TWI851285B - Gas mixing device and treatment equipment for oxidation process - Google Patents

Abstract

A gas mixing device and processing equipment for oxidation process, relating to the field of semiconductor manufacturing technology, comprises a gas mixer, a first pipeline provided with a first MFC and a second MFC, a second pipeline provided with a third MFC and a third pipeline provided with a pressure controller, the gas mixer is connected to a processing chamber through the first pipeline, the connection point between the second pipeline and the first pipeline is located between the first MFC and the second MFC, and the connection point between the third pipeline and the first pipeline is located between the second MFC and the processing chamber; a mixed gas of a first preset ratio is mixed with a first component gas under the control of the third MFC to form a processing gas of a second preset ratio under the control of the first MFC, a part of the processing gas is discharged through the third pipeline under the diversion of the pressure controller, and another part of the processing gas flows to the processing chamber under the control of the second MFC. The gas mixing device can adjust the mixing ratio and flow rate of the mixed gas before it enters the processing chamber.

Description

Gas mixing devices and processing equipment for oxidation processes

The present invention relates to the field of semiconductor manufacturing technology, and more specifically, to a gas mixing device and processing equipment for an oxidation process.

The semiconductor manufacturing process can be divided into wafer processing, oxidation, photolithography, etching, thin film deposition, interconnection, testing and packaging. The oxidation process is to form an oxide film on the surface of the wafer to protect the wafer from chemical impurities, prevent leakage current from entering the circuit, prevent diffusion during ion implantation, and prevent the wafer from slipping during etching. The mixing ratio and flow rate of the processing gas in the oxidation process are extremely important and will affect the thickness of the formed oxide film.

In the prior art, various gases of different components are first mixed in a gas mixer according to a preset ratio, and the mixed gas is then introduced into a processing chamber to oxidize the wafer. However, the above device has the following disadvantages: on the one hand, the mixed gas can only be oxidized at the preset ratio when mixed in the gas mixer before entering the processing chamber, and there is a problem that the mixing ratio cannot be adjusted. On the other hand, the flow rate of the mixed gas flowing into the processing chamber through the gas mixer cannot be controlled and adjusted, which is easy to affect the oxidation process.

The purpose of the present invention is to provide a gas mixing device and processing equipment for oxidation process, which can solve the problem in the prior art that the mixing ratio of the mixed gas cannot be adjusted before entering the processing chamber and the flow rate cannot be controlled.

The embodiment of the present invention is implemented as follows: One aspect of the embodiment of the present invention provides a gas mixing device for an oxidation process, comprising a gas mixer, a first pipe, a second pipe, a third pipe, a fourth pipe, a fifth pipe, a sixth pipe and a liquid storage tank, the gas mixer is connected to a processing chamber of the oxidation process through the first pipe, a first MFC and a second MFC are arranged on the first pipe in sequence, the connection between the second pipe and the first pipe is located between the first MFC and the second MFC, a third MFC is arranged on the second pipe, the connection between the third pipe and the first pipe is located between the second MFC and the processing chamber, and a pressure controller is arranged on the third pipe; a mixed gas of a first preset ratio discharged from the gas mixer is mixed with a first component gas introduced through the second pipe under the control of the first MFC under the control of the third MFC to form a mixed gas of a second preset ratio. The pressure controller diverts a portion of the second preset ratio of the processing gas to be discharged through the third pipeline, and another portion of the second preset ratio of the processing gas flows to the processing chamber under the control of the second MFC; and a fourth MFC and a fifth MFC are respectively arranged on the fourth pipeline and the fifth pipeline, and the fourth pipeline and the fifth pipeline are respectively connected to the gas mixer through the fourth MFC and the fifth MFC; a second MFC introduced through the fourth pipeline The component gas under the control of the fourth MFC and the third component gas introduced through the fifth pipeline under the control of the fifth MFC flow into the gas mixer to mix to form the mixed gas of the first preset ratio, and the liquid storage tank is used to store water, the sixth pipeline extends below the liquid level of the liquid storage tank, and the fourth pipeline is exposed above the liquid level of the liquid storage tank. The fourth component gas introduced through the sixth pipeline is humidified by the water in the liquid storage tank to form the second component gas. The gas mixing device used for the oxidation process can solve the problem in the prior art that the mixing ratio of the mixed gas cannot be adjusted before entering the processing chamber and the flow rate cannot be controlled.

