Ultrahigh Vacuum Furnaces: Technical Principles, Application Scenarios and Industry Development

In the high-end manufacturing field of modern scientific research, the requirements for the material processing environment have reached an unprecedented level. Normal vacuum environments are no longer able to meet the stringent demands for cleanliness and low gas pressure of some cutting-edge technologies, and the ultra-high vacuum furnace has emerged. This kind of equipment can create 10-⁶ Pa or even lower pressure environment, by virtue of its excellent performance, has become the key equipment to explore the mystery of the microscopic world, the manufacture of materials and devices. xvacuum technology (jiangsu) co., ltd. with the profound technical accumulation and continuous innovation spirit, in the field of ultra-high vacuum furnace research and development and manufacturing achievements, for the development of the related industries Provides a strong support for the development of related industries.

First, the working principle and structural composition of the ultra-high vacuum furnace

(A) the core working principle

The working principle of ultra-high vacuum furnace is based on the theory of gas molecular dynamics and vacuum physics. In the conventional atmospheric environment, each cubic centimeter of space contains about 10¹⁹ gas molecules, these molecules frequently collide with the surface of the material, which will trigger oxidation, adsorption and a series of physicochemical reactions, interfering with the material properties. The ultra-high vacuum furnace works through a multi-stage vacuum pumping unit to gradually reduce the air pressure inside the furnace, reducing the number of gas molecules. When the gas pressure is reduced to 10-⁶ Pa below, the gas molecular density is greatly reduced, the collision probability between molecules and molecules and the material surface is significantly reduced, thus effectively avoiding the material is affected by gas contamination and adverse chemical reactions. In practice, the ultra-high vacuum furnace first starts the mechanical pump to carry out rough pumping, and quickly reduces the gas pressure in the furnace from atmospheric pressure to about 1 Pa. Subsequently, molecular pumps and other equipment work in succession to further pump the gas pressure to the ultra-high vacuum level. During this process, the residual gas molecules in the furnace are continuously pumped out, while the heating system can warm up the samples placed in the furnace. Under the dual action of ultra-high vacuum and high temperature, the gases adsorbed on the surface and inside the sample are completely discharged, and the physicochemical processes such as atomic diffusion and phase transition inside the material can be carried out in a pure environment to realize the optimization of the material properties and the specific process treatment.

(ii) Structural composition

Ultra-high vacuum furnace mainly consists of furnace body, vacuum system, heating system, control system and safety protection devices and other components. Furnace body is the main body of the ultra-high vacuum furnace, usually made of high-strength, high-sealing stainless steel to withstand external atmospheric pressure and prevent gas leakage. The interior of the furnace body is designed with a heat insulation layer, mostly made of high-temperature-resistant ceramic fiber or multi-layer metal foil, which can effectively reduce heat dissipation and improve energy efficiency. The interior space of the furnace chamber is designed according to the actual demand, equipped with sample placing platform and bracket for fixing and supporting the samples. Meanwhile, the furnace body is equipped with an observation window, which is made of special high-temperature and high-pressure-resistant glass material, which is convenient for the operator to observe the sample status in the furnace in real time, and the observation window has good sealing performance, which will not affect the vacuum environment in the furnace. Vacuum system is the core component of ultra-high vacuum furnace to realize ultra-high vacuum environment, which is generally composed of mechanical pumps, molecular pumps, Roots pumps, vacuum pipelines, vacuum valves and vacuum measuring instruments.

Mechanical pump as a pre-stage pump, used for rough pumping, quickly reduce the furnace air pressure; molecular pump is the key equipment to obtain ultra-high vacuum, through the high-speed rotor and gas molecules collision, the gas molecules will be driven to the pre-stage pump discharged; Roots pump in the mechanical pump and molecular pumps play a role in the role of pressurization between the pump, to improve the efficiency of pumping. Vacuum pipeline is used to connect various components and transmit gas; vacuum valve is used to control gas flow and pipeline through and through; vacuum measuring instrument real-time monitoring of the furnace vacuum, common Pirani vacuum gauge, ionization vacuum gauge, etc., can accurately measure the air pressure value within the range of different vacuum degrees, and feedback the data to the control system. The heating system adopts highly efficient heating elements, such as resistance wire, silicon molybdenum rod, tungsten wire, etc., which are selected according to different operating temperatures and process requirements.

