An ion energy controlled screen device and semiconductor etching equipment

Abstract

This invention relates to the field of semiconductor equipment technology, and more specifically, to an ion energy controlled screen device and semiconductor etching equipment for atomic layer etching. The device includes at least a first metal mesh, a second metal mesh, a third metal mesh, and a fourth metal mesh, as well as an electric field electrode plate. The first and second metal meshes are arranged sequentially; the electric field electrode plate is disposed between the second and third metal meshes; and the fourth metal mesh is disposed below the third metal mesh. The aperture arrays of the first and second metal meshes are aligned; the aperture array pattern of the third metal mesh is offset relative to the aperture array pattern of the second metal mesh in a direction parallel to the mesh surface; and the aperture arrays of the fourth and third metal meshes are aligned. This invention achieves precise matching of the atomic layer etching process window, significantly improving the selectivity, directionality, and surface roughness of the atomic layer etching process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and more specifically, to an ion energy controlled screen device and semiconductor etching equipment for atomic layer etching. Background Technology

[0002] In the semiconductor manufacturing field, etching is a crucial step in achieving wafer patterning, and its precision directly determines the integration and performance of semiconductor devices. As device feature sizes continue to shrink, higher demands are placed on the morphological integrity, surface roughness control, and material selection ratio of etching processes. Atomic layer etching technology, capable of achieving precise etching at the single-atom-layer level, has become a core technology direction to meet these requirements.

[0003] The core prerequisite for atomic layer etching (ALT) is the precise control of the energy and flux of ions incident on the wafer surface. The ion energy must be within a specific process window: too low an energy will prevent the etching reaction from being effectively triggered, while too high an energy will penetrate the target atomic layer, causing sputtering damage to the underlying material and negating the self-limiting properties of ALT. However, in a plasma environment, ions naturally exhibit a relatively broad energy distribution due to physical mechanisms such as thermal motion and inter-particle collisions. This uneven ion energy distribution becomes a key bottleneck restricting the precision of ALT.

[0004] In existing technologies, the mainstream approach to controlling ion energy is to use a low-frequency bias power supply: by applying a low-frequency bias voltage to the wafer stage or plasma confinement structure, the ions are accelerated using an electric field, thereby adjusting the energy level of the ions reaching the wafer surface. However, this approach can only shift and increase the overall energy based on the original ion energy distribution of the plasma, and cannot eliminate the energy differences caused by thermal motion and collisions of the ions. As a result, the ions that finally reach the wafer surface still maintain a wide energy distribution, and the ion incident direction also deviates accordingly. It is difficult to ensure the consistency of ion energy and direction, and ultimately it cannot meet the process requirements of atomic layer etching for selectivity, atomic layer etching performance, and surface roughness.

[0005] Therefore, there is an urgent need in this field for a novel ion energy control scheme. Summary of the Invention

[0006] The purpose of this invention is to provide an ion energy controlled screen device and a semiconductor etching equipment, which solves the problem of poor precision in atomic layer etching processes caused by the wide distribution of ion energy, the inability to perform effective screening, and the limited energy control capability in the prior art.

[0007] To achieve the above objectives, the present invention provides an ion energy control screen device, comprising at least a first metal mesh, a second metal mesh, a third metal mesh and a fourth metal mesh, and an electric field electrode plate;

[0008] The first metal mesh and the second metal mesh are arranged sequentially;

[0009] The electric field electrode plate is disposed between the second metal mesh and the third metal mesh;

[0010] The fourth metal mesh is disposed below the third metal mesh;

[0011] Wherein, the first metal mesh is configured to apply a first voltage, the second metal mesh is configured to be grounded or to apply a second voltage; the third metal mesh is configured to be grounded; and the fourth metal mesh is configured to apply a third voltage.

[0012] The aperture arrays of the first metal mesh and the second metal mesh are aligned.

[0013] The aperture array pattern of the third metal mesh is offset relative to the aperture array pattern of the second metal mesh in a direction parallel to the mesh surface.

