Amorphous Silicon by LPCVD

Polysilicon films are grown at 600-650 °C and amorphous silicon films (a-Si) are grown at 500-550 °C. Lower temperatures result in lower stress and smaller grain size. A post-growth anneal can be used to relieve film stress. Both large-grained and amorphous films have compressive stresses while smaller grains have tensile stresses. By alternating compressive and tensile layers, the overall stress can be kept low enough that a stress-relieving anneal is not required. Smaller grains have lower thermal conductivities and are etched faster by HF. Between 600 and 650 °C the film's orientation is predominantly (110), while at higher temperatures (100) dominates.

• Typical Film Thickness: 0.1 to 2 µm
• Batch Size: 50
• Deposition rate: 1-3 nm/min. (10 - 30 Å/min.)
• Deposition Temperature: 500 - 550 °C
• Refractive index at 550nm
• Uniformity: < 3% using 1 σ
• Gases: Silane SiH₄

Applications: thin-film transistors for LCDs, thin-film photovoltaic solar cells

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