CN117942690A

CN117942690A - Tail gas particulate matter purifying device and purifying method in semiconductor process flow

Info

Publication number: CN117942690A
Application number: CN202410273085.4A
Authority: CN
Inventors: 冯小军; 张华霞
Original assignee: Baoding Tuplas Semiconductor Technology Co ltd
Current assignee: Baoding Tuplas Semiconductor Technology Co ltd
Priority date: 2024-03-11
Filing date: 2024-03-11
Publication date: 2024-04-30

Abstract

The invention discloses a tail gas particulate matter purifying device and a purifying method in a semiconductor process flow. The device comprises a cooling module, a plasma generation module, a flow guiding module, a dust collecting module and a Y-shaped pipeline; the Y-shaped pipeline is provided with an input port, a straight through outlet and a side outlet pipe; the plasma generation module and the flow guide module are arranged in the Y-shaped pipeline; the cooling module is used for cooling the discharged waste gas, so that chemical components in the waste gas are accelerated to condense and grow into particles after being cooled; the plasma generation module is used for forming a plasma area above the inlet of the side outlet pipe and charging the flow particles to form charged particles; the flow guiding module is used for leading charged particle repulsion into the side outlet pipe; the dust collection module is connected with an outlet of a side outlet pipe of the Y-shaped pipeline and used for collecting inflow particles. The device has the advantages of convenient operation, all weather, high efficiency and low cost.

Description

Tail gas particulate matter purifying device and purifying method in semiconductor process flow

Technical Field

The invention belongs to the technical field of particulate matter removal in a semiconductor manufacturing process, and relates to a tail gas particulate matter purifying device in a semiconductor process flow.

Background

Particulate matter control has been accompanied by the development of semiconductor manufacturing processes, such as thin film deposition, chemical Vapor Deposition (CVD), atomic Layer Deposition (ALD), plasma vapor deposition (PECVD), etc., as well as thin film removal, plasma etching (PLASMA ETCH), plasma ashing (PLASMA ASHER), etc., in which the deposition and removal processes of the thin film are continuously performed with the mutual conversion of the gaseous and solid states, and particulate matters are also continuously generated.

Integrated circuit fabrication is driven by moore's law with smaller and smaller chip sizes and tighter control over particulate matter. In the process of manufacturing integrated circuit chips, particularly in the process of depositing and removing thin films (metal and nonmetal), a large amount of micro-nano particles are inevitably generated, and the occurrence of the particles in a vacuum chamber not only reduces the yield of wafers, but also enters an exhaust system along with a vacuum pipeline, so that the burden of the vacuum system is increased, and the maintenance difficulty is increased. Particulate contaminant removal is therefore a critical aspect of semiconductor manufacturing processes.

The particles originate from the factory processing production environment on the one hand and from solid particles of various dimensions generated by complex gas phase reactions in the flow sheet process on the other hand, wherein the particles generated in the flow sheet process are the most main sources. It is counted that 50% of the contaminating particles in the 4M DRAM production for a 1mm design line width are due to the factory process environment and the remaining 50% are due to the process equipment. In the production of 16M DRAM with the line width of 0.5mm, the particle generated by the process equipment is increased to 60 percent; in the production of 64M DRAM with a 0.35mm line width, the particulate matter produced by the process equipment increases to 75%; in the production of 256M DRAM with a line width of 0.25mm, the particulate matter generated by the process equipment is up to 90%, which is the most important pollution source.

As described above, particles are mainly formed in the vacuum chamber, and the vacuum chamber is connected to the exhaust system, so that the particles necessarily enter the exhaust system along with the residual gas after the gas phase reaction, and form pollution to the exhaust system. On the one hand, the particles can be adsorbed on the pipeline wall when passing through the exhaust pipeline, and are difficult to fall off, so that permanent pollution is formed. On the other hand, particulate matter can enter the environment through the exhaust system and pollute the environment. Because the vacuum system is continuously operated in all weather to maintain the vacuum level in the vacuum chamber, particulate matter can accumulate continuously in the exhaust line, and if the system is shut down for maintenance, the continuous operation of the semiconductor manufacturing process can be affected, and the system cost is increased. Therefore, removal of particulate matter in an exhaust system and collection of particulate matter is a critical technical problem in the current semiconductor manufacturing field.

