High temperature vapor etching apparatus and control method

Abstract

The application provides a high-temperature vapor etching device and a control method, which comprises a vapor module and a lifting module. The vapor module comprises a vapor generating unit and a vapor spray head. The vapor generating unit is connected with the vapor spray head. The vapor spray head is arranged at the top of a reaction chamber. The lifting module is connected with a wafer carrier. The chemical reaction between etching vapor and wafer surface material is utilized to realize efficient etching of the wafer, produce less waste liquid, realize more accurate etching rate and selective etching, and effectively avoid the problems of uneven etching, over-etching or under-etching. Before etching, the distance between the wafer carrier and the vapor spray head is reduced, the diffusion loss of etching vapor is reduced, and the utilization rate of etching vapor and the etching efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a high-temperature vapor etching apparatus and control method. Background Technology

[0002] Traditional isotropic etching technologies mainly include multi-tank wet etching equipment, single-wafer wet etching equipment, and chemical-physical etching equipment.

[0003] Multi-tank wet etching equipment uses chemical solutions to dissolve and etch materials, offering advantages such as low cost and simple process. However, it suffers from difficulties in controlling the etching rate, significant isotropy, susceptibility to lateral etching, and challenging waste disposal. Single-wafer wet etching equipment uses chemical solutions to spray and etch materials in an atmospheric environment, offering advantages such as low risk and simple process. However, it faces challenges in controlling etching uniformity, generates large amounts of dilution acid and organic waste, and has low uptime. Traditional wet etching methods often employ immersion or spraying with liquid chemical reagents, resulting in high chemical consumption, complex waste disposal, and limited etching uniformity. Especially in MEMS or 3D integration processes requiring isotropic etching and high standards for surface cleanliness and microstructure conformation, liquid etching can easily lead to structural collapse, residue, or edge erosion.

[0004] Chemical physical etching equipment utilizes microwave-excited ions and free radicals to physically or chemically bombard materials. It features good isotropy and high control precision, but the equipment is expensive, inefficient, and prone to material damage. Furthermore, the use of electrostatic chucks poses a risk of stress fragmentation. In MEMS processes, wafer surfaces often contain microstructures with high aspect ratios (such as accelerometer cantilever arms, microphone diaphragms, and pressure sensor cavities). These structures require low-damage, non-directional etching and are extremely sensitive to mechanical stress and particle contamination.

[0005] Therefore, it is necessary to provide a novel high-temperature vapor etching apparatus and control method to solve the above-mentioned problems existing in the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature vapor etching apparatus and control method to reduce waste liquid, provide better intra-wafer and inter-wafer uniformity, and a more stable and controllable etching process.

[0007] To achieve the above objectives, the high-temperature vapor etching apparatus of the present invention includes: A steam module includes a steam generating unit and a steam spray head; the steam generating unit is located outside the reaction chamber and connected to the steam spray head, for generating and supplying etching steam to the steam spray head; the steam spray head is disposed at the top of the reaction chamber, for uniformly spraying the etching steam into the reaction chamber; and... A lifting module, connected to the wafer stage, is used to reduce the distance between the wafer stage and the vapor spray head before vapor etching begins, or to adjust the distance between the wafer stage and the vapor spray head during vapor etching.

[0008] Optionally, the high-temperature vapor etching apparatus further includes a heating unit disposed on the wafer stage for heating the wafer to a set temperature; The steam module also includes a steam delivery pipeline, a steam temperature regulation unit, and a steam pressure regulation unit; One end of the steam conveying pipe is connected to the steam generating unit, and the other end extends into the reaction chamber and is connected to the steam spray head; Both the steam temperature regulating unit and the steam pressure regulating unit are installed on the steam conveying pipeline. The steam temperature regulating unit is used to regulate the temperature of the etching steam in the steam conveying pipeline to prevent the temperature of the etching steam from falling below a preset temperature. The steam pressure regulating unit is used to regulate the pressure of the etching steam in the steam conveying pipeline so that the pressure of the etching steam matches the spray pressure of the steam spray head, so that it is evenly sprayed into the reaction chamber.

[0009] Optionally, the steam module further includes a selection unit. The steam generating unit includes a liquid heating element and a gas vaporization element. The selection unit is connected to the liquid heating element, the gas vaporization element, and the steam conveying pipeline, respectively, and is used to select the liquid heating element to be connected to the steam conveying pipeline, or to select the gas vaporization element to be connected to the steam conveying pipeline.

