CN117169128A - Multichannel chamber cleaning endpoint monitoring device and method - Google Patents

Abstract

A multi-channel chamber cleaning endpoint monitoring device and method relate to the technical field of semiconductors. The structure is as follows: a light source, a gas chamber, a detector and a lens assembly. The method comprises the following steps: the device is vertically arranged beside a tail drain pipeline at the front end of a cleaning chamber of a target process machine, and a power switch is turned on; removing (purge) fine particulate impurities and residual gas from the gas chamber; introducing the gas to be detected in the cleaning chamber into the gas chamber; the light source works to generate infrared light rays which pass through the gas to be detected after passing through the collimating light path of the collimating lens; the detector monitors and collects the light intensity change of the light rays at the receiving end of the gas chamber after gas absorption in real time, a gas concentration-time curve chart is output through a GUI interface, the gas concentration-time curve chart is increased from a zero point to a stable interval and then is reduced to a preset gas concentration end point monitoring minimum value, and the cleaning end point is obtained. The invention is convenient to install and use, can accurately identify low-concentration gas, effectively improves the types and the quantity of the monitoring gas and expands the applicable process range.

Description

A multi-channel chamber cleaning endpoint monitoring device and method

Technical field

The invention relates to the technical field of semiconductor equipment, specifically a multi-channel chamber cleaning endpoint monitoring device and method.

Background technique

Thin film technology is a key technology for manufacturing semiconductor devices. It is a miniature "building" built on layers of films grown layer by layer and combined with other processes. Mastering more advanced semiconductor technology is the key to rejuvenating the country. At present, the chamber cleaning of the thin film production process is subject to certain restrictions. The environment of the chamber is affected by many factors such as sediment thickness, sediment type, temperature, pressure and active gas. It is difficult to calibrate an optimal cleaning time, resulting in Film accumulation or over-etching phenomenon. Improper or excessive cleaning of the chamber will greatly affect the quality and yield of wafers. And due to the limitation of a single type of current thin film cleaning equipment, it is impossible to clean thin film production processes involving numerous types of deposition materials.

There are three types of chamber cleaning devices currently available at home and abroad, including:

The first is to put the filter into the optical path and rotate the filter wheel to generate the incident angle, thereby transmitting the wavelength. However, the aging structure of this equipment is prone to test errors, and it is only used to test a single gas SIF ₄ in the CVD process.

Second, the principle of infrared absorbance is used to compare the target gas species in the effluent absorbance with a reference signal to calculate the concentration of the target gas species. However, this equipment is only used to test two gases SIF ₄ and CF ₄ in the CVD process, which has great limitations.

The third type is that this equipment is only used to test one SIF ₄ gas in the CVD process. The test gas is single and the process is limited.

To sum up, the above-mentioned existing devices have defects such as aging equipment test system structure, single type of measurement gas, narrow process application range, and difficulty in identifying multiple low-concentration gases, etc., thus limiting the production development of semiconductor thin film processes to a higher level. .

Contents of the invention

The present invention aims to overcome the shortcomings of the existing technology and aims to provide a multi-channel chamber cleaning endpoint monitoring device and method. This device can simultaneously monitor multiple types of gases involved in membrane chamber cleaning and accurately identify low concentrations. gases and are used in a wide range of thin film processes.

In order to accomplish the above tasks, the present invention provides the following technical solution: a multi-channel chamber cleaning endpoint monitoring device, which is installed vertically next to the front end and tail pipe of the cleaning chamber for real-time gas concentration monitoring. The device structure includes:

light source;

Gas chamber, the gas chamber includes a cylindrical chamber body and an air inlet pipe and an air outlet pipe vertically located on the side of the chamber body. The air inlet pipe and air outlet pipe ports are standard NW25 flange interfaces;

A detector, which includes a filter and a pyroelectric detection element;

The lens group includes a collimating lens and a focusing lens respectively located on both sides of the gas chamber for collimating and converging light and sealing the gas chamber.