Currently, in the field of semiconductor manufacturing, a general vacuum system is shown in fig. 1: the vacuum chamber is internally provided with a plurality of physical and chemical reactions for converting gas state and solid state, such as: siH ₄ (gas) +nh ₃ (gas) →si ₃N₄ (solid) +h ₂ (gas), and most of the time, the chemical combination reaction is insufficient, and various byproducts are generated, which are also a main source of particle generation. The vacuum pump is connected with the vacuum chamber through a foreline vacuum pipeline and maintains the vacuum environment in the chamber. The vacuum pump exhaust is connected with the tail gas treatment equipment through an exhaust pipeline, and the tail gas treatment equipment is used for treating harmful gas and then discharging the harmful gas into a plant emission main pipeline of a factory.

The publication CN117357991a discloses a process for treating semiconductor process exhaust gas, which comprises: preprocessing, namely introducing an object into a front-end mechanism to participate in front-end dust removal; mixing gas treatment, namely introducing the object output by the front-end mechanism into a mixing gas mechanism to participate in slow flow speed reduction treatment; purifying, namely introducing the object output by the gas mixing mechanism into the purifying mechanism to participate in plasma combustion purifying; cooling treatment, namely introducing the object output by the purification treatment into a cooling mechanism to perform cooling treatment; and discharging the object output by the cooling mechanism through the discharging mechanism. The scheme is complex in structure, needs combustion treatment and has certain potential safety hazard.

In actual working conditions, particles are mainly generated in the vacuum chamber, and in addition, the particles are gradually agglomerated into particles due to gradual attenuation of the reactivity of the reaction gas and can also be generated in a preceding-stage vacuum pipeline, so that the particles enter a vacuum pump, a subsequent exhaust pipeline and tail gas treatment equipment and are discharged from a main pipeline of factories.

The scheme for removing particles aiming at the vacuum exhaust pipeline comprises the following or a combination of the following;

1. A filtering device, such as a screen, is added before maintaining the dry pump of the vacuum system, and the particles are filtered by controlling the pore size of the screen, as shown in fig. 2. The disadvantage of this method is that the screen will affect the pumping speed of the vacuum pump and that the screen is at risk of clogging and therefore less is used.

2. The heat preservation function is added on the foreline vacuum pipeline and the exhaust pipeline, and the high temperature of the pipeline is maintained, so that the aim of inhibiting particle generation is fulfilled, and the method is more common, as shown in fig. 3. The disadvantage of this approach is that particles generated in the chamber can still accumulate in the subsequent vacuum system, thus increasing the burden on the vacuum system and not fundamentally solving the problem.

3. On the basis of the second method, the reverse concept is adopted, and a cold trap is added in the front vacuum pipeline, so that the active gas is quickly condensed or combined into particles, and then removed, as shown in fig. 4. A disadvantage of this approach is that it is difficult for the cold trap to function effectively due to the excessive gas flow rate in the pipe.

Disclosure of Invention

The invention aims to solve the key technical problem of how to remove particles in an exhaust system in the field of semiconductor manufacturing, and provides a tail gas particle purifying device in a semiconductor process flow, which has the advantages of convenient operation, all weather, high efficiency and low cost.