[0014] The aperture arrays of the fourth metal mesh and the third metal mesh are aligned.

[0015] In some embodiments, the first metal mesh and the second metal mesh are used to accelerate or decelerate ions passing through metal pores;

[0016] The electric field electrode plate is used to generate a transverse electric field to control the deflection angle of ions;

[0017] The third metal mesh is used to intercept and filter ions whose deflection angle does not meet the preset conditions;

[0018] The fourth metal mesh is used for further energy control of ions passing through the third metal mesh.

[0019] In some embodiments, the first metal mesh, the second metal mesh, the third metal mesh, and the fourth metal mesh are made of thin metal sheets, on which a hole array of a specified shape is uniformly distributed.

[0020] In some embodiments, the specified shape is a circle or a square.

[0021] In some embodiments, the ion energy controlled screen device further includes a first DC power supply and a second DC power supply.

[0022] The first voltage is provided by a first DC power supply, and the third voltage is provided by a second DC power supply.

[0023] In some embodiments, the adjustment range of the first voltage is -500V to +2000V.

[0024] In some embodiments, the aperture array pattern of the third metal mesh is offset relative to the aperture array pattern of the second metal mesh by 0.1-50 mm.

[0025] In some embodiments, the distance between the third metal mesh and the second metal mesh is 1-200 mm.

[0026] In some embodiments, the materials of the first, second, third, and fourth metal meshes are selected from one of iron, copper, steel, and aluminum, or an alloy formed from any two or more metals, and the surface of the alloy may selectively have a coating or an oxide layer.

[0027] To achieve the above objectives, the present invention provides a semiconductor etching apparatus, comprising at least a reaction chamber, a wafer stage, a plasma generator, and the aforementioned ion energy control screen device:

[0028] The wafer stage is located at the lower part of the reaction chamber and is used to support the wafer to be etched;

[0029] The plasma generator is located at the top of the reaction chamber and is used to generate plasma;

[0030] The ion energy control screen device is disposed between the plasma generation device and the wafer stage, and is used to screen and control the energy of ions moving toward the wafer.

[0031] In some embodiments, the plasma generating device includes at least a quartz cylinder and an inductor coil:

[0032] The quartz tube is used to provide space for plasma generation and confinement;

[0033] The inductor coil, wound around the outside of the quartz tube and connected to a radio frequency power supply, is used to generate an alternating magnetic field under the excitation of the radio frequency power supply, thereby stimulating an induced electric field inside the quartz tube, ionizing the working gas to generate plasma.

[0034] The present invention provides an ion energy controlled screen device and a semiconductor etching equipment. By adopting a multi-level metal mesh aperture array design, combined with the lateral electric field regulation of the electric field electrode plate and the independent control of the voltage of each metal mesh, the atomic layer etching process window is precisely matched, significantly improving the selectivity and directionality of the atomic layer etching process, and improving the surface roughness. Attached Figure Description

[0035] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features, wherein:

[0036] Figure 1A cross-sectional structural schematic diagram of an ion energy controlled screen device for atomic layer etching according to an embodiment of the present invention is disclosed;

[0037] Figure 2a A schematic diagram of ion energy distribution using a traditional method is shown.

[0038] Figure 2b A schematic diagram of the ion energy distribution of an ion energy controlled screen device according to an embodiment of the present invention is disclosed.

[0039] Figure 3 A schematic cross-sectional view of an etching apparatus according to an embodiment of the present invention is disclosed.

[0040] Figure 4a An effect diagram of an atomic layer etching process with ion energy located within a window, according to an embodiment of the present invention, is shown.

[0041] Figure 4b The diagram shows the effect of an atomic layer etching process with low ion energy sites according to an embodiment of the present invention;

[0042] Figure 4c The diagram shows the effect of an atomic layer etching process with excessively high ion energy sites according to an embodiment of the present invention.

