CN116005135A - Automatic multi-piece flat silicon epitaxial device - Google Patents

Abstract

The invention relates to an automatic multi-chip flat silicon epitaxial equipment in the field of chemical vapor phase thin film deposition CVD equipment for semiconductor silicon wafers, including a chassis, a transmission chamber module, a process chamber module, a Load Lock chamber, a loading chamber module, a unit cleaning system and a cooling system. Among them, the process chamber module includes the upper cover of the reaction chamber, the lifting device, the quartz chamber, the heating module, the lower cover of the reaction chamber and the rotating mechanism; the upper cover of the reaction chamber, the quartz chamber and the lower cover of the reaction chamber are installed on the lifting device, and the heating module It is connected with the lower cover of the reaction chamber, and the heating module is provided with a graphite base; the quartz chamber is located between the upper cover of the reaction chamber and the lower cover of the reaction chamber, and the rotating mechanism is connected with the graphite base. Through optimized gas control, temperature control and defect control, the present invention realizes the growth of highly reliable 50μm-200μm thick epitaxy, improves the uniformity of resistivity of high-voltage thick epitaxial silicon wafers, and effectively reduces the generation of surface defects of silicon epitaxy, thereby It is conducive to adapting to the production process of high-voltage products with automotive specifications.

Description

An automatic multi-chip flat silicon epitaxial equipment

technical field

The invention relates to the field of chemical vapor phase thin film deposition CVD equipment for semiconductor silicon wafers, in particular to an automatic multi-chip flat silicon epitaxy equipment and equipment adapted to the vehicle-level thick epitaxy process.

Background technique

In the development of semiconductor science and technology, vapor phase epitaxy has played an important role, and this technology has been widely used in the industrial production of Si semiconductor devices and integrated circuits. The manufacturing process of semiconductor discrete components and integrated circuits requires epitaxial growth technology. Because the impurities contained in semiconductors are N-type and P-type, through different types of combinations, semiconductor devices and integrated circuits have various functions. Application of epitaxy Growth techniques are readily available. Silicon epitaxial growth methods can be divided into gas phase epitaxy, liquid phase epitaxy, and solid phase epitaxy. At present, the chemical vapor deposition growth method is widely used in the world to meet the integrity of the growth of epitaxial silicon wafers below 30 μm in thickness, the diversification of device structures, the device is controllable and simple, mass production, purity assurance, and uniformity requirements.

The prior art generally requires that the equipment used for chemical vapor phase epitaxy is usually called an epitaxial growth reaction furnace. Generally, it is mainly composed of four parts: transmission system, gas transportation system, electronic control system, reaction chamber process system, and exhaust system. According to the structure of the reaction chamber, the silicon epitaxial growth system has a flat plate type and a barrel type. Flat-plate multi-chip epitaxial furnace, the base rotates continuously during epitaxial growth, the air flow is parallel to the substrate directly above, and the bottom coil is used for induction heating, so the uniformity is good and the production capacity is large. The growth system is required to have good air tightness, otherwise it will A large number of epitaxial defects are generated due to air leakage and require uniform temperature zone and gas flow distribution. After decades of development, epitaxial technology has become more and more mature and stable, especially its precise doping concentration control and thickness control.

Problems existing in the existing technology: For high-voltage devices such as automotive-grade IGBT/FRD, thicker epitaxial layers need to be grown: single-chip epitaxial furnaces on the market usually use epitaxial silicon wafers with a thickness of less than 30 μm for growth, which is not suitable for high-voltage thick epitaxy. Existing Flat furnaces are generally suitable for epitaxy below 60 μm. With the upgrading of the market from consumer grade to industrial grade and automotive grade, the domestic high-voltage device market continues to grow. High-voltage devices are accompanied by the demand for thick epitaxy. The industrial market has evolved from 800V platforms, 1200V platforms and higher voltage platforms. It requires an epitaxial structure with a thickness of more than 80 μm, or even >100 μm, so higher requirements are placed on the design of the equipment, but in the existing technology, there are 1. The slip line defect in the thick epitaxial layer is not easy to control, and the generation of slip line is The epitaxial layer mechanical stress and thermal stress act together. 2. The epitaxial surface particles are not easy to control, because the growth time is long, the purity of the reaction chamber is required to be higher, and the poor environment of the chamber may easily cause the surface particles to exceed the standard. 3. The uniformity of the gas on the surface of the product is unstable and the adjustment method is relatively simple. 4. The base adopts the low-speed Hall speed measurement and revolution mode, and the speed control and detection capabilities are weak. 5. The manipulator method is equipped with a suction method on the front of the quartz, the failure rate is extremely high and it is difficult to stably guarantee the epitaxial surface defects.