The technical scheme of the invention is as follows:

The tail gas particulate matter purifying device in the semiconductor process flow is characterized by comprising a cooling module, a plasma generating module, a flow guiding module, a dust collecting module and a Y-shaped pipeline; the Y-shaped pipeline is provided with an input port, a straight-through outlet and a side outlet pipe; the plasma generation module and the flow guide module are arranged in the Y-shaped pipeline; wherein,

One end of the cooling module is connected with an exhaust port of a vacuum chamber in the semiconductor manufacturing process, and the other end of the cooling module is connected with an input port of the Y-shaped pipeline and is used for cooling waste gas discharged from the vacuum chamber, so that chemical components in the waste gas are accelerated to condense and grow into particles after being cooled and then enter the Y-shaped pipeline;

The plasma generation module is used for forming a plasma region above the inlet of the side outlet pipe of the Y-shaped pipeline and charging particles flowing through the plasma region to form charged particles;

the flow guiding module is used for leading the charged particles into the side outlet pipe in a repulsive mode by utilizing an electric field generated by the flow guiding module;

The dust collection module is connected with the outlet of the side outlet pipe of the Y-shaped pipeline and is used for collecting inflow particles;

and the straight-through outlet of the Y-shaped pipeline is connected with a vacuum pump through an exhaust pipe and is used for exhausting residual gas with filtered particles through the vacuum pump.

Further, the plasma generation module and the flow guiding module are the same metal grid; the metal grid mesh is electrically connected with a power supply positioned outside the Y-shaped pipeline, and negative pressure is provided for the metal grid mesh.

Further, the power supply is a radio frequency power supply with the power of 1-200W and the frequency of 13.56 MHz; or the power supply is an alternating current power supply.

Further, the metal grid mesh is obliquely arranged in the Y-shaped pipeline at an angle of 45 degrees; the mesh radius of the metal grid is 3mm, and the thickness of the wire is 1mm.

Further, the metal grid is an elliptic metal grid, and the major axis of the elliptic metal grid is 170mm, and the minor axis of the elliptic metal grid is 120mm; the inner diameter of the Y-shaped pipeline is 160mm, and the outer diameter of the Y-shaped pipeline is 165mm; the lower end of the elliptical metal grid mesh is inserted into the inlet of the lateral outlet pipeline of the Y-shaped pipeline.

Further, the minimum distance between the edge of the elliptical metal grid net and the inner wall of the Y-shaped pipeline is 20mm.

Further, the cooling module comprises an air duct and a water cooling pipe, wherein one end of the air duct is connected with an air outlet of a vacuum chamber in the semiconductor manufacturing process through a flange, and the other end of the air duct is connected with an input port of the Y-shaped pipeline; the water cooling pipe is tightly wound on the outer wall of the air duct.

Further, the dust collecting module is a collecting tank, and the inner diameter and the outer diameter of the collecting tank are matched with the inner diameter and the outer diameter of the Y-shaped pipeline.

A purifying method based on the tail gas particulate matter purifying device in the semiconductor process flow comprises the following steps:

1) Turning on a power supply system to enable residual gas from a semiconductor manufacturing vacuum chamber to flow near the plasma generating module in the Y-shaped pipeline to form gas discharge, and generating plasma to form a plasma region; providing negative pressure for the flow guiding module;

2) When particles in the residual gas flow along with the residual gas through a plasma region formed in the Y-shaped pipeline, charging the particles by utilizing plasma to obtain charged particles; when the charged particles continuously move downwards along with the airflow and approach the diversion module, the charged particles are repelled by an electric field generated by the diversion module and are guided into a side outlet pipe of the Y-shaped pipeline to enter the collection module, so that the collection process of the particles in the residual gas is completed.

The invention comprises four modules: the device comprises a cooling module, a plasma generating module, a flow guiding module and a dust collecting module, wherein the cooling module, the plasma generating module and the flow guiding module are assembled and integrated in sequence and are integrally arranged on a pipeline of an exhaust system for manufacturing a semiconductor, and the dust collecting module is connected with a side outlet of the plasma generating module and a side outlet of the flow guiding module.

The cooling module comprises an air duct and a water cooling pipe, the water cooling pipe is wound on the air duct after being arranged at the exhaust port of the vacuum chamber, cold water is introduced into the pipe orifice at the lower part, and the water flows out from the pipe orifice at the upper part. The chemical components in the residual gas are accelerated to condense and grow into particles after being cooled. The cooling module is added to promote the growth of particles in the residual gas, improve the removal efficiency of the particles in the residual gas and reduce the pollutant components in the residual gas discharged finally.