[0043] The meanings of the labels in the figures are as follows:

[0044] 100 Ion Energy Controlled Screen Device;

[0045] 101 First Metal Mesh;

[0046] 102 Second Metal Mesh;

[0047] 103 Third Metal Mesh;

[0048] 104 fourth metal mesh;

[0049] 110 electric field electrode plate;

[0050] 121 First DC power supply;

[0051] 122 Second DC power supply;

[0052] 123 Third DC power supply;

[0053] 130a first ion;

[0054] 130b second ion;

[0055] 130C third ion;

[0056] 200 reaction chamber;

[0057] 210 wafer stage;

[0058] 220 plasma generator;

[0059] 221 Quartz tube;

[0060] 222 inductor coil;

[0061] 230 RF power supply;

[0062] 240 matcher. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0064] To address the problem that traditional bias power supplies in existing technologies can only raise the overall ion energy distribution but cannot effectively narrow the distribution, resulting in insufficient precision in atomic layer etching processes, this invention proposes an innovative ion energy control screen device. Through an active screening mechanism, it obtains an ion beam with high monoenergeticity and precise energy control from plasmas with a wide energy distribution, achieving precise matching of the atomic layer etching process window.

[0065] Figure 1 A cross-sectional structural schematic diagram of an ion energy controlled screen device for atomic layer etching according to an embodiment of the present invention is disclosed, as shown below. Figure 1 As shown, the ion energy control screen device proposed in this invention includes at least a first metal mesh 101, a second metal mesh 102, a third metal mesh 103 and a fourth metal mesh 104, as well as an electric field electrode plate 110.

[0066] The first metal mesh 101 and the second metal mesh 102 are arranged sequentially;

[0067] The electric field electrode plate 110 is disposed between the second metal mesh 102 and the third metal mesh 103;

[0068] The fourth metal mesh 104 is disposed below the third metal mesh 103;

[0069] Wherein, the first metal mesh 104 is configured to apply a first voltage, the second metal mesh 102 is configured to be grounded or to apply a second voltage; the third metal mesh 103 is configured to be grounded; and the fourth metal mesh 104 is configured to apply a third voltage.

[0070] The pore arrays of the first metal mesh 101 and the second metal mesh 102 are aligned to form ion channels;

[0071] The aperture array pattern of the third metal mesh 103 is offset relative to the aperture array pattern of the second metal mesh 102 in a direction parallel to the mesh surface.

[0072] The aperture arrays of the fourth metal mesh 104 and the third metal mesh 103 are aligned.

[0073] This invention proposes an ion energy control screen device for atomic layer etching, which filters ions with a wide energy distribution into an ion beam with an extremely narrow energy distribution and precise energy control. This fundamentally solves the process precision problem caused by excessively wide ion energy distribution, meets the stringent requirements of atomic layer etching for ion energy uniformity and controllability, and provides a reliable foundation for achieving etching effects with higher selectivity, better directionality, and better surface roughness.

[0074] To illustrate the technical solution of the present invention in more detail, the specific structure, materials and functional characteristics of each component of the ion energy control screen device will be described in detail below with reference to the accompanying drawings.

[0075] In this embodiment, the first metal mesh 101 and the second metal mesh 102 are used to accelerate or decelerate ions passing through the metal pores of their pore array.

[0076] The electric field electrode plate 110 is used to generate a transverse electric field to control the deflection angle of ions.

[0077] The third metal mesh 103 is used to intercept and filter ions whose deflection angle does not meet the preset conditions, and further to intercept ions whose lateral offset does not match the offset distance (i.e., offset) of the pore array.

[0078] The fourth metal mesh 104 is used to further control the energy of ions passing through the third metal mesh 103;

[0079] The preset condition is that the deflection angle of the ions under the action of the transverse electric field must be such that the transverse offset of the ions is matched with the offset of the aperture array of the third metal mesh relative to the second metal mesh, so that ions with ions energy within the target screening energy window can pass through the aperture array of the third metal mesh.