[0010] Optionally, the wafer stage has an internal gas supply cavity, and the wafer stage has a plurality of gas outlet holes communicating with the gas supply cavity on its bearing surface, and the plurality of gas outlet holes are arranged circumferentially around the central axis of the bearing surface. The high-temperature vapor etching equipment also includes a gas supply unit, which includes a bellows, a gas supply pipe, and a gas storage unit. One end of the gas supply pipe is connected to the gas storage unit, and the other end of the gas supply pipe passes through the wall of the reaction chamber and is connected to one end of the bellows. The other end of the bellows is connected to the gas supply chamber. The gas storage unit is used to store protective gas, which is then delivered to the back side of the wafer via the gas supply pipe, the corrugated pipe, the gas supply cavity, and the gas outlet.

[0011] Optionally, at least three lifting units are provided at the edge of the wafer stage, and each lifting unit is evenly distributed along the circumference of the wafer stage, for lifting the wafer during vapor etching, so that the back side of the wafer is separated from the bearing surface of the wafer stage.

[0012] Optionally, the lifting unit includes a support body, an extension bracket, a first driving assembly, and a second driving assembly; The support includes a rocker arm and a movable arm. One end of the rocker arm and one end of the movable arm are sleeved together and form a sliding fit. The other end of the rocker arm is rotatably connected to the wafer stage. The other end of the movable arm is provided with a clamping part, which is used to support and clamp the wafer. The first driving assembly includes a first driving member and a first transmission member. The second driving assembly includes a second driving member, a second transmission member, and a reset member. The epitaxial support is fixedly disposed on the edge of the wafer stage. The first driving member is fixedly connected to the epitaxial support. The first driving member is connected to the first transmission member. The first transmission member abuts against the second driving member. The first driving member is used to drive the first transmission member to move, thereby driving the second driving member closer to the wafer stage. The second transmission member is connected to the second driving member and the movable rod respectively. The second driving member is used to drive the second transmission member to move, thereby driving the movable rod to move along its length direction. The reset member is disposed between the rocker arm and the wafer stage, and is used to drive the rocker arm away from the wafer stage.

[0013] Optionally, the first driving component includes a first pneumatic motor and a first transmission gear. The first transmission component includes a first transmission rod, a first rack, and an angle fixing frame. The angle fixing frame is fixedly mounted on the first pneumatic motor. The first transmission rod is slidably connected to the angle fixing frame, and the angle fixing frame defines the sliding direction of the first transmission rod. The first rack is disposed at one end of the first transmission rod and extends along the length direction of the first transmission rod. The first transmission gear is mounted on the output shaft of the first pneumatic motor and meshes with the first rack. The other end of the first transmission rod abuts against the second driving component. And / or, The second driving component includes a second pneumatic motor, a second transmission gear, and a positioning frame. The second transmission component includes a second rack. The positioning frame is fixedly connected to the second pneumatic motor and the rocker arm, respectively. The second rack is disposed on the movable rod and extends along the length direction of the movable rod. The second transmission gear is mounted on the output shaft of the second pneumatic motor and meshes with the second rack.

[0014] Optionally, the high-temperature vapor etching equipment further includes a vacuum module, which includes a vacuum generating unit, a pressure sensing unit, a liquid collecting unit, and a vacuum pipeline. The pressure sensing unit is disposed in the reaction chamber and is used to detect the pressure in the reaction chamber; one end of the vacuum pipe is connected to the reaction chamber, and the other end of the vacuum pipe is connected to the vacuum generating unit. The vacuum generating unit is connected to the pressure sensing unit and is used to adjust the pressure in the reaction chamber to the target pressure according to the pressure detected by the pressure sensing unit; the liquid collecting unit is disposed on the vacuum pipe and is used to condense the etching vapor.

[0015] Optionally, the liquid collection unit includes a spiral condenser pipe, a straight condenser pipe, an anti-sucking pipe, and a condensate storage container. The spiral condenser pipe surrounds the outside of the straight condenser pipe. One end of the spiral condenser pipe is connected to a first interface of the condensate storage container, and one end of the straight condenser pipe is connected to a second interface of the condensate storage container. The other ends of both the spiral condenser pipe and the straight condenser pipe are connected to the vacuum pipe. One end of the anti-sucking pipe is connected to the other end of the spiral condenser pipe, and the other end of the anti-sucking pipe is connected to the other end of the straight condenser pipe.

