How to process silicon nitride in CVD electric furnace?

CVD (Chemical Vapor Deposition) furnace mainly achieves surface treatment or thin film deposition of silicon nitride through a series of complex process steps when processing silicon nitride. The following is the detailed process of treating silicon nitride with CVD electric furnace:

Commonly used CVD electric furnaces (click on the image to view product details)

1. Heating principle
The heating principle of CVD chemical vapor deposition furnace is mainly based on the principles of thermal energy transfer and chemical reactions. The heating system converts electrical or other energy sources into thermal energy, creating a high-temperature environment. Heat is conducted to the interior of the furnace through heating rods, while the gas and base materials inside the furnace also absorb heat through convection and radiation, achieving overall heating.

2. Processing procedure
Preprocessing:
Mechanical pretreatment: By using mechanical means such as grinding and polishing, impurities and defects on the surface of silicon nitride are removed, improving its surface smoothness and cleanliness.
Chemical pretreatment: In some cases, it may be necessary to use chemical methods to remove contaminants from the surface of silicon nitride or perform surface modification to improve its adhesion to deposited films. But according to specific experimental results, chemical etching is not a necessary step for good CVD diamond quality in silicon nitride.

Sedimentary process:
Reaction gas selection: Select appropriate reaction gases such as silane (SiH4), ammonia (NH3), etc. based on the required properties and application scenarios of silicon nitride thin films.
Reactive gas activation: Under high temperature conditions, one or more reactive gases introduced into the reaction chamber are activated. The activation method is through direct heating. This activation method enhances the chemical activity of the reaction gas, making it more prone to chemical reactions.
Chemical reaction generates deposits: The activated reaction gas undergoes a chemical reaction on the surface of the silicon nitride substrate material, producing solid silicon nitride deposits. These sediments continuously accumulate on the substrate surface, ultimately forming the required thin film.

Post processing:
Cooling: After deposition, remove the silicon nitride substrate material from the CVD electric furnace and cool it down.
Detection and characterization: Various detection methods such as laser Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) are used to characterize the deposited silicon nitride film to determine whether its composition, structure, and properties meet the requirements.

3. Precautions
Temperature control: In order to ensure the smooth progress of chemical reactions and the quality of deposits, CVD chemical vapor deposition furnaces are usually equipped with precise temperature control systems. The system can monitor the temperature inside the furnace in real time and automatically adjust it according to the preset heating curve to maintain a constant temperature environment.
Gas flow control: Gas flow is one of the important factors affecting CVD reactions. Therefore, it is necessary to precisely control the flow rate and proportion of the reaction gas to ensure the stability and controllability of the reaction process.
Safety protection: When handling high-temperature materials such as silicon nitride, necessary safety measures should be taken, such as wearing protective goggles, gloves, etc., to prevent high temperatures and harmful substances from causing harm to personnel.

Touch screen CVD electric furnace (click on the image to view product details)

So, when processing silicon nitride in CVD electric furnaces, it is necessary to strictly control process parameters such as heating temperature, reaction gas flow rate, and ratio to ensure the deposition of high-quality silicon nitride films. At the same time, it is also necessary to pay attention to safety protection measures to ensure the safety of operators.Click to learn more CVD devices! Or click on online customer service to learn more about product information!