[0080] More specifically, the first metal mesh 101 and the second metal mesh 102 work together to form an initial electric field, which accelerates or decelerates the ions passing through the metal holes. When a potential difference is formed between the first voltage and the second voltage (or ground potential), the ions are subjected to force in the electric field between the two meshes, realizing the initial adjustment of energy and laying the energy foundation for subsequent screening.

[0081] The electric field electrode plate 110 forms a uniform transverse electric field between the second metal mesh 102 and the third metal mesh 103 by applying a preset voltage. When ions pass through this region, they are deflected by the transverse electric field force. The deflection angle is positively correlated with the ion energy, thereby achieving energy-based sorting.

[0082] The aperture array of the third metal mesh 103 is staggered from that of the second metal mesh 102, and it is grounded so that it can absorb impacting ions. Its function is to intercept and filter ions whose deflection angle does not meet the preset conditions. Only ions whose deflection angle is exactly aligned with the aperture of the third metal mesh 103 can pass through, and the rest of the ions are impacted on the mesh surface and filtered.

[0083] The fourth metal mesh 104, together with the grounded third metal mesh 103, forms a fine-tuned electric field to further control the energy of ions passing through the third metal mesh 103, so that the ion energy is ultimately stabilized within the precise range required for atomic layer etching.

[0084] In this embodiment, the first metal mesh 101, the second metal mesh 102, the third metal mesh 103 and the fourth metal mesh 104 are made of thin metal plates. The thickness of the thin metal plates is set according to the size of the device cavity and the ion penetration requirements, and the thin metal plates are uniformly distributed with an array of holes of a specified shape.

[0085] The specified shape of the pore is circular or square, and the shape can be selected according to the ion flux requirements in practical applications.

[0086] In this embodiment, the materials of the first metal mesh 101, the second metal mesh 102, the third metal mesh 103 and the fourth metal mesh 104 are selected from one of iron, copper, steel and aluminum or an alloy formed from any two or more metals, and the surface of the alloy may selectively have a coating or an oxide layer.

[0087] Alloy materials can combine the excellent properties of various metals and can be flexibly selected according to the equipment's requirements for the conductivity, structural strength, and other aspects of the metal mesh.

[0088] For surface coatings or oxide layers, not only can corrosion resistance be further enhanced, but also the ion sputtering of metal mesh in plasma environment can be reduced, avoiding metal impurities from contaminating the wafer surface and ensuring the purity of the etching process.

[0089] For example, aluminum is lightweight and low-cost, making it suitable for small and medium-sized etching equipment, while copper-aluminum alloys can combine the high conductivity of copper with the lightweight properties of aluminum.

[0090] For example, the coating may be a plasma sputtering resistant ceramic coating to reduce metal contamination caused by high-energy ion bombardment;

[0091] For example, an oxide layer grown on the surface of an alloy through processes such as anodizing can improve its resistance to plasma corrosion and extend the service life of the device.

[0092] The ion energy controlled screen device also includes a first DC power supply 121 and a second DC power supply 122.

[0093] The first voltage required by the first metal mesh 101 is provided by the first DC power supply 121, and the third voltage required by the fourth metal mesh 104 is provided by the second DC power supply 122.

[0094] Furthermore, the second metal mesh 102 can be grounded or have an independent second voltage applied to form an accelerating or decelerating electric field, depending on actual process requirements such as the initial ion energy of the plasma and the width of the target screening energy window, providing flexibility for the initial ion energy adjustment scheme under different process requirements.

[0095] If the second metal mesh 102 needs to be subjected to a second voltage (instead of grounding), a third DC power supply 123 can be additionally configured to ensure that the voltage of each mesh is independently adjustable to meet the energy adjustment requirements of different process scenarios.

[0096] The first DC power supply 121 provides a first voltage adjustment range of -500V to +2000V, which can be flexibly set according to the initial ion energy of the plasma. When the initial ion energy of the plasma is low, a positive voltage is applied to achieve acceleration; when the initial ion energy of the plasma is high, a negative voltage is applied to achieve deceleration.

[0097] More specifically, the aperture array pattern of the third metal mesh 103 has a preset offset relative to the aperture array pattern of the second metal mesh 102 in a direction parallel to the mesh surface.