[0016] Optionally, the high-temperature vapor etching equipment further includes an ultrapure water vapor module and an ultrapure water vapor spray head. The ultrapure water vapor module is located outside the reaction chamber and connected to the ultrapure water vapor spray head, and is used to generate and deliver ultrapure water vapor to the ultrapure water vapor spray head. The ultrapure water vapor spray head is disposed at the top of the reaction chamber and surrounds the vapor spray head.

[0017] Optionally, the steam module further includes a steam delivery pipe, one end of which is connected to the steam generating unit, and the other end extends into the reaction chamber and is connected to the steam spray head; the high-temperature steam etching equipment further includes an ultrapure water vapor module, which is located outside the reaction chamber and connected to the steam delivery pipe, for generating and delivering ultrapure water vapor to the steam delivery pipe.

[0018] Optionally, a heating plate is provided on the inner or outer surface of the reaction chamber wall to heat the reaction chamber wall and prevent the etching vapor from condensing on the inner surface of the reaction chamber wall.

[0019] This invention provides a control method for the high-temperature vapor etching equipment, comprising the following steps: Place the wafer on the wafer carrier; The lifting module reduces the distance between the wafer stage and the steam spray head; The steam generating unit generates and delivers etching steam to the steam spray head to achieve steam etching of the wafer.

[0020] The beneficial effects of this invention are as follows: On the one hand, the steam generating unit is located outside the reaction chamber and connected to the steam spray head, which is used to generate and deliver etching steam to the steam spray head. The steam spray head is set at the top of the reaction chamber and is used to uniformly spray the etching steam into the reaction chamber. It can use the etching steam to chemically react with the wafer surface material in a high-temperature environment to achieve efficient etching of the wafer. Moreover, the high-temperature etching steam environment is more stable and controllable, with less waste liquid, which can achieve more precise etching rate and selective etching, and effectively avoid the problems of uneven etching, over-etching or under-etching. On the other hand, the lifting module is connected to the wafer stage and is used to reduce the distance between the wafer stage and the vapor spray head before the start of vapor etching, thereby reducing the diffusion loss of etching vapor and improving the utilization rate and etching efficiency of etching vapor. During the vapor etching process, the distance between the wafer stage and the vapor spray head is adjusted, that is, the spacing can be dynamically adjusted during the etching process to adapt to the requirements of different process stages for etching vapor throughput and reaction space, thereby enhancing process flexibility and controllability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a high-temperature vapor etching apparatus in some embodiments of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a high-temperature vapor etching apparatus in some embodiments of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the wafer stage in some embodiments of the present invention; Figure 4 This is a schematic diagram of the lifting unit in some embodiments of the present invention; Figure 5 This is a schematic diagram of the structure of the first driving member and the first transmission member in some embodiments of the present invention; Figure 6 This is a schematic diagram of the structure of the second driving member and the second transmission member in some embodiments of the present invention; Figure 7 This is a schematic diagram of the liquid collection unit in some embodiments of the present invention; Figure 8 This is a schematic diagram showing the positions of the rocker arm and the movable arm in some embodiments of the present invention.

[0022] Explanation of reference numerals in the attached figures: 10. Reaction chamber; 20. Steam module; 21. Steam generating unit; 22. Steam spray head; 23. Steam delivery pipe; 24. Steam temperature regulating unit; 25. Steam pressure regulating unit; 31. Wafer stage; 311. Vent outlet; 312. Lifting unit; 3121. Epitaxial support; 3122. First drive assembly; 31221. First drive component; 312211. First pneumatic motor; 312212. First transmission gear; 31222. First transmission component; 312221. First transmission rod; 312222. First rack; 312223. Angle fixing bracket; 3122231. Cylindrical through hole; 3123. Second drive assembly; 31 231. Second driving component; 312311. Second pneumatic motor; 3123111. Supporting part; 312312. Second transmission gear; 312313. Positioning frame; 312314. Second rack; 31232. Reset part; 3124. Rocker arm; 3125. Movable rod; 3126. Clamping part; 32. Lifting module; 33. Heating unit; 34. Gas supply unit; 341. Corrugated pipe; 342. Gas supply pipe; 343. Gas storage unit; 351. Vacuum generating unit; 352. Liquid collection unit; 3521. Spiral condenser pipe; 3522. Straight condenser pipe; 3523. Anti-suction pipe; 3524. Condensate storage container; 353. Vacuum pipe. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but do not exclude other elements or objects.

