Low-Stress Silicon Nitride LPCVD

Low stress nitride is performed at a high ratio of DCS to NH₃ flow rates (typically ~ 6). The consequence of such silicon-enriched deposition is a very low tensile stress. The stress depends mainly on the gas mixing ratio and the process temperature. The processing pressure is typically a few Torr or lower. Increasing the pressure and the temperature increases the deposition but sacrifices the uniformity.

Applications: MEMS structures, diffusion barriers, passivation layers, oxidation masks, etch masks, ion implant masks, insulation, encapsulation, mechanical protection, gate dielectrics, optical waveguides, CMP and etch stop layers.

• Typical film thickness: 0.1 - 2 µm
• Refractive index at 550 nm / 2.0 - 2.3
• Batch Size: 50
• Deposition rate: 3 - 4.5 nm/min
• Gases: dichlorosilane, ammonia
• Uniformity: < 5%
• Stress: 50 - 300 MPa
• Deposition Temperature: 800 - 840 °C Flat

LPCVD Processes

• Silicon Carbide Devices
• Silicon Nitride Resonators
• Doped Silicon by LPCVD
• POLYSILICON LPCVD WITH SILANE (SiH₄)
• POLYSILICON LPCVD WITH DISILANE (Si₂H₆)
• LTO, DOPED LTO, BPSG, BSG, AND PSG LPCVD
• HTO LPCVD
• TEOS LPCVD
• Silicon Nitride LPCVD
• Low-Stress Silicon Nitride LPCVD
• Stochiometric Silicon Nitride LPCVD
• Silicon Oxynitride (SiN_xO_y) LPCVD
• Silicon Germanium (Si-Ge) LPCVD
• SIPOS (Semi-Insulating Polycrystalline Silicon)
• Polycrystalline Silicon Carbide
• Epitaxial Silicon
• Nano Materials LPCVD