[0098] In this embodiment, the offset of the aperture array pattern of the third metal mesh 103 relative to the aperture array pattern of the second metal mesh 102 is 0.1-50 mm. The offset can be adjusted according to the ion energy window of the target screening.

[0099] The distance between the third metal mesh 103 and the second metal mesh 102 is 1-200 mm. This distance determines the distance the ions travel in the transverse electric field. The larger the distance, the greater the deflection angle of ions with the same energy. In practical applications, it can be set in combination with the cavity height and electric field strength requirements.

[0100] The working principle of the ion energy controlled screen device provided by this invention is as follows:

[0101] Ions entering the sieve device from the plasma have a wide energy distribution, assumed to be 2-8 eV. The ions are accelerated or decelerated by voltages applied to the first metal mesh 101 and the second metal mesh 102. For example, after acceleration, the overall ion energy increases by 2 eV, becoming 4-10 eV.

[0102] When ions enter the region between the second metal mesh 102 and the third metal mesh 103, they are subjected to the transverse electric field generated by the electric field electrode plate 110.

[0103] In this embodiment, to achieve the screening effect of only target energy ions passing through the third metal mesh, the offset of the pore array of the third metal mesh relative to the second metal mesh is set to 2 mm. This offset is not randomly selected, but precisely matched with the lateral offset of the target energy ions under the action of the transverse electric field.

[0104] The second metal mesh 102 and the third metal mesh 103 are spaced 10 mm apart, and a voltage is applied so that the transverse electric field strength is about 400 volts per meter.

[0105] Energy is E k When ions enter the transverse electric field region between the second metal mesh 102 and the third metal mesh 103, their transverse offset y can be calculated using the following formula:

[0106] ;

[0107] Where e is the ionic charge, E is the electric field strength, and m e is the ion mass, and l is the electrode spacing.

[0108] From the above formula, it can be seen that for a given electric field strength E and electrode spacing l, the lateral displacement y of the ion is equal to its energy E. k The function is such that the lateral offset y falls within an allowable range defined by the hole positions of the third metal mesh 103, the upper limit of which is determined by the offset of the hole array and the size of the holes.

[0109] Taking argon ions as an example, the lateral offset of 5 eV ions is approximately 2 mm. If the edge spacing (pore array offset) between the corresponding sieve holes of the second metal mesh 102 and the third metal mesh 103 is set to 2 mm, then ions with energies greater than 5 eV will be filtered out by colliding with the third metal mesh 103 due to insufficient lateral offset.

[0110] The third metal mesh 103 produces ions with an energy distribution of 4-5 eV, reducing the ion energy window from the original 6 eV (2-8 eV) to 1 eV, thus reducing the ion energy distribution by a factor of 6.

[0111] like Figure 1As shown, after initial adjustment by the first metal mesh 101 and the second metal mesh 102, the ions enter the transverse electric field region formed by the electric field electrode plate 110, and the three ions with different energies exhibit different motion states:

[0112] The energy of the first ion 130a is within the target screening window (e.g., 4-5 eV). Its deflection angle in the transverse electric field is just aligned with the hole of the third metal mesh 103, and then passes through the third metal mesh 103. After being finely adjusted by the fourth metal mesh 104, it moves towards the wafer with precise energy.

[0113] The energy of the second ion 130b is greater than the upper limit of the screening window (e.g., > 5eV). Due to its high energy and fast movement speed, its lateral offset is less than the offset of the aperture array, so it cannot be aligned with the aperture of the third metal mesh 103 and is eventually filtered by impacting the mesh surface of the third metal mesh 103.

[0114] The energy of the third ion 130c is less than the lower limit of the screening window (e.g., < 4eV). In the transverse electric field, the deflection angle caused by the electric field force is too large, and its own energy is insufficient to overcome the electric field binding. After being decelerated and attracted by the electrode plate, it returns and finally hits the mesh surface of the second metal mesh 102 and is filtered.