[0024] To address the problems existing in the prior art, embodiments of the present invention provide a high-temperature vapor etching apparatus. (Refer to...) Figure 1 and Figure 2The high-temperature vapor etching equipment includes a reaction chamber 10, a vapor module 20, a wafer stage 31, and a lifting module 32. The vapor module 20 includes a vapor generating unit 21 and a vapor spray head 22. The vapor generating unit 21 is located outside the reaction chamber 10 and connected to the vapor spray head 22, used to generate and supply etching vapor to the vapor spray head 22. The vapor spray head 22 is disposed at the top of the reaction chamber 10, used to uniformly spray etching vapor into the reaction chamber 10. The wafer stage 31 is disposed inside the reaction chamber 10, used to support the wafer. The lifting module 32 is connected to the wafer stage 31, used to reduce the distance between the wafer stage 31 and the vapor spray head 22 before vapor etching begins, or to adjust the distance between the wafer stage 31 and the vapor spray head 22 during vapor etching.

[0025] In this application, on the one hand, the vapor generating unit is located outside the reaction chamber and connected to the vapor spray head, used to generate and supply etching vapor to the vapor spray head. The vapor spray head is disposed at the top of the reaction chamber, used to uniformly spray the etching vapor into the reaction chamber. This allows for efficient etching of the wafer by utilizing the etching vapor to chemically react with the wafer surface material at high temperatures. Furthermore, the high-temperature etching vapor environment is more stable and controllable, resulting in less waste liquid. This enables more precise etching rates and selective etching, and effectively avoids uneven etching and over-etching. On the one hand, the lifting module is connected to the wafer stage and is used to reduce the distance between the wafer stage and the vapor spray head before the start of vapor etching, or to adjust the distance between the wafer stage and the vapor spray head during the vapor etching process. Reducing the distance between the wafer stage and the vapor spray head before etching reduces the diffusion loss of etching vapor, improves the utilization rate of etching vapor and etching efficiency. The distance can be dynamically adjusted during the etching process to adapt to the requirements of different process stages for etching vapor throughput and reaction space, and enhances process flexibility and controllability.

[0026] In some embodiments, reference is made to Figure 1 and Figure 2The high-temperature vapor etching equipment further includes a heating unit 33, which is disposed on the wafer stage 31 and used to heat the wafer to a set temperature. The vapor module 20 also includes a vapor delivery pipe 23, a vapor temperature regulating unit 24, and a vapor pressure regulating unit 25; wherein, one end of the vapor delivery pipe 23 is connected to the vapor generating unit 21, and the other end extends into the reaction chamber and is connected to the vapor spray head; the vapor temperature regulating unit 24 and the vapor pressure regulating unit 25 are both disposed on the vapor delivery pipe 23; the vapor temperature regulating unit 24 is used to regulate the temperature of the etching vapor in the vapor delivery pipe 23 to prevent the temperature of the etching vapor from falling below the preset temperature; the vapor pressure regulating unit 25 is used to regulate the pressure of the etching vapor in the vapor delivery pipe 23 so that the pressure of the etching vapor matches the spray pressure of the vapor spray head, so as to uniformly spray it into the reaction chamber.

[0027] This application incorporates a steam temperature regulating unit on the steam delivery pipeline, which can adjust and maintain the etching steam temperature in real time to ensure it is not lower than the preset temperature. This effectively prevents the steam from condensing or liquefying due to cooling during delivery, avoids blockage of the steam delivery pipeline or fluctuations in steam concentration, and ensures that the steam entering the steam spray head is stable and consistent. The steam pressure regulating unit precisely controls the pressure in the steam delivery pipeline, matching the steam pressure to the design spray pressure of the steam spray head, ensuring that the etching steam is sprayed out at a stable and uniform pressure, further improving the uniformity of the etching steam distribution in the reaction chamber and enhancing the etching uniformity.

