What thin films can be deposited on a plasma enhanced PECVD coating electric furnace?

The plasma enhanced chemical vapor deposition (PECVD) coating electric furnace, with its low-temperature process, high deposition rate, and precise control capability, can deposit various functional thin films and is widely used in fields such as semiconductors, photovoltaics, microelectronics, optics, and biomedicine. The following are the main types of thin films that can be deposited and their typical applications:

1. Semiconductor and Microelectronics Field
Silicon nitride (SiNx) thin film
Function: As a passivation layer, isolation layer, or anti reflection layer, it suppresses surface defects and reduces leakage current.
Applications: transistor gate insulation layer, passivation film for solar cells, protective layer for MEMS devices.
Advantages: High dielectric constant, excellent chemical stability, PECVD low-temperature process avoids thermal damage.
Silicon oxide (SiO ₂) thin film
Function: As a gate oxide layer, interlayer dielectric layer, or mask layer.
Application: Insulation layer for CMOS devices, hard mask for photolithography process.
Advantages: High density, low pinhole rate, PECVD can accurately control thickness (<10nm).
Silicon oxynitride (SiON) thin film
Function: Combining the characteristics of silicon oxide and silicon nitride, adjust the refractive index (1.6-2.0).
Applications: Anti reflective coatings, waveguide materials, semiconductor device buffer layers.
Advantages: PECVD achieves refractive index gradient design by controlling the composition of gas ratios.

2. Photovoltaic field
Silicon nitride anti reflection film (SiNx: H)
Function: Reduce the surface reflectivity of silicon wafers (<2%) and improve light absorption efficiency. Application: Surface passivation and anti reflection of crystalline silicon solar cells. Advantages: PECVD has a high deposition rate (>50nm/min), and the film contains hydrogen, which can passivate grain boundary defects.
Aluminum oxide (Al ₂ O3) thin film
Function: Provide negative fixed charges to achieve efficient field-effect passivation.
Application: Surface passivation of n-type crystalline silicon cells.
Advantages: PECVD low-temperature process is compatible with the preparation process of heterojunction cells (HJT).

3. Optics and Display Field
Diamond like carbon (DLC) thin film
Function: High hardness (>20GPa), low friction coefficient (<0.2), high transparency.
Application: Scratch resistant coating for optical lenses, protective layer for flexible display substrates.
Advantages: PECVD can regulate the sp ³/sp ² key ratio, achieving a balance between hardness and transparency.
Magnesium fluoride (MgF ₂) thin film
Function: Extremely low refractive index (n ≈ 1.38), wide band anti reflection.
Application: High power laser system, astronomical telescope lens coating.
Advantages: PECVD low-temperature deposition avoids substrate thermal deformation and is suitable for complex shaped optical components.

4. Biomedical field
Titanium dioxide (TiO ₂) thin film
Function: Antibacterial, hydrophilic, biocompatible.
Application: Surface modification of medical devices (such as catheters, implants).
Advantages: The TiO ₂ thin film deposited by PECVD has high photocatalytic activity and can inhibit bacterial adhesion.
Silicon based composite films (such as SiO ₂ – TiO ₂)
Function: Regulate surface wettability and chemical stability.
Application: Packaging layer for biosensors, coating for tissue engineering scaffolds.
Advantages: PECVD can achieve multi-layer nanostructure deposition and enhance interfacial bonding strength.

5. Other functional films
Silicon carbide (SiC) thin film
Function: High hardness, wear resistance, corrosion resistance.
Application: Coating for cutting tools, wear-resistant layer for MEMS devices.
Advantages: SiC thin films deposited by PECVD have high crystal quality and low friction coefficient.
Titanium nitride (TiN) thin film
Function: High conductivity, golden appearance, biocompatibility.
Application: Microelectronic diffusion barrier layer, decorative coating for medical devices.
Advantages: PECVD can achieve low stress deposition and avoid film peeling.

6. Conclusion
PECVD coating furnace breaks through the temperature limitation of traditional thermal CVD through plasma assisted reaction, and can deposit various functional thin films such as dielectric materials, semiconductor materials, optical coatings, bioactive coatings, and hard wear-resistant coatings. Its core advantages lie in:
Low temperature process (<400 ℃) compatible with flexible substrates and thermosensitive materials; High sedimentation rate (>50nm/min) improves production efficiency;
Accurate regulation of composition and structure to meet diverse functional requirements.
In the future, with the development of new plasma sources and gas delivery technologies, PECVD will play a greater role in cutting-edge fields such as flexible electronics, quantum devices, and biochips.