Grounding ring for improving plasma etching uniformity
By improving the uniformity of plasma etching with grounding rings and electrostatic chucks, the problems of uneven plasma distribution and inaccurate wafer fixation in etching equipment were solved, achieving uniform etching and stable wafer etching effects, and improving the quality of etched products.
Patent Information
- Application Number
- CN202422554426.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-10-22
AI Technical Summary
Existing semiconductor etching equipment suffers from uneven plasma distribution and inaccurate wafer fixation, resulting in uneven etching effects and wafer damage.
By employing grounding rings that improve the uniformity of plasma etching, and by setting grounding rings with different media and electrostatic chucks, the high-frequency electric field strength and frequency of the RF power source are controlled. Combined with an air pump to maintain a vacuum environment, this ensures etching uniformity and stable wafer fixation.
It improves the uniformity of plasma etching, enhances the quality of etched products, avoids wafer damage, and ensures vacuum sealing and a highly efficient etching process.
Smart Images
Figure CN223471565U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to semiconductor etching process equipment technical field, especially for the ground ring of improvement plasma etching uniformity. BACKGROUND
[0002] The semiconductor etching process equipment is one of the core processes in semiconductor manufacturing, and its importance is only second to the photoetching machine. The equipment utilizes the large number of charged particles contained in the plasma, such as electrons, ions, excited state atoms, molecules and free radicals, to cause various physical and chemical reactions on the surface of the wafer to be processed, thereby completing the etching process, and the etching equipment is mainly used for removing materials in specific areas to form a microstructure pattern, and is one of the three core equipment in semiconductor manufacturing together with photoetching and film deposition. The etching equipment can be divided into wet etching and dry etching according to the working principle. Wet etching uses chemical solution to remove materials, has the characteristics of low cost and fast etching speed, but has the problem of isotropy, and is suitable for larger size circuit diagram. Dry etching uses gas (or / and) plasma, and the plasma etching is divided into capacitive plasma etching (CCP) and inductive plasma etching (ICP). The dry etching technology has high precision and is suitable for the manufacturing of high-precision circuit diagram.
[0003] However, the existing semiconductor etching process equipment still has some shortcomings in use. In the prior art, the lower surface of the cavity electrostatic chuck of the existing semiconductor etching process equipment is insulated by coating oxide, and then a focusing ring is added to change the electric field, highlight the electric field difference between the cathode surface and the lower surface, and increase the central etching effect. However, due to the chamber gas loop and vacuum pumping loop, the plasma distribution is uneven, which causes problems such as critical dimension error, surface roughness and bottom damage. These factors directly affect the performance and reliability of the chip. In addition, the wafer to be processed is generally fixed in the reaction cavity by using clamping tools, but the clamping tools cannot accurately control the force during use, which may cause damage to the wafer to be processed. UTILITY MODEL CONTENTS
[0004] The utility model aims at providing the ground ring of improvement plasma etching uniformity to solve the problems in the above background.
[0005] In order to achieve the above purpose, the utility model provides the following technical scheme:
[0006] The utility model provides an improve the ground ring of plasma etching uniformity, including reaction cavity, the reaction cavity is by the component part such as chamber wall, electrostatic chuck, radio frequency power source, gas pump, insulating window and coil, the top of chamber wall is provided with ESC and ground ring, the top of ESC and ground ring and ceramic wi ndows abut, the top of ceramic wi ndows is provided with ion source radio frequency inductive coil, is provided with gas nozzle at the center of ion source radio frequency inductive coil, the bottom of gas nozzle and ceramic wi ndows fixed connection, the ESC and ground ring assembly are by two parts of ESC and ground ring, and the ground ring is located the outside of ESC.
[0007] As the preferred scheme of the utility model, the top of the reaction cavity is provided with an insulating window, and the top of the insulating window is provided with a coil.
[0008] As the preferred scheme of the utility model, the top of the electrostatic chuck is provided with a wafer to be processed, and the wafer to be processed is fixed on a pedestal in the reaction cavity by the electrostatic chuck.
[0009] As the preferred scheme of the utility model, the electrostatic chuck is provided with an electrostatic electrode inside, and the electrostatic electrode generates an electrostatic attraction to support the wafer to be processed.
