A plasma processing apparatus

Abstract

The utility model discloses a kind of plasma processing equipment, including process cavity and radio frequency cavity, pedestal is equipped in process cavity to carry substrate, radio frequency cavity is equipped with radio frequency assembly, radio frequency assembly is electrically connected with radio frequency source, radio frequency source is fed into radio frequency energy to process cavity by radio frequency assembly, to excite plasma in process cavity to process substrate;Wherein, valve assembly is equipped in radio frequency cavity, electromagnetic shielding component is arranged between valve assembly and radio frequency assembly, electromagnetic shielding component is grounded to shield the electromagnetic radiation of the radio frequency assembly to the valve assembly.Such setting, both shorten the air path length between valve assembly and process cavity, improve gas switching rate, effectively isolate the electromagnetic interference of radio frequency electromagnetic field to valve assembly, significantly reduce the failure rate of valve assembly, improve the overall reliability and process stability of equipment.

Description

Technical Field

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

[0002] In plasma processing equipment, the location of the inlet valve affects the inlet response speed. To improve the inlet response speed, one approach is to shorten the flow path at the rear end of the inlet valve and install it closer to the process chamber. Another approach, to reduce the space occupied by the inlet valve, is to place it within the radio frequency chamber. However, after a period of operation, it was found that the failure rate of the inlet valve was higher than the baseline value. Therefore, how to improve the service life of the inlet valve while shortening the gas path length by placing the valve assembly closer to the process chamber has become a pressing issue. Utility Model Content

[0003] To solve the above problems, the present invention adopts the following technical solution: A plasma processing device includes a process chamber and a radio frequency (RF) chamber. The process chamber contains a base to support a substrate, and the RF chamber contains an RF component electrically connected to an RF source. The RF source feeds RF energy into the process chamber through the RF component to excite plasma within the process chamber to process the substrate. The RF chamber also contains a valve assembly, the outlet of which is connected to the inlet of the process chamber. An electromagnetic shielding component is disposed between the valve assembly and the RF component, and the electromagnetic shielding component is grounded to shield the RF component from electromagnetic radiation to the valve assembly.

[0004] This invention significantly shortens the gas path length between the valve assembly and the process chamber by directly placing the valve assembly within the radio frequency cavity. This allows gas to rapidly enter the process chamber after the valve opens and to quickly cut off the gas supply after the valve closes, achieving rapid gas supply switching. This meets the stringent gas switching rate requirements of advanced processes such as atomic layer etching and atomic layer deposition. Simultaneously, it effectively shields the valve assembly from interference by the strong electromagnetic field within the radio frequency cavity, preventing malfunctions, signal distortion, or damage to the electronic components within the valve assembly. This significantly reduces the valve assembly's failure rate and improves the overall reliability and process stability of the equipment.

[0005] In one embodiment, the radio frequency (RF) component includes an RF coil, and the process cavity and the RF cavity are hermetically separated by a dielectric window. This structure is suitable for inductively coupled plasma (ICP) or transformer-coupled plasma (VCP) processing equipment, where the RF coil couples RF energy into the process cavity through the dielectric window to generate plasma. By placing the valve assembly within the RF cavity of this structure and employing electromagnetic shielding components, interference from the alternating electromagnetic field generated by the RF coil on the valve assembly can be effectively shielded.

[0006] In one embodiment, the valve assembly is arranged around the RF coil or located inside the RF coil. The installation position of the valve assembly can be flexibly selected based on the overall structure and spatial layout of the equipment. When the valve assembly is arranged around the RF coil, it facilitates the uniform arrangement of multiple valve assemblies, which is beneficial for achieving uniform gas distribution within the process chamber; when the valve assembly is located inside the RF coil, central gas supply can be achieved.

[0007] In one embodiment, the RF component includes an upper electrode, and the process cavity and the RF cavity are hermetically isolated by the upper electrode. This structure is suitable for capacitively coupled plasma processing equipment, where the upper electrode acts as one plate of a capacitor, forming capacitive coupling with the base, feeding RF energy into the process cavity, and exciting the generation of capacitively coupled plasma. By placing the valve assembly within the RF cavity of this structure and encasing it with electromagnetic shielding components, interference from the alternating electric field generated by the upper electrode on the valve assembly can be effectively shielded.