As an implementable method, a first water level monitor is provided in the liquid storage tank, and the first water level monitor is used to detect the liquid level height of the liquid storage tank.

As an implementable method, a second water level monitor is also provided in the liquid storage tank, and the second water level monitor is used to detect the liquid level height of the liquid storage tank. Along the liquid level height direction, the second water level monitor is spaced below the first water level monitor.

As a feasible method, a temperature monitor is provided in the liquid storage tank, and the temperature monitor is used to detect the temperature of the water in the liquid storage tank.

As an implementable method, the first component gas, the third component gas and the fourth component gas have the same composition and humidity, and the fourth component gas has the same composition as the second component gas.

As a practical approach, the first component gas is nitrogen.

As an practicable method, a collector is also included, which is connected to the third pipe and is used to collect the second preset proportion of the treated gas discharged through the third pipe.

Another aspect of the embodiment of the present invention provides a processing equipment for an oxidation process, including a reaction furnace and the above-mentioned gas mixing device for the oxidation process, wherein the reaction furnace has a processing chamber, and a first pipe of the gas mixing device for the oxidation process is connected to the processing chamber. The gas mixing device for the oxidation process can solve the problem in the prior art that the mixing ratio of the mixed gas cannot be adjusted before entering the processing chamber and the flow rate cannot be controlled.

The beneficial effects of the embodiment of the present invention include: the gas mixing device includes the gas mixer, the first pipeline, the second pipeline and the third pipeline, the gas mixer is connected to the processing chamber of the oxidation process through the first pipeline, the first MFC and the second MFC are sequentially arranged on the first pipeline, the connection between the second pipeline and the first pipeline is located between the first MFC and the second MFC, the third MFC is arranged on the second pipeline, and the connection between the third pipeline and the first pipeline is located between the second MFC and the second MFC. C and the processing chamber, the third pipeline is provided with the pressure controller; the mixed gas of the first preset ratio discharged through the gas mixer is mixed with the first component gas introduced through the second pipeline under the control of the first MFC to form the processing gas of the second preset ratio under the control of the third MFC, the pressure controller diverts a part of the processing gas of the second preset ratio to be discharged through the third pipeline, and another part of the processing gas of the second preset ratio flows to the processing chamber under the control of the second MFC. The gas mixing device provided by the present application not only realizes the adjustment of the mixed gas of the first preset ratio to the processing gas of the second preset ratio, solving the problem that the mixed gas ratio cannot be adjusted before entering the processing chamber in the prior art, but also realizes the adjustment of the actual flow rate of the mixed gas of the first preset ratio flowing to the processing chamber to the actual flow rate of another part of the processing gas of the second preset ratio flowing to the processing chamber, solving the problem that the flow rate of the mixed gas cannot be controlled before entering the processing chamber in the prior art.

100: Gas mixing device

10: Gas mixer

20: First pipeline

21: The first MFC

22: Second MFC

30: Second pipeline

31: The third MFC

40: The third pipeline

41: Pressure controller

50: The fourth channel

51: The fourth MFC

60: The fifth channel

61: Fifth MFC

70: Liquid storage device

71: First water level monitor

72: Second water level monitor

73: Temperature monitor

80: The sixth pipeline

90: Collector

FIG. 1 is a structural schematic diagram of a gas mixing device for an oxidation process provided in an embodiment of the present invention; FIG. 2 is a structural schematic diagram of a gas mixing device for an oxidation process provided in an embodiment of the present invention; FIG. 3 is a structural schematic diagram of a gas mixing device for an oxidation process provided in an embodiment of the present invention; FIG. 4 is a structural schematic diagram of a gas mixing device for an oxidation process provided in an embodiment of the present invention.

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative labor are within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined or explained in the subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the attached figure, or the orientation or position relationship in which the product of the invention is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

In addition, the terms "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and it does not mean that the structure must be completely horizontal, but can be slightly tilted.

