for oxidation processes)
• Gas Types: H₂, O₂, N₂, DCE (with a note that H₂ should not be used for annealing).
• WTW: ≤±3% for 100 nm thickness
• Processing Capability:
  6" wafers: 25 pieces per furnace.
  8" wafers: 25 pieces per furnace.

Furnace St4: Poly-Si LPCVD Using SiH₄

Applications

Furnace St4 is used for the thermal decomposition of silane (SiH₄) to deposit polycrystalline silicon (Poly-Si) films.

Technical Specifications

• Sample Size: Standard sizes include 4", 6", and 8" wafers.
• Temperature: 600°C-750°C
• Process Pressure: ~200 mtorr
• Gas Type: SiH₄ (silane), which is decomposed to form Poly-Si.
• WTW: ≤±3% for 250 nm thickness
• Processing Capability:
  6" wafers: 25 pieces per furnace.
  8" wafers: 20 pieces per furnace.

Operating under controlled low-pressure conditions, our LPCVD system provides superior process control for depositing materials like silicon nitride, silicon dioxide, and polycrystalline silicon. With versatile furnace configurations and a broad range of process capabilities, our LPCVD technology is perfect for both research and high-volume production, supporting diverse applications across the electronics and materials industries. For more services, please feel free to contact us.

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