Deposition apparatus

Abstract

This invention relates to the field of semiconductor manufacturing technology, specifically providing a deposition apparatus designed to address the problem of easy formation of defects on the wafer surface after TEOS processing. The deposition apparatus includes a reaction chamber, a premixing chamber, and an inlet piping assembly. The outlet of the premixing chamber is connected to the inlet of the reaction chamber. A spiral baffle is rotatably mounted within the premixing chamber, which also includes a heating element. The inlet piping assembly includes at least two branch inlet pipes, which converge and connect to the inlet of the premixing chamber. This invention not only effectively improves gas mixing efficiency by adding a premixing chamber between the reaction chamber and the inlet piping assembly and installing a rotatable spiral baffle within it, but also maintains the temperature of the premixing chamber through the heating element to prevent gas condensation, thus reducing defects on the wafer surface after TEOS processing.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, specifically providing a deposition device. Background Technology

[0002] In semiconductor manufacturing, thin film deposition is one of the core steps. TEOS (Tetraethylorthosilicate, also known as tetraethyl silicate) is a common silicon source in thin film chemical vapor deposition (CVD) processes, playing an irreplaceable role, especially in the low-temperature silicon oxide formation process. Due to its excellent step coverage and low side reactions, TEOS has become the preferred material to replace silane (SiH4), particularly for the formation of silicon dioxide (SiO2) films. TEOS generates SiO2 films using PECVD (plasma-enhanced chemical vapor deposition), which can be used as dielectric layers, isolation layers, and protective layers. The chemical formula of TEOS is Si(OC2H5)4. It reacts with oxygen to form silicon dioxide (SiO2), and the chemical reaction equation is: Si(OC2H5)4 + O2 → SiO2 + volatile byproducts (such as ethanol, carbon dioxide, etc.).

[0003] In actual TEOS (Thin Film Optical Sequence) processes, although the process performs excellently in thin film deposition, defects often appear on the surface of the wafers after TEOS treatment. These defects take various forms and may include particle contamination, uneven film thickness, increased surface roughness, and pinholes. The presence of these defects can have a serious negative impact on the performance and reliability of semiconductor devices.

[0004] A thorough analysis of the causes of wafer surface defects in the TEOS process reveals that gas mixing efficiency and gas condensation are two key influencing factors. In the TEOS process, the TEOS gas needs to be thoroughly mixed before entering the reaction chamber to ensure the uniformity and stability of the reaction. However, existing technologies typically use one main pipeline and two branch pipelines for gas mixing. Gases can only mix simply within the direct pipeline, resulting in low mixing uniformity and causing defects such as uneven film thickness in different areas of the wafer surface.

[0005] Furthermore, TEOS gas is prone to condensation during pipeline transportation if temperature control is inadequate. TEOS gas easily transforms from a gaseous state to a liquid state at lower temperatures. Once condensed, it not only affects the gas flow rate and concentration, leading to an imbalance in the reactant ratio, but the condensed liquid may also form particulate contamination, which can easily adhere to the wafer surface, thus creating defects on the wafer surface. Utility Model Content

[0006] The present invention aims to solve the above-mentioned technical problems, namely, to at least solve the problem that defects are easily formed on the wafer surface after the TEOS process.

[0007] This utility model provides a deposition apparatus, the deposition apparatus comprising:

[0008] reaction chamber;

[0009] The premixing chamber has its outlet connected to the inlet of the reaction chamber. The premixing chamber is equipped with a spiral baffle, which is rotatably installed inside the premixing chamber. The premixing chamber is also equipped with a heating element.

[0010] An intake piping assembly comprising at least two branch intake pipes that converge and connect to the inlet of the premixing chamber.

[0011] In some feasible embodiments of the deposition apparatus described above, the premixing chamber includes a first end face located in the axial direction of the helical turbulence element, and the inlet of the premixing chamber is formed on the first end face.

[0012] In some feasible embodiments of the deposition apparatus described above, the helical turbulence element includes a central shaft and helical blades arranged around the central shaft, the distance between the helical blades and the inner wall of the premixing chamber being D1, wherein 0 < D1 ≤ 2 mm.

[0013] In some feasible embodiments of the deposition apparatus described above, the heating element is a heating belt, which is disposed outside the premixing chamber.

[0014] In some feasible embodiments of the deposition apparatus described above, the heating element is a heating wire, which is spirally arranged on the inner wall of the premixing chamber.

[0015] In some feasible embodiments of the deposition apparatus described above, the premixing chamber is further provided with a heat insulation layer.

[0016] In some feasible embodiments of the deposition equipment described above, the air intake pipeline assembly further includes a main air intake pipeline, the outlets of the at least two branch air intake pipelines are connected to the inlet of the main air intake pipeline, the outlet of the main air intake pipeline is connected to the inlet of the premixing chamber, and a filter is provided on the main air intake pipeline.

[0017] In some feasible embodiments of the deposition equipment described above, the main air intake pipe is also equipped with a pressure sensor, and each of the branch air intake pipes is equipped with a flow sensor and an electric regulating valve.

[0018] In some feasible embodiments of the deposition apparatus described above, the deposition apparatus further includes a backflow pump, which is disposed on the air inlet side of the filter.

[0019] In some feasible embodiments of the deposition equipment described above, the main air intake line is equipped with a master valve;

[0020] The filter and the main valve are sequentially arranged on the main intake pipe along the airflow direction.

[0021] The beneficial effects of this utility model are:

[0022] In the wafer manufacturing process, by adding a premixing chamber between the reaction chamber and the gas inlet pipeline assembly, and installing a rotatable spiral baffle in the premixing chamber, the gas can be fully mixed in the premixing chamber before entering the reaction chamber. During the rotation of the spiral baffle, it can generate complex and orderly airflow disturbances, which enhances the collision and exchange between gas molecules, thereby improving the gas mixing efficiency and mixing uniformity. This helps to reduce the defect of uneven film thickness in different areas of the wafer surface caused by low gas mixing uniformity.

[0023] Furthermore, the premixing chamber is also equipped with a heating element. While the spiral turbulence element stirs and mixes the gas, the heating element continuously provides a stable heat source to the premixing chamber, ensuring that the internal temperature of the premixing chamber is always maintained within a suitable range. This effectively avoids gas condensation and greatly reduces the risk of gas condensation forming particles that adhere to the wafer surface, thereby solving the problem of defects easily forming on the wafer surface after the TEOS process. Attached Figure Description

[0024] The preferred embodiments of this utility model are described below with reference to the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram of the deposition apparatus provided in an embodiment of this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Reaction chamber; 2. Premixing chamber; 21. Insulation layer; 22. Heating element; 23. Spiral baffle; 3. Main valve; 4. Filter; 5. Pressure sensor; 6. Back-pump; 7. Electric regulating valve; 8. Flow sensor; 9. Main intake pipe; 91. First intake pipe; 92. Second intake pipe; 10. Extraction pipe. Detailed Implementation

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. To better illustrate the present invention, numerous specific details are provided in the following detailed description. Those skilled in the art should understand that the present invention can be implemented even without certain specific details.

[0029] In the description of this utility model, terms such as "upper," "lower," "inner," "outer," "left," "right," "front," and "rear," which indicate direction or positional relationships, are based on the actual direction or positional relationships in practical application. These terms are used merely for ease of description and do not indicate or imply that the device to be protected must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, ordinal numbers such as "first" and "second" are used only for convenience of explanation and are not used to indicate or imply relative importance.

[0030] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] like Figure 1 As shown, this utility model provides a deposition apparatus, which includes a reaction chamber 1, a premixing chamber 2, and an air inlet pipeline assembly. The outlet of the premixing chamber 2 is connected to the inlet of the reaction chamber 1. A spiral baffle 23 is provided inside the premixing chamber 2, and the spiral baffle 23 is rotatably installed inside the premixing chamber 2. The premixing chamber 2 is also provided with a heating element 22. The air inlet pipeline assembly includes at least two branch air inlets, which converge and connect to the inlet of the premixing chamber 2.

[0032] In the TEOS process, reaction chamber 1 is the core reaction site, providing an independent and controlled environment for gaseous chemical reactions. It allows for precise control of parameters such as temperature, pressure, and gas flow rate, enabling the gases to generate reaction products under specific conditions and deposit them on the wafer, thus achieving the fabrication of thin films with different properties. Premixing chamber 2 serves as a gas pretreatment unit. Using a spiral flow deflector 23, it ensures thorough and uniform mixing of different gases, preventing differences in gas composition from affecting the reaction products. Simultaneously, a heating element 22 maintains the internal temperature, preventing gas condensation and ensuring that the gases enter reaction chamber 1 in a stable state, thereby improving reaction efficiency and product quality.

[0033] In one or more embodiments, the premixing chamber 2 includes a first end face located along the axial direction of the helical turbulence member 23, and the inlet of the premixing chamber 2 is formed on the first end face. In this way, after the gas enters the premixing chamber 2 from the inlet, it will be directly subjected to the shearing and stirring action of the helical turbulence member 23, and eddies and turbulence will be formed rapidly. This strong mixing action can accelerate the diffusion speed between gas molecules, so that different gases can be fully mixed in a short time.

[0034] Furthermore, compared to designs where the inlet of the premixing chamber 2 is located circumferentially, this invention places the inlet of the premixing chamber 2 on the first end face along the axial direction of the spiral baffle 23. This allows for direct axial pipe connections, reducing unnecessary pipe connections and bends, making the premixing chamber 2 more compact, reducing system complexity and floor space. It also prevents localized direct gas flow to the sides of the premixing chamber 2, resulting in a more uniform pressure distribution on the premixing chamber 2 wall and reducing the possibility of stress concentration. This contributes to improving the structural stability and service life of the premixing chamber 2, and reducing the risk of equipment failure. In addition, the gas to be mixed enters the premixing chamber 2 from the first end face and begins to be stirred at the end of the spiral baffle 23 until it flows out of the premixing chamber 2. The longer interaction time between the gas and the spiral baffle 23 within the premixing chamber 2 further enhances the mixing uniformity.

[0035] Furthermore, the premixing chamber 2 also includes a second end face located along the axial direction of the helical baffle 23, and a side surface located between the first and second end faces. The side surface is a circumferential surface. The second end face is parallel to the first end face and is respectively located at both ends of the side surface. The outlet of the premixing chamber 2 is formed on the second end face, and the inlet of the reaction chamber 1 is connected to the outlet of the premixing chamber 2. Alternatively, the first and second end faces may not be parallel, such as not being perpendicular to the axis of the helical baffle 23.

[0036] In one or more embodiments, the helical baffle 23 includes a central shaft and helical blades arranged around the central shaft. The deposition apparatus also includes an output motor, the output shaft of which is connected to the central shaft. The helical baffle 23 can be completely housed within the premixing chamber 2, or it can partially extend out of the premixing chamber 2 to be connected to the output motor. For example, the end of the central shaft connected to the output shaft is rotatably sealed to the first end face. The inlet of the premixing chamber 2 is located off-center on the first end face (such as in the edge region, or in the intermediate region between the center and the edge region), that is, the inlet of the premixing chamber 2 is offset from the axis of the helical baffle 23.

[0037] Furthermore, the distance between the helical blades and the inner wall of the premixing chamber 2 is D1, where 0 < D1 ≤ 2 mm. Precisely controlling the distance between the helical blades and the inner wall of the premixing chamber 2 within a reasonable range has multiple positive effects. From an equipment protection perspective, this effectively prevents the helical blades from directly contacting the inner wall during rotation, avoiding blade wear caused by friction and collision, helping to reduce equipment failure rates and minimizing downtime and maintenance costs associated with blade replacement. In terms of fluid mixing, a reasonable spacing plays a crucial role. Specifically, when the helical blades rotate, they exert significant shear force on the fluid near the inner wall. This shear force breaks the original laminar flow state of the fluid, making the internal flow turbulent, thus promoting easier interpenetration and thorough mixing of different components in the fluid, laying the foundation for an efficient mixing process. In addition, the narrow gap causes a high velocity gradient as the fluid passes through. The existence of a velocity gradient is an important factor promoting turbulence formation. Once turbulence forms, it enhances momentum exchange and mass transfer within the fluid. Enhanced momentum exchange and mass transfer can further improve mixing, ensuring a more uniform distribution of components in the fluid and meeting the TEOS process's requirement for uniform gas mixing.

[0038] In this invention, the heating element 22 is used to heat the premixing chamber 2 and maintain its internal temperature to prevent gas condensation. The heating element 22 can be disposed outside the premixing chamber 2, or inside or in a sandwich structure within the premixing chamber 2. In one embodiment, the heating element 22 is a heating belt, which is disposed outside the premixing chamber 2 and covers the entire premixing chamber 2. This allows for uniform heating of the gas within the premixing chamber 2, enabling rapid and even heat transfer to all parts of the premixing chamber 2, ensuring a uniform rise in gas temperature, avoiding localized overheating or overcooling, and helping to prevent gas condensation, thereby ensuring product quality. In another embodiment, such as... Figure 1 As shown, the heating element 22 is a heating wire, which is spirally arranged on the inner wall of the premixing chamber 2. In this case, to avoid collision between the heating wire and the spiral baffle 23, the distance between the heating wire and the spiral baffle 23 is less than or equal to D1. The spiral heating wire can effectively increase the length of the heating wire in a limited space, thereby increasing the heating area and making the heat transfer to the gas in the premixing chamber 2 more efficient. Furthermore, the spiral heating wire can be evenly distributed on the inner wall of the premixing chamber 2, forming a relatively uniform heat distribution throughout the entire premixing chamber 2. This avoids local overheating or overcooling and helps prevent gas condensation, thus ensuring product quality.

[0039] Furthermore, the premixing chamber 2 is also provided with a heat insulation layer 21. The heat insulation layer 21 effectively prevents heat from being transferred outwards through the inner wall of the premixing chamber 2. By reducing heat loss, the heat insulation layer 21 ensures that the energy provided by the heating element 22 is used more to heat the fluid inside the premixing chamber 2, rather than being dissipated into the surrounding environment, effectively preventing gas condensation. The heat insulation layer 21 is typically located on the outer side of the side wall of the premixing chamber 2.

[0040] In this invention, the intake pipe assembly includes at least two branch intake pipes. The specific number of branch intake pipes in the intake pipe assembly is usually closely related to the number of types of gases participating in the reaction in reaction chamber 1; that is, the minimum number of branch intake pipes is determined by the number of types of gases participating in the reaction. Taking the TEOS process as an example, since the TEOS process requires TEOS gas and oxygen to react chemically to generate silicon dioxide (SiO2), the intake pipe assembly includes two branch intake pipes. Figure 1 As shown, for ease of description, the two intake pipes are defined as the first intake pipe 91 and the second intake pipe 92, respectively. The first intake pipe 91 is used to introduce TEOS gas, and the second intake pipe 92 is used to introduce oxygen.

[0041] The intake piping assembly also includes a main intake pipe 9, with the outlets of at least two branch intake pipes connected to the inlet of the main intake pipe 9. The outlet of the main intake pipe 9 is connected to the inlet of the premixing chamber 2. A filter 4 is installed on the main intake pipe 9. When TEOS gas is not completely vaporized, the incompletely vaporized TEOS gas, as well as impurity particles generated during the mixing of TEOS gas and oxygen, will be effectively intercepted by the filter 4. In this way, these impurity particles cannot enter the premixing chamber 2 and the reaction chamber 1 with the airflow, thereby further reducing the risk of defects on the wafer surface and providing strong protection for the stability of the semiconductor manufacturing process and product quality.

[0042] Furthermore, the main intake pipe 9 is equipped with a pressure sensor 5, and each branch intake pipe is equipped with a flow sensor 8 and an electric regulating valve 7. Specifically, the first branch intake pipe 91 is equipped with a flow sensor 8 and an electric regulating valve 7, and the second branch intake pipe 92 is equipped with a flow sensor 8 and an electric regulating valve 7. The pressure sensor 5 can measure the gas pressure in the main intake pipe 9 in real time. When the pressure in the main intake pipe 9 exceeds or falls below the set safety range, the pressure sensor 5 can promptly issue an alarm signal. The flow sensor 8 can measure the gas flow rate in each branch intake pipe in real time, and the electric regulating valve 7 can automatically adjust the valve opening based on the feedback signal from the flow sensor 8, thereby precisely controlling the flow rate of each gas.

[0043] Specifically, during gas delivery, after pre-setting the target pressure value of the main intake pipe 9 and the target gas flow rate values ​​of each branch intake pipe, the flow sensor 8 of each branch intake pipe monitors the gas flow rate in real time and feeds it back to the control system. If the actual flow rate does not match the target value, the control system adjusts the opening of the electric regulating valve 7 accordingly to change the flow rate. The pressure sensor 5 of the main intake pipe 9 monitors the pressure synchronously. When the actual pressure deviates from the target value, the control system integrates the flow rate of each branch intake pipe and adjusts the opening of the electric regulating valve 7 to change the total gas flow rate, thereby restoring the pressure to the target value. In this way, the combined action of the pressure sensor 5, the flow sensor 8, and the electric regulating valve 7 ensures the precise ratio of the two gases, avoids thin film quality defects caused by flow fluctuations, and helps improve the uniformity of the deposited thin film on the wafer surface.

[0044] Furthermore, the deposition equipment also includes a backflow pump 6, which is located on the inlet side of the filter 4. For example... Figure 1 As shown, the deposition equipment also includes an extraction pipe 10. The inlet of the extraction pipe 10 is connected to the main intake pipe 9, the first intake pipe 91, or the second intake pipe 92. The inlet of the extraction pipe 10 is located between the intake side of the filter 4 and the outlet side of the electric regulating valve 7. Furthermore, if the main intake pipe 9 is equipped with a pressure sensor 5, the inlet of the extraction pipe 10 is located between the pressure sensor 5 and the filter 4. When the system has been running for a period of time or when a risk of impurity accumulation is detected, the extraction system constructed by the back-pump 6 and the extraction pipe 10 can perform extraction operations on the main intake pipe 9. This allows impurity particles filtered out by the filter 4 to be extracted from the main intake pipe 9, preventing the accumulation of impurity particles from causing blockage in the main intake pipe 9.

[0045] Furthermore, the main intake pipe 9 is equipped with a master valve 3. The filter 4 and the master valve 3 are sequentially arranged on the main intake pipe 9 along the airflow direction, meaning that the master valve 3 is located closer to the premixing chamber 2 and the reaction chamber 1 than the filter 4. With this arrangement, after the master valve 3 is closed, impurity ions such as fluoride ions in the reaction chamber 1 will not flow back to the deeper parts of the main intake pipe 9, nor will they enter the first intake pipe 91 and the second intake pipe 92, reducing the risk of corrosion and contamination of the pipes.

[0046] In the wafer manufacturing process, this invention adds a premixing chamber 2 between the reaction chamber 1 and the gas inlet pipeline assembly, and installs a rotatable spiral baffle 23 in the premixing chamber 2. This design allows the gas to be fully mixed in the premixing chamber 2 before entering the reaction chamber 1 with the help of the spiral baffle 23. During rotation, the spiral baffle 23 generates complex and orderly airflow disturbances, which enhances the collision and exchange between gas molecules, thereby improving the gas mixing efficiency and mixing uniformity. This helps to reduce the defect of uneven film thickness in different areas of the wafer surface caused by low gas mixing uniformity.

[0047] Furthermore, the premixing chamber 2 is also equipped with a heating element 22. While the spiral turbulence element 23 stirs and mixes the gas, the heating element 22 continuously provides a stable heat source for the premixing chamber 2, ensuring that the internal temperature of the premixing chamber 2 is always maintained within a suitable range. This effectively avoids the occurrence of gas condensation and greatly reduces the risk of gas condensation forming particles that adhere to the wafer surface, thereby solving the problem of defects easily forming on the wafer surface after the TEOS process.

[0048] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A deposition apparatus, characterized in that, The deposition apparatus includes: Reaction chamber (1); The premixing chamber (2) has its outlet connected to the inlet of the reaction chamber (1). The premixing chamber (2) is provided with a spiral baffle (23), which is rotatably installed in the premixing chamber (2). The premixing chamber (2) is also provided with a heating element (22). An intake piping assembly comprising at least two branch intake piping lines which converge and connect to the inlet of the premixing chamber (2).

2. The deposition apparatus according to claim 1, characterized in that, The premixing chamber (2) includes a first end face located in the axial direction of the spiral spoiler (23), and the inlet of the premixing chamber (2) is formed on the first end face.

3. The deposition apparatus according to claim 2, characterized in that, The spiral spoiler (23) includes a central shaft and spiral blades arranged around the central shaft. The distance between the spiral blades and the inner wall of the premixing chamber (2) is D1, where 0 < D1 ≤ 2 mm.

4. The deposition apparatus according to claim 1, characterized in that, The heating element (22) is a heating belt, which is disposed outside the premixing chamber (2).

5. The deposition apparatus according to claim 1, characterized in that, The heating element (22) is a heating wire, which is spirally arranged on the inner wall of the premixing chamber (2).

6. The deposition apparatus according to claim 1, characterized in that, The premixing chamber (2) is also provided with a heat insulation layer (21).

7. The deposition apparatus according to any one of claims 1 to 6, characterized in that, The intake pipe assembly also includes a main intake pipe (9), the outlets of the at least two branch intake pipes are connected to the inlet of the main intake pipe (9), the outlet of the main intake pipe (9) is connected to the inlet of the premixing chamber (2), and a filter (4) is provided on the main intake pipe (9).

8. The deposition apparatus according to claim 7, characterized in that, The main intake pipe (9) is also equipped with a pressure sensor (5), and each of the branch intake pipes is equipped with a flow sensor (8) and an electric regulating valve (7).

9. The deposition apparatus according to claim 7, characterized in that, The deposition equipment also includes a back-pump (6), which is located on the air inlet side of the filter (4).

10. The deposition apparatus according to claim 7, characterized in that, The main intake pipe (9) is equipped with a main valve (3); The filter (4) and the main valve (3) are sequentially arranged on the main intake pipe (9) along the airflow direction of the main intake pipe (9).

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