[0115] Through the above screening process, ions with an initial energy distribution of 2-8 eV in the plasma are reduced to only ions with a specific energy of 4-5 eV, which can pass through the third metal mesh 103 and the fourth metal mesh 104. They are then further accelerated or decelerated to reach a specific energy and reach the wafer surface for etching. At this time, the ion energy window is reduced from 6 eV to 1 eV, and the energy distribution width is reduced by 6 times, achieving the core goal of narrow energy distribution.

[0116] Figure 2a This reveals a schematic diagram of ion energy distribution using a traditional method, such as... Figure 2a As shown, in traditional methods, even with a bias power supply applied, the ion energy distribution remains very broad, ranging from approximately 10 eV to 70 eV, with a distribution width as high as 60 eV. This broad energy distribution leads to poor selectivity and surface damage in atomic layer etching processes.

[0117] Figure 2b A schematic diagram of the ion energy distribution of an ion energy controlled sieve device according to an embodiment of the present invention is shown, such as... Figure 2b As shown, after being screened by the energy control screen device of the present invention, the ion energy distribution is greatly narrowed, and its energy is concentrated in an extremely narrow window, for example, 22 eV to 24 eV, with a distribution width of only about 2 eV.

[0118] This result verifies that the present invention, through the synergistic screening mechanism of multi-level metal mesh and deflection electric field, can effectively extract ion beams with highly uniform energy and precisely controllable size from plasmas with a wide energy distribution. This ability to compress the ion energy distribution width from the tens of electron volts to the several electron volts provides a crucial prerequisite for realizing high-precision, low-damage atomic layer etching processes.

[0119] The present invention also proposes a semiconductor etching apparatus that achieves precise etching based on the aforementioned ion energy controlled screen device.

[0120] Figure 3 A schematic cross-sectional view of a semiconductor etching apparatus according to an embodiment of the present invention is disclosed, as shown below. Figure 3 As shown, the semiconductor etching apparatus proposed in this invention includes a reaction chamber 200, a wafer stage 210, a plasma generator 220, and the aforementioned ion energy control screen device 100.

[0121] The wafer stage 210 is located at the lower part of the reaction chamber 200 and is used to support the wafer to be etched.

[0122] A plasma generator 220 is located on the upper part of the reaction chamber 200 and is used to generate the plasma required for etching.

[0123] An ion energy control screen device 100 is disposed between the plasma generator 220 and the wafer stage 210, specifically at the boundary between the upper and lower cavities within the reaction chamber 200, and is used to screen and control the ion energy moving toward the wafer.

[0124] The plasma generator 220 includes a quartz cylinder 221 and an inductor coil 222.

[0125] The quartz tube 221 is used to provide space for plasma generation and confinement.

[0126] The inductor coil 222 is wound around the outside of the quartz tube and connected to a radio frequency power supply. It is used to generate an alternating magnetic field under the excitation of the radio frequency power supply, thereby stimulating an induced electric field inside the quartz tube and ionizing the working gas to generate plasma.

[0127] In one specific embodiment, the quartz tube 221 has a diameter of 400 mm, and the gas enters from the air inlet at the top of the quartz tube 221 to ensure that the gas is evenly distributed inside the tube.

[0128] The inductor coil 222 has 3 turns and is connected to the RF power supply 230 through a matching adapter 240;

[0129] The RF power supply 230 uses a 13.56MHz RF frequency and has a maximum power of 3000W. The plasma density can be controlled by adjusting the RF power.

[0130] When the radio frequency power supply 230 is activated, the inductor coil 222 generates an alternating magnetic field, which induces an electric field inside the quartz tube 221. The induced electric field ionizes the working gas inside the tube, thereby generating the plasma required for etching.

[0131] In the semiconductor etching apparatus of this embodiment, the parameters of the ion energy controlled screen device 100 are further refined to adapt to the equipment process requirements:

[0132] In terms of the metal mesh material, the first metal mesh 101 and the second metal mesh 102 are made of aluminum, while the third metal mesh 103 and the fourth metal mesh 104 are made of aluminum alloy to improve corrosion resistance.