[0008] In one embodiment, the valve assembly includes a valve body and a position detection unit. The position detection unit is disposed on the valve body and includes detection circuit elements. An electromagnetic shielding component encloses the position detection unit. The position detection unit is the part of the valve assembly most susceptible to electromagnetic interference because it contains sensitive detection circuit elements. By enclosing the position detection unit, the most effective electromagnetic shielding can be achieved with minimal cost and the simplest structure, protecting the position detection unit from interference from radio frequency electromagnetic fields.

[0009] In one embodiment, the valve body is a pneumatic diaphragm valve, which includes a conductive housing that is grounded. The pneumatic diaphragm valve exhibits excellent response speed, achieving millisecond-level opening and closing. Simultaneously, the grounded conductive housing forms a double electromagnetic shielding structure with external electromagnetic shielding components, further enhancing the isolation effect against radio frequency electromagnetic fields. This effectively prevents electromagnetic fields from entering the valve and interfering with its normal operation, and also prevents the valve housing from becoming energized, improving the operational safety of the equipment.

[0010] In one embodiment, the RF component includes an RF feed rod, with the position detection unit located along the axial direction of the RF cavity. This arrangement fully utilizes the spare space within the RF component to house the valve assembly, minimizing space occupation. However, in this compact layout, the position detection unit is located in the region with the strongest RF electromagnetic field, experiencing the most severe electromagnetic interference. Therefore, encasing the position detection unit with an electromagnetic shielding component is particularly necessary to effectively protect it from abnormal operation in strong electromagnetic field environments.

[0011] In one embodiment, the electromagnetic shielding component includes a Faraday cage or a shielding plate. A Faraday cage is a closed structure made of metal mesh or metal plate that can effectively shield external electromagnetic fields; a shielding plate is a simple and effective electromagnetic shielding structure suitable for shielding electromagnetic fields in a specific direction. The appropriate type of electromagnetic shielding component can be selected based on the structure and installation location of the valve assembly.

[0012] In one embodiment, the electromagnetic shielding component is electrically connected to the radio frequency cavity housing, which is conductive and grounded. Directly connecting the electromagnetic shielding component to the grounded radio frequency cavity housing ensures reliable grounding and guarantees the electromagnetic shielding effect. Furthermore, this grounding method eliminates the need for additional grounding lines, simplifying the device structure and reducing manufacturing costs.

[0013] In one embodiment, the process chamber is provided with an air intake ring surrounding the sidewall of the process chamber. The air intake ring has multiple air inlets for supplying air into the process chamber. The valve assembly includes multiple air intake valves, which are installed on the air intake ring and correspond one-to-one with each air inlet. This structure minimizes air intake delay and ensures uniform gas distribution within the process chamber, improving the uniformity of the process. Furthermore, since each air inlet corresponds to an independent air intake valve, independent control of the air intake volume in different areas can be achieved, further enhancing the flexibility and precision of the process.

[0014] The beneficial effects of this utility model are as follows: This invention significantly shortens the gas path length between the valve assembly and the process chamber by directly placing the valve assembly inside the radio frequency cavity, enabling rapid gas supply switching and meeting the stringent requirements of advanced processes such as atomic layer etching and atomic layer deposition for gas switching rates.

[0015] Furthermore, by employing grounded electromagnetic shielding components, the interference of strong electromagnetic fields within the radio frequency cavity on the valve assembly can be effectively shielded, preventing malfunctions, signal distortion, or damage to electronic components within the valve assembly. This significantly reduces the failure rate of the valve assembly and improves the overall reliability and process stability of the equipment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope of this utility model. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the plasma processing device in one embodiment of the present invention; Figure 2 for Figure 1 A magnified structural diagram of part A in the middle; Figure 3 This is a three-dimensional structural diagram of an embodiment of the present invention where the electromagnetic shielding component is a Faraday cage; Figure 4 This is a schematic diagram of the plasma processing device in another embodiment of the present invention; Figure 5 This is a schematic diagram of the plasma processing device in another embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: W-Substrate, 1-Process cavity, 2-RF cavity, 21-Housing, 3-Base, 4-RF component, 5-RF source, 6-Valve assembly, 7-Electromagnetic shielding component, 8-Dielectric window, 9-Upper electrode, 10-Inlet ring, 11-Inlet port, 20-Exhaust port, 41-RF coil, 42-RF feed rod, 61-Valve body, 62-Position detection unit, 63-Conductive housing. Detailed Implementation

[0019] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. The technical solution of this utility model can be implemented in many different forms and is not limited to the specific embodiments described herein. The purpose of providing these specific embodiments is to enable a more thorough and comprehensive understanding of the disclosure of this utility model.

