Application of Vacuum Tube CVD Electric Furnace in Semiconductor Industry

In the semiconductor industry, the vacuum tube CVD electric furnace achieves the deposition of various key materials and device manufacturing through precise control of gas injection and high-temperature reaction conditions. Its application covers multiple core links from basic thin film preparation to high-end device integration. The specific application scenarios and technical advantages are as follows:

1. Core application scenarios
Deposition of insulation layer and protective layer
Material types: silicon dioxide (SiO ₂), silicon nitride (Si ∝ N ₄), etc.
Function: As an electrical insulation layer to isolate conductive layers and prevent device short circuits; Simultaneously providing chemical protection to prevent oxidation or corrosion of the substrate material.
Typical process: Deposition of SiO ₂ thin film on the wafer surface for MOSFET gate dielectric layer or chip packaging protective layer.
Preparation of metal layers and interconnect structures
Material types: tungsten (W), titanium (Ti), titanium nitride (TiN), aluminum (Al), etc.
Function: Form metal interconnect lines to achieve internal electrical signal transmission of devices; TiN and other materials serve as diffusion barriers to prevent metal migration in copper interconnects.
Typical process: Deposition of tungsten plugs by CVD, filling high aspect ratio vias, and improving the interconnect density of three-dimensional integrated circuits (3D ICs).
Doping layer and surface passivation
Material types: phosphosilicate glass (PSG), borosilicate glass (BSG), etc.
Function: By locally doping, the conductivity of semiconductors can be changed to form PN junctions or transistor source/drain regions; The surface passivation layer can reduce the interface state density and improve device performance.
Typical process: In solar cell manufacturing, depositing PSG layer to achieve N-type doping and improve photoelectric conversion efficiency.
Epitaxial growth and preparation of single crystal materials
Material types: monocrystalline silicon, silicon carbide (SiC), gallium nitride (GaN), etc.
Function: To grow high-quality single crystal layers on the surface of wafers, providing low defect substrates for devices; GaN epitaxial layer is used to manufacture high brightness LEDs and RF power devices.
Typical process: Low pressure CVD technology is used to grow GaN epitaxial layers on an 8-inch silicon substrate, achieving large-scale production of LED chips.
High k materials and deposition of new media
Material types: hafnium oxide (HfO ₂), zirconium oxide (ZrO ₂), etc.
Function: As a MOSFET gate dielectric, it replaces traditional SiO ₂, reduces leakage current, and improves device switching speed.
Typical process: By using atomic layer deposition (ALD) technology, HfO ₂ thin films are grown layer by layer on the wafer surface to achieve nanoscale thickness control.
Preparation of Nanomaterials and Functional Coatings
Material types: carbon nanotubes, graphene, diamond films, etc.
Function: Carbon nanotubes are used for high-sensitivity gas sensors; Graphene enhances the conductivity and thermal conductivity of devices; Diamond film is used as a heat dissipation substrate for 5G base station power amplifiers.
Typical process: CVD growth of graphene film on copper substrate for high-frequency transistor electrodes, significantly reducing contact resistance.

2. Technical advantages
High purity and low defect control
The CVD process is carried out in a vacuum environment to avoid impurity contamination and can deposit thin films with a purity of over 99.999%; By precisely controlling the reaction temperature and gas flow rate, crystal growth with defect density below 10 ⁶ cm ⁻ ² can be achieved.
Uniformity and controllability of thickness
Using a Mass Flow Controller (MFC), the gas flow stability reaches ± 0.5%, ensuring film thickness uniformity within ± 2%; The multi zone heating system eliminates temperature gradients and achieves uniform deposition of large-sized wafers (12 inches).
Material compatibility and process diversity
Supporting the deposition of various materials such as metals, semiconductors, ceramics, etc., suitable for the full process manufacturing from insulation layers to functional coatings; By adjusting the gas combination (such as SiH ₄/NH ∝/H ₂), continuous deposition of materials such as Si ∝ N ₄, SiO ₂, and polycrystalline silicon can be achieved.
3D integration and heterostructure capability
By using through silicon via (TSV) technology, high-quality insulation layers and metal filling materials are deposited by CVD to achieve vertical interconnection of 3D ICs; The heterogeneous integration of SiC and GaN can manufacture ultra-high frequency power devices to meet the needs of 5G communication.

3. Industry impact
Drive device performance improvement: CVD deposition technology with high-k dielectric and metal gate reduces MOSFET leakage current by 3 orders of magnitude and increases switching speed by 20%.
Reduce manufacturing costs: CVD mass production technology for 8-inch silicon carbide wafers reduces chip costs by 50% and accelerates the popularization of power devices for electric vehicles.
Expanding application boundaries: The application of CVD diamond coating in rocket engine nozzles has increased component lifespan by 5 times, supporting deep space exploration missions.