The heating elements are evenly distributed around or at the bottom of the furnace chamber to ensure the temperature uniformity inside the chamber. The heating system is equipped with high-precision temperature sensors, such as thermocouples, RTDs, etc., to monitor the temperature inside the furnace in real time and transmit the temperature signal to the control system. The control system realizes precise control of the temperature by adjusting the power of the heating element according to the set temperature curve, and the temperature control accuracy can reach ±1℃ or even higher, which meets the strict requirements of temperature for all kinds of precision processes. The control system is the “brain” of the ultra-high vacuum furnace, which usually adopts programmable logic controller (PLC) or computer control system. The operator can conveniently set the process parameters such as vacuum degree, temperature, heating rate, holding time and so on through the human-computer interaction interface, such as touch screen or computer terminal.

The control system can automatically coordinate the work of the vacuum system and heating system to realize the automatic operation of the equipment. During the operation, real-time data such as vacuum degree and temperature are collected and recorded, and analyzed and processed. When there are abnormal situations, such as over-temperature, substandard vacuum, equipment failure, etc., the control system will immediately issue an alarm and take corresponding protective measures, such as cutting off the heating power supply, activating the safety valve, etc., to ensure the safety of the equipment and samples. Safety protection device is an important part to ensure the normal operation of ultra-high vacuum furnace and personnel safety. In addition to the basic over-temperature protection and over-voltage protection functions, it is also equipped with devices such as leakage protection, short-circuit protection and vacuum system failure alarm. For example, when the temperature inside the furnace exceeds the set safety value, the over-temperature protection device will automatically cut off the heating power supply; if there is any abnormality in the vacuum system that causes the pressure inside the furnace to be too high, the over-pressure protection device will be activated to release the pressure in order to prevent the danger from occurring. In addition, the equipment shell adopts grounding design, effectively preventing electric leakage accidents and safeguarding the personal safety of operators.

Second, the application areas of ultra-high vacuum furnace

(A) semiconductor and microelectronics field

In the semiconductor and microelectronics industry, ultra-high vacuum furnace is an indispensable key equipment. Semiconductor chip manufacturing process in a number of links are dependent on ultra-high vacuum environment. In the epitaxial growth process of the chip, a specific gas source needs to be decomposed in the ultra-high vacuum furnace, so that atoms or molecules are deposited on the surface of the substrate to form a high-quality semiconductor epitaxial layer. The ultra-high vacuum environment can avoid the mixing of gas impurities and ensure the integrity of the crystal structure of the epitaxial layer and excellent electrical properties, thus improving the performance and reliability of the chip. For chip encapsulation process, ultra-high vacuum furnace can be used for vacuum welding and encapsulation, to prevent oxidation of the welding parts, improve the welding quality and encapsulation of the sealing, to avoid external moisture, impurities and other damage to the chip, to extend the service life of the chip. In addition, in the research and development of new semiconductor materials and devices, researchers use ultra-high vacuum furnace to simulate a variety of extreme environments, research materials in ultra-high vacuum and high-temperature conditions of the physical and chemical changes, to explore the new chip manufacturing process and technology, and to promote the semiconductor industry continues to move forward.

(B) Research and Application of Superconducting Materials

Superconducting materials have great potential for application in energy transmission, medical imaging, quantum computing and other fields due to their unique properties such as zero resistance and complete antimagnetism. However, the properties of superconducting materials are extremely sensitive to the environment, and tiny impurities and defects can affect their superconducting properties. Ultra-high vacuum furnaces provide an ideal environment for the research and preparation of superconducting materials. During the synthesis of superconducting materials, the ultra-high vacuum furnace can avoid the reaction between the materials and the oxygen and nitrogen in the air, and ensure the purity and composition accuracy of the materials. In the heat treatment and surface modification of superconducting materials, the ultra-high vacuum environment can prevent the surface oxidation of the material, and at the same time precisely control the process parameters, optimize the crystal structure and electronic structure of the material, improve the critical temperature of the superconducting material, the critical current density and other key performance indicators, and accelerate the process of the practical application of superconducting materials.

(C) Preparation of nanomaterials

Nanomaterials have unique physicochemical properties and show broad application prospects in many fields. Ultra-high vacuum furnace plays an important role in the preparation of nanomaterials. In the preparation of nanoparticles, nanofilms and other materials, the ultrahigh vacuum environment can reduce the interference of gas molecules on the growth process of nanomaterials, and accurately control the size, morphology and structure of nanomaterials. For example, the preparation of nanofilms in ultrahigh vacuum furnaces by molecular beam epitaxy enables precise control at the atomic level, resulting in highly uniform and ordered films. In addition, when studying the properties and applications of nanomaterials, the ultrahigh vacuum furnace can be used to simulate different environmental conditions, explore the stability and change rule of nanomaterials under various working conditions, and provide theoretical and experimental basis for the application development of nanomaterials.