[0028] In some embodiments, the set temperature is 300℃-800℃. Specifically, the set temperature is 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃ or 800℃, or any value between any two of the aforementioned temperature values.

[0029] In some embodiments, the preset temperature is 300℃-800℃. Specifically, the preset temperature is 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, or 800℃, or any value between any two of the aforementioned temperature values.

[0030] In some embodiments, the preset temperature is the same as the set temperature.

[0031] In some embodiments, the steam temperature regulating unit includes an electric heating wire, a temperature sensor, and a temperature controller. The electric heating wire is arranged around the steam delivery pipe, the temperature sensor is embedded in the pipe wall of the steam delivery pipe, and the temperature controller is connected to both the electric heating wire and the temperature sensor. The power of the electric heating wire is adjusted based on the temperature detected by the temperature sensor, thereby achieving temperature regulation.

[0032] In some specific embodiments, the steam pressure regulating unit is a flow regulating valve.

[0033] In some embodiments, the steam module further includes a selection unit, and the steam generating unit includes a liquid heating element and a gas vaporizing element. The selection unit is connected to the liquid heating element, the gas vaporizing element and the steam conveying pipeline respectively, and is used to select the liquid heating element to be connected to the steam conveying pipeline, or to select the gas vaporizing element to be connected to the steam conveying pipeline.

[0034] This application, by setting up a selection unit, can flexibly switch between liquid heating elements or gas vaporization elements and steam delivery pipelines according to different etching process requirements. This enables free switching between two steam generation modes: liquid source (anhydrous ethanol, hydrofluoric acid, sulfuric acid, hydrogen peroxide) evaporation and gas source (ammonia, CF4, SF6, HF, NF3) evaporation. This broadens the applicable process scenarios and material etching range of the equipment. The two steam generation modes share a single set of steam delivery pipelines and steam spray heads, eliminating the need for separate pipeline and chamber structures for different gas sources. This simplifies the overall equipment layout and reduces structural complexity and manufacturing costs.

[0035] In some specific embodiments, the selection unit is a three-way valve, the first end of which is connected to the liquid heating element, the second end of which is connected to the gas vaporization element, and the third end of which is connected to the steam conveying pipeline. The three-way valve is used to connect the liquid heating element to the steam conveying pipeline or the gas vaporization element to the steam conveying pipeline.

[0036] In some specific embodiments, the liquid heating element includes a tank and a heating rod. The heating rod is disposed on the inner bottom surface or outer bottom surface of the tank and is used to generate heat at a constant power, thereby causing the liquid inside the tank to evaporate and form etching vapor. Alternatively, the liquid heating element may also include a temperature sensor and a temperature controller. The temperature sensor is disposed inside the tank and is used to detect the temperature of the liquid or etching vapor inside the tank in real time. The temperature sensor is connected to the temperature controller, and the temperature controller adjusts the power of the heating rod according to the temperature signal fed back from the temperature sensor to maintain the temperature inside the tank at a set value, thereby stabilizing the temperature of the generated etching vapor.

[0037] In some specific embodiments, the gas vaporization element differs from the liquid heating element in that the tank is replaced by a pipe, and the heating rod is replaced by a heating wire, with the heating wire wrapped around the pipe.

[0038] In some embodiments, reference is made to Figure 1 , Figure 2 and Figure 3 The wafer stage 31 has a gas supply cavity inside, and a plurality of gas outlet holes 311 communicating with the gas supply cavity are formed on the bearing surface of the wafer stage 31. The plurality of gas outlet holes 311 are arranged circumferentially around the central axis of the bearing surface. The high-temperature vapor etching equipment also includes a gas supply unit 34, which includes a corrugated pipe 341, a gas supply pipe 342, and a gas storage unit 343. One end of the gas supply pipe 342 is connected to the gas storage unit 343, and the other end of the gas supply pipe 342 passes through the cavity wall of the reaction chamber and is connected to one end of the corrugated pipe 341. The other end of the corrugated pipe 341 is connected to the gas supply cavity. The gas storage unit 343 is used to store protective gas and delivers it to the back side of the wafer in sequence through the gas supply pipe 342, the corrugated pipe 341, the gas supply cavity, and the gas outlet holes 311.

