Spraying disc temperature control mechanism and thin film deposition equipment and control method thereof

Abstract

The invention discloses a spraying disc temperature control mechanism and thin film deposition equipment and a control method thereof. The spraying disc temperature control mechanism comprises a heating spraying disc, a pressure control unit and a liquid level control unit, wherein the pressure control unit and the liquid level control unit are connected to the heating spraying disc; a backflow cavity and a cooling cavity are formed in the heating spraying disc, the backflow cavity is located above the cooling cavity and communicated with the cooling cavity, the pressure control unit is used for controlling the pressure in the backflow cavity, and the liquid level control unit is used for controlling the liquid level in the cooling cavity. According to the spraying disc temperature control mechanism and the thin film deposition equipment and the control method thereof, the pressure value in the heating spraying disc and the liquid level height of the cooling liquid are controlled according to specific temperature control requirements through the external pressure control unit and the liquid level control unit, the temperature of the spraying disc is controlled in a mode of latent heat of vaporization of the cooling liquid, and the temperature of the spraying disc is controlled. The cooling efficiency is high, the temperature control precision is high, the heating spraying disc can keep the set temperature threshold value, and finally the film deposition quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of a heating spray plate mechanism in semiconductor equipment, and in particular to a spray plate temperature control mechanism and a thin film deposition device and a control method thereof. Background Art

[0002] Low-temperature PECVD (low-temperature plasma chemical vapor deposition) Si H4 process is a low-temperature PECVD thin film deposition method. Low temperature generally refers to a deposition temperature below 200°C. A heating plate is often used to heat the wafer, and excess heat is dissipated through the handle of the heating plate to control the temperature. The existing temperature control method uses a method where a fluid flows through the component to cool the component that needs to be cooled. However, the heat carried by the fluid will gradually dissipate as it flows, and the temperature gradually drops, resulting in poor heat dissipation. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a spray plate temperature control mechanism and a thin film deposition device and a control method thereof, so as to solve the technical problem that the existing spray plate has poor heat dissipation effect.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect, an embodiment of the present invention provides a spray plate temperature control mechanism, which includes: a heating spray plate, a pressure control unit and a liquid level control unit connected to the heating spray plate; a reflux chamber and a cooling chamber are provided in the heating spray plate, the reflux chamber is located above the cooling chamber, and the reflux chamber and the cooling chamber are interconnected, the pressure control unit is used to control the pressure in the reflux chamber, and the liquid level control unit is used to control the liquid level in the cooling chamber.

[0006] Among them, the heating spray plate includes: a reflux pipe and a spray plate connected to the lower end of the reflux pipe, the reflux chamber is arranged in the reflux pipe, and the cooling chamber is arranged in the spray plate; a heat dissipation part is also provided on the top of the reflux pipe, and the heat dissipation part is used to condense the vaporized coolant.

[0007] Wherein, the cooling cavity is filled with a cooling liquid, and the cooling liquid includes ethanol or fluorinated liquid.

[0008] Wherein, the heat dissipation part is a plurality of heat dissipation fins protruding from the top end surface of the return pipe.

[0009] Wherein, a spray surface is provided at the bottom of the heating spray plate, spray holes are provided on the spray surface, and the cooling cavity is a columnar cavity with the same prism as that of the spray surface.

[0010] Wherein, the return pipe is a circular pipe, the top of the circular pipe is a heat dissipation part which is sealed and connected to the return pipe, and the circular pipe is connected to the top center of the heating spray plate.

[0011] In a second aspect, an embodiment of the present invention provides a thin film deposition device, wherein the thin film deposition device comprises a spray plate temperature control mechanism as described in any one of the above.

[0012] In a third aspect, an embodiment of the present invention provides a method for controlling the temperature of a spray plate, the method being performed by the spray plate temperature control mechanism as described above, and comprising the following steps:

[0013] According to the temperature control requirements, set the pressure value of the reflux chamber in the heating spray plate;

[0014] Start the heated spray plate to start spraying process gas into the process chamber;

[0015] Real-time monitoring of the pressure value in the reflux chamber;

[0016] The pressure in the reflux chamber is pressurized or released according to the detected pressure value in the reflux chamber.

[0017] Wherein, the step of setting the pressure value of the reflux chamber in the heating spray plate according to the temperature control requirement also includes: synchronously setting the liquid level height value of the coolant in the cooling chamber.

[0018] The step of real-time monitoring of the pressure value in the reflux chamber also includes: synchronously detecting the liquid level value of the coolant in the cooling chamber, and controlling the input or discharge of the coolant into the cooling chamber according to the detected liquid level value.