Contents of the invention

In order to solve the technical problems of low reliability and resistivity uniformity of high-voltage thick epitaxial silicon wafers in the prior art, and excessive particles on the surface of high-voltage thick epitaxial silicon wafers, the invention discloses an automatic multi-chip flat silicon epitaxial equipment.

Technical scheme of the present invention is realized like this:

An automatic multi-chip flat silicon epitaxial equipment, including a chassis, a transmission chamber module, a process chamber module, a Load Lock chamber, a loading chamber module, a unit cleaning system and a cooling system;

The transmission chamber module, the process chamber module, the Load Lock chamber and the loading chamber module are in the case;

One end of the transfer chamber module is connected to the unit cleaning system, and the other end is connected to the Load Lock chamber;

The Load Lock cavity is connected to the loading cavity module;

The unit cleaning system is connected to the process chamber module;

The process chamber module includes a reaction chamber upper cover, a lifting device, a quartz chamber, a heating module, a reaction chamber lower cover and a rotating mechanism;

The upper cover of the reaction chamber, the quartz chamber and the lower cover of the reaction chamber are installed on the lifting device, the heating module is connected with the lower cover of the reaction chamber, and the quartz chamber adopts an airflow multi-inlet structure, so A graphite base is arranged in the quartz chamber, and the rotating mechanism is connected with the graphite base;

The quartz chamber is located between the upper cover of the reaction chamber and the lower cover of the reaction chamber;

The loading chamber module includes a cassette platform and a first manipulator; the cassette platform is located on both sides of the first manipulator;

The transfer chamber module includes a second manipulator; the second manipulator is located in the transfer chamber module.

The cooling system includes a water cooling system and an air cooling system;

The water cooling system is connected to the process chamber module;

The air cooling system is connected to the upper side of the case.

Preferably, special gas panel and air pressure system are also included;

The special gas panel is connected to the process chamber module, and the air pressure system is connected to the upper cover of the reaction chamber, the lower cover of the reaction chamber and the lifting device.

Preferably, the loading chamber module includes a cassette platform and a first manipulator; the cassette platform is located on both sides of the first manipulator.

Preferably, the transfer chamber module includes a second manipulator; the second manipulator is located in the transfer chamber module.

Preferably, the process chamber module further includes an exhaust gas treatment system, and the exhaust gas treatment system is located at the rear end of the quartz chamber.

Preferably, the heating module includes a high-frequency sensor and an infrared heating system.

Preferably, the graphite base is a silicon carbide coated graphite base.

Preferably, the quartz chamber adopts an airflow multi-inlet structure.

Preferably, the inner or outer wall of the quartz chamber is coated with a high reflection coating.

Preferably, the heating module is provided with an adjustable coil.

The present invention can solve the technical problems of low reliability and resistivity uniformity of high-voltage thick epitaxial silicon wafers in the prior art, and excessive particles on the surface of high-voltage thick epitaxial silicon wafers; the present invention can be used through optimized gas control and temperature control. Realize highly reliable 50μm-200μm thick epitaxial growth, improve the uniformity of resistivity of high-voltage thick epitaxial silicon wafers, and effectively reduce the technical effect of silicon particles.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below, wherein the same parts use the same drawings mark indicates. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings.

Fig. 1 is the structural representation of present embodiment;

Figure 2 is a schematic structural diagram of the process chamber module, the transmission chamber module, the Load Lock chamber, and the loading chamber module;

Fig. 3 is a schematic diagram of the structure of the process chamber module;

Fig. 4 is a structural schematic diagram of a heating module;

Fig. 5 is a schematic diagram of the airflow multi-inlet structure;

Fig. 6 is a schematic structural diagram of the second manipulator.

In the above-mentioned accompanying drawings, each figure number sign represents respectively:

1. Chassis

2. Transmission cavity module

2-1. The second manipulator

3. Process chamber module

3-1. Reaction chamber cover

3-2. Lifting device

3-3. Quartz chamber

3-4. Heating module

3-5. Lower cover of the reaction chamber

3-6. Rotating mechanism

3-7. Graphite base

a. Air flow multi-inlet structure

4. Load Lock cavity

5. Loading chamber module

5-1. Cassette platform

5-2. The first manipulator

6. Water cooling system

7. Air cooling system

8. Air pressure system

9. Special gas panel

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example

As shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, an automatic multi-chip flat silicon epitaxial equipment includes a chassis 1, a transmission chamber module 2, a process chamber module 3, a Load Lock chamber 4, a loading chamber module 5 and cooling system, in which the transmission chamber module 2 is made of aluminum alloy and hard anodized on the inner surface, which has anti-corrosion and weather-resistant effects.