[0039] This application incorporates a gas supply chamber within the wafer stage and circumferentially arranged vent holes on the support surface. This allows the protective gas to act uniformly on the back side of the wafer, forming a stable gas film between the wafer and the support surface. This achieves non-contact support or uniform back pressure for the wafer, preventing surface scratches and contamination caused by direct contact between the wafer and the stage. Simultaneously, it ensures uniform temperature distribution across the wafer, improving etching uniformity. A corrugated pipe connects the gas supply pipe and the gas supply chamber. When the lifting module moves the wafer stage up and down, the corrugated pipe expands and contracts synchronously with the wafer stage. This ensures the airtightness and continuity of the gas delivery path without affecting the stage's lifting motion, achieving stable gas supply under dynamic operating conditions and avoiding issues such as pipe pulling and leakage. The continuous supply of protective gas to the back side of the wafer effectively prevents etching vapor from diffusing to the back side, preventing accidental etching or deposition of byproducts, ensuring the cleanliness of the back side. Simultaneously, it applies pressure to the back side of the wafer, helping to maintain flatness during high-temperature etching, suppressing warping and improving product yield.

[0040] In some specific embodiments, the gas storage unit is a gas storage tank.

[0041] In some specific embodiments, the protective gas is nitrogen or helium.

[0042] In some embodiments, the wall material of the reaction chamber is silicon carbide or ceramic-coated iron-nickel alloy.

[0043] In some specific embodiments, reference is made to Figure 1 and Figure 2The heating unit is a resistance heating element (e.g., heating wire, heating plate) and is located on the underside of the wafer stage.

[0044] In some embodiments, the high-temperature vapor etching apparatus further includes a wafer temperature detection module for detecting the temperature of the wafer. This module works in conjunction with the heating unit to heat the wafer to a set temperature. Specifically, the wafer temperature detection module is an infrared temperature sensor or a thermocouple.

[0045] In some embodiments, the number of lifting modules may be set to three or more, and they are equally spaced at the bottom of the wafer stage. The shortest distance from each lifting module to the central axis of the wafer stage is the same, thereby improving the stability of the wafer stage during the lifting process.

[0046] The specific structure can adopt common lifting structures in existing technologies such as pneumatic lifting and screw lifting, which will not be described in detail here.

[0047] In some embodiments, reference is made to Figure 4 At least three lifting units 312 are provided at the edge of the wafer stage 31, and each lifting unit 312 is evenly distributed along the circumference of the wafer stage 31. They are used to lift the wafer during the vapor etching process, so that the back side of the wafer is separated from the bearing surface of the wafer stage 31.

[0048] This application features at least three lifting units uniformly arranged circumferentially along the edge of the wafer stage. During etching, the wafer can be smoothly lifted, separating the back side of the wafer from the support surface. This enables contactless etching of both sides of the wafer. Furthermore, this structure ensures that etching vapor can fully reach the high aspect ratio gap on the front side of the wafer and the back side, significantly improving the integrity and uniformity of sacrificial layer removal and avoiding etching residues caused by local or contact shading. After lifting the wafer, a uniform air gap is formed between the back side of the wafer and the support surface. Combined with the protective gas supply structure on the back side of the wafer (i.e., vent holes, supply cavities, etc.), the protective gas can flow more fully within the air gap, further improving wafer temperature uniformity, suppressing local overheating or etching rate deviations, and improving etching uniformity. Moreover, it can achieve radiative heating, further improving wafer temperature uniformity.

[0049] In some embodiments, reference is made to Figure 4The lifting unit 312 includes a support body, an epitaxial support 3121, a first driving assembly 3122, and a second driving assembly 3123. The support body includes a rocker arm 3124 and a movable rod 3125. One end of the rocker arm 3124 and one end of the movable rod 3125 are sleeved together and form a sliding fit. The other end of the rocker arm 3124 is rotatably connected to the wafer stage 31. The other end of the movable rod 3125 is provided with a clamping part 3126, which is used to support and clamp the wafer. The first driving assembly 3122 includes a first driving member 31221 and a first transmission member 31222. The second driving assembly 3123 includes a second driving member 31231, a second transmission member, and a reset member 31232. The epitaxial support 3121 is fixedly disposed on the edge of the wafer stage 31. The first driving member 31221 is fixedly connected to the epitaxial support 3121. The first driving member 31221 is connected to the first transmission member 31222. The first transmission member 31222 abuts against the second driving member 31231. The first driving member 31221 is used to drive the first transmission member 31222 to move, so as to drive the second driving member 31231 closer to the wafer stage 31. The second transmission member is connected to the second driving member 31231 and the movable rod 3125 respectively. The second driving member 31231 is used to drive the second transmission member to move, so as to drive the movable rod 3125 to move along its length direction. The reset member 31232 is disposed between the rocker arm 3124 and the wafer stage 31, and is used to drive the rocker arm 3124 away from the wafer stage 31.

