Liquid evaporation source, control method for output air pressure of liquid evaporation source and thin film deposition device

Abstract

The invention provides a liquid evaporation source, a control method of output air pressure of the liquid evaporation source and a thin film deposition device. The liquid evaporation source comprises a tank body which comprises a gas outlet and is used for accommodating a liquid reactant and steam thereof and outputting the steam of the liquid reactant through the gas outlet; the air pressure control assembly comprises multiple circles of heating belts, a liquid level sensor and a controller, the multiple circles of heating belts are wound at different heights of the periphery of the tank body, and the controller adjusts the temperature of at least one circle of first heating belt above the liquid level height according to the liquid level height collected by the liquid level sensor. The actual output air pressure of the air outlet is controlled to be the preset target output air pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial equipment manufacturing, and in particular to a liquid evaporation source, a method for controlling the output gas pressure of the liquid evaporation source, and a thin film deposition device. Background Art

[0002] Liquid sources are widely used in industrial production, laboratories, semiconductor manufacturing and other fields. Especially in the field of semiconductor manufacturing technology, the application of liquid source cylinders mainly involves key process steps such as chemical vapor deposition, etching, atomic layer deposition, etc., which have a vital impact on the performance of semiconductor devices. In order to ensure the stable output of liquid sources, precise temperature control of the cylinders is required.

[0003] Most existing liquid source cylinders use silicone heating belts as temperature control elements. The heating belt is composed of Teflon, heating elements, insulation layer, silicone rubber insulation layer and outer skin layer. Although this heating belt can meet the temperature control requirements to a certain extent, due to the design limitations of the heating element, the overall bottle temperature can only reach a unified set value, and it is impossible to achieve independent temperature control in different zones, resulting in low temperatures at locations far from the heating wire, making the saturated vapor pressure unstable, which in turn has an adverse effect on product quality.

[0004] In order to overcome the above-mentioned defects of the prior art, the art is in urgent need of a liquid evaporation source technology for more precise and stable temperature control of the liquid source, thereby stabilizing the saturated vapor pressure and improving product quality. Summary of the invention

[0005] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or decisive elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a liquid evaporation source, a method for controlling the output gas pressure of the liquid evaporation source, and a thin film deposition device, which are used to independently control the temperature of the bottle body in different zones, thereby stabilizing the saturated vapor pressure to improve product quality.

[0007] Specifically, the liquid evaporation source provided according to the first aspect of the present invention includes: a tank body, including an outlet, used to accommodate a liquid reactant and its vapor, and output the vapor of the liquid reactant through the outlet; and an air pressure control component, including a plurality of heating belts, a liquid level sensor and a controller, wherein the plurality of heating belts are respectively wound around the tank body at different heights, and the controller adjusts the temperature of at least one first heating belt above the liquid level height according to the liquid level height collected by the liquid level sensor, so as to control the actual output air pressure of the outlet to a preset target output air pressure.

[0008] Furthermore, in some embodiments of the present invention, the controller is configured to: determine the at least one circle of first heating zone above the liquid level height and determine the steam volume above the liquid level height based on the liquid level height collected by the liquid level sensor; determine the first target temperature of the at least one circle of first heating zone based on the steam volume, the target output air pressure, and the single air outlet mass of the air outlet at an air outlet window; and adjust the at least one circle of first heating zone to the first target temperature so as to control the actual output air pressure of the air outlet at the air outlet window at the target output air pressure.

[0009] Furthermore, in some embodiments of the present invention, the step of adjusting the at least one circle of the first heating belt to the first target temperature includes: obtaining the actual temperature of the first heating belt, and comparing the actual temperature with the first target temperature to determine the corresponding temperature difference; performing PID operation on the temperature difference to determine the corresponding temperature control amount; and adjusting the heating power of the at least one circle of the first heating belt according to the temperature control amount to adjust its actual temperature to the first target temperature.

[0010] Furthermore, in some embodiments of the present invention, the tank body further comprises a heating base for heating the liquid reactant to a second target temperature above its boiling point to form the steam thereover.

[0011] Furthermore, in some embodiments of the present invention, the heating base includes: a base body, which is made of a heat-conducting material and thermally contacts the liquid reactant through the bottom of the tank body; and a liquid guide tube, which is evenly distributed in the base body, heats the base body by transmitting high-temperature liquid, and then evenly heats the liquid reactant through the base body.

[0012] Furthermore, in some embodiments of the present invention, the base body is made of aluminum, the bottom of the tank body is made of corrosion-resistant stainless steel, and the high-temperature liquid is made of ethylene glycol or perfluoropolyether.

[0013] Furthermore, in some embodiments of the present invention, the controller is also configured to: determine at least one circle of second heating zone below the liquid level height according to the liquid level height collected by the liquid level sensor; determine the third target temperature of each circle of the second heating zone according to the difference between the first target temperature and the second target temperature, and the number of circles of the at least one circle of the second heating zone; and adjust each circle of the second heating zone to its corresponding third target temperature to block the heat transfer of the steam to the liquid reactant.

[0014] Furthermore, in some embodiments of the present invention, the third target temperature of each circle of the second heating zone changes linearly according to the spacing distance between each circle of the second heating zone.

[0015] In addition, the method for controlling the output gas pressure of a liquid evaporation source provided according to the second aspect of the present invention comprises the following steps: collecting the liquid level height of the liquid reactant in the tank body of the liquid evaporation source as described in any one of the first aspects of the present invention; determining at least one circle of first heating belt above the liquid level height according to the liquid level height, and determining the steam volume above the liquid level height; determining a first target temperature of the at least one circle of first heating belt according to the steam volume, a preset target output gas pressure, and a single gas outlet mass of the gas outlet of the tank body at an gas outlet window; and adjusting the at least one circle of first heating belt to the first target temperature to control the actual output gas pressure of the gas outlet at one of the gas outlet windows to the target output gas pressure.

[0016] In addition, the thin film deposition device provided according to the third aspect of the present invention includes: a process chamber for accommodating a semiconductor device to be processed; and a liquid evaporation source as described in any one of the first aspects of the present invention, for providing the vapor of a liquid reactant to the process chamber at a constant pressure and in a quantitative manner according to process requirements, so as to perform a thin film deposition process on the semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0018] Figure 1 A schematic structural diagram of a liquid evaporation source provided according to some embodiments of the present invention is shown.

[0019] Figure 2 A schematic structural diagram of a heating base provided according to some embodiments of the present invention is shown.

[0020] Reference numerals:

[0021] 10 Tank

[0022] 11 Air outlet

[0023] 12 multi-circle heating belt

[0024] 13 Gas Zone

[0025] 14 Liquid Area

[0026] 20 Heating base

[0027] 21 Base body

[0028] 22 Catheter

[0029] 23 Thermal Conductive Agent Inlet

[0030] 24 Thermal Conductive Agent Outlet DETAILED DESCRIPTION

[0031] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 indirectly connected through an intermediate medium, or it can be the internal communication of 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.

[0033] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0034] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, regions, layers and / or parts, these components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers and / or parts. Therefore, the first component, region, layer and / or part discussed below may be referred to as a second component, region, layer and / or part without departing from some embodiments of the present invention.

[0035] As mentioned above, liquid source cylinders are widely used in industrial production, laboratories, semiconductor manufacturing and other fields. Especially in the field of semiconductor manufacturing technology, the application of liquid source cylinders mainly involves key process steps such as chemical vapor deposition, etching, atomic layer deposition, etc., which have a vital impact on the performance of semiconductor devices. In order to ensure the stable output of the liquid source, the cylinder needs to be precisely temperature controlled.

[0036] Most existing liquid source cylinders use silicone heating belts as temperature control elements. The heating belt is composed of Teflon, heating elements, insulation layer, silicone rubber insulation layer and outer skin layer. Although this heating belt can meet the temperature control requirements to a certain extent, due to the design limitations of the heating element, the overall bottle temperature can only reach a unified set value, and it is impossible to achieve independent temperature control in different zones, resulting in low temperatures at locations far from the heating wire, making the saturated vapor pressure unstable, which in turn has an adverse effect on product quality.

[0037] In order to overcome the above-mentioned defects of the prior art, the present invention provides a liquid evaporation source, a method for controlling the output gas pressure of the liquid evaporation source, and a thin film deposition device, which are used to independently control the temperature of the bottle body in different zones, thereby stabilizing the saturated vapor pressure to improve product quality.

[0038] In some non-limiting embodiments, the method for controlling the output gas pressure of the liquid evaporation source provided in the second aspect of the present invention can be implemented based on the liquid evaporation source provided in the first aspect of the present invention. The liquid evaporation source provided in the first aspect of the present invention can be configured in the thin film deposition device provided in the third aspect of the present invention. Specifically. The thin film deposition device includes a process chamber and a liquid evaporation source as described in any one of the first aspects of the present invention. The process chamber is used to accommodate a semiconductor device to be processed. The liquid evaporation source is used to provide a vapor of a liquid reactant to the process chamber at a constant pressure and quantitatively according to process requirements, so as to perform a thin film deposition process on the semiconductor device.

[0039] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a liquid evaporation source provided according to some embodiments of the present invention is shown.

[0040] like Figure 1As shown, the liquid evaporation source includes a tank body 10 and a gas pressure control component.

[0041] The tank body 10 includes a gas outlet 11. The tank body 10 is used to contain a liquid reactant and its vapor, and output the vapor of the liquid reactant (e.g., TiCl4) through the gas outlet 11. Here, the area where the liquid reactant is located is a liquid area 14 in the tank body 10, and the area where the vapor is located is a gas area 13 in the tank body 10.

[0042] The air pressure control assembly includes multiple heating belts 12, a liquid level sensor and a controller. The multiple heating belts 12 are respectively wound around the tank body 10 at different heights. The controller adjusts the temperature of at least one first heating belt above the liquid level according to the liquid level collected by the liquid level sensor, so as to control the actual output air pressure of the air outlet 11 to a preset target output air pressure p0.

[0043] In some embodiments of the present invention, the liquid evaporation source may also be configured with a controller, which may first collect the liquid level height of the liquid reactant in the tank body 10 of the liquid evaporation source, determine at least one circle of the first heating zone above the liquid level height based on the liquid level height collected by the liquid level sensor, and determine the steam volume V above the liquid level height.

[0044] Afterwards, the first target temperature T1 of at least one circle of the first heating zone is determined according to the steam volume V, the target output gas pressure p0, and the single gas outlet mass n of the gas outlet 11 at a gas outlet window.

[0045] Specifically, the pressure continues to drop during the process until it stops and then rises again. When the valve switch is switched, it is approximately a closed container, and during a single process run, the liquid source consumption is very small, so the volume change is negligible.

[0046] Furthermore, the ideal gas equation is: pV = nRT, where p is the output pressure (Pa) and V is the volume of the gas (m 3 ), n is the amount of gas (mol), R is called the molar gas constant (J / (mol·K)), and T is the temperature (K). Here, in the application scenario of this application, V is the steam volume (m 3 ), n is the single gas outlet mass (mol), both of which are constants. Therefore, the front-end pressure can be balanced by increasing the temperature.

[0047] Finally, at least one circle of the first heating belt is adjusted to the first target temperature T1, so as to control the actual output air pressure of the air outlet 11 at an air outlet window to the target output air pressure p0.

[0048] Specifically, the controller can obtain the actual temperature of the first heating belt, and compare the actual temperature with the first target temperature T1 to determine the corresponding temperature difference. Then, the temperature difference is subjected to PID operation to determine the corresponding temperature control amount. For example: the algorithm is written into the software and added to the process formula. When the process formula is executed, the pressure change is monitored in real time, and then fed back to the software to calculate how much temperature is needed to balance the pressure, and finally the appropriate heating rate is given by the PID system. Finally, according to the temperature control amount, the heating power of at least one circle of the first heating belt is adjusted to adjust its actual temperature to the first target temperature T1.

[0049] Thus, the tank body 10 is divided into several equally divided independent control areas according to the liquid level, and independent temperature control is achieved in each area. At the same time, the liquid level sensor and controller are linked with the temperature of the heating belt in real time, and the temperature is adjusted through pressure feedback to balance the front-end pressure, so as to control the liquid source with more accurate and stable temperature, thereby stabilizing the saturated vapor pressure and improving product quality.

[0050] Please refer to Figure 2 , Figure 2 A schematic structural diagram of a heating base provided according to some embodiments of the present invention is shown.

[0051] like Figure 2 As shown, the tank body 10 further includes a heating base 20 for heating the liquid reactant to a second target temperature T2 above its boiling point to form steam thereon.

[0052] Specifically, the heating base 20 includes a base body 21 and a liquid guide tube 22. The base body 21 is made of a heat-conducting material and is in heat-conducting contact with the liquid reactant through the bottom of the tank body 10. The liquid guide tube 22 is evenly distributed in the base body 21, and heats the base 20 body by transmitting high-temperature liquid, and then evenly heats the liquid reactant through the base body 21.

[0053] Here, the base body 21 can be made of aluminum, the bottom of the tank body 10 can be made of corrosion-resistant stainless steel, and the high-temperature liquid can be made of ethylene glycol (Glycol) or perfluoropolyether (Galden).

[0054] In some embodiments of the present invention, the controller may also determine at least one circle of the second heating zone below the liquid level height according to the liquid level height collected by the liquid level sensor.

[0055] Afterwards, the third target temperature of each circle of the second heating zone is determined according to the difference between the first target temperature T1 and the second target temperature T2 and the number of circles of the at least one circle of the second heating zone.

[0056] Finally, each circle of the second heating belt is adjusted to its corresponding third target temperature to block the heat transfer of the steam to the liquid reactant. Here, the third target temperature of each circle of the second heating belt changes linearly according to the spacing distance between each circle of the second heating belt. For example, each circle of the heating belt is equidistantly distributed, and the third target temperature of each circle of the heating belt increases or decreases uniformly.

[0057] Here, those skilled in the art can first heat the thermal conductor, and let it flow in through the central thermal conductor inlet 23 and out from the outer ring thermal conductor outlet 24 to form a thermal cycle. Then, the heat is transferred to the surface of the tank body 10 through the base body 21 to improve the thermal stability of the bottom. Furthermore, since the thermal conductor has a large heat capacity, a more stable temperature control is achieved, and the liquid source is controlled with a more precise and stable temperature, thereby stabilizing the saturated vapor pressure to improve product quality.

[0058] In summary, the liquid evaporation source, the method for controlling the output gas pressure of the liquid evaporation source, and the thin film deposition device provided by the present invention can be used to independently control the temperature of the bottle body in different zones, thereby stabilizing the saturated vapor pressure and improving product quality.

[0059] Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0060] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid evaporation source, characterized in that: include: A tank body, including a gas outlet, for containing a liquid reactant and its vapor, and outputting the vapor of the liquid reactant through the gas outlet; as well as The air pressure control component includes a plurality of heating belts, a liquid level sensor, a pressure gauge and a controller, wherein the plurality of heating belts are respectively wound around the tank body at different heights, and the controller adjusts the temperature of at least one first heating belt above the liquid level according to the liquid level collected by the liquid level sensor and the actual output air pressure of the air outlet collected by the pressure gauge, so as to control the actual output air pressure to a preset target output air pressure.

2. The liquid evaporation source according to claim 1, characterized in that: The controller is configured to: According to the liquid level height collected by the liquid level sensor, determining the at least one circle of the first heating zone above the liquid level height, and determining the steam volume above the liquid level height; Determining a first target temperature of the at least one circle of the first heating belt according to the steam volume, the target output gas pressure, and the single gas outlet mass of the gas outlet at a gas outlet window; as well as The at least one circle of the first heating belt is adjusted to the first target temperature to control the actual output air pressure of the air outlet at one of the air outlet windows to the target output air pressure.

3. The liquid evaporation source according to claim 2, characterized in that: The step of adjusting the at least one first heating belt to the first target temperature comprises: The actual output air pressure of the air outlet is collected by the pressure gauge, and the actual output air pressure is compared with the target output air pressure to determine the corresponding air pressure difference; Performing PID calculation on the air pressure difference to determine the corresponding control amount; and According to the control amount, the heating power of the at least one circle of the first heating belt is adjusted to adjust its actual temperature to the first target temperature.

4. The liquid evaporation source according to claim 2, characterized in that: The tank body further comprises a heating base for heating the liquid reactant to a second target temperature above the liquid reactant's boiling point to form the steam thereon.

5. The liquid evaporation source according to claim 4, characterized in that: The heating base comprises: A base body, made of a heat-conducting material, and in heat-conducting contact with the liquid reactant via the bottom of the tank body; and The liquid guide tubes are evenly distributed in the base body, and heat the base body by transmitting high-temperature liquid, and then evenly heat the liquid reactant through the base body.

6. The liquid evaporation source according to claim 5, characterized in that: The base body is made of aluminum, the bottom of the tank body is made of corrosion-resistant stainless steel, and the high-temperature liquid is made of ethylene glycol or perfluoropolyether.

7. The liquid evaporation source according to claim 4, characterized in that: The controller is also configured to: Determine at least one second heating zone below the liquid level height according to the liquid level height collected by the liquid level sensor; Determining a third target temperature of each circle of the second heating zone according to a difference between the first target temperature and the second target temperature and the number of circles of the at least one circle of the second heating zone; as well as Each circle of the second heating belt is adjusted to its corresponding third target temperature to block the heat transfer from the steam to the liquid reactant.

8. The liquid evaporation source according to claim 7, characterized in that: The third target temperature of each circle of the second heating zone changes linearly according to the interval distance between each circle of the second heating zone.

9. A method for controlling the output gas pressure of a liquid evaporation source, characterized in that: The following steps are involved: Collecting the liquid level height of the liquid reactant in the tank of the liquid evaporation source according to any one of claims 1 to 8; According to the liquid level, determining at least one circle of first heating zone above the liquid level, and determining the steam volume above the liquid level; Determining a first target temperature of the at least one circle of the first heating belt according to the steam volume, the preset target output pressure, and the single gas outlet mass of the gas outlet of the tank body at a gas outlet window; as well as The at least one circle of the first heating belt is adjusted to the first target temperature to control the actual output air pressure of the air outlet at one of the air outlet windows to the target output air pressure.

10. A thin film deposition device, characterized in that: include: A process chamber for accommodating semiconductor devices to be processed; as well as The liquid evaporation source according to any one of claims 1 to 8 is used to provide the vapor of a liquid reactant to the process chamber at a constant pressure and in a quantitative manner according to process requirements, so as to perform a thin film deposition process on the semiconductor device.

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