The transmission chamber module 2, the process chamber module 3, the Load Lock chamber 4 and the loading chamber module 5 are connected to the cabinet 1, the upper side of the loading chamber module 5 is connected to the unit cleaning system, and the other end is connected to the Load Lock The chamber 4 is connected, and the LoadLock chamber 4 is connected with the loading chamber module 5; the transmission chamber module 2 has a fully automated transmission mode, and can be a silicon wafer on the cassette platform 5-1, the transmission chamber module 2 and the quartz chamber 3- 3 automatic transmission (modified a bit statement). In this embodiment, the normal-pressure handling system of the equipment is required to operate under the condition of cleanliness level 10, so as to avoid excessive particles on the surface of the silicon wafer caused by the poor environment of the loading chamber module 5 .

The unit cleaning system is connected to the upper side of the loading chamber module 5, through the unit cleaning system, the clean environment in the loading chamber area is improved, the particle size of the surface of the silicon wafer before epitaxy is effectively controlled, and the surface defects after thick epitaxy growth of the silicon wafer are reduced.

The process chamber module 3 is the core component of silicon epitaxial process growth, including the upper cover of the reaction chamber 3-1, the lifting device 3-2, the quartz chamber 3-3, the heating module 3-4, the lower cover of the reaction chamber 3-5 and the rotating Mechanism 3-6, wherein the reaction chamber upper cover 3-1, the quartz chamber 3-3 and the reaction chamber lower cover 3-5 are installed on the lifting device 3-2, and the heating module 3-4 is connected to the The reaction chamber lower cover 3-5 is connected, the rotating mechanism 3-6 is connected with the graphite base 3-7, the graphite base 3-7 is arranged in the quartz chamber 3-3, and the quartz chamber The chamber 3-3 is located between the reaction chamber upper cover 3-1 and the reaction chamber lower cover 3-5, and the rotating mechanism 3-6 is connected with the reaction chamber lower cover 3-5.

The cooling system includes a water cooling system 6 and an air cooling system 7. The water cooling system 6 is connected to the process chamber module 3. In this embodiment, the quartz chamber 3-3 is cooled by the water cooling system 6. The The air cooling system 7 is connected above the cabinet 1 and cools the environment in the entire cabinet 1 . In this embodiment, through the heating module 3-4 and the water cooling system 6, the accuracy of the process temperature can be guaranteed to be within ±1°C, and a controllable temperature gradient can be realized. Normal operation under process conditions.

Specifically, the loading chamber module 5 includes a cassette platform 5-1 and a first manipulator 5-2; the cassette platform 5-1 is located on both sides of the first manipulator 5-2; the transfer chamber module 2 includes a second Two manipulators 2-1; the second manipulator 2-1 is located in the transmission cavity module 2, wherein, since the traditional manipulators are all installed in the way of quartz vacuum front suction pieces, in order to reduce epitaxial surface defects, the second The quartz disk of the vacuum suction piece of manipulator 2-1 has been redesigned, including the overall shape, the position of the suction nozzle and the angle of the opening, as shown in Figure 6.

When the equipment is working, the cassette platform 5-1 is placed in the loading chamber, wherein the cassette platform 5-1 is equipped with silicon wafers, and the first manipulator 5-2 takes out the silicon wafers from the cassette platform 5-1 and places them in the Load Lock chamber In 4, the second manipulator 2-1 takes out the silicon chip from the Load Lock chamber 4 and places it on the graphite base 3-7, and heats the graphite base 3-7 to the process temperature through the heating module 3-4, and at the same time, heats the graphite base 3-7 to the quartz The reaction gas is introduced into the chamber 3-3. During this period, the reaction gas flows out horizontally from the front end of the quartz chamber 3-3 in multiple rows through the gas flow multi-inlet structure a, and flows through the graphite base 3-7. Surface, in this way, the process gas on the surface of the product is in a uniform and stable state, and the gas flow multi-inlet structure a is shown in Figure 5. During the process, the graphite base 3-7 is driven by the rotating mechanism 3-6 and rotates at a constant speed at a set speed. After the above work is completed, according to the growth time, while the silicon wafer grows a 50μm-200μm high-voltage thick epitaxial silicon wafer, the uniformity of the resistivity of the high-voltage thick epitaxial silicon wafer is guaranteed, and the quartz chamber 3-3 can effectively Reduce the production of silicon particles on the surface of high-voltage thick epitaxial silicon wafers, which is conducive to adapting to the production process of automotive-grade high-voltage products.

In this embodiment, through the above-mentioned installation method, the device has a precise heating module, which achieves better temperature accuracy and thermal field uniformity.

In a preferred embodiment, the heating module 3-4 includes a high-frequency sensor and an infrared heating system. In this embodiment, the graphite base 3-7 is heated by a high-frequency sensor and assisted by an infrared heating system. Composite heating mode, which is different from the traditional single heating mode, has the following characteristics: 1. Induction heating or infrared heating is transmitted to the bottom of the film through base heating; 2. Infrared heating irradiates the front surface of the film through infrared rays and we are Both the bottom and the front of the sheet are heated at the same time through bottom induction heating and front heating assistance. Through the composite heating mode, the axial temperature of the silicon wafer is smoother and the temperature difference is reduced.

In a preferred embodiment, in order to prevent impurities in the graphite base 3-7 from overflowing and affecting electrical parameters, in this embodiment, the graphite base 3-7 uses a silicon carbide coated graphite base 3-7 .

In a preferred embodiment, in order to improve the heating effect (increase reflection) and protect the quartz, strengthen the weather resistance and acid corrosion resistance, so in this embodiment, the inner wall or outer wall of the quartz chamber 3-3 is coated with a high reflective coating .

In a preferred embodiment, it also includes a special gas panel 9 and an air pressure system 8, the special gas panel 9 is connected to the process chamber module 3, the air pressure system 8 and the reaction chamber upper cover 3-1 , The lower cover 3-5 of the reaction chamber is connected with the lifting device 3-2.

The air pressure system 8 is used to drive the telescopic deformation of the lifting device 3-2. Through the air pressure system 8, the upper cover 3-1 of the reaction chamber and the lower cover 3-5 of the reaction chamber are attached to the quartz chamber 3-3 to prevent impurities enter, and at the same time heat the silicon wafer through the heating module 3-4 installed on the lower cover 3-5 of the reaction chamber;

In a preferred embodiment, since the epitaxial growth of the silicon wafer will generate certain waste gas, the rear end of the process chamber module 3 also includes a tail gas treatment system, and the generated waste gas is discharged by the tail gas treatment system.

In a preferred embodiment, in order to adapt to different graphite bases 3-7, silicon chip sizes and temperature field distributions, adjustable coils are provided on the heating modules 3-4.

The beneficial effects of the present invention are: through optimized gas control, temperature control and defect control, thick epitaxy can be realized, especially the growth of highly reliable 50 μm-200 μm thick epitaxy, and can effectively reduce the generation of silicon particles on the surface of high-voltage thick epitaxial silicon wafers, This is conducive to adapting to the production process of automotive-grade high-voltage products, suitable for mass production, and has controllability and repeatability.

Claims (9)

1. The automatic multi-piece flat silicon epitaxial device is characterized by comprising a case, a transmission cavity module, a process cavity module, a Load Lock cavity, a loading cavity module, a unit cleaning system and a cooling system;

the transmission cavity module, the process cavity module, the Load Lock cavity, the loading cavity module and the chassis are arranged in the chassis;

one end of the transmission cavity module is connected with the unit cleaning system, and the other end of the transmission cavity module is connected with the Load Lock cavity;

the Load Lock cavity is connected with the loading cavity module;

the unit cleaning system is connected with the process chamber module;

the process chamber module comprises a reaction chamber upper cover, a lifting device, a quartz chamber, a heating module, a reaction chamber lower cover and a rotating mechanism;

the reaction chamber upper cover, the quartz chamber and the reaction chamber lower cover are arranged on the lifting device, the heating module is connected with the reaction chamber lower cover, the quartz chamber adopts an airflow multi-air inlet structure, and a graphite base is arranged in the quartz chamber; the rotating mechanism is connected with the graphite base;

the quartz chamber is positioned between the reaction chamber upper cover and the reaction chamber lower cover;

the cooling system comprises a water cooling system and an air cooling system;

the water cooling system is connected with the process chamber module;

the air cooling system is connected to one side of the case.

2. The automated multi-wafer flat silicon epitaxial apparatus of claim 1, wherein the load chamber module comprises a cassette platform and a first robot; the cassette platform is located at two sides of the first manipulator.

3. The automated multi-wafer flat silicon epitaxial apparatus of claim 1, wherein the transfer chamber module comprises a second robot; the second manipulator is located in the transmission cavity module.

4. The automated multi-wafer flat silicon epitaxial apparatus of claim 1, further comprising a turbo-panel and an air compression system;

the special gas panel is connected with the process chamber module, and the air compression system is connected with the reaction chamber upper cover, the reaction chamber lower cover and the lifting device.

5. The automated multi-wafer flat panel silicon epitaxial apparatus of claim 1, wherein the process chamber module further comprises an exhaust gas treatment system positioned at a rear end of the quartz chamber.

6. The automated multi-wafer flat silicon epitaxial apparatus of claim 1, wherein the heating module comprises a high frequency sensor and an infrared heating system.

7. An automated multi-wafer flat silicon epitaxial apparatus according to claim 1 wherein the graphite susceptor is a silicon carbide coated graphite susceptor.

8. The automated multi-wafer flat panel silicon epitaxial apparatus of claim 7, wherein the quartz chamber inner or outer walls are coated with a highly reflective coating.

9. An automated multi-wafer flat silicon epitaxial apparatus according to claim 6 wherein the heating module is provided with an adjustable coil.

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