[0050] In this application, the support body is a composite support structure with a rocker arm and a movable rod sliding together. Combined with the rotatable connection between the rocker arm and the wafer stage, it enables multi-degree-of-freedom attitude adjustment of the support body on the wafer. While lifting and suspending the wafer, it achieves precise positioning and clamping, ensuring stable centering of the wafer during non-contact etching, avoiding offset and wobbling, and guaranteeing the uniformity of sacrificial layer removal for high aspect ratio structures. Through graded driving of the first and second driving components, the support body can move towards the wafer stage as a whole, and the movable rod can extend and retract. The driving logic is clear, and the actions are independent and controllable. It can reliably clamp the wafer and flexibly adjust the suspension height to adapt to the etching requirements of wafers of different thicknesses and thinned wafers. A reset component is located between the rocker arm and the wafer stage. After the first driving component relieves the force on the second driving component, it drives the rocker arm to automatically reset, enabling the support body to quickly return to its original position. This facilitates smooth wafer handling after the process is completed and reduces the time spent on auxiliary machine actions.

[0051] In some embodiments, reference is made to Figure 4 and Figure 5The first driving component 31221 includes a first pneumatic motor 312211 and a first transmission gear 312212. The first transmission component 31222 includes a first transmission rod 312221, a first rack 312222, and an angle fixing bracket 312223. The angle fixing bracket 312223 is fixedly mounted on the first pneumatic motor 312211. The first transmission rod 312221 is slidably connected to the angle fixing bracket 312223. The sliding direction of the first transmission rod 312221 is defined. The first rack 312222 is disposed at one end of the first transmission rod 312221 and extends along the length direction of the first transmission rod 312221. The first transmission gear 312212 is mounted on the output shaft of the first pneumatic motor 312211 and meshes with the first rack 312222. The other end of the first transmission rod 312221 abuts against the second driving member.

[0052] This application employs a first pneumatic motor in conjunction with a first transmission gear and a first rack, resulting in high transmission efficiency and stable driving force. It allows for precise control of the linear displacement of the first transmission rod, ensuring stable pushing of the second driving component and guaranteeing accurate and reliable lifting unit operation. This avoids wafer positioning deviations caused by excessive transmission clearance. The angle fixing bracket provides sliding guidance and attitude constraint for the first transmission rod, strictly limiting its sliding direction and preventing wobbling, shaking, or angular deviation during movement. This ensures a stable and consistent transmission path, improving the repeatability and process consistency of the lifting action. The gear and rack transmission structure is compact and responsive. Combined with the pneumatic drive, it can operate stably in vacuum or high-temperature vapor etching environments and is less susceptible to interference from chamber conditions.

[0053] In some embodiments, reference is made to Figure 5 The angle fixing bracket 312223 has a cylindrical through hole 3122231, and the first transmission rod 312221 passes through the cylindrical through hole 3122231.

[0054] In some embodiments, reference is made to Figure 4 and Figure 6The second driving component 31231 includes a second pneumatic motor 312311, a second transmission gear 312312, and a positioning frame 312313. The second transmission component includes a second rack 312314. The positioning frame 312313 is fixedly connected to the second pneumatic motor 312311 and the rocker arm 3124 respectively. The second rack 312314 is disposed on the movable rod 3125 and extends along the length direction of the movable rod 3125. The second transmission gear 312312 is mounted on the output shaft of the second pneumatic motor 312311 and meshes with the second rack 312314.

[0055] This application employs a second pneumatic motor in conjunction with a second transmission gear and a second rack for drive, which can precisely drive the movable rod to move linearly along the length direction, realizing reliable clamping and releasing of the wafer by the clamping part. The action is stable and the response is fast, ensuring accurate positioning of the wafer and preventing it from shifting during the suspension etching process. The gear and rack transmission structure is compact and responds quickly. Combined with the pneumatic drive method, it can work stably in vacuum or high-temperature vapor etching environments and is not easily affected by the working conditions of the chamber.