The plasma generating module and the flow guiding module are arranged in a Y-shaped pipeline below the cooling module. The plasma generation module is mainly used for generating uniform plasmas, and aims to obtain uniform electron ion distribution in space. When the particles in the residual gas flow through the plasma, electrons and ions in the plasma collide with the particles and are adsorbed on the surfaces of the particles, so that the particles are charged. When the electron charging current and the ion charging current reach equilibrium, the amount of charge obtained by the particulate matter reaches saturation. Since the electron mass is much less than the ion mass, the thermal velocity of the electrons is much greater than that of the ions, and therefore, typically, the particulate matter eventually becomes electronegative. And parameters such as electron density and the like are changed by adjusting discharge parameters, so that the charge quantity of the particulate matters can be finally controlled. In summary, the purpose of the plasma module is to generate a uniform plasma and to charge the particles flowing therethrough.

The flow guiding module is a grid structure with negative bias, is characterized by being elliptical and obliquely arranged in the Y-shaped pipeline, and aims to repel electronegative particles by utilizing the negative bias of the grid and guide the particles in the exhaust pipeline to the side outlet of the Y-shaped pipeline. The diversion module and the plasma generation module share a metal grid structure. When the particles flow through the plasma module to charge, the particles are simultaneously repelled by the electric field biasing the surface of the grid structure negatively, and the negatively charged particles move along the surface of the grid structure. The residual gas particles generated in the semiconductor process vacuum chamber enter the exhaust pipeline and then are uniformly distributed in the pipeline in density. When the particles reach the flow guiding module, the particles move to the outlet below the Y-shaped pipeline along the inclined grid structure, so that the particles are not existed in the pipeline. The particles flow through the flow guiding module and then enter the dust collecting module.

The dust collection module mainly has the function of collecting particles from the flow guide module by arranging a collecting tank at a side outlet of the flow guide module. A groove structure of a certain size may be provided according to actual needs. Particles in the exhaust pipeline are subjected to the action of gravity and the repulsive force of the metal grid with negative bias, move towards the side of the Y-shaped pipeline along the surface of the grid, naturally fall into the groove of the side dust collecting module after passing through the flow guiding module, and realize the collection of the particles. The particles in the exhaust pipeline pass through the four modules in sequence and are finally collected in the dust collecting module. Since the plasma module and the flow guiding module are negatively biased, the negatively charged particles are repelled, so that the particles do not pollute the two modules, i.e. the two modules do not need to be cleaned. The dust collection module can be taken down regularly according to actual conditions and cleaned.

The method mainly comprises the following steps:

A. One end of the air duct is connected with an air outlet of an exhaust system pipeline of the semiconductor manufacturing process through a flange, and the other end of the air duct is connected with an input port of a Y-shaped pipeline; the Y-shaped pipeline is provided with an input port, a straight-through outlet and a side outlet pipe; the outside of the air duct is tightly clung to the spiral water cooling pipe, cold water is introduced into the water cooling pipe, enters from the lower pipe opening and flows out from the upper pipe opening.

B. The Y-shaped pipeline is connected to a vertical pipeline between the vacuum chamber and the vacuum pump, an input port of the Y-shaped pipeline is connected with the air duct through a flange, and a straight-through outlet of the Y-shaped pipeline is connected with the vacuum pump through an exhaust pipe.

C. The Y-shaped pipeline comprises a plasma generation module and a flow guide module. One elliptical metal grid mesh is obliquely arranged at the center of the Y-shaped pipeline and used for forming a plasma area above the inlet of the side outlet pipe of the Y-shaped pipeline, charging particles flowing through the plasma area to form plasma, and repelling the plasma to be led into the side outlet pipe; and a proper amount of space is reserved between the metal grid and the Y-shaped pipeline, and the metal grid can be bent to a certain extent if necessary so as to conveniently guide the movement of particles. The metal grid is connected with an external power supply of the Y-shaped pipeline, and a certain voltage is firstly applied to the metal grid to enable nearby gas to discharge to generate plasma, at the moment, the metal grid can automatically form negative bias, and the negative bias can generate an electric field to repel negatively charged particles to form a diversion effect, so that the metal grid is used as a plasma generation module and a diversion module.