(D) Aerospace

The aerospace field requires extremely high performance of materials and components, and any minor defects may lead to serious consequences. Ultra-high vacuum furnaces are used in the research and development, treatment and manufacture of aerospace materials and components. In the heat treatment process of high-temperature alloys, titanium alloys and other aerospace materials, the ultra-high vacuum environment can avoid material oxidation and contamination, improve the material's high-temperature strength, oxidation resistance and fatigue performance, and ensure the stable and reliable operation of aero-engines, spacecraft structural parts and other parts in extreme environments. For the welding and packaging of aerospace parts and components, the ultra-high vacuum furnace can realize high-quality vacuum welding, enhance the connection strength between parts and components, improve the sealing performance, prevent leakage and damage in the space of high vacuum, extreme temperature and other harsh environments, and safeguard the safety and reliability of spacecraft and aviation equipment.

(E) scientific research experiment field

In scientific research experiments, ultra-high vacuum furnace provides an important platform for researchers to explore the unknown. In surface science research, researchers use UHV furnace to study the atomic structure of the material surface, electronic state and chemical reaction process, to understand the physicochemical properties of the material surface, to provide a theoretical basis for the development of new materials and new technologies. In physical-chemical experiments, UHV furnace can be used to simulate extreme environments such as cosmic space, to study the kinetics and thermodynamics of chemical reactions of substances under the conditions of ultra-high vacuum and high temperature, and to explore new mechanisms of chemical reactions and synthetic methods. In addition, in condensed matter physics, quantum physics and other fields of research, ultra-high vacuum furnace also plays an important role in helping researchers to create a special experimental environment to carry out cutting-edge scientific research.

III. Technical Advantages and Contributions of XVACUUM Technology (Jiangsu) Co.

(I) Technological innovation ability

XVACUUM TECHNOLOGY (JIANGSU) CO., LTD. has always insisted on technological innovation in the research and development process of ultra-high vacuum furnace, constantly overcome technical problems, and demonstrated strong technical strength. The company's R&D team has studied vacuum physics, material science and thermal principles in depth, combined with advanced manufacturing technology to optimize and improve each system of the ultra-high vacuum furnace. In terms of vacuum system design, the pumping efficiency and vacuum stability have been improved by optimizing the combination method of vacuum pumps and the layout of vacuum pipelines. A new type of vacuum sealing structure is developed, and special sealing materials and precise processing technology are used to effectively reduce the leakage rate of the furnace body, so that the equipment can reach a higher vacuum level in a shorter period of time and maintain a stable ultra-high vacuum environment for a long time.

At the same time, the vacuum measuring instrumentation is improved to enhance the accuracy and reliability of vacuum measurement, which provides a strong guarantee for precise control of experimental and technological processes. In terms of heating system innovation, new heating materials and intelligent temperature control algorithm are adopted. The new heating material has the advantages of high heating efficiency, high temperature resistance and long service life, which can quickly and evenly heat the furnace chamber. Intelligent temperature control algorithm combined with high-precision temperature sensor realizes precise control and fast response to temperature, and can flexibly adjust the temperature change curve according to different process demands, ensuring the accuracy and stability of temperature in the experimental and production process. In addition, the company also applies IOT technology to the ultra-high vacuum furnace to realize remote monitoring and data transmission of the equipment. Operators can view the running status and experimental data of the equipment in real time through cell phones, computers and other terminals, set and adjust process parameters remotely, and operate and manage the equipment conveniently and quickly.

(II) Product customization service

XVACUUM Technology takes into full consideration the diversified needs of different industries and customers for ultra-high vacuum furnaces, and provides a full range of customized product solutions. The company's technical staff will deeply understand the customer's specific application scenarios, process requirements and special needs, and carry out personalized customization from the overall structural design of the equipment, the configuration of functional modules to the setting of process parameters. For semiconductor enterprises, according to the characteristics of their chip manufacturing process, we customize ultra-high vacuum furnaces with specific temperature range, vacuum and heating uniformity requirements, and equipped with precise gas flow control system and automated operation functions to meet the needs of mass production. For scientific research institutions, according to different research directions and experimental needs, flexible sample loading methods, adjustable process parameter ranges and rich data acquisition functions are designed to facilitate researchers to conduct experimental research under different conditions. At the same time, the company can also develop customized function modules according to the special needs of customers, such as special gas treatment system, on-line detection device, etc., to provide customers with the most suitable equipment to help customers solve practical problems and improve the efficiency of their scientific research and production.