[0133] Regarding the hole array parameters, the first metal mesh 101 and the second metal mesh 102 have the same hole array distribution, with a hole diameter of 3mm, a hole spacing of 6mm, and a spacing of 5mm between them;

[0134] The hole array distribution of the third metal mesh 103 and the fourth metal mesh 104 is the same as that of the first metal mesh 101 and the second metal mesh 102, but the hole array is staggered by 2mm relative to the first metal mesh 101 and the second metal mesh 102, and the distance between the third metal mesh 103 and the second metal mesh 102 is 10mm, and the distance between the third metal mesh 103 and the fourth metal mesh 104 is 5mm.

[0135] In terms of voltage configuration, the first metal mesh 101 is supplied with an adjustable DC voltage of -100V to 100V, the second metal mesh 102 is supplied with a DC voltage of -100V to 100V, the third metal mesh 103 is grounded, and the fourth metal mesh 104 is supplied with a DC voltage of -100V to 100V.

[0136] The electric field electrode plate 110 is made of aluminum alloy and consists of a left electrode and a right electrode. The left electrode is subjected to a DC current of 0-3000V, while the right electrode is grounded, ensuring that the transverse electric field strength can be flexibly adjusted.

[0137] The core requirement of atomic layer etching is to strip only a single atomic layer without damaging the underlying material. Whether the ion energy is within the process window directly determines the etching effect. The following will explain this in detail with reference to the effect diagrams in Figures 4a, 4b, and 4c.

[0138] Figure 4a , 4b Figure 4c reveals the effect of different ion energies on atomic layer etching processes, such as... Figure 4aAs shown, when the ion energy is within the process window (e.g., 4-6 eV), atomic layer etching will occur normally. The ion kinetic energy is just enough to precisely strip the atoms of the outermost layer of the target material without impacting the underlying material. That is, after only a single atomic layer is stripped, the etching automatically stops, meeting the requirements of atomic layer etching for precision and surface roughness.

[0139] like Figure 4b As shown, when the ion energy is less than the lower limit of the atomic layer etching process window (e.g., 4 eV), etching will not occur. The kinetic energy of the ions is insufficient to overcome the binding energy of the atoms on the surface of the target material, and the etching reaction cannot be triggered, resulting in the etching process not occurring. No atomic layer is peeled off on the wafer surface, and patterning cannot be achieved.

[0140] like Figure 4c As shown, when the ion energy is greater than the upper limit of the process window (e.g., 6eV), the ion kinetic energy is too large. It will not only strip the atoms of the outermost layer of the target material, but also penetrate the surface layer and cause sputtering damage to the 2-10 atomic layers below, resulting in the destruction of the crystal structure of the underlying material, the deterioration of the etching morphology, and the complete loss of the single-atom-layer selectivity of atomic layer etching.

[0141] In summary, the ion energy control screen device of the present invention ensures that the ion energy is stably within the process window through precise screening and energy regulation, fundamentally solving the problem of excessively wide ion energy distribution in the prior art, and providing a higher selectivity and more directional atomic layer etching solution for semiconductor etching equipment.

[0142] The ion energy controlled screen device and semiconductor etching equipment provided by this invention have the following beneficial effects:

[0143] 1) Effectively screen ions with a wide energy distribution in plasma. Through the synergistic effect of multi-layer mesh staggered alignment design and deflection electrode, ions with energy higher or lower than the target window are filtered out, greatly reducing the width of ion energy distribution. Finally, ions with a single energy distribution and controlled size are obtained, fundamentally solving the problems of excessively wide ion energy distribution and weak control capability in existing technologies.

[0144] 2) With the help of multiple adjustable DC power supplies, the energy of ions can be adjusted in both directions (acceleration or deceleration). This can increase the ion energy to meet the etching requirements, or decrease the ion energy to avoid over-etching, significantly enhancing the control range of ion energy and adapting to the energy window requirements of different atomic layer etching processes.