[0020] Research revealed that the primary cause of the increased intake valve failure rate is that when the intake valve is installed close to the process chamber, it is often placed inside the radio frequency (RF) cavity to avoid increasing the radial footprint of the cavity. The RF components inside the RF cavity generate a high-intensity RF electromagnetic field during operation, which excites the plasma within the process chamber. This strong electromagnetic field causes severe electromagnetic interference to nearby electronic components. Intake valves typically contain precision electronic components such as position detection units and solenoid valve drive circuits. These components are prone to malfunction, signal distortion, or even permanent damage under the interference of the strong RF electromagnetic field, thus significantly increasing the intake valve failure rate.

[0021] In addition, radio frequency electromagnetic fields may induce eddy currents on the metal components of the intake valve, causing the components to heat up. This not only affects the normal working life of the intake valve, but may also have a heating effect on the process gas passing through the intake valve, changing the temperature and density of the gas, and thus affecting the plasma characteristics and process results.

[0022] Therefore, this utility model provides a plasma processing device, such as... Figure 1As shown, in one embodiment, the plasma processing equipment mainly includes two parts: a process chamber 1 and a radio frequency chamber 2. The process chamber 1 is a sealed space for plasma processing. Generally, the process chamber 1 has an exhaust port 20 for connecting a vacuum pumping component to maintain a vacuum state in the process chamber 1 during the process. A base 3 is provided inside the process chamber 1 to support the substrate W to be processed. In some embodiments, the base 3 may also be equipped with a heating unit, a rotation drive mechanism, or a bias radio frequency feed structure according to process requirements to achieve functions such as heating, rotating, or applying bias radio frequency power to the substrate W.

[0023] The radio frequency cavity 2 is arranged adjacent to the process cavity 1. In this embodiment, the radio frequency cavity 2 is located above the process cavity 1. In other embodiments, the radio frequency cavity 2 can also be arranged on the side of the process cavity 1 according to the overall layout requirements of the device. The valve assembly 6 is located in the radio frequency cavity 2, which is beneficial for its proximity to the air inlet 11 of the process cavity 1, and can shorten the air path length from the valve assembly 6 to the air inlet 11.

[0024] The radio frequency cavity 2 is equipped with a radio frequency component 4, which is electrically connected to an external radio frequency source 5 via a radio frequency feed rod 42. The radio frequency energy generated by the radio frequency source 5 is fed into the process cavity 1 through the radio frequency component 4, ionizing the process gas in the process cavity 1 and generating plasma, thereby performing plasma processing processes such as etching and deposition on the substrate W.

[0025] A valve assembly 6 is installed within the RF cavity 2. The outlet of the valve assembly 6 is connected to the inlet 11 of the process cavity 1 to control the on / off state or flow rate of the process gas. Because the valve assembly 6 is directly located within the RF cavity 2 and very close to the inlet 11 of the process cavity 1, the gas path length between the valve assembly 6 and the process cavity 1 is significantly shortened. When the valve assembly 6 is open, the process gas can quickly enter the process cavity 1 through the inlet 11; when the valve assembly 6 is closed, the gas supply can be quickly cut off, leaving very little gas in the intermediate gas path, which will not affect subsequent processes. This rapid gas supply switching capability is beneficial for improving the process efficiency and yield of processes such as atomic layer etching and atomic layer deposition.

[0026] However, the radio frequency component 4 within the radio frequency cavity 2 generates a high-intensity radio frequency electromagnetic field during operation. This strong electromagnetic field can cause severe electromagnetic interference to the electronic components in the valve assembly 6. To address this issue, this invention incorporates an electromagnetic shielding component 7 between the valve assembly 6 and the radio frequency component 4, and this electromagnetic shielding component 7 is grounded. The electromagnetic shielding component 7 confines the radio frequency electromagnetic field to its external space, preventing the electromagnetic field from propagating to the valve assembly 6, thereby protecting the electronic components in the valve assembly 6 from electromagnetic interference. Grounding allows for the rapid conduction of induced charges on the electromagnetic shielding component 7, ensuring the stability of the shielding effect. The grounded electromagnetic shielding component utilizes the Faraday cage principle to discharge the eddy currents induced by the radio frequency electromagnetic field through a grounding path, creating a zero-field region within the shield, thus protecting the internal electronic components from interference.

[0027] In one embodiment, the valve assembly 6 is at least partially enclosed by an electromagnetic shielding component 7 to enhance electromagnetic protection of the valve assembly 6.