[0019] The spray plate temperature control mechanism and its thin film deposition equipment and control method of the present invention control the pressure value inside the heated spray plate and the liquid level height of the coolant according to specific temperature control requirements through an external pressure control unit and a liquid level control unit, and control the temperature of the spray plate by using the latent heat of vaporization of the coolant. It has high cooling efficiency and high temperature control accuracy, which is beneficial for the heated spray plate to maintain the set temperature threshold, thereby ultimately improving the quality of thin film deposition.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the spray plate temperature control mechanism according to an embodiment of the present invention.

[0022] Figure 2 and Figure 3 Schematic diagram of the structure of the heating spray plate part of the spray plate temperature control mechanism according to an embodiment of the present invention from different viewing angles.

[0023] Figure 4 It is a side view of a heating spray plate according to an embodiment of the present invention.

[0024] Figure 5 for Figure 4 AA section view is shown.

[0025] Description of reference numerals:

[0026] The spray plate temperature control mechanism 100 , the heating spray plate 1 , the reflux pipe 11 , the heat dissipation part 111 , the reflux chamber 112 , the spray plate 12 , the spray surface 121 , the cooling chamber 122 , the process gas inlet connector 13 , and the cleaning gas inlet connector 14 . DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships described in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0034] The low-temperature PECVD (low-temperature plasma chemical vapor deposition) Si H4 process is a low-temperature PECVD thin film deposition method. Low temperature generally refers to a deposition temperature below 200°C. A heating plate is often used to heat the wafer, and excess heat is dissipated through the handle of the heating plate to control the temperature. Existing temperature control methods use a method in which a fluid flows through a component to cool the component that needs to be cooled. However, the heat carried by the fluid will gradually dissipate as it flows, and the temperature gradually drops, resulting in poor heat dissipation. In order to solve the above problems, the present embodiment discloses a spray plate temperature control mechanism 100.

[0035] See also Figures 1 to 5This embodiment discloses a spray plate temperature control mechanism 100, which includes: a heating spray plate 1, a pressure control unit 3 and a liquid level control unit 2 connected to the heating spray plate 1; a reflux chamber 112 and a cooling chamber 122 are provided in the heating spray plate 1, the reflux chamber 112 is located above the cooling chamber 122, and the reflux chamber 112 and the cooling chamber 122 are interconnected, the pressure control unit 3 is used to control the pressure in the reflux chamber 112, and the liquid level control unit 2 is used to control the liquid level in the cooling chamber 122. Among them, since the reflux chamber 112 and the cooling chamber 122 are interconnected, the liquid level control unit 2 and the pressure control unit 3 are equivalent to also controlling the liquid level height and pressure of the temperature control chamber interconnected by the reflux chamber 112 and the cooling chamber 122.

[0036] The spray plate temperature control mechanism 100 of this embodiment controls the pressure value in the temperature control cavity through the pressure control unit 3 to control the vaporization temperature of the corresponding coolant. The lower the gas pressure, the lower the vaporization temperature, and the lower the corresponding temperature control range, and vice versa. The spray plate temperature control mechanism of this embodiment is mainly used in low-temperature plasma chemical vapor deposition processes. Therefore, the vaporization temperature control of the coolant can control the temperature of the heated spray plate 1, and can control the temperature of the process gas output from the spray plate.

[0037] In addition, the spray plate temperature control mechanism 100 of the present embodiment also controls the liquid level height in the cooling chamber 122 through the liquid level control unit 2. The liquid level height represents the volume of the coolant. The larger the volume of the coolant, the faster the vaporization and volatilization, that is, the more obvious the latent heat of vaporization effect is, thereby increasing the cooling cycle speed and reducing the temperature fluctuation, so as to improve the temperature control accuracy of the spray plate.

[0038] Please refer again Figures 2 to 5 The heating spray plate 1 includes: a reflux pipe 11 and a spray plate 12 connected to the lower end of the reflux pipe 11, the reflux chamber 112 is arranged in the reflux pipe 11, and the cooling chamber 122 is arranged in the spray plate 12; a heat dissipation portion 111 is also provided on the top of the reflux pipe 11, and the heat dissipation portion 111 is used to condense the vaporized coolant.

[0039] like Figure 5As shown, the coolant is stored in the cooling chamber 122. When the temperature of the heating spray plate 12 is increased after being heated, when the temperature exceeds the set limit, the heat will be transferred to the coolant through the spray plate. The coolant is vaporized after being heated, and the vaporized vapor rises upward, rising to the heat dissipation part 111 along the reflux chamber 112, and condenses into condensate after contacting the heat dissipation part 111. The condensate flows back to the cooling chamber 122 under the action of its own gravity. The heat dissipation part 111 contacts the external space or the cooling channel to release the vaporization heat of the coolant to the outside. The coolant circulates in the cooling chamber 122 and the reflux chamber 112 according to the above process, thereby realizing rapid cooling and precise temperature control of the heating spray plate 1. Since the coolant circulates in a relatively closed space instead of flowing with a long external path, its temperature control is more precise and the fluctuation is smaller.

[0040] See also Figure 5 The cooling chamber 122 is filled with a coolant, and the coolant includes a liquid refrigerant such as ethanol or a fluorinated liquid.

[0041] For different refrigerants, the calculation method of evaporation heat is as follows:

[0042] The Riedel formula is commonly used to calculate the heat of evaporation:

[0043] △H=1.093RT(ln(Pc)-1) / (0.93-Tb / Tc)

[0044] Where △H is the heat of evaporation at normal boiling point; R is the molar gas constant; Tb is the normal boiling point, Tc is the critical temperature, T is the temperature to be measured; Pc is the critical pressure (kgf / cm^ 2 ).

[0045] The Watson formula is also commonly used to calculate the heat of evaporation:

[0046] △H2=△H1*(1-T2 / Tc)*(1-T1 / Tc)^0.38

[0047] The subscripts 1 and 2 represent the heat of evaporation at two different temperatures, respectively, and Tc is the critical temperature. This formula is used to calculate the heat of evaporation at another temperature from the heat of evaporation at one temperature.

[0048] The following table shows the relationship between the latent heat of vaporization, boiling point and specific heat capacity of common refrigerants:

[0049]

[0050] Saturated vapor pressure calculation formula: l gP = AB / (T+C);

[0051] Where P represents the saturated vapor pressure of the substance (mmHg), T represents temperature, and A, B, and C are corresponding constants.

[0052] For example, the saturated vapor pressure of H2O is calculated as:

[0053] Calculated using the Antony equation: l gP = 7.96681-(1668.21 / (T+228)).

[0054] The heat dissipation portion 111 is a plurality of heat dissipation fins protruding from the top end surface of the return pipe 11 , and its characteristic is that the heat dissipation area between the return pipe 11 and the external space can be increased.

[0055] like Figure 3 As shown, a spray surface 121 is provided at the bottom of the spray plate 12 of the heating spray plate 1, and spray holes are provided on the spray surface 121. The cooling chamber 122 is a cylindrical cavity with the same prism as the spray surface 121. In this embodiment, the spray surface 121 is a circular surface, and the spray holes are evenly arranged on the spray surface 121. A spray chamber is also provided in the spray plate 12. The process gas input from the outside is first sent into the spray chamber, and after being evenly mixed and heated in the spray chamber, it is output from the spray holes to the process chamber (i.e., the chamber for thin film deposition). The spray surface 121 and the cooling chamber 122 have the same or similar outer prisms, so that the coolant in contact with the spray surface 121 of the spray plate 12 is distributed more evenly, and the temperature of each part of the corresponding spray surface 121 is also more even. A process gas inlet connector 13 and a cleaning gas inlet connector 14 connected to the spray chamber are also provided at the top of the spray plate 12, which are used to connect with an external process gas delivery unit and a cleaning gas delivery unit.

[0056] In this embodiment, the return pipe 11 is a circular pipe, the top of the circular pipe is a heat dissipation portion 111 sealed and connected to the return pipe, and the circular pipe is connected to the top center of the spray plate 12 .

[0057] An embodiment of the present invention provides a thin film deposition device, which includes the spray plate temperature control mechanism 100 as described above. The thin film deposition device is mainly used for low-temperature vapor phase chemical deposition process.

[0058] An embodiment of the present invention provides a method for controlling the temperature of a spray plate. The method is performed by the spray plate temperature control mechanism 100 as described above, and comprises the following steps:

[0059] Step 1. Set the pressure value of the reflux chamber in the heating spray plate according to the temperature control requirements and the type of coolant. Different thin film deposition processes have different temperature requirements. According to the process temperature requirements, select appropriate air pressure and liquid level values. Adjust the temperature control speed and accuracy to meet the process requirements. The air pressure and liquid level height values ​​are calculated as shown in the above formula.

[0060] Step 2: Start the heated spray plate to spray process gas into the process chamber. When the process gas spray is turned on or before, the spray plate 12 is heated to a set temperature through an internal heating unit. When the process gas is heated in the spray plate 12, it is sprayed into the process chamber at the set temperature to deposit a thin film on the wafer surface.

[0061] Step 3: monitor the pressure value in the reflux chamber in real time; the pressure value in the reflux chamber can be obtained by real-time detection by a pressure sensor, such as a pressure gauge.

[0062] Step 4: Control the pressure of the reflux chamber according to the pressure value detected in the reflux chamber. That is, when the real-time detected pressure value exceeds the upper limit of the set pressure value, the reflux chamber is controlled to release pressure until the set value is reached. On the contrary, if the pressure value is lower than the lower limit of the set range, the boost function is activated to increase the internal pressure until the set pressure value is reached.

[0063] The temperature control method controls the vaporization temperature of different coolants by setting the pressure value of the vaporization and evaporation environment, thereby matching it with the temperature required by the process, and further ensures that the pressure is always within the set range during the entire process through a real-time detection method, thereby maintaining more stable temperature control.

[0064] Wherein, the step of setting the pressure value of the reflux chamber in the heating spray plate according to the temperature control requirement also includes: synchronously setting the liquid level height value of the coolant in the cooling chamber.

[0065] The step of real-time monitoring of the pressure value in the reflux chamber also includes: synchronously detecting the liquid level value of the coolant in the cooling chamber, and controlling the input or discharge of the coolant into the cooling chamber according to the detected liquid level value.

[0066] That is, in the temperature control method of the spray plate of the present embodiment, the air pressure value and the liquid level value inside the heating spray plate 1 are synchronously controlled, and the two are organically combined to ensure a higher temperature control effect while ensuring the temperature control accuracy.

[0067] The spray plate temperature control mechanism and its thin film deposition equipment and control method of this embodiment control the pressure value inside the heated spray plate and the liquid level of the coolant according to specific temperature control requirements through an external pressure control unit and a liquid level control unit, and control the temperature of the spray plate by using the latent heat of vaporization of the coolant. It has high cooling efficiency and high temperature control accuracy, which is beneficial for the heated spray plate to maintain the set temperature threshold, thereby ultimately improving the quality of thin film deposition.

[0068] The above examples are only used to further illustrate the technical content of the present invention, so that readers can understand it more easily, but they do not mean that the implementation of the present invention is limited to this. Any technical extension or re-creation made according to the present invention is protected by the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A spray plate temperature control mechanism, characterized in that: include: A heating spray plate is connected to a pressure control unit and a liquid level control unit of the heating spray plate; a reflux chamber and a cooling chamber are provided in the heating spray plate, the reflux chamber is located above the cooling chamber, and the reflux chamber and the cooling chamber are interconnected, the pressure control unit is used to control the pressure in the reflux chamber, and the liquid level control unit is used to control the liquid level in the cooling chamber.

2. The spray plate temperature control mechanism according to claim 1, characterized in that: The heating spray plate includes: a reflux pipe and a spray plate connected to the lower end of the reflux pipe, the reflux chamber is arranged in the reflux pipe, and the cooling chamber is arranged in the spray plate; a heat dissipation part is also arranged on the top of the reflux pipe, and the heat dissipation part is used to condense the vaporized coolant.

3. The spray plate temperature control mechanism according to claim 2, characterized in that: The cooling cavity is filled with a cooling liquid, and the cooling liquid includes ethanol or fluorinated liquid.

4. The spray plate temperature control mechanism according to claim 2, characterized in that: The heat dissipation part is a plurality of heat dissipation fins protruding from the top end surface of the return pipe.

5. The spray plate temperature control mechanism according to claim 4, characterized in that: A spray surface is provided at the bottom of the heating spray plate, spray holes are provided on the spray surface, and the cooling cavity is a columnar cavity with the same prism as that of the spray surface.

6. The spray plate temperature control mechanism according to claim 5, characterized in that: The return pipe is a circular pipe, the top of the circular pipe is a heat dissipation part which is sealed and connected to the return pipe, and the circular pipe is connected to the top center of the spray plate.

7. A thin film deposition device, characterized in that: The thin film deposition equipment comprises the spray plate temperature control mechanism according to any one of claims 1 to 6.

8. A method for controlling the temperature of a spray plate, the method being performed by the spray plate temperature control mechanism according to any one of claims 1 to 6, characterized in that: The following steps are involved: According to the temperature control requirements and the type of coolant, set the pressure value of the reflux chamber in the heating spray plate; Start the heated spray plate to start spraying process gas into the process chamber; Real-time monitoring of the pressure value in the reflux chamber; The pressure in the reflux chamber is pressurized or released according to the detected pressure value in the reflux chamber.

9. The method for controlling the temperature of the spray plate according to claim 8, characterized in that: The step of setting the pressure value of the reflux chamber in the heating spray plate according to the temperature control requirement also includes: synchronously setting the liquid level height value of the coolant in the cooling chamber.

10. The method for controlling the temperature of the spray plate according to claim 9, characterized in that: The step of real-time monitoring of the pressure value in the reflux chamber also includes: synchronously detecting the liquid level value of the coolant in the cooling chamber, and controlling the input or discharge of the coolant into the cooling chamber according to the detected liquid level value.

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