[0145] 3) The device has a compact overall structure and low cost; based on precise ion energy control, it can achieve atomic layer etching processes with higher selectivity, higher directionality and better surface roughness, ensuring etching accuracy and wafer processing quality, and meeting the manufacturing requirements of advanced semiconductor devices.

[0146] As indicated in this invention and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0147] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0148] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0149] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0150] The above embodiments are provided for those skilled in the art to implement or use the present invention. Those skilled in the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope that conforms to the innovative features mentioned in the claims.

Claims

1. An ion energy controlled screen device, characterized in that, It includes at least a first metal mesh, a second metal mesh, a third metal mesh, and a fourth metal mesh, as well as an electric field electrode plate; The first metal mesh and the second metal mesh are arranged sequentially; The electric field electrode plate is disposed between the second metal mesh and the third metal mesh; The fourth metal mesh is disposed below the third metal mesh; Wherein, the first metal mesh is configured to apply a first voltage, the second metal mesh is configured to be grounded or to apply a second voltage; the third metal mesh is configured to be grounded; and the fourth metal mesh is configured to apply a third voltage. The aperture arrays of the first metal mesh and the second metal mesh are aligned. The aperture array pattern of the third metal mesh is offset relative to the aperture array pattern of the second metal mesh in a direction parallel to the mesh surface. The aperture arrays of the fourth metal mesh and the third metal mesh are aligned. The first metal mesh and the second metal mesh are used to accelerate or decelerate ions passing through the metal pores. The electric field electrode plate is used to generate a transverse electric field to control the deflection angle of ions; The third metal mesh is used to intercept and filter ions whose deflection angle does not meet the preset conditions; The fourth metal mesh is used for further energy control of ions passing through the third metal mesh.

2. The ion energy controlled screen device according to claim 1, characterized in that, The first, second, third, and fourth metal meshes are made of thin metal sheets, on which a hole array of a specified shape is uniformly distributed.

3. The ion energy controlled screen device according to claim 2, characterized in that, The specified shape is either circular or square.

4. The ion energy controlled screen device according to claim 1, characterized in that, It also includes a first DC power supply and a second DC power supply: The first voltage is provided by a first DC power supply, and the third voltage is provided by a second DC power supply.

5. The ion energy controlled screen device according to claim 1, characterized in that, The adjustment range of the first voltage is -500V to +2000V.

6. The ion energy controlled screen device according to claim 1, characterized in that, The offset of the aperture array pattern of the third metal mesh relative to the aperture array pattern of the second metal mesh is 0.1-50 mm.

7. The ion energy controlled screen device according to claim 1, characterized in that, The distance between the third metal mesh and the second metal mesh is 1-200mm.

8. The ion energy controlled screen device according to claim 1, characterized in that, The materials of the first metal mesh, the second metal mesh, the third metal mesh, and the fourth metal mesh are selected from one of iron, copper, steel, and aluminum, or an alloy formed from any two or more metals, and the surface of the alloy has a ceramic coating or an oxide layer.

9. A semiconductor etching apparatus, characterized in that, It includes at least a reaction chamber, a wafer stage, a plasma generator, and an ion energy control screen device as described in any one of claims 1-8: The wafer stage is located at the lower part of the reaction chamber and is used to support the wafer to be etched; The plasma generator is located at the top of the reaction chamber and is used to generate plasma; The ion energy control screen device is disposed between the plasma generation device and the wafer stage, and is used to screen and control the energy of ions moving toward the wafer.

10. The semiconductor etching apparatus according to claim 9, characterized in that, The plasma generating device includes at least a quartz cylinder and an inductor coil: The quartz tube is used to provide space for plasma generation and confinement; The inductor coil, wound around the outside of the quartz tube and connected to a radio frequency power supply, is used to generate an alternating magnetic field under the excitation of the radio frequency power supply, thereby stimulating an induced electric field inside the quartz tube, ionizing the working gas to generate plasma.

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