[0028] like Figure 1 As shown, in one embodiment, the RF component 4 includes an RF coil 41, and the process cavity 1 and the RF cavity 2 are hermetically separated by a dielectric window 8. The dielectric window 8 is made of an insulating material that allows the RF electromagnetic field to pass through. In some embodiments, the dielectric window 8 may be made of quartz, ceramic, or other suitable insulating materials. The dielectric window 8 also ensures the vacuum seal of the process cavity 1. The alternating electromagnetic field generated by the RF coil 41 is coupled into the process cavity 1 through the dielectric window 8, ionizing the process gas in the process cavity 1 and generating inductively coupled plasma or transformer-coupled plasma.

[0029] like Figure 1 As shown, in one embodiment, the valve assembly 6 is arranged around the radio frequency coil 41. This arrangement facilitates the uniform distribution of multiple valve assemblies 6 along the circumference, which is beneficial for achieving uniform gas supply and distribution within the process chamber 1 and improving the uniformity of the process.

[0030] like Figure 4 As shown, in another embodiment, the valve assembly 6 is located inside the radio frequency coil 41. This arrangement allows for central gas supply while further shortening the gas path length and improving the response speed of gas supply switching.

[0031] like Figure 5 As shown, in another embodiment, the RF component 4 includes an upper electrode 9, which hermetically isolates the process cavity 1 and the RF cavity 2. The upper electrode 9 is made of a conductive metal material and serves as one plate of a capacitor, forming a capacitive coupling with the base 3. The alternating electric field generated by the upper electrode 9 ionizes the process gas within the process cavity 1, generating capacitively coupled plasma.

[0032] like Figure 2As shown, in one embodiment, the valve assembly 6 includes a valve body 61 and a position detection unit 62. The position detection unit 62 is disposed on the valve body 61 and is used to detect the open and closed states of the valve and feed back the detection signal to the control system of the device. The position detection unit 62 includes detection circuit elements; in some embodiments, the detection circuit elements may be Hall sensors, photoelectric sensors, microswitches, or other suitable detection elements. An electromagnetic shielding component 7 encloses the position detection unit 62 to protect it from interference from radio frequency electromagnetic fields. In other embodiments, the electromagnetic shielding component 7 may also enclose other parts or the entire valve assembly 6 as needed.

[0033] In one embodiment, the valve body 61 is a pneumatic diaphragm valve. The pneumatic diaphragm valve has a diaphragm inside, which is deformed by compressed air to open and close the gas passage. The pneumatic diaphragm valve has advantages such as no packing gland, good sealing performance, low flow resistance, and corrosion resistance. It is particularly suitable for the high vacuum and highly corrosive process gas environments in semiconductor manufacturing, and has excellent response speed, achieving millisecond-level opening and closing.

[0034] like Figure 2 As shown, in one embodiment, the valve body 61 includes a conductive housing 63, which is grounded. The conductive housing 63 is made of a conductive metal material; in some embodiments, it may be made of stainless steel, aluminum alloy, or other suitable conductive metal materials. The conductive housing 63 is electrically connected to the grounded RF cavity 2 housing 21 via a wire. The grounding of the conductive housing 63, together with the external electromagnetic shielding component 7, forms a double electromagnetic shielding structure, further enhancing the isolation effect against RF electromagnetic fields, effectively preventing electromagnetic fields from entering the valve and interfering with its normal operation, and preventing the valve housing from becoming energized, thus improving the operational safety of the equipment.

[0035] like Figure 1 and Figure 2 As shown, in one embodiment, the position detection unit 62 is located within the axial range of the radio frequency component 4 along the axial direction of the radio frequency cavity 2. This arrangement makes full use of the empty space above and below the radio frequency component 4 to arrange the valve component 6, minimizing the overall space occupation of the device. However, in this compact layout, the position detection unit 62 is located in the area with the strongest radio frequency electromagnetic field and is most severely affected by electromagnetic interference. Therefore, it is particularly necessary to enclose the position detection unit 62 with an electromagnetic shielding component 7 to effectively protect the position detection unit 62 from normal operation in a strong electromagnetic field environment. In other embodiments, the position detection unit 62 can also be located at other positions outside the axial range of the radio frequency component 4 as needed.

[0036] like Figure 3As shown, in one embodiment, the electromagnetic shielding component 7 is a Faraday cage structure. The Faraday cage is made of metal mesh or metal plate, completely enclosing the part that needs to be shielded, and can effectively shield external alternating electromagnetic fields.