D. And the outlet of the side outlet pipe of the Y-shaped pipeline is connected with the collecting module. And a collecting groove is arranged at the side outlet of the Y-shaped pipeline, and the collecting groove is connected with the outlet of the side outlet pipe of the Y-shaped pipeline by using a flange. And the flange is connected with the Y-shaped pipeline and is used for collecting the particles guided by the metal grid.

E. When the power supply system is turned on and the residual gas from the vacuum chamber for semiconductor manufacture flows near the metal grid mesh in the Y-shaped pipeline, gas discharge is formed, and uniform plasma is generated. The required plasma is satisfied by controlling the power of the power source or the like. The metal grid is connected with an external power supply and has a negative bias.

F. When the particles in the residual gas flow along with the residual gas through a plasma region formed in the Y-shaped pipeline, the plasma rapidly charges the particles, and the particles are electronegative. As the electronegative particulate matter continues to move downwardly with the airflow and approaches the vicinity of the electronegative elliptical metal grid, the electronegative particulate matter is repelled by the elliptical metal grid surface electric field and moves down the elliptical metal grid surface and toward the entrance of the side outlet tube of the Y-shaped duct. And when the particles flow to the lower part of the outlet of the side outlet pipe of the Y-shaped pipeline, the particles enter the collecting tank, and the collection process of the particles in the residual gas is completed.

G. and after a certain working time, the collecting tank is taken down from the exhaust pipeline, the particulate matters in the collecting tank are cleaned, and the particulate matters in the residual gas can be continuously recovered by being installed back to the original position again.

The duct sizes described in steps a and B may be set according to the actual plant exhaust duct sizes.

And C, setting an external power supply of the elliptical metal grid, wherein the purpose is to generate uniform plasmas by utilizing gas discharge near the elliptical metal grid, the power supply can use a radio frequency power supply with the frequency of 13.56MHz and the power of 1-200W or a common alternating current power supply with the frequency of tens to tens of thousands of Hz, and a certain negative bias voltage is required no matter what power supply is used. The oval metal grid mesh is obliquely arranged in the Y-shaped pipeline to block the straight-through outlet of the Y-shaped pipeline and guide particles to the side outlet pipe of the Y-shaped pipeline.

Step D the collecting vat size can be set up by oneself according to granule recovery frequency, and the size is bigger, and the particulate matter quantity that can hold just is more, and collection device's continuous operating time is longer, if required, can increase anti-return device in the collecting vat, avoids falling into the particulate matter in the collecting vat and is influenced by the air current and fly out the collecting vat.

After the plasma described in step E is generated, a quasi-electrically neutral environment containing free electrons, ions and various other reactive species is formed in this region. When the particles are close to the elliptical metal grid along with the airflow, surrounding free electrons and ions collide with the particles and adhere to the particles to charge the particles, and the charged particles generally show electronegativity after the charged particles reach balance because the moving speed of the free electrons is far greater than that of the ions.

The generated plasmas in the step F enable the surface of the elliptical metal grid to generate a non-electric neutral area, and a strong electric field is arranged in the area, so that repulsive force can be generated for the electronegative particles. The particles are repelled and then move along the inclined direction of the elliptical metal grid, and cannot pass through the metal grid and move along the side outlet of the Y-shaped pipeline.

The invention has the following advantages:

The efficiency of purifying the particles in the residual gas of the semiconductor manufacturing process can reach 100% theoretically, the method not only can realize green and environment-friendly effect and no emission of the particles, but also can protect the rear-stage vacuum pump of the vacuum system to a great extent. The device designed by the method can operate for a long time and has very low equipment cost.

Drawings

Fig. 1 is a schematic diagram of a vacuum system in the field of semiconductor fabrication.