Preferably, the light source is a broadband far-infrared light source with a wavelength ranging from 2 μm to 20 μm.

Preferably, the optical path of the light source is 600mm.

Preferably, the inner surface of the gas chamber is smoothly polished, with a roughness of less than 0.2 μm.

Preferably, the detector is of dual-channel, four-channel or eight-channel type.

A multi-channel chamber cleaning end point monitoring method, through a multi-channel chamber cleaning end point monitoring device, includes the following steps:

Step 1: Install the device vertically next to the front and rear pipes of the cleaning chamber of the target process machine, and turn on the power switch;

Step 2: Purge the fine particle impurities and residual gas in the gas chamber;

Step 3: Pass the gas to be measured in the clean chamber into the gas chamber;

Step 4: The infrared light generated by the operation of the light source passes through the gas to be measured after being collimated by the collimating lens and passing through the light path;

Step 5: The detector monitors and collects in real time the light intensity changes of the light at the receiving end of the gas chamber after gas absorption, and outputs the gas concentration-time curve through the GUI interface, rising from zero to the stable range and then falling to the preset value. The minimum value of gas concentration endpoint monitoring is the cleaning endpoint.

Preferably, the application process in step 1 is any one of CVD, PVD or SEG.

Preferably, the gas to be measured in step 3 is one or more of SIF ₄ , CF ₄ , WF ₆ , TiF ₄ , CuF ₂ , AlF ₂ , CoF ₂ and TaF ₅ .

Preferably, the real-time monitoring in step 5 is a dynamic detection method that uses an embedded algorithm to achieve accurate calculation of multi-channel gas concentration taking into account various drift conditions, including temperature, pressure, film thickness and Air velocity factor.

Preferably, the gas concentration end point monitoring minimum value setting range in step 5 is 1.0*10 ^-6 -50.0*10 ^-6 VOL.

Due to the adoption of the above technical solution, the positive effects of the present invention compared with the prior art are:

(1) The device of the present invention is simple and convenient to install and easy to operate.

(2) The gas pipeline is made of special gas corrosion-resistant material and the inner surface of the gas chamber is smoothly polished to minimize gas absorption, so each low-concentration gas can be accurately identified.

(3) The present invention can monitor the real-time concentration values of up to seven gases at the same time, and the feedback on the end point of chamber cleaning can play a very good protective role in the chamber.

(4) The present invention expands the application of cleaning endpoint monitoring in CVD, PVD and SEG processes, can effectively improve chamber cleaning efficiency and improve production levels in the field of thin film processes.

Therefore, the present invention has the characteristics of simple and convenient installation and use, accurate identification of low-concentration gases, monitoring of multiple types of gases, and a wide range of applicable processes.

Description of drawings

Figure 1 is a flow chart of the multi-channel chamber cleaning method provided by the present invention;

Figure 2 is a schematic structural diagram of a cleaning end point detection device according to Embodiment 1 of the present invention;

Figure 3 is a working curve diagram of the cleaning end point detection device according to Embodiment 1 of the present invention;

Figure 4 is a schematic structural diagram of a cleaning end point detection device according to Embodiment 2 of the present invention;

Figure 5 is a schematic structural diagram of the detection pattern of the cleaning end point detection device in Embodiment 2 of the present invention;

Figure 6 is a schematic structural diagram of a cleaning end point detection device according to Embodiment 3 of the present invention;

Figure 7 is a schematic structural diagram of the detection pattern of the cleaning end point detection device in Embodiment 3 of the present invention.

Detailed ways

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

It should be noted:

The terms "first", "second" and "third" (if present) in the description and claims of the present invention and the drawings of the embodiments of the present invention are only used to distinguish different objects, rather than to describe a specific sequence;

In addition, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units and is not limited to the listed steps or units. Rather, steps or elements not listed may optionally be included, or other steps or elements inherent to the process, method, product or apparatus may optionally be included.

What needs to be understood is:

In the description of the embodiments of the present invention, the terms "upper", "lower", "top", "bottom" and other indicative orientation or position words are only based on the orientation or positional relationships shown in the drawings of the embodiments of the present invention. , is for the convenience of describing the embodiments of the present invention and simplifying the description, but does not indicate or imply the specific orientation, specific orientation configuration and operation that the described device or element must have, and therefore cannot be understood as a limitation of the present invention.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or a movable connection. It can also be integrated into one body; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements. Unless otherwise clearly limited, for those of ordinary skill in the art Personnel may understand the specific meanings of the above terms in the present invention according to specific circumstances.

What also needs to be explained is:

The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

Below, the technical solution of the present invention is described in detail with specific embodiments.

Example 1

Embodiment 1 provides a dual-channel chamber cleaning endpoint monitoring device, as shown in Figure 2, which is installed vertically on the side of the tail pipe at the front end of the cleaning chamber for real-time gas concentration monitoring, including:

light source 1;

Gas chamber 2. The gas chamber 2 includes a cylindrical chamber body 21 and an air inlet pipe 22 and a gas outlet pipe 23 that are vertically arranged on the chamber body and connected thereto. The air inlet pipe 23 and the gas outlet pipe 23 have two ports. It is a standard NW25 flange interface;

Detector 3, the detector includes optical filters 31, 31 and pyroelectric detection elements 35, 36;

The lens group includes a collimating lens 12 and a focusing lens 26 respectively located on both sides of the gas chamber 2 for collimating and converging light and sealing the gas chamber 2 .

Specifically, the light source 1 is a broadband far-infrared light source with a wavelength ranging from 2 μm to 20 μm.

Specifically, the optical path of light source 1 is 600mm.

Specifically, the gas chamber 2 is made of special gas corrosion-resistant material and the inner surface is smoothly polished with a roughness of less than 0.2 μm.

Specifically, detector 3 is a dual-channel type.

This embodiment also provides a dual-channel chamber cleaning endpoint monitoring method. As shown in Figure 1, the above-mentioned dual-channel chamber cleaning endpoint monitoring device includes the following steps:

Step 1: Install the device vertically next to the front and rear pipes of the cleaning chamber of the target process machine, and turn on the power switch;

Step 2: Purge the fine particle impurities and residual gas in the gas chamber;

Step 3: Pass the gas to be measured in the clean chamber into the gas chamber;

Step 4: The infrared light generated by the operation of the light source passes through the gas to be measured after being collimated by the collimating lens and passing through the light path;

Step 5: The detector monitors and collects in real time the light intensity changes of the light at the receiving end of the gas chamber after gas absorption, and outputs the gas concentration-time curve through the GUI interface, rising from zero to the stable range and then falling to the preset value. The minimum value of gas concentration endpoint monitoring is the cleaning endpoint.

Specifically, the application process in step 3 is SEG.

Specifically, the gas to be measured in step 4 is SIF ₄ 24.

Specifically, the real-time monitoring in step 5 is a dynamic detection method that uses an embedded algorithm to achieve accurate calculation of dual-channel gas concentration taking into account various drift conditions, including temperature, pressure, film thickness and air flow velocity. factor.

Specifically, the minimum value for gas concentration endpoint monitoring preset in step 5 is 10.0*10 ^-6 VOL.

Figure 2 shows the working process of this embodiment 1: the gas SIF ₄ 24 to be measured enters the cylindrical chamber body 21 of the gas chamber 2 through the air inlet pipe 22 (and is discharged through the gas outlet pipe 23), and the light source 1 works to emit infrared light 11 , after being collimated by the collimating mirror 12, a parallel light 13 is formed, which passes through the SiF ₄ 24 gas in the cylindrical chamber body 21. The parallel light 13 changes in light intensity after being absorbed by the gas. After being absorbed, the light 25 passes through the focusing mirror 26 Converge and reach the filter 31 (reference channel window) and filter 32. The filtered and selected transmitted light 33 and 34 reach the pyroelectric detection units 35 and 36 respectively, and are then calculated by the embedded algorithm and output on the GUI interface. SiF ₄ gas concentration (c) - time (t) curve (as shown in Figure 3), first rises from zero to the stable range, and reaches the set gas concentration endpoint monitoring minimum value 10*10-6VOL at t1 , t1 is the cleaning end point.

