Gas mixing and uniformizing device for hydrogen fluoride gas phase etching

Abstract

The invention discloses a gas mixing and uniformizing device for hydrogen fluoride gas phase etching, which comprises a device body, the device body internally comprises a first-stage mixing cavity, a second-stage mixing cavity, a third-stage mixing cavity and a reaction cavity which are sequentially communicated, the first-stage mixing cavity is arranged at the top of the device, and three groups of gas inlet pipelines are respectively arranged outside the device and are communicated with the first-stage mixing cavity; a plurality of groups of spiral blades which are arranged in an annular array are arranged in the second-stage mixing cavity, an annular hole partition plate is arranged at the communication part of the third-stage mixing cavity and the second-stage mixing cavity, a porous partition plate is arranged between the third-stage mixing cavity and the reaction cavity, and flow guide holes which are communicated up and down are formed in the annular hole partition plate and the porous partition plate; a manual sample inlet and a manipulator sample inlet are respectively arranged in front of and behind the reaction cavity, and an exhaust port is arranged at the bottom of the reaction cavity. The method has the advantages that the efficient mixing and uniform distribution of the ethanol steam, the hydrogen fluoride gas and the carrier gas can be realized, and the stability and the etching quality of the etching process are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a gas mixing and homogenizing device for hydrogen fluoride vapor phase etching. Background Technology

[0002] In the hydrogen fluoride gas-phase etching process for semiconductor manufacturing, hydrogen fluoride gas, ethanol vapor, and a carrier gas (such as nitrogen) need to be mixed and then delivered to the etching chamber. Existing gas mixing and homogenization devices have several problems:

[0003] Poor mixing uniformity: Traditional simple pipeline mixers or single-layer static mixers cannot fully mix the gas in a short time, resulting in uneven gas composition entering the etching chamber, causing inconsistent etching rates on the wafer surface and affecting product yield.

[0004] High gas flow resistance and complex internal structures in some devices result in significant resistance during gas mixing, leading to severe pressure loss, reduced gas transport efficiency, and increased energy consumption.

[0005] Lacking real-time monitoring and dynamic adjustment capabilities, existing devices struggle to detect the composition and uniformity of mixed gases in real time, cannot adjust the mixing state promptly according to process requirements, and are ill-suited to diverse etching process requirements. Summary of the Invention

[0006] The purpose of this invention is to provide a gas mixing and homogenizing device for hydrogen fluoride gas phase etching, which can achieve efficient mixing and uniform distribution of ethanol vapor, hydrogen fluoride gas and carrier gas, thereby improving the stability and etching quality of the etching process.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0008] A gas mixing and homogenizing device for hydrogen fluoride gas phase etching is characterized by comprising a device body, wherein the device body includes a primary mixing chamber, a secondary mixing chamber, a tertiary mixing chamber, and a reaction chamber connected in sequence. The primary mixing chamber is located at the top of the device. Three sets of gas inlet pipes are respectively provided on the outside of the device and connected to the primary mixing chamber. The secondary mixing chamber is provided with multiple sets of spiral blades arranged in annular array. The tertiary mixing chamber is provided with an annular perforated baffle at the connection point with the secondary mixing chamber. A porous baffle is provided between the tertiary mixing chamber and the reaction chamber. Both the annular perforated baffle and the porous baffle are provided with guide holes that connect the upper and lower parts. The reaction chamber is provided with a manual sample inlet and a robotic sample inlet at the front and rear, respectively. An exhaust port is provided at the bottom of the reaction chamber.

[0009] Preferably, the device body is also provided with three sets of interfaces communicating with the three-stage mixing chamber. The three sets of interfaces can be connected to a gas analyzer equipped with a flow rate sensor and a corresponding gas component. The device body is also provided with an atmospheric vacuum gauge and a process vacuum gauge communicating with the inside of the reaction chamber. Both the atmospheric vacuum gauge and the process vacuum gauge are equipped with angle valves.

[0010] Preferably, the manual injection port is equipped with a manual sealing door, and the robotic arm injection port is equipped with an electric sealing door.

[0011] Preferably, the three sets of air intake pipes are a carrier gas intake pipe, an ethanol vapor intake pipe, and an HF intake pipe. The carrier gas intake pipe is connected to the top of the primary mixing chamber, and the ethanol vapor intake pipe and the HF intake pipe are both connected to the side of the primary mixing chamber.