Fig. 2 is a schematic diagram of a vacuum system with a filter device added before the dry pump.

Fig. 3 is a schematic diagram of a vacuum system with added thermal insulation.

Fig. 4 is a schematic diagram of a vacuum system with added cooling function.

FIG. 5 is a schematic view of the structure of the present invention;

Reference numerals: 1-a semiconductor process chamber; 2-particulate matter; 3-an airway; 4-a water-cooled tube; a 5-Y type pipeline; 6-a metal grid; 7-a radio frequency (alternating current) negative pressure power supply; 8-a collecting tank; 9-exhaust pipe; 10-vacuum pump.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings, which are given by way of illustration only and are not intended to limit the scope of the invention.

As shown in fig. 5, the method for collecting particles in a semiconductor process by using plasma provided by the invention specifically comprises the following steps:

The particles 2 in the semiconductor process chamber 1 are pumped out along with the exhaust gas through an exhaust pipeline of an exhaust system for semiconductor manufacture, enter the Y-shaped pipeline 5 through the gas guide pipe 3, and have the inner diameter of 160mm, the outer diameter of 165mm and the length of 400mm. The water-cooled tube 4 is wound on the outer wall of the air duct 3 to cool the exhaust gas, and the condensation growth of the particulate matters 2 becomes more and then flows into the adjacent Y-shaped pipeline 5. The Y-shaped pipeline 5 is made of glass, and has an inner diameter of 160mm and an outer diameter of 165 mm. One side of the elliptic metal grid 6 is obliquely arranged in the Y-shaped pipeline 5 at an angle of 45 degrees with the horizontal direction, the major axis of the elliptic metal grid 6 is 170mm, the minor axis of the elliptic metal grid 6 is 120mm, the edge of the elliptic metal grid is 20mm away from the inner wall of the Y-shaped pipeline 5, and the lower end of the elliptic metal grid 6 extends into the inlet of the lateral outlet pipeline of the Y-shaped pipeline 5. Connecting an elliptical metal grid 6 with an external radio frequency power supply 7 through a preformed hole on the wall of a Y-shaped pipeline 5 by using a wire wrapping an insulating layer, and sealing the elliptical metal grid, wherein the power of the radio frequency power supply 7 is 80W, and the frequency is 13.56MHz; after the residual gas is discharged from the vacuum chamber and the radio frequency power supply 7 is electrified, uniform plasmas can be generated on the side face of the elliptical metal grid 6.

The side outlet of the Y-shaped pipeline 5 is provided with a collecting tank 8, the outlet of the side outlet pipe of the Y-shaped pipeline 5 is connected with the collecting tank 8 through a flange, the inner diameter and the outer diameter of the collecting tank 8 can be correspondingly consistent with those of the Y-shaped pipeline 5, 160mm and 165mm are adopted, and the depth of the collecting tank 8 is 200mm.

The straight-through outlet of the Y-shaped pipeline 5 is connected with a flange vacuum pump 10 through an exhaust pipe 9, and the residual gas collected by the particulate matters is discharged through the vacuum pump 10.

When the device is operated, an external radio frequency power supply 7 is turned on, uniform plasmas are generated near the elliptic metal grid 6, residual gas and particles 2 flowing out of the semiconductor process chamber 1 enter the gas guide tube 3, the temperature is reduced, the growth of the particles is promoted, and then the particles enter the Y-shaped pipeline 5. The particles 2 will absorb a lot of charges when passing the plasma near the elliptical metal grid 6, and will carry negative electricity when the charged amount of the particles is stabilized, since the movement speed of electrons is greater than that of ions. Negatively charged particles are repelled by the electric field on the surface of the negative potential elliptic metal grid 6, are guided by the inclined elliptic metal grid 6 to enter the side outlet pipeline of the Y-shaped pipeline 5 and then fall into the collecting tank 8, and the residual gas is not influenced when passing through the metal grid 6.