(III) Perfect after-sales service system

XVACUUM Technology attaches great importance to after-sales service and has established a perfect after-sales service system. The company has a professional after-sales service team, which can provide customers with all-round, one-stop service. In the stage of equipment installation and commissioning, the technicians will go to the customer's site for equipment installation and commissioning to ensure the normal operation of the equipment, and provide systematic training to the customer's operators to make them skillful in the operation of the equipment, routine maintenance and troubleshooting skills. In the process of equipment use, the after-sales service team regularly visits and maintains the equipment, finds and solves potential problems in time, and prolongs the service life of the equipment. When equipment failure occurs, the after-sales service team can quickly respond by remote diagnosis or send technicians to the scene for maintenance, greatly reducing equipment downtime, to protect the customer's experiments and production work smoothly. In addition, the company also provides customers with equipment upgrading and remodeling services, according to technological development and changes in customer demand, the performance of the equipment to enhance and expand the function, so that customers are always able to use advanced, reliable equipment.

Fourth, the market status and development trend of ultra-high vacuum furnace

(A) the current market situation

At present, with the rapid development of semiconductor, superconductivity, nanomaterials and other emerging industries, as well as scientific research in the field of extreme experimental environment needs to increase, the market demand for ultra-high vacuum furnace shows a sustained growth trend. In the market, the suppliers of ultra-high vacuum furnace are mainly divided into international enterprises and domestic enterprises. Some international veteran enterprises occupy a larger share of the high-end market by virtue of their long-term technical accumulation, advanced manufacturing process and perfect sales and service network, mainly serving large-scale semiconductor enterprises, scientific research institutions and aerospace enterprises with extremely high requirements for equipment performance and precision. XVACUUM Technology (Jiangsu) Co., Ltd. as a representative of the rapid development of domestic enterprises in recent years, through continuous increase in R & D investment, improve product quality and technical level, in the domestic market has gradually gained a firm foothold, and began to expand to the international market. With in-depth understanding of the local market demand, high cost-effective and good customized services, domestic enterprises have won the recognition of many customers in scientific research institutes, small and medium-sized enterprises and other market areas, and gradually expanding market share. At the same time, domestic enterprises continue to make breakthroughs in some key technologies, and the gap with international enterprises is gradually narrowing.

(B) Development trend

Higher performance and precision: In the future, with the continuous progress of science and technology, the performance and precision requirements of ultra-high vacuum furnace will be increasingly high. The equipment will move toward higher vacuum, more precise temperature control, more stable operation performance direction to meet the semiconductor chip process continues to shrink, superconducting materials to further enhance the performance of cutting-edge technologies such as the demanding needs of the process environment. For example, we are developing ultra-high vacuum furnaces capable of realizing vacuum levels of 10-⁸ Pa or even lower, as well as heating systems with a temperature control accuracy of ±0.1 °C.

Intelligence and automation: Intelligence and automation will become an important development trend of ultra-high vacuum furnace. The introduction of artificial intelligence, machine learning and other technologies, so that the equipment can automatically analyze experimental data and process parameters, according to the sample characteristics and process requirements, automatically optimize the vacuum, temperature, heating time and other parameters to achieve intelligent operation. At the same time, it realizes the automatic operation of the equipment, including automatic feeding, automatic heating, automatic cooling, automatic testing and other functions, which reduces human error in operation and improves the production efficiency and accuracy of experimental data. In addition, through the Internet of Things technology to realize the remote monitoring and management of the equipment, it is convenient for the operator to grasp the operating status of the equipment at any time and any place.

Multifunctional integration: In order to meet the diversified needs of customers, the ultra-high vacuum furnace will integrate more functional modules. In addition to the existing vacuum extraction and heating functions, it will also integrate gas atmosphere control, surface treatment, online testing, sample transmission and other functions to realize multi-purpose and provide customers with more comprehensive solutions. Meanwhile, through the modular design, the functional modules of the equipment can be flexibly combined and replaced according to customer needs, which is convenient for equipment upgrading and maintenance, and improves the versatility and adaptability of the equipment.

Green environmental protection and energy saving: In the context of increasing environmental awareness, the ultra-high vacuum furnace will pay more attention to green environmental protection and energy-saving design. Adopt energy-saving heating elements, vacuum pumps and control systems, optimize the energy management system of the equipment and reduce the energy consumption of the equipment. At the same time, reduce the emissions of waste gas, waste water and waste residue produced during the operation of the equipment, and adopt environmentally friendly materials and processes to realize sustainable development. For example, develop new energy-saving heating materials to improve energy utilization efficiency; adopt oil-free vacuum pumps to avoid lubricant pollution of the environment.