[0012] Preferably, the entire main body of the device is made of 316L stainless steel, and the inner wall, spiral blades, annular baffles and porous baffles in contact with the air intake are all plated with a layer of highly corrosion-resistant nickel.

[0013] Preferably, a mass flow controller is provided at the front end of each of the carrier gas inlet pipeline, the ethanol vapor inlet pipeline, and the HF inlet pipeline.

[0014] Preferably, the perforated partition plate is provided with at least two rings of annular array of guide holes, and the guide holes on the porous partition plate are evenly spaced.

[0015] Preferably, the guide holes on both the annular baffle and the porous baffle are arranged in an inverted conical shape.

[0016] Preferably, a tapered chamfer is provided at the connection between the primary mixing chamber and the secondary mixing chamber, and at the connection between the secondary mixing chamber and the tertiary mixing chamber.

[0017] Preferably, a sample holder is fixedly installed at the bottom of the reaction chamber above the exhaust port. Several sets of openings are provided around the exhaust port at the bottom of the reaction chamber. A guide connecting rod is vertically and movably installed in each of the several sets of openings. A sample heating plate is installed at the top of the guide connecting rod inside the reaction chamber. The sample heating plate is located below the sample holder. A mounting plate is connected to the bottom of the device body. Several cylinders are fixedly installed at the bottom of the device body. The output ends of the cylinders are fixedly connected to the bottom of the mounting plate. A telescopic corrugated pipe is provided around the guide connecting rod between the opening and the bottom of the sample heating plate.

[0018] In summary, the present invention has the following beneficial effects:

[0019] 1. High mixing uniformity: The design of the multi-stage composite mixing unit, through the synergistic effect of spiral mixing, split mixing and porous gas uniformity, can make the gas mixed uniformly and evenly distributed in the etching cavity, which significantly improves the uniformity of etching, effectively improves product yield and reduces scrap rate.

[0020] 2. Low flow resistance: The application of drag-reducing structures such as conical chamfers between cavities, helical blades, and conical guide holes reduces the pressure loss of gas within the device, improves gas delivery efficiency, reduces energy consumption, and saves production costs.

[0021] 3. Dynamic adjustment: The system can sense changes in gas state in real time through the interface and respond quickly to adjust gas flow and mixing parameters, enabling the device to adapt to different etching process requirements and improving the flexibility and adaptability of the process.

[0022] 4. Long service life: Made of 316L stainless steel and with special corrosion-resistant surface treatment, it effectively resists the corrosion of hydrogen fluoride gas, greatly extending the service life of the equipment, reducing equipment maintenance and replacement costs, and improving the continuity and stability of production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a front view of the overall structure of the present invention;

[0025] Figure 3 yes Figure 2 Schematic diagram of the structure at point AA;

[0026] Figure 4 This is a schematic diagram of the annular hole partition structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the porous partition structure of the present invention. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These embodiments do not constitute a limitation on the present invention.

[0029] like Figures 1 to 5The device shown is a gas mixing and homogenizing apparatus for hydrogen fluoride gas phase etching. It includes a device body 1, which contains a primary mixing chamber 2, a secondary mixing chamber 3, a tertiary mixing chamber 4, and a reaction chamber 5 connected in sequence. The primary mixing chamber 2 is located at the top of the device body 1. Three sets of gas inlet pipes 6 are respectively provided on the outside of the device body 1 and connected to the primary mixing chamber 2. The secondary mixing chamber 3 is provided with multiple sets of spiral blades 7 arranged in annular array. The tertiary mixing chamber 4 is provided with an annular perforated baffle 8 at the connection point with the secondary mixing chamber 3. A porous baffle 9 is provided between the tertiary mixing chamber 4 and the reaction chamber 5. Both the annular perforated baffle 8 and the porous baffle 9 have guide holes 10 that connect the upper and lower parts. A manual sample inlet 14 and a robotic sample inlet 15 are respectively provided at the front and rear of the reaction chamber. An exhaust port 16 is provided at the bottom of the reaction chamber. A manual sealing door 17 is installed on the manual sample inlet 14, and an electric sealing door 18 is provided on the robotic sample inlet 15.

[0030] The three sets of air intake pipes 6 are the carrier gas intake pipe, the ethanol vapor intake pipe, and the HF intake pipe. The carrier gas intake pipe is connected to the top of the primary mixing chamber 2, and the ethanol vapor intake pipe and the HF intake pipe are both connected to the side of the primary mixing chamber 2. A mass flow controller 12 is installed at the front end of each of the carrier gas intake pipe, the ethanol vapor intake pipe, and the HF intake pipe.

[0031] The main body 1 of the device is also equipped with three sets of interfaces 11 that communicate with the three-stage mixing chamber 4. These interfaces 11 can be connected to a gas analyzer equipped with a flow rate sensor and corresponding gas components. The gas analyzer uses spectral analysis technology to detect the concentrations of ethanol vapor, hydrogen fluoride gas, and carrier gas in the mixed gas in real time and with an accuracy of ±0.1%. The flow rate sensor is installed at the gas outlet of the three-stage mixing chamber 4 to monitor the gas flow rate in real time. The detection data is transmitted to the external control system in real time via a data transmission module. If the gas composition or flow rate deviates from the set value, the external control system immediately issues a command to adjust the mass flow controller 12, adjusting the input of each gas to ensure that the composition and flow rate of the mixed gas meet the process requirements, achieving dynamic and precise adjustment.

[0032] The main body of the device 1 is also equipped with an atmospheric vacuum gauge 19 and a process vacuum gauge 20, which are connected to the inside of the reaction chamber 5. Angle valves 21 are installed on both the atmospheric vacuum gauge 19 and the process vacuum gauge 20.

[0033] The main body of the device 1 is made entirely of 316L stainless steel. The inner wall of the device 1 that comes into contact with the air intake, the spiral blades 7, the annular baffle 8 and the porous baffle 9 are all plated with a layer of highly corrosion-resistant nickel to further enhance corrosion resistance, extend the service life of the device 1, and ensure stable operation of the device 1 in harsh gas environments.

[0034] The annular baffle 8 is provided with at least two rings of annular array of guide holes 10, and the guide holes 10 on the porous baffle 9 are evenly spaced.

[0035] The guide holes 10 on both the annular baffle 8 and the porous baffle 9 are inverted conical.

[0036] A tapered chamfer 13 is provided at the connection points between the primary mixing chamber 2 and the secondary mixing chamber 3, and between the secondary mixing chamber 3 and the tertiary mixing chamber 4, to guide the gas through a smooth transition and avoid eddies and pressure losses caused by abrupt changes in orifice size. Simultaneously, the nitrogen flow rate is set to the maximum to assist the flow of HF and ethanol vapor into the reaction chamber 5, ensuring that the gas enters the mixing unit with a more uniform flow rate and direction, further reducing flow resistance and improving gas delivery efficiency.

[0037] A sample holder 22 is fixedly installed above the exhaust port 16 at the bottom of the reaction chamber 5. Several sets of openings 23 are provided around the exhaust port 16 at the bottom of the reaction chamber 5. A guide connecting rod 24 is vertically and movably installed in the several sets of openings 23. A sample heating plate 25 is installed at the top of the guide connecting rod 24 inside the reaction chamber 5. The sample heating plate 25 is located below the sample holder 22. A mounting plate 26 is connected to the outside of the device body 1 at the bottom of the guide connecting rod 24. Several cylinders 27 are fixedly installed at the bottom of the device body 1. The output ends of the several cylinders 27 are fixedly connected to the bottom of the mounting plate 26. A telescopic corrugated pipe 28 is provided between the openings 23 and the bottom of the sample heating plate 25 around the guide connecting rod 24. The sample heating is achieved by driving the sample heating plate 25 to rise and fall through the cylinders 27.

[0038] This invention employs a three-stage series structure. The first-stage mixing chamber 2 is the initial mixing chamber. Through the layered arrangement of the inlet pipes 6, airflow collisions are prevented, and the carrier gas (nitrogen) is placed at the top layer with the nitrogen flow rate set to maximum, assisting the flow of HF and ethanol vapor into the reaction chamber 5. The second-stage mixing chamber 3 is a spiral mixing chamber, internally equipped with spiral blades 7, causing the gas to generate spiral motion under the action of the spiral blades 7, enhancing the gas stirring and mixing effect. The third-stage mixing chamber 4 is an annular perforated uniform flow mixing chamber, with annular perforated baffles 8 installed inside. When the gas passes through the annular perforated baffles 8, it is divided into fine streams, which collide and diffuse under the action of the annular perforated baffles 8, achieving thorough and uniform mixing of the gas. Finally, the gas enters the reaction chamber 5 uniformly through the porous baffles 9.

[0039] The workflow of this invention is as follows:

[0040] 1. Carrier gas, ethanol vapor, and HF are introduced into the main body 1 of the integrated mixing device through the inlet pipe 6 respectively;

[0041] 2. The three gases are thoroughly mixed in a three-stage mixing device to form a mixed gas;

[0042] 3. The mixed gas finally passes through the porous partition 9 and enters the reaction chamber 5 evenly.

[0043] A gas analyzer and a flow rate sensor are installed in the three-stage mixing chamber 4 to read the gas composition and feed the values ​​back to the external control system. The flow rates of the three gases are adjusted by the mass flow controller 12 to change the concentration of HF gas and optimize the process results.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the scope of its essence and protection. Such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A gas mixing and homogenizing device for hydrogen fluoride vapor phase etching, characterized in that, The device includes a main body, which comprises a primary mixing chamber, a secondary mixing chamber, a tertiary mixing chamber, and a reaction chamber connected in sequence. The primary mixing chamber is located at the top of the device. Three sets of air inlet pipes are respectively provided on the outside of the device and connected to the primary mixing chamber. The secondary mixing chamber is provided with multiple sets of spiral blades arranged in annular array. The tertiary mixing chamber is provided with an annular perforated baffle at the connection point with the secondary mixing chamber. A porous baffle is provided between the tertiary mixing chamber and the reaction chamber. Both the annular perforated baffle and the porous baffle have guide holes that connect the upper and lower parts. The reaction chamber is provided with a manual sample inlet and a robotic sample inlet at the front and rear, respectively. An exhaust port is provided at the bottom of the reaction chamber.

2. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: The device body is also provided with three sets of interfaces that communicate with the three-stage mixing chamber. The three sets of interfaces can be connected to a gas analyzer equipped with a flow rate sensor and the corresponding gas components. The device body is also provided with an atmospheric vacuum gauge and a process vacuum gauge that communicate with the inside of the reaction chamber. Both the atmospheric vacuum gauge and the process vacuum gauge are equipped with angle valves.

3. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: The manual injection port is equipped with a manual sealing door, and the robotic arm injection port is equipped with an electric sealing door.

4. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: The three sets of air intake lines are a carrier gas intake line, an ethanol vapor intake line, and an HF intake line. The carrier gas intake line is connected to the top of the primary mixing chamber, and the ethanol vapor intake line and the HF intake line are both connected to the side of the primary mixing chamber.

5. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: The main body of the device is made entirely of 316L stainless steel. The inner wall, spiral blades, annular baffles and porous baffles in contact with the air intake are all plated with a layer of highly corrosion-resistant nickel.

6. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 4, characterized in that: Each of the carrier gas inlet pipeline, ethanol vapor inlet pipeline, and HF inlet pipeline is equipped with a mass flow controller at its front end.

7. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: The perforated partition plate is provided with at least two rings of annular array of guide holes, and the guide holes on the porous partition plate are evenly spaced.

8. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 7, characterized in that: The guide holes on both the annular baffle and the porous baffle are arranged in an inverted conical shape.

9. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: A tapered chamfer is provided at the connection between the primary mixing chamber and the secondary mixing chamber, and at the connection between the secondary mixing chamber and the tertiary mixing chamber.

10. The gas mixing and homogenizing device for hydrogen fluoride vapor phase etching according to claim 1, characterized in that: A sample holder is fixedly installed above the exhaust port at the bottom of the reaction chamber. Several sets of openings are provided around the exhaust port at the bottom of the reaction chamber. A guide connecting rod is vertically and movably installed in each of the openings. A sample heating plate is installed at the top of the guide connecting rod inside the reaction chamber. The sample heating plate is located below the sample holder. A mounting plate is connected to the outside of the device body at the bottom of the guide connecting rod. Several cylinders are fixedly installed at the bottom of the device body. The output ends of the cylinders are fixedly connected to the bottom of the mounting plate. Telescopic corrugated pipes are provided around the guide connecting rod between the opening and the bottom of the sample heating plate.

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