This implementation provides a dual-channel chamber cleaning endpoint monitoring method that expands the application of SEG technology in the thin film field. It monitors the SIF ₄ gas concentration in real time and senses the SEG chamber cleaning endpoint. Accurate cleaning endpoint monitoring can play a role in the SEG chamber. It has a very good protective effect and improves SEG chamber cleaning efficiency and thin film process production efficiency. This embodiment shows a good positive effect. Since the gas pipeline is made of special gas corrosion-resistant material and the inner surface is smoothly polished, the absorption of SIF ₄ 24 gas by the entire chamber wall can be minimized, and the embedded algorithm is taking into account It achieves accurate calculation of the concentration of dual-channel gas (SIF ₄ gas channel and reference channel) under various drift conditions of temperature, pressure, film thickness and gas flow rate, and expands the application of chamber cleaning end-point monitoring in the SEG process.

Example 2

This embodiment provides a four-channel chamber cleaning endpoint monitoring device, as shown in Figure 4, which is installed vertically next to the tail pipe at the front end of the cleaning chamber for real-time gas concentration monitoring, including:

light source 10;

Gas chamber 20. The gas chamber 20 includes a cylindrical chamber body 210 and an air inlet pipe 220 and a gas outlet pipe 230 that are vertically provided on the chamber body and connected thereto. The ports of the gas inlet pipe and the gas outlet pipe are standard NW25 flange interface;

Detector 30, the detector includes optical filters 310, 320, 330, 340 and pyroelectric detection elements 350, 360, 370, 380;

The lens group includes a collimating lens 120 and a focusing lens 280 respectively located on both sides of the gas chamber 20 for collimating and converging light and sealing the gas chamber 20 .

Specifically, the light source 10 is a broadband far-infrared light source with a wavelength ranging from 2 μm to 20 μm.

Specifically, the optical path of the light source 10 is 600mm.

Specifically, the gas chamber 20 is made of special gas corrosion-resistant material and the inner surface is smoothly polished with a roughness of less than 0.2 μm.

Specifically, the detector 30 is a four-channel type.

This embodiment also provides a four-channel chamber cleaning endpoint monitoring method. As shown in Figure 1, the above-mentioned four-channel chamber cleaning endpoint monitoring device includes the following steps:

Step 1: Install the device vertically next to the front and rear pipes of the cleaning chamber of the target process machine, and turn on the power switch;

Step 2: Purge the fine particle impurities and residual gas in the gas chamber;

Step 3: Pass the gas to be measured in the clean chamber into the gas chamber;

Step 4: The infrared light generated by the operation of the light source passes through the gas to be measured after being collimated by the collimating lens and passing through the light path;

Step 5: The detector monitors and collects in real time the light intensity changes of the light at the receiving end of the gas chamber after gas absorption, and outputs the gas concentration-time curve through the GUI interface, rising from zero to the stable range and then falling to the preset value. The minimum value of gas concentration endpoint monitoring is the cleaning endpoint.

Specifically, the application process in step 3 is CVD.

Specifically, the gases to be measured in step 4 are SIF ₄ 240, CF ₄ 250 and WF ₆ 260.

Specifically, the real-time monitoring in step 5 is a dynamic detection method that uses an embedded algorithm to accurately calculate the gas concentration of the four channels while considering various drift conditions, including temperature, pressure, film thickness and air flow velocity. factor.

Specifically, the minimum value for gas concentration endpoint monitoring in step 5 is set to 30.0*10 ^-6 VOL.

Figure 4 shows the working process of this embodiment as follows: the gases SIF ₄ 240, CF ₄ 250 and WF ₆ 260 to be measured enter the cylindrical chamber body 210 of the gas chamber 20 through the air inlet pipe 220 (discharged through the gas outlet pipe 230), the light source 10 works to emit infrared light 110, which is collimated by the collimating mirror 120 to form parallel light 130, which passes through the SIF ₄ 240, CF ₄ 250 and WF ₆ 260 gases in the cylindrical chamber body 210. The parallel light 130 is absorbed by the gas. The light intensity changes. After being absorbed, the light 270 converges through the focusing lens 280 and reaches the filter 310 (refer to the channel window) and the filters 320, 330, 340. The filtered and selected transmitted light 311, 321, 331, 341 Reach the pyroelectric detection units 350, 360, 370, and 380 respectively, and then calculate the SIF ₄ 230, CF ₄ 240, and WF ₆ 250 gas concentration (c)-time (t) curves on the GUI interface after calculation by the embedded algorithm. (As shown in Figure 5), first rise from zero to the stable range, and reach the set gas concentration endpoint monitoring minimum value at t1 (WF ₆ 260), t2 (CF ₄ 250), and t3 (SIF ₄ 240) respectively. 30*10 ^-6 VOL, t3 is the cleaning end point.

This implementation provides a four-channel chamber cleaning endpoint monitoring method that effectively improves the monitoring gas type and quantity compared to Embodiment 1, monitors SIF ₄ 230, CF ₄ 240, and WF ₆ 250 gas concentrations in real time and senses the CVD chamber cleaning endpoint. , accurate cleaning endpoint monitoring can play a very good role in protecting the CVD chamber and improve the cleaning efficiency of the CVD chamber and the production efficiency of the thin film process. This embodiment shows a good positive effect. Since the gas pipeline is made of special gas corrosion-resistant material and the inner surface is smoothly polished, the absorption of SIF ₄ 240, CF ₄ 250 and WF ₆ 260 gases by the entire chamber wall can be minimized. , and the embedded algorithm achieves accurate calculation of the concentration of the four-channel gas (SIF ₄ , CF ₄ , WF ₆ gas channel and reference channel) taking into account various drifts in temperature, pressure, film thickness and gas flow velocity to prevent excessive cleaning Damage to chamber walls.

Example 3

This embodiment provides an eight-channel chamber cleaning endpoint monitoring device, as shown in Figure 6, which is installed vertically next to the tail pipe at the front end of the cleaning chamber for real-time gas concentration monitoring, including:

light source 100;

Gas chamber 200. The gas chamber 2 includes a cylindrical chamber body 2100 and an air inlet pipe 2200 and a gas outlet pipe 2300 that are vertically provided on the chamber body and connected with it. The ports of the gas inlet pipe and the gas outlet pipe are standard NW25 flange interface;

Detector 300, which includes optical filters 3100, 3200, 3300, 3400, 3500, 3700 and 3800 and pyroelectric detection elements 3900, 4000, 4100, 4200, 4300, 4400, 4500 and 4600;

The lens group includes a collimating lens 120 and a focusing lens 3000 respectively located on both sides of the gas chamber 200 for collimating and converging light and sealing the gas chamber 200 .

Specifically, the light source 100 is a broadband far-infrared light source with a wavelength ranging from 2 μm to 20 μm.

Specifically, the optical path of the light source 100 is 600mm.

Specifically, the gas chamber 200 is made of special gas corrosion-resistant material and the inner surface is smoothly polished with a roughness of less than 0.2 μm.

Specifically, the detector 300 is an eight-channel type.

This embodiment also provides an eight-channel chamber cleaning endpoint monitoring method. As shown in Figure 1, the above-mentioned eight-channel chamber cleaning endpoint monitoring device includes the following steps:

Step 1: Install the device vertically next to the front and rear pipes of the cleaning chamber of the target process machine, and turn on the power switch;

Step 2: Purge the fine particle impurities and residual gas in the gas chamber;

Step 3: Pass the gas to be measured in the clean chamber into the gas chamber;

Step 4: The infrared light generated by the operation of the light source passes through the gas to be measured after being collimated by the collimating lens and passing through the light path;

Step 5: The detector monitors and collects in real time the light intensity changes of the light at the receiving end of the gas chamber after gas absorption, and outputs the gas concentration-time curve through the GUI interface, rising from zero to the stable range and then falling to the preset value. The minimum value of gas concentration endpoint monitoring is the cleaning endpoint.

Specifically, the application process in step 3 is PVD.

Specifically, the gases to be measured in step 4 are SIF ₄ 2400, WF ₆ 2500, TiF ₄ 2600, CuF ₂ 2700, AlF ₂ 2800 and CoF ₂ 2900.

Specifically, the real-time monitoring in step 5 is a dynamic detection method that uses embedded algorithms to achieve accurate calculation of eight-channel gas concentrations while considering various drift conditions, including temperature, pressure, film thickness and air flow velocity. factor.

Specifically, the minimum value for gas concentration endpoint monitoring in step 5 is set to 50.0*10 ^-6 VOL.

Figure 5 shows the working process of this embodiment as follows: the gases to be measured SIF ₄ 2300, WF ₆ 2400, TiF ₄ 2500, CuF ₂ 2600, AlF ₂ 2700 and CoF ₂ 2800 enter the cylindrical cavity of the gas chamber 200 through the air inlet pipe 2200 The chamber body 2100 (exhausted through the air outlet pipe 2300), the light source 100 works to emit infrared light 1100, which is collimated by the collimating mirror 1200 to form parallel light 1300, which passes through the SIF ₄ 2400, WF ₆ 2500, and TiF ₄ 2600, CuF ₂ 2700, AlF ₂ 2800 and CoF ₂ 2900 gases, the parallel light 1300 changes in light intensity after being absorbed by the gas. After being absorbed, the light 3000 converges through the focusing mirror 3001 and reaches the filter 3100 (refer to the channel window) and filters 3200, 3300, 3400, 3500, 3600, 3700, 3800. After filtering and selecting, the transmitted light 3101, 3201, 3301, 3401, 3501, 3601, 3701, 3801 reaches the pyroelectric detection units 3900 and 4000 respectively. , 4100, 4200, 4300, 4400, 4500, 4600, and then calculated by the embedded algorithm and output SIF ₄ 2400, WF ₆ 2500, TiF ₄ 2600, CuF ₂ 2700, AlF ₂ 2800 and CoF ₂ 2900 gas concentrations in the GUI interface ( c)--Time (t) curve (shown in Figure 7), first rises from zero to the stable range, t1 (AlF ₂ 2800), t2 (CoF ₂ 2900), t3 (TiF ₄ 2600), t4 (WF ₆ 2500), t5 (CuF ₂ 2700), and t6 (SIF ₄ 2400) respectively reach the set gas concentration endpoint monitoring minimum value 30*10 ^-6 VOL, and t6 is the cleaning endpoint.

This implementation provides an eight-channel chamber cleaning endpoint monitoring method. Compared with Embodiment 1 and 2, it improves the type and quantity of monitored gases to a greater extent and expands the application of PVD technology in the field of thin films. It monitors SIF ₄ 2400 in real time. , WF ₆ 2500, TiF ₄ 2600, CuF ₂ 2700, AlF ₂ 2800 and CoF ₂ 2900 gas concentrations and sense the cleaning endpoint of the SEG chamber. Accurate cleaning endpoint monitoring can play a very good protective role in the PVD chamber and improve PVD Chamber cleaning efficiency and film process production efficiency. This embodiment 3 shows good positive effects. Since the gas pipeline is made of special gas corrosion-resistant material and the inner surface is smoothly polished, the impact of the entire chamber wall on SIF ₄ 2400, WF ₆ 2500, TiF ₄ 2600, The absorption of CuF ₂ 2700, AlF ₂ 2800 and CoF ₂ 2900 gases, and the embedded algorithm realizes eight-channel gases (SIF ₄ , WF ₆ , TiF ₄ , Accurate calculation of CuF ₂ , AlF ₂ and CoF ₂ gas channel and reference channel) concentrations, and expands the application of chamber cleaning endpoint monitoring in PVD processes.

In the description process of the above manual:

Descriptions of the terms "this embodiment", "embodiments of the present invention", "as shown in...", "further", "further improved technical sub-solutions", etc., mean the specific features described in the embodiment or example , structures, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example, and the specific features, structures, Materials or features may be combined or combined in a suitable manner in any one or more embodiments or examples;

In addition, those of ordinary skill in the art may combine or combine different embodiments or examples and features of different embodiments or examples described in this specification, provided that no contradiction occurs.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principles and spirit of the invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (10)

1. A multi-channel chamber cleaning endpoint monitoring device, which is installed vertically next to the front end and tail pipe of the cleaning chamber for real-time gas concentration monitoring. It is characterized in that the structure of the device includes: light source; Gas chamber, the gas chamber includes a cylindrical chamber body and an air inlet pipe and a gas outlet pipe that are vertically located on the chamber body and connected with it. The ports of the air inlet pipe and the gas outlet pipe are standard NW25 flange interfaces; A detector, which includes a filter and a pyroelectric detection element; The lens group includes a collimating lens and a focusing lens respectively located on both sides of the gas chamber for collimating and converging light and sealing the gas chamber. 2. A multi-channel chamber cleaning endpoint monitoring device according to claim 1, characterized in that the light source is a broadband far-infrared light source with a wavelength ranging from 2 μm to 20 μm. 3. A multi-channel chamber cleaning endpoint monitoring device according to claim 1, characterized in that the optical path of the light source is 600 mm. 4. A multi-channel chamber cleaning endpoint monitoring device according to claim 1, characterized in that the gas chamber is made of special gas corrosion-resistant material and the inner surface is smoothly polished with a roughness of less than 0.2 μm. 5. A multi-channel chamber cleaning endpoint monitoring device according to claim 1, characterized in that the detector is a dual-channel, four-channel or eight-channel type. 6. A multi-channel chamber cleaning end point monitoring method, utilizing a multi-channel chamber cleaning end point monitoring device according to claims 1 to 6, characterized in that it includes the following steps: Step 1: Install the device vertically next to the front and rear pipes of the cleaning chamber of the target process machine, and turn on the power switch; Step 2: Purge the fine particle impurities and residual gas in the gas chamber; Step 3: Pass the gas to be measured in the clean chamber into the gas chamber; Step 4: The infrared light generated by the operation of the light source passes through the gas to be measured after being collimated by the collimating lens and passing through the light path; Step 5: The detector monitors and collects in real time the light intensity changes of the light at the receiving end of the gas chamber after gas absorption, and outputs the gas concentration-time curve through the GUI interface, rising from zero to the stable range and then falling to the preset value. The minimum value of gas concentration endpoint monitoring is the cleaning endpoint. 7. A multi-channel chamber cleaning endpoint monitoring method according to claim 6, characterized in that the application process in step 1 is any one of CVD, PVD or SEG. 8. A multi-channel chamber cleaning endpoint monitoring method according to claim 6, characterized in that the gas to be measured in step 3 is SIF ₄ , CF ₄ , WF ₆ , TiF ₄ , CuF ₂ , and AlF ₂ , one or more of CoF ₂ and TaF ₅ . 9. A multi-channel chamber cleaning endpoint monitoring method according to claim 6, characterized in that the real-time monitoring in step 5 is a dynamic detection method that uses an embedded algorithm to consider various drift situations. Achieve accurate calculation of multi-channel gas concentration, the drift condition includes temperature, pressure, film thickness and gas flow velocity factors. 10. A multi-channel chamber cleaning endpoint monitoring device and method according to claim 6, characterized in that the gas concentration endpoint monitoring minimum value setting range in step 5 is 1.0*10 ^-6 -50.0*10 ^{- 6} VOL.