In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Please refer to Figures 1 to 4. One aspect of the embodiment of the present application provides a gas mixing device 100 for an oxidation process (referred to as the gas mixing device 100 for short), including a gas mixer 10, a first pipe 20, a second pipe 30 and a third pipe 40. The gas mixer 10 is connected to a processing chamber (PC) of the oxidation process through the first pipe 20. A first MFC 21 and a second MFC 22 are sequentially arranged on the first pipe 20. The connection between the second pipe 30 and the first pipe 20 is located between the first MFC 21 and the second MFC 22. A third MFC 31 is arranged on the second pipe 30. The connection between the third pipe 40 and the first pipe 20 is located between the second MFC 22 and the processing chamber. A pressure controller 41 is arranged on the third pipe 40.

A mixed gas of a first preset ratio discharged from the gas mixer 10 is mixed with a first component gas introduced through the second pipe 30 under the control of the third MFC 31 to form a processing gas of a second preset ratio under the control of the first MFC 21. The pressure controller 41 diverts a portion of the processing gas of the second preset ratio to be discharged through the third pipe 40, and another portion of the processing gas of the second preset ratio flows to the processing chamber under the control of the second MFC 22. The gas mixing device 100 for oxidation process can solve the problem in the prior art that the mixing ratio of the mixed gas cannot be adjusted before entering the processing chamber and the flow rate cannot be controlled.

It should be noted that, as shown in Figures 1 to 4, the gas mixing device 100 includes the gas mixer 10 and the first pipe 20. The gas mixer 10 is connected to the processing chamber of the oxidation process through the first pipe 20, so that the mixed gas of the first preset ratio discharged through the gas mixer 10 can flow to the processing chamber through the first pipe 20, thereby oxidizing the wafer in the processing chamber. In order to solve the problem in the prior art that the mixing ratio of the mixed gas cannot be adjusted and the flow rate cannot be controlled before the mixed gas is introduced into the processing chamber, the gas mixing device 100 provided in the present application further includes the second pipeline 30 and the third pipeline 40, and the first MFC 21 and the second MFC 22 are sequentially arranged on the first pipeline 20, so that the mixed gas of the first preset ratio discharged through the gas mixer 10 can flow to the processing chamber under the control of the first MFC 21, the connection between the second pipeline 30 and the first pipeline 20 is located between the first MFC 21 and the second MFC 22, and the third MFC 31 is arranged on the second pipeline 30, so that the first component gas introduced through the second pipeline 30 can flow into the processing chamber under the control of the third MFC 31 flows to the first pipeline 20, and after flowing through the connection between the second pipeline 30 and the first pipeline 20, it can also be mixed with the mixed gas of the first preset ratio in the first pipeline 20 to form the processing gas of the second preset ratio. The connection between the third pipeline 40 and the first pipeline 20 is located between the second MFC 22 and the processing chamber. The pressure controller 41 is arranged on the third pipeline 40, so that part of the mixed processing gas of the second preset ratio can be discharged through the third pipeline 40 under the diversion effect of the pressure controller 41, and the other part can flow to the processing chamber under the control of the second MFC 22.

Assuming that the maximum flow rate _M1 of the first MFC 21 is 1000, the maximum flow rate _M2 of the second MFC 22 is 1000, the maximum flow rate _M3 of the third MFC 31 is 1000, and the maximum flow rate _M4 of the pressure controller 41 is 2000, in the actual production process, for example, the actual flow rate _S1 of the first MFC 21 can be set to 1000, the actual flow rate _S2 of the second MFC 22 can be set to 500, the actual flow rate _S3 of the third MFC 31 can be set to 500, and the actual flow rate _S4 of the pressure controller 41 can be set to 1000. At this time, the actual flow rate Q of the other part of the second preset ratio of the process gas flowing to the process chamber is calculated as follows:

This means that the actual flow rate Q of the other part of the second preset ratio of the processing gas flowing into the processing chamber is 0.167 times the actual flow rate of the first preset ratio of the mixed gas discharged through the gas mixer 10 in the present application (i.e., the actual flow rate of the mixed gas discharged through the gas mixer 10 in the prior art).

In this way, the gas mixing device 100 provided by the present application not only realizes the adjustment of the mixed gas of the first preset ratio to the processing gas of the second preset ratio, solving the problem that the mixed ratio of the mixed gas cannot be adjusted before entering the processing chamber in the prior art, but also realizes the adjustment of the actual flow rate of the mixed gas of the first preset ratio flowing to the processing chamber to the actual flow rate Q of another part of the processing gas of the second preset ratio flowing to the processing chamber, solving the problem that the flow rate of the mixed gas cannot be controlled before entering the processing chamber in the prior art.

In addition, it should be noted that the above-mentioned MFC (English name: Mass Flow Controller, Chinese name: Gas Mass Flow Controller) can accurately measure and control the mass flow of gas. Its working principle is to place two pairs of heaters in a smaller diameter sensor tube and control them at the same temperature. When the fluid flows, the gas brings part of the heat from the upstream to the downstream, and the downstream heater obtains heat from the upper part and the temperature rises. At this time, the temperature difference between the upper and lower heaters is proportional to the mass flow of the fluid to measure the flow rate, the thermal flow The meter sensor contains two sensing elements, a speed sensor and a temperature sensor, which automatically compensate and correct the temperature change of the gas. The electric heating part of the instrument heats the speed sensor to a certain value higher than the working temperature, so that a constant temperature difference is formed between the speed sensor and the sensor measuring the working temperature. When the temperature difference is kept constant, the energy consumed by the electric heating, or the heat dissipation value, is proportional to the mass flow rate of the gas flowing through, and can be applied to the measurement of single gas and fixed-ratio multi-component gas.

As shown in FIGS. 2 to 4 , as an practicable manner, the gas mixing device 100 further comprises a fourth pipeline 50 and a fifth pipeline 60, on which a fourth MFC 51 and a fifth MFC 61 are respectively arranged, and the fourth pipeline 50 and the fifth pipeline 60 are respectively connected to the gas mixer 10 through the fourth MFC 51 and the fifth MFC 61; a second component gas introduced through the fourth pipeline 50 under the control of the fourth MFC 51 and a third component gas introduced through the fifth pipeline 60 under the control of the fifth MFC 61 flow into the gas mixer 10 to mix and form the mixed gas of the first preset ratio, so that the gas mixing device 100 can pass through the fourth MFC 51 and the fifth MFC The cooperation of 61 controls and adjusts the mixing ratio of the first preset mixed gas ratio formed in the gas mixer 10.

According to the different oxidants in the oxidation reaction, the thermal oxidation process can be divided into dry oxidation and wet oxidation. Dry oxidation uses pure oxygen to produce a silicon dioxide layer. The speed is slow, but the oxide film is thin and dense. Wet oxidation requires the use of oxygen and highly soluble water vapor at the same time. Its characteristics are fast growth speed but the oxide film is relatively thick and low in density.

When the gas mixing device 100 provided by the present application is applied to wet oxidation, as shown in FIG. 3 and FIG. 4, as an practicable method, the gas mixing device 100 further includes a liquid storage tank 70 and a sixth pipe 80. The liquid storage tank 70 is used to store water. The sixth pipe 80 extends below the liquid level of the liquid storage tank 70. The fourth pipe 50 is exposed above the liquid level of the liquid storage tank 70. The fourth component gas introduced through the sixth pipe 80 is humidified by the water in the liquid storage tank 70 to form the second component gas, so that the humidity of the fourth component gas is flexibly adjusted through the liquid storage tank 70.

As shown in FIG3 and FIG4, as an implementable method, a first water level monitor 71 is provided in the liquid storage tank 70, and the first water level monitor 71 is used to detect the liquid level of the liquid storage tank 70, so as to prevent the liquid level of the liquid storage tank 70 from exceeding the upper limit value represented by the first water level monitor 71 through the first water level monitor 71, thereby preventing the water in the liquid storage tank 70 from easily overflowing.

As shown in FIG3 and FIG4, as an practicable method, a second water level monitor 72 is further provided in the liquid storage tank 70, and the second water level monitor 72 is used to detect the liquid level of the liquid storage tank 70. Along the liquid level direction, the second water level monitor 72 is arranged below the first water level monitor 71, so as to prevent the liquid level of the liquid storage tank 70 from being lower than the lower limit value represented by the second water level monitor 72 through the second water level monitor 72, thereby preventing the water in the liquid storage tank 70 from being too little, resulting in the water in the liquid storage tank 70 weakening the regulating effect of the humidity of the fourth component gas.

As shown in Figures 3 and 4, as an implementable method, a temperature monitor 73 is provided in the liquid storage tank 70, and the temperature monitor 73 is used to detect the temperature of the water in the liquid storage tank 70. There is no restriction on the temperature threshold of the water in the liquid storage tank 70. The technicians in this field should be able to make reasonable selections and designs according to the actual situation.

As an practicable method, the first component gas, the third component gas and the fourth component gas have the same composition and humidity, and the fourth component gas has the same composition as the second component gas. For example, the first component gas is nitrogen.

As shown in FIG4 , as an practicable method, the gas mixing device 100 further includes a collector 90, which is connected to the third pipe 40 and is used to collect the second preset ratio of the treated gas discharged through the third pipe 40 to avoid direct discharge into the air and cause waste.

Another aspect of the embodiment of the present application provides a processing device for an oxidation process, including a reaction furnace and the gas mixing device 100 for the oxidation process, wherein the reaction furnace has the processing chamber, and the first pipe 20 of the gas mixing device 100 for the oxidation process is connected to the processing chamber. Since the structure and beneficial effects of the gas mixing device 100 for the oxidation process have been described in detail in the aforementioned embodiment, they will not be described here in detail.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For technicians in this field, the present invention may have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

It should also be noted that the specific technical features described in the above specific implementation methods can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further explain various possible combinations.

100: Gas mixing device

10: Gas mixer

20: First pipeline

21: The first MFC

22: Second MFC

30: Second pipeline

31: The third MFC

40: The third pipeline

41: Pressure controller

Claims (8)

A gas mixing device for an oxidation process is characterized in that it comprises: a gas mixer, a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, a fifth pipeline, a sixth pipeline and a liquid storage tank, wherein the gas mixer is connected to a processing chamber of the oxidation process through the first pipeline, a first MFC and a second MFC are sequentially arranged on the first pipeline, a connection point between the second pipeline and the first pipeline is located between the first MFC and the second MFC, a third MFC is arranged on the second pipeline, a connection point between the third pipeline and the first pipeline is located between the second MFC and the processing chamber, and a pressure controller is arranged on the third pipeline; a mixed gas of a first preset ratio discharged through the gas mixer is mixed with a first component gas introduced through the second pipeline under the control of the first MFC to form a processing gas of a second preset ratio under the control of the third MFC, and the pressure controller A portion of the second preset ratio of the processing gas is diverted and discharged through the third pipe, and another portion of the second preset ratio of the processing gas flows to the processing chamber under the control of the second MFC; and a fourth MFC and a fifth MFC are respectively arranged on the fourth pipe and the fifth pipe, and the fourth pipe and the fifth pipe are respectively connected to the gas mixer through the fourth MFC and the fifth MFC; a second component gas introduced through the fourth pipe flows into the gas mixer under the control of the fourth MFC and a third component gas introduced through the fifth pipe flows into the gas mixer under the control of the fifth MFC to mix and form the mixed gas of the first preset ratio, and the liquid storage tank is used to store water, the sixth pipe extends below the liquid level of the liquid storage tank, the fourth pipe is exposed above the liquid level of the liquid storage tank, and the fourth component gas introduced through the sixth pipe is humidified by the water in the liquid storage tank to form the second component gas. As described in claim 1, a gas mixing device for an oxidation process, wherein a first water level monitor is provided in the liquid storage tank, and the first water level monitor is used to detect the liquid level of the liquid storage tank. As described in claim 2, a gas mixing device for an oxidation process is provided in the liquid storage tank, wherein a second water level monitor is provided in the liquid storage tank, and the second water level monitor is used to detect the liquid level of the liquid storage tank, and the second water level monitor is provided below the first water level monitor along the liquid level direction. A gas mixing device for an oxidation process as described in claim 1, wherein a temperature monitor is provided in the liquid storage tank, and the temperature monitor is used to detect the temperature of the water in the liquid storage tank. A gas mixing device for an oxidation process as described in claim 1, wherein the first component gas, the third component gas and the fourth component gas have the same composition and humidity, and the fourth component gas has the same composition as the second component gas. A gas mixing device for an oxidation process as described in claim 5, wherein the first component gas is nitrogen. The gas mixing device for oxidation process as described in claim 1 further includes a collector connected to the third pipe for collecting the second preset ratio of the treated gas discharged through the third pipe. A processing equipment for an oxidation process, comprising a reaction furnace and a gas mixing device for an oxidation process as described in any one of claims 1 to 7, wherein the reaction furnace has a processing chamber, and a first pipe of the gas mixing device for an oxidation process is connected to the processing chamber.

Images