For the collection of the residual gas particles 2, the metal grid 6 plays a decisive role, so that the size and placement of the metal grid 6 need to be particularly careful. On the one hand, the inclination angle of the metal grid is proper, so that the particles in the residual gas can enter the side outlet channel of the Y-shaped pipeline in enough time under the guidance of the metal grid. On the other hand, the radius of the holes of the metal grid is not more than 5mm, so that the particles can be intercepted and guided by the metal grid under the condition of small influence on air flow. Tests prove that the hole radius of the metal grid is 3mm, and the effect is better when the thickness of the wire is 1 mm.

The particulate matter falling into the collection tank 8 should be periodically recovered and cleaned.

In this example, collection efficiency was tested by taking the continuous artificial input of pollen Pini particles as an example. The air pressure of the system was maintained at 80 Pa during the experiment, and 5.437 g of pollen Pini particles having an average particle size of about 40 μm were uniformly and slowly sprinkled into the air duct 2. The particles are for the most part effectively collected by the method and enter the collection tank 8. The particle in the collecting tank 8 is 5.421 g after the experiment, and the collecting efficiency reaches 99.7%.

The invention adopts a plasma environment to charge particles in the semiconductor manufacturing residual gas, and further achieves the purpose of removing the particles in the residual gas by controlling the movement of the particles in the residual gas. The device adopted by the invention has simple structure, sustainable use, low cost, environmental protection and energy saving, can be conveniently installed in the tail gas treatment pipeline flow, has high efficiency for collecting the particulate matters, and has great significance for industrial production and environmental protection.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

It will be evident to those skilled in the art that the application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. The tail gas particulate matter purifying device in the semiconductor process flow is characterized by comprising a cooling module, a plasma generating module, a flow guiding module, a dust collecting module and a Y-shaped pipeline; the Y-shaped pipeline is provided with an input port, a straight-through outlet and a side outlet pipe; the plasma generation module and the flow guide module are arranged in the Y-shaped pipeline; one end of the cooling module is connected with an exhaust port of a vacuum chamber in the semiconductor manufacturing process, and the other end of the cooling module is connected with an input port of the Y-shaped pipeline and is used for cooling waste gas discharged from the vacuum chamber, so that chemical components in the waste gas are accelerated to condense and grow into particles after being cooled and then enter the Y-shaped pipeline;

2. The apparatus of claim 1, wherein the plasma generation module and the flow guide module are the same metal grid; the metal grid mesh is electrically connected with a power supply positioned outside the Y-shaped pipeline, and negative pressure is provided for the metal grid mesh.

3. The device according to claim 2, wherein the power source is a radio frequency power source with a power of 1-200W and a frequency of 13.56 MHz; or the power supply is an alternating current power supply.

4. The apparatus of claim 2, wherein the metal grid is inclined at a 45 ° angle within the Y-pipe;

The mesh radius of the metal grid is 3mm, and the thickness of the wire is 1mm.

5. The device of claim 2, wherein the metal grid is an oval metal grid with a major axis of 170mm and a minor axis of 120mm; the inner diameter of the Y-shaped pipeline is 160mm, and the outer diameter of the Y-shaped pipeline is 165mm; the lower end of the elliptical metal grid mesh is inserted into the inlet of the lateral outlet pipeline of the Y-shaped pipeline.

6. The apparatus of claim 5, wherein the edge of the oblong metal grid is a minimum distance of 20mm from the inner wall of the Y-shaped conduit.

7. The device according to claim 1, wherein the cooling module comprises an air duct and a water cooling pipe, one end of the air duct is connected with an air outlet of a vacuum chamber in a semiconductor manufacturing process through a flange, and the other end of the air duct is connected with an input port of the Y-shaped pipeline; the water cooling pipe is tightly wound on the outer wall of the air duct.

8. The apparatus of claim 1, wherein the dust collection module is a collection tank having inner and outer diameters that match the inner and outer diameters of the Y-shaped conduit.

9. A purification method based on the exhaust particulate matter purification device in the semiconductor process flow of claim 1, comprising the steps of: