Liquid evaporation source, method for controlling the gas pressure of the output thereof, and thin film deposition device

Abstract

The application provides a liquid evaporation source, a method for controlling the output gas pressure of the liquid evaporation source, and a thin film deposition device. The liquid evaporation source comprises a tank body including an outlet for containing a liquid reactant and its vapor and outputting the vapor of the liquid reactant through the outlet; and a gas pressure control assembly including a plurality of heating belts, a liquid level sensor and a controller, wherein the plurality of heating belts are wound at different heights on the periphery of the tank body, 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 gas pressure of the outlet at a preset target output gas pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial equipment manufacturing, and in particular to a liquid evaporation source, a control method of output gas pressure of the liquid evaporation source, and a thin film deposition device. BACKGROUND

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

[0003] The existing liquid source cylinders mostly use silica gel heating belts as temperature control elements. The heating belt is composed of Teflon, heating elements, insulation layers, silicone rubber insulation layers and outer skin layers. Although this heating belt can meet the temperature control requirements to some extent, due to the design limitations of the heating elements, the overall cylinder temperature can only reach a uniform set value, and independent temperature control in different zones cannot be achieved, resulting in lower temperature at positions far from the heating wire, unstable saturated vapor pressure, and thus adverse effects on product quality.

[0004] In order to overcome the above-mentioned defects existing in the prior art, there is an urgent need in the field for a liquid evaporation source technology for more accurate and stable temperature control of the liquid source, so as to stabilize the saturated vapor pressure and improve product quality. SUMMARY

[0005] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0006] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a liquid evaporation source, a control method of output gas pressure of the liquid evaporation source, and a thin film deposition device for independent temperature control in different zones of the cylinder, so as to stabilize the saturated vapor pressure and improve product quality.

[0007] Specifically, the liquid evaporation source according to the first aspect of the present application comprises: a tank body comprising a gas outlet for containing a liquid reactant and a vapor thereof, and outputting the vapor of the liquid reactant via the gas outlet; and a gas pressure control assembly comprising a plurality of heating belts, a liquid level sensor, and a controller, wherein the plurality of heating belts are wound at different heights on the periphery of the tank body, and the controller adjusts the temperature of at least one first heating belt above the liquid level height acquired by the liquid level sensor to control the actual output gas pressure of the gas outlet at a preset target output gas pressure.

[0008] Further, in some embodiments of the present application, the controller is configured to: determine the at least one first heating belt above the liquid level height acquired by the liquid level sensor, and determine a vapor volume above the liquid level height; determine a first target temperature of the at least one first heating belt according to the vapor volume, the target output gas pressure, and a single gas output mass of the gas outlet in one gas output window; and adjust the at least one first heating belt to the first target temperature to control the actual output gas pressure of the gas outlet in one gas output window at the target output gas pressure.

[0009] Further, in some embodiments of the present application, the step of adjusting the at least one first heating belt to the first target temperature comprises: acquiring an actual temperature of the first heating belt, and comparing the actual temperature with the first target temperature to determine a corresponding temperature difference; performing a PID operation on the temperature difference to determine a corresponding temperature control amount; and adjusting the heating power of the at least one first heating belt according to the temperature control amount to adjust its actual temperature to the first target temperature.

[0010] Further, in some embodiments of the present application, the tank body further comprises a heating base for heating the liquid reactant to a second target temperature above the boiling point of the liquid reactant to form the vapor above the liquid reactant.

[0011] Further, in some embodiments of the present application, the heating base comprises: a base body made of a heat-conductive material and in heat-conductive contact with the liquid reactant via the bottom of the tank body; and liquid guide pipes uniformly distributed in the base body to heat the base body by transmitting a high-temperature liquid, and then uniformly heat the liquid reactant via the base body.

[0012] Further, in some embodiments of the present application, 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 selected from ethylene glycol and perfluoropolyether.

[0013] Further, in some embodiments of the present application, the controller is further configured to: determine at least one turn of the second heating belt below the liquid level height according to the liquid level height collected by the liquid level sensor; determine a third target temperature of each turn of the second heating belt respectively according to a difference between the first target temperature and the second target temperature, and a number of turns of the at least one turn of the second heating belt; and adjust each turn of the second heating belt to its corresponding third target temperature respectively, to block the heat transfer of the vapor to the liquid reactant.

[0014] Further, in some embodiments of the present application, the third target temperature of each turn of the second heating belt varies linearly according to a spacing distance between each turn of the second heating belt.

[0015] Further, the method for controlling the output gas pressure of the liquid evaporation source according to the second aspect of the present application comprises the following steps: collecting a liquid level height of a liquid reactant in a tank of a liquid evaporation source according to any one of the first aspect of the present application; determining at least one turn of the first heating belt above the liquid level height according to the liquid level height, and determining a vapor volume above the liquid level height; determining a first target temperature of the at least one turn of the first heating belt according to the vapor volume, a preset target output gas pressure, and a single gas output mass of a gas outlet of the tank in one gas output window; and adjusting the at least one turn of the first heating belt to the first target temperature, to control an actual output gas pressure of the gas outlet in one gas output window at the target output gas pressure.

[0016] Further, the thin film deposition apparatus according to the third aspect of the present application comprises: a process chamber for accommodating a semiconductor device to be processed; and a liquid evaporation source according to any one of the first aspect of the present application, for providing a vapor of a liquid reactant to the process chamber at a constant pressure and a constant quantity according to a process requirement, to perform a thin film deposition process on the semiconductor device. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above features and advantages of the present application will be better understood through reading the detailed description of embodiments of the present application in conjunction with the following drawings, in which: components are not necessarily drawn to scale, and components of similar or identical function or features can have the same or similar reference label.

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

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

[0020] REFERENCE NUMERALS:

[0021] 10 tank body

[0022] 11 gas outlet

[0023] 12 multi-turn heating belt

[0024] 13 gas zone

[0025] 14 liquid zone

[0026] 20 heating base

[0027] 21 base body

[0028] 22 liquid guide pipe

[0029] 23 heat transfer agent inlet

[0030] 24 heat transfer agent outlet DETAILED DESCRIPTION

[0031] The specific embodiments of the present application will now be described, by way of example, with reference to the appended drawings, in which: Other aspects and advantages of the present application will be better understood from the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0032] In the description of the present application, it is to be understood that the

[0033] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" as used in the following description and shown in the drawings are described by their orientation in the figures and relative to the apparatuses being described. The terms "upper", "lower", "left", "right", "top", "bottom", "horizontal", "vertical" are used only for convenience and are not intended to confine the apparatuses described to any specific orientation. Therefore, these terms, as used herein, are intended to mean the particular orientation shown in the figures and are not intended to limit the scope of the application.

[0034] It is to be understood that, although terms such as "first", "second", "third", etc. can be used herein to describe various components, regions, layers and / or sections, these components, regions, layers and / or sections should not be limited by these terms, and these terms are merely used to distinguish different components, regions, layers and / or sections. Therefore, the first components, regions, layers and / or sections discussed below can be referred to as the second components, regions, layers and / or sections without departing from some embodiments of the present application.

[0035] As described above, liquid source cylinders are widely used in the fields of industrial production, laboratories and semiconductor manufacturing. In particular, in the field of semiconductor manufacturing technology, the application of liquid source cylinders mainly involves chemical vapor deposition, etching, atomic layer deposition and other key process steps, which have a crucial influence on the performance of semiconductor devices. In order to ensure the stable output of the liquid source, accurate temperature control of the cylinder is required.

[0036] The existing liquid source cylinders mostly use silicone heating belts as temperature control elements. The heating belt is composed of Teflon, a heating element, an insulating layer, a silicone rubber insulation layer and an outer skin layer. Although this heating belt can meet the temperature control requirements to some extent, due to the design limitations of the heating element, the overall bottle temperature can only reach a uniform set value, and independent temperature control in different zones cannot be achieved, resulting in lower temperature in the position far from the heating wire, unstable saturated vapor pressure, and thus adverse effects on product quality.

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

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

[0039] Reference is made to Figure 1 , Figure 1 A structural schematic diagram of a liquid evaporation source according to some embodiments of the present application is shown.

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

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

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

[0043] In some embodiments of the present application, the liquid evaporation source can also be configured with a controller, which can first collect the liquid level of the liquid reactant in the tank 10 of the liquid evaporation source, determine at least one of the first heating belts above the liquid level according to the liquid level collected by the liquid level sensor, and determine the vapor volume V above the liquid level.

[0044] Then, the first target temperature T1 of at least one of the first heating belts is determined according to the vapor volume V, the target output pressure p0, and the single gas outlet mass n of the gas outlet 11 in one gas outlet window.

[0045] Specifically, the pressure continuously decreases during the process until it rises after stopping, the valve switch is approximately airtight when switching, and the liquid source consumption is extremely small when running a single process, so the volume change is negligible.

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

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

[0048] Specifically, the controller can acquire the actual temperature of the first heating band, and compare the actual temperature with the first target temperature T1 to determine a corresponding temperature difference. Then, the temperature difference is subjected to PID operation to determine a corresponding temperature control amount. For example, the algorithm is written in software and added to the process recipe. When the process recipe is executed, the pressure change is monitored in real time, so as to feedback to the software to calculate how much temperature needs to be provided to balance the pressure, and finally the appropriate temperature rise rate is given through the PID system. Finally, according to the temperature control amount, the heating power of at least one circle of the first heating band is adjusted to adjust the actual temperature thereof to the first target temperature T1.

[0049] Thus, according to the independent control area divided by the several equal parts of the liquid level of the tank body 10, the partition independent temperature control is realized. At the same time, the liquid level sensor and the controller are linked with the heating band temperature in real time, and the temperature is adjusted through pressure feedback to balance the front-end pressure, so as to control the liquid source more accurately and stably, thereby stabilizing the saturated vapor pressure to improve the product quality.

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

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

[0052] Specifically, the heating base 20 comprises a base body 21 and a liquid guide pipe 22. The base body 21 is made of a heat-conducting material and contacts the liquid reactant via the bottom of the tank body 10. The liquid guide pipe 22 is uniformly distributed in the base body 21 and heats the base body 20 by transmitting high-temperature liquid to uniformly heat the liquid reactant via 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 material, and the high-temperature liquid can be selected from glycol or galden.

[0054] In some embodiments of the present application, the controller can further determine at least one circle of the second heating band below the liquid level height according to the liquid level height collected by the liquid level sensor.

[0055] Then, 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 band, the third target temperature of each circle of the second heating band is determined.

[0056] Finally, each of the second heating bands is adjusted to its corresponding third target temperature to block the heat transfer of the vapor to the liquid reactant. Here, the third target temperature of each of the second heating bands varies linearly according to the interval distance between each of the second heating bands. For example, the second heating bands are equally distributed, and the third target temperature of each of the second heating bands is uniformly increased or decreased.

[0057] Here, the skilled person can first heat the heat conductive agent and flow in through the central heat conductive agent inlet 23 and out from the outer heat conductive agent outlet 24 to form a heat cycle. Then, the heat is transferred to the surface of the tank body 10 through the base body 21 to improve the bottom heat stability. Further, since the heat conductive agent has a large heat capacity, more stable temperature control is achieved to more accurately and stably control the temperature of the liquid source, thereby stabilizing the saturated vapor pressure to improve product quality.

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

[0059] Although the above-described methods are illustrated and described as a series of acts, it will be appreciated that not all of the acts are necessarily present in every implementation thereof, and that the methods can be implemented in different orders and with different and / or additional acts than those depicted and described herein without departing from the scope of the present disclosure. One or more additional or different acts can also be performed before, after, concurrently with, or as part of the acts described herein.

[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 generic principles defined herein can 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 is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid vaporisation source, characterised in that, The application relates to a liquid evaporation source, comprising: a tank body comprising a gas outlet for containing liquid reactant and vapor thereof and outputting the vapor of the liquid reactant through the gas outlet; and a gas pressure control assembly comprising a plurality of heating belts, a liquid level sensor, a pressure gauge and a controller, wherein the plurality of heating belts are wound at different heights on the periphery of the tank body respectively, the controller is configured to: determine the at least one first heating belt above the liquid level height according to the liquid level height collected by the liquid level sensor, determine the vapor volume above the liquid level height, determine the first target temperature of the at least one first heating belt according to the vapor volume, the target output gas pressure and the single gas output mass of the gas outlet in one gas outlet window, and adjust the at least one first heating belt to the first target temperature to control the actual output gas pressure of the gas outlet in one gas outlet window to the target output gas pressure. The step of adjusting the at least one first heating belt to the first target temperature comprises:

2. The liquid vaporization source of claim 1, wherein collecting the actual output gas pressure of the gas outlet through the pressure gauge and comparing the actual output gas pressure with the target output gas pressure to determine a corresponding gas pressure difference value; performing PID operation on the gas pressure difference value to determine a corresponding control amount; and adjusting the heating power of the at least one first heating belt according to the control amount to adjust the actual temperature thereof to the first target temperature. The tank body further comprises a heating base for heating the liquid reactant to a second target temperature above the boiling point of the liquid reactant to form the vapor above the liquid reactant.

3. The liquid vaporization source of claim 1, wherein The heating base comprises:

4. The liquid vaporization source of claim 3, wherein a base body made of heat-conductive material and in heat-conductive contact with the liquid reactant through the bottom of the tank body; and liquid guide pipes uniformly distributed in the base body and heating the base body by transmitting high-temperature liquid to uniformly heat the liquid reactant through the base body. The base body is made of aluminum, the bottom of the tank body is made of corrosion-resistant stainless steel material, and the high-temperature liquid is ethylene glycol or perfluoropolyether.

5. The liquid vaporization source of claim 4, wherein The controller is further configured to:

6. The liquid vaporization source of claim 3, wherein determine the at least one second heating belt below the liquid level height according to the liquid level height collected by the liquid level sensor; determine the third target temperature of each of the second heating belts according to the difference between the first target temperature and the second target temperature and the number of the at least one second heating belt; and adjust each of the second heating belts to the corresponding third target temperature to block the heat transfer of the vapor to the liquid reactant. The third target temperature of each of the second heating belts linearly changes with the interval distance between each of the second heating belts. The method comprises the following steps:

7. The liquid vaporization source of claim 6, wherein collecting the liquid level height of the liquid reactant in the tank body of the liquid evaporation source according to any one of claims 1-7; 8. A method for controlling the output gas pressure of a liquid evaporation source, characterized in that, determining the at least one first heating belt above the liquid level height and the vapor volume above the liquid level height according to the liquid level height; ​ ​ determining a first target temperature of the at least one first heating band according to the vapor volume, a preset target output gas pressure, and a single gas outlet mass of the gas outlet of the can body in a gas outlet window; and adjusting the at least one first heating band to the first target temperature to control an actual output gas pressure of the gas outlet in the gas outlet window to the target output gas pressure.

9. A thin film deposition apparatus characterized by comprising: including: a process chamber for accommodating a semiconductor device to be processed; and the liquid evaporation source of any one of claims 1-7 for providing a vapor of a liquid reactant to the process chamber at a constant pressure and a constant quantity according to a process requirement to perform a thin film deposition process on the semiconductor device.

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