[0010] As the preferred scheme of the utility model, the bottom of the reaction cavity is provided with a gas pump, and the gas pump is used for discharging reaction byproducts and maintaining a vacuum environment.
[0011] As the preferred scheme of the utility model, the working frequency of the radio frequency power source is set to be between 2 MHz and 60 MHz, and the radio frequency power source is remotely controlled by using an RS232 and an RJ45 network port.
[0012] As the preferred scheme of the utility model, the radio frequency power source includes a transformer, a rectifier circuit, a filter circuit, a regulating circuit, and a high-frequency oscillation circuit and other key components, and the high-frequency oscillation circuit is used for converting a direct-current voltage into a high-frequency alternating-current voltage.
[0013] As the preferred scheme of the utility model, the radio frequency power source applies a bias radio frequency voltage to a pedestal in the reaction cavity through a radio frequency matching network, and the radio frequency power source precisely controls the movement and bombardment direction of charged particles by controlling the intensity and frequency of a high-frequency electric field.
[0014] Compared with the prior art, the utility model has the beneficial effects that:
[0015] 1. In the present invention, by providing grounding rings of different dielectrics and replacing conductive grounding ring covers of different dielectrics, the size of the sheath edge range on the ESC surface can be improved, thereby improving the ER uniformity of the wafer to be processed located on the top of the ESC. At the same time, by controlling the intensity and frequency of the high-frequency electric field of the RF power source, the RF distribution is improved, thereby ensuring the uniformity of the etching rate and improving the overall quality of the etched product.
[0016] 2. In the present invention, an electrostatic suction cup is provided to solve the problem that the clamping tool cannot accurately control the force when in use, which easily causes damage to the wafer to be processed. An electrostatic electrode is provided inside the electrostatic suction cup, and the electrostatic electrode generates an electrostatic suction force to support the wafer to be processed. At the same time, an air pump is provided in the reaction chamber, which can quickly achieve a large-scale vacuum in the reaction chamber to ensure the vacuum seal in the reaction chamber. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the internal cross-section of the plasma processing equipment of the present invention;
[0018] Figure 2 This is a schematic diagram of the installation of the first grounding ring of the utility model;
[0019] Figure 3 This is a schematic diagram of the installation of the second grounding ring of the present invention;
[0020] Figure 4 Schematic diagram for comparing the improvement effects of the present invention.
[0021] Figure: 1. Chamber wall; 2. ESC and ground ring assembly; 3. Ceramic windows; 4. Ion source RF inductor coil; 5. Gas nozzle. DETAILED DESCRIPTION
[0022] The following will combine 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, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0023] For examples, see Figures 1-4 , the utility model provides a technical solution:
[0024] The application discloses an improved grounding ring for improving plasma etching uniformity, which comprises a reaction cavity composed of a chamber wall 1, an electrostatic chuck, an RF power source, a gas pump, an insulating window and a coil and the like, the top of the chamber wall 1 is provided with an ESC and a grounding ring assembly 2, the top of the ESC and the grounding ring assembly 2 abuts against a ceramic window 3, the top of the ceramic window 3 is provided with an ion source RF inductive coil 4, the center of the ion source RF inductive coil 4 is provided with a gas nozzle 5, the bottom of the gas nozzle 5 is fixedly connected with the ceramic window 3, the ESC and the grounding ring assembly are composed of two parts of the ESC and the grounding ring, and the grounding ring is located outside the ESC.
[0025] In this embodiment, as shown in Figure 1 、 Figure 2 and Figure 3 , the working frequency of the RF power source is set to be between 2MHz and 60MHz, the RF power source is remotely controlled by using RS232 and RJ45 network interfaces, the RF power source comprises a transformer, a rectifier circuit, a filter circuit, a regulating circuit and a high-frequency oscillation circuit and the like key components, the high-frequency oscillation circuit is used for realizing the process of converting a direct-current voltage into a high-frequency alternating-current voltage, the RF power source applies a bias RF voltage to a susceptor in the reaction cavity through an RF matching network, and the RF power source precisely controls the movement and bombardment direction of charged particles by controlling the intensity and frequency of the high-frequency electric field.
[0026] The grounding ring of different media and the conductive grounding ring cover plate of different media are arranged, the size of the sheath layer edge range of the ESC surface is improved, the ER uniformity of the wafer to be treated located on the top of the ESC is improved, the intensity and frequency of the high-frequency electric field of the RF power source are controlled, the RF distribution is improved, the uniformity of the etching rate is ensured, and the overall quality of the etching product is improved.
[0027] In this embodiment, as shown in Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , the top of the reaction cavity is provided with an insulating window, the top of the insulating window is provided with a coil, the top of the electrostatic chuck is provided with a wafer to be treated, the wafer to be treated is fixed on a susceptor in the reaction cavity through the electrostatic chuck, the inside of the electrostatic chuck is provided with an electrostatic electrode, the electrostatic electrode generates an electrostatic attraction force to support the wafer to be treated, the bottom of the reaction cavity is provided with a gas pump, and the gas pump is used for discharging reaction by-products and maintaining a vacuum environment.
[0028] The electrostatic chuck solves the problem that the clamping tool cannot be accurately controlled in use and is easy to damage the wafer to be processed, the interior of the electrostatic chuck is provided with an electrostatic electrode, the electrostatic electrode generates electrostatic suction force to support the wafer to be processed, and a gas pump is arranged in the reaction cavity, so that a large range of vacuum can be quickly reached in the reaction cavity, and the vacuum sealing in the reaction cavity is ensured.
[0029] The utility model discloses a work flow: use the ground ring of the improvement plasma etching uniformity designed in this scheme when working, in the equipment, first, the wafer to be processed is fixed on the base through the electrostatic chuck, the electrostatic electrode generates electrostatic suction force to support the wafer to be processed.
[0030] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.
Claims
1. A ground ring for improving uniformity of plasma etching comprising a reaction chamber, characterized in that: The reaction cavity is composed of chamber wall (1), electrostatic chuck, radio frequency power source, air pump, insulating window and coil and other components, the top of the chamber wall (1) is provided with ESC and grounding ring assembly (2), the top of the ESC and grounding ring assembly (2) and ceramic window (3) abut, the top of the ceramic window (3) is provided with ion source radio frequency inductive coil (4), the center of the ion source radio frequency inductive coil (4) is provided with gas nozzle (5), the bottom of the gas nozzle (5) and ceramic window (3) are fixedly connected, the ESC and grounding ring assembly (2) is composed of ESC and grounding ring two parts, the grounding ring is located outside the ESC.
2. The ground ring for improving plasma etching uniformity according to claim 1, wherein: The top of the reaction cavity is provided with an insulating window, and the top of the insulating window is provided with a coil.
3. The ground ring to improve plasma etching uniformity of claim 1, wherein: The top of the electrostatic chuck is provided with a wafer to be processed, and the wafer to be processed is fixed on the pedestal in the reaction cavity by the electrostatic chuck.
4. The ground ring to improve plasma etching uniformity of claim 1, wherein: The inside of the electrostatic chuck is provided with an electrostatic electrode, which generates electrostatic attraction to support the wafer to be processed.
5. The ground ring to improve uniformity of plasma etching according to claim 1, wherein: The bottom of the reaction cavity is provided with an air pump, which is used for discharging reaction byproducts and maintaining a vacuum environment.
6. The ground ring to improve uniformity of plasma etching according to claim 1, wherein: The working frequency of the radio frequency power source is set to 2-60 MHz, and the radio frequency power source is remotely controlled by RS232 and RJ45 network interface.
7. The ground ring to improve uniformity of plasma etching according to claim 1, wherein: The radio frequency power source includes transformer, rectifier circuit, filter circuit, regulating circuit and high frequency oscillation circuit and other key components, and the high frequency oscillation circuit is used for realizing the process of converting direct current voltage into high frequency alternating current voltage.
8. The ground ring to improve uniformity of plasma etching according to claim 7, wherein: The radio frequency power source applies bias radio frequency voltage to the pedestal in the reaction cavity through the radio frequency matching network, and the radio frequency power source precisely controls the movement and bombardment direction of charged particles by controlling the intensity and frequency of high frequency electric field.