Working principle of rapid annealing RTP tube furnace

The working principle of the rapid annealing RTP tube furnace is based on the combination of rapid heat treatment (RTP) technology and tube furnace structure, which achieves rapid temperature rise and fall of the sample through a high-power heat source, while utilizing the uniform heating environment of the tube furnace to ensure the quality of heat treatment. The core process can be divided into three stages: rapid heating, insulation treatment, and rapid cooling, as follows:

1. Rapid heating stage
Heat source selection
RTP tube furnaces usually use high-power halogen lamps or infrared lamps as heat sources, which directly act on the surface of the sample through radiative heat transfer. The radiation energy of halogen lamps can be efficiently absorbed by the sample, achieving a heating rate of tens to hundreds of degrees Celsius per second (such as some devices reaching 150 ℃/s). For example, in the post-treatment of semiconductor ion implantation, rapid heating can reduce the diffusion time of impurities and prevent lattice defects from diffusing into deeper layers.
Optimization of Heating Uniformity
Double sided heating structure: By symmetrically arranging the upper and lower layers of infrared halogen lamps, the pattern loading effect is eliminated, ensuring that the temperature uniformity on the chip is better than ± 1.5 ℃.
Quartz cavity design: The interior adopts high-purity quartz cavity insulation to reduce heat loss and avoid chemical reactions between the cavity material and the sample.
Water cooled shell: The cavity shell is designed with water-cooled aluminum alloy to reduce the surface temperature of the equipment and improve operational safety.

2. Insulation treatment stage
Temperature stability control
After the sample reaches the target temperature, the RTP tube furnace maintains temperature stability through a PID closed-loop control system. The system monitors the sample temperature in real-time (with the temperature measurement point placed at the sample location), and combines feedback control technology to control the temperature fluctuation range within ± 1 ℃, ensuring process reproducibility.
Process time control
The insulation time is usually short (a few seconds to a few minutes), depending on the material type and process requirements. For example, in the preparation of GaN thin films, short-term insulation can optimize the crystal quality of the film and reduce defect density.

3. Rapid cooling stage
Cooling method selection
Air cooling/water cooling combination: The sample is quickly exposed to the air through a slide design, while using air cooling or water cooling systems to accelerate cooling. For example, some devices can lower the sample from 1000 ℃ to room temperature within seconds.
Inert gas cooling: Fill the chamber with nitrogen or argon gas, achieve rapid cooling through gas convection, and avoid sample oxidation.
Cooling rate control
Rapid cooling can solidify structures or alter material properties during processing, while reducing opportunities for impurity diffusion. For example, in the processing of silicon carbide (SiC) materials, rapid cooling can eliminate the internal stress in the film and improve the photoelectric performance.

4. Key technical support
High precision temperature control system
Using infrared temperature measurement device and PID closed-loop control technology, the power of the heating element is adjusted in real time to ensure temperature uniformity.
Support multi segment temperature curve programming to meet complex process requirements such as segmented annealing and gradient heating.
Atmosphere control system
Equipped with a multi-channel gas mass flow controller (MFC), non hazardous gases such as nitrogen, argon, oxygen, etc. can be introduced to achieve heat treatment under vacuum or specific atmosphere.
The gas purification device can remove impurities and avoid sample contamination.
Security protection design
Emergency switches, furnace wall high temperature alarms, chamber safety valves, and other devices ensure safe operation.
The water cooling system protects the heating elements and sealing rings, extending the lifespan of the equipment.

5. Application scenarios
Semiconductor Manufacturing
Annealing after ion implantation: repairing lattice defects and activating doped impurities.
Metal silicide formation: preparing low resistance contact layers to enhance device performance.
Oxide/nitride growth: Growth of high-quality dielectric layers such as SiO ₂ and Si ∝ N ₄.
New material research and development
Nanomaterial synthesis: controlling crystal structure and morphology, adjusting optoelectronic properties.
Wide bandgap semiconductor processing: optimizing the crystal quality of materials such as GaN and SiC.
Manufacturing of solar cells
Quality control of silicon wafer crystals: improving photoelectric conversion efficiency.
Thin film battery bonding: achieving a strong bond between the thin film and the substrate.