[0037] In another embodiment, the electromagnetic shielding component 7 is a shielding plate structure. The shielding plate is made of a metal plate and covers the top and sides of the part requiring shielding, suitable for shielding electromagnetic fields in a specific direction. In other embodiments, the electromagnetic shielding component 7 can also adopt any other structural form capable of achieving electromagnetic shielding.

[0038] In one embodiment, the electromagnetic shielding component 7 is electrically connected to the housing 21 of the radio frequency cavity 2. The housing 21 of the radio frequency cavity 2 is conductive and grounded, forming electromagnetic shielding inside and outside the radio frequency cavity 2. Directly connecting the electromagnetic shielding component 7 to the grounded housing of the radio frequency cavity 2 ensures reliable grounding and guarantees the electromagnetic shielding effect. Furthermore, this grounding method eliminates the need for additional grounding lines, simplifying the device structure and reducing manufacturing costs. In other embodiments, the electromagnetic shielding component 7 can be grounded in other ways, as long as reliable grounding is achieved. The radio frequency cavity 2 is enclosed by the housing 21 to prevent radio frequency energy leakage.

[0039] like Figure 1 As shown, in one embodiment, the process chamber 1 is provided with an air intake ring 10, which surrounds the side wall of the process chamber 1. The air intake ring 10 has multiple air inlets 11 for supplying air to the process chamber 1. The valve assembly 6 includes multiple air intake valves, which are installed on the air intake ring 10 and correspond one-to-one with the air inlets 11. The outlet of each air intake valve is directly connected to the corresponding air inlet 11, minimizing air intake delay, greatly shortening the air path length, and achieving rapid air supply switching. Simultaneously, this structure enables uniform gas distribution within the process chamber 1, improving the uniformity of the process. Since each air inlet 11 corresponds to an independent air intake valve, independent control of the air intake volume in different areas can be achieved, further improving the flexibility and precision of the process.

[0040] This utility model is not limited to the specific embodiments described above. Any modifications made by those skilled in the art based on the above concept without creative effort shall fall within the protection scope of this utility model.

Claims

1. A plasma processing device, characterized in that, The system includes a process cavity and a radio frequency (RF) cavity. The process cavity contains a base to support a substrate, and the RF cavity contains an RF component electrically connected to an RF source. The RF source feeds RF energy into the process cavity through the RF component to excite plasma within the process cavity to process the substrate. The radio frequency cavity is equipped with a valve assembly, the outlet of the valve assembly is connected to the inlet of the process cavity, and an electromagnetic shielding component is provided between the valve assembly and the radio frequency assembly. The electromagnetic shielding component is grounded to shield the electromagnetic radiation of the radio frequency assembly to the valve assembly.

2. The plasma processing equipment as described in claim 1, characterized in that, The radio frequency component includes a radio frequency coil, and the process cavity and the radio frequency cavity are hermetically separated by a dielectric window.

3. The plasma processing equipment as described in claim 2, characterized in that, The valve assembly is arranged around the radio frequency coil or located inside the radio frequency coil.

4. The plasma processing apparatus as described in claim 1, characterized in that, The radio frequency component includes an upper electrode, and the process cavity and the radio frequency cavity are hermetically separated by the upper electrode.

5. The plasma processing apparatus as described in claim 1, characterized in that, The valve assembly includes a valve body and a position detection unit. The position detection unit is disposed on the valve body and includes detection circuit elements. The electromagnetic shielding component encloses the position detection unit.

6. The plasma processing apparatus as described in claim 5, characterized in that, The valve body is a pneumatic diaphragm valve, and the valve body includes a conductive housing, which is grounded.

7. The plasma processing apparatus as described in claim 5, characterized in that, The radio frequency component includes a radio frequency feed rod, which is axially aligned with the radio frequency cavity, and the position detection unit is located within the axial range of the radio frequency component.

8. The plasma processing apparatus as described in claim 1, characterized in that, The electromagnetic shielding component includes a Faraday cage or a shielding plate.

9. The plasma processing apparatus as described in claim 1, characterized in that, The electromagnetic shielding component is electrically connected to the radio frequency cavity housing, which is conductive and grounded.

10. The plasma processing apparatus as described in claim 1, characterized in that, The process chamber is provided with an air intake ring, which surrounds the side wall of the process chamber. The air intake ring is provided with multiple air inlets for supplying air into the process chamber. The valve assembly includes multiple air intake valves, which are installed on the air intake ring and are configured to correspond one-to-one with the air inlets.

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