[0056] In some embodiments, reference is made to Figure 6 The reset element 31232 is a spring, one end of which is connected to the rocker arm 3124, and the other end of which is connected to the wafer stage.

[0057] In some embodiments, reference is made to Figure 5 and Figure 6 The second pneumatic motor 312311 has a supporting part 3123111 on one side, which is used to abut against the first transmission rod 312221. Specifically, the supporting part 3123111 is a metal plate.

[0058] In some embodiments, reference is made to Figure 1 and Figure 2 The high-temperature vapor etching equipment further includes a vacuum module, which comprises a vacuum generating unit 351, a pressure sensing unit, a liquid collecting unit 352, and a vacuum pipe 353. The pressure sensing unit is disposed within the reaction chamber 10 and is used to detect the pressure within the reaction chamber 10. One end of the vacuum pipe 353 is connected to the reaction chamber 10, and the other end of the vacuum pipe 353 is connected to the vacuum generating unit 351. The vacuum generating unit 351 is connected to the pressure sensing unit and is used to adjust the pressure within the reaction chamber 10 to a target pressure based on the pressure detected by the pressure sensing unit. The liquid collecting unit 352 is disposed on the vacuum pipe 353 and is used to condense the etching vapor.

[0059] In this application, the pressure in the reaction chamber is monitored in real time by a pressure sensing unit and regulated in a closed loop by a vacuum generating unit. This allows the pressure in the reaction chamber to be quickly and accurately stabilized at the target pressure, providing a stable vacuum environment for high-temperature vapor etching and ensuring a uniform and controllable etching rate. A liquid collection unit is installed on the vacuum pipeline to effectively condense and collect unreacted etching vapor and process byproducts, preventing vapor from directly entering the vacuum generating unit and causing corrosion, condensation, and blockage. This protects core components such as the vacuum pump, extends the service life of the equipment, and reduces maintenance costs.

[0060] In some specific embodiments, the vacuum generating unit is a vacuum pump, and the pressure sensing unit is a pressure sensor.

[0061] In some embodiments, reference is made to Figure 7 The liquid collection unit includes a spiral condenser pipe 3521, a straight condenser pipe 3522, an anti-sucking pipe 3523, and a condensate storage container 3524. The spiral condenser pipe 3521 surrounds the outside of the straight condenser pipe 3522. One end of the spiral condenser pipe 3521 is connected to the first interface of the condensate storage container 3524, and one end of the straight condenser pipe 3522 is connected to the second interface of the condensate storage container 3524. The other ends of the spiral condenser pipe 3521 and the straight condenser pipe 3522 are both connected to the vacuum pipe. One end of the anti-sucking pipe 3523 is connected to the other end of the spiral condenser pipe 3521, and the other end of the anti-sucking pipe 3523 is connected to the other end of the straight condenser pipe 3522.

[0062] This application employs a combined structure of a spiral condenser pipe and a straight condenser pipe, which significantly increases the contact area and flow path between the etching vapor and the pipe wall, extends the vapor condensation residence time, and achieves efficient and complete condensation of unreacted etching vapor and water vapor, thereby significantly improving condensation recovery efficiency. The spiral pipe is arranged around the outside of the straight pipe, forming a synergistic cooling effect (i.e., mutual cooling), which can quickly reduce the vapor temperature, promote the rapid liquefaction of vapor and its flow into the condensate storage container, and effectively prevent vapor from entering the vacuum generating unit and causing corrosion and damage. An anti-suction pipe is added to connect the spiral condenser pipe and the straight condenser pipe, which can prevent the liquid in the condensate storage container from being sucked into the vacuum generating unit when the container is full of liquid.

[0063] In some embodiments, the high-temperature vapor etching apparatus further includes an ultrapure water vapor module and an ultrapure water vapor spray head. The ultrapure water vapor module is located outside the reaction chamber and connected to the ultrapure water vapor spray head, and is used to generate and deliver ultrapure water vapor to the ultrapure water vapor spray head. The ultrapure water vapor spray head is disposed at the top of the reaction chamber and surrounds the vapor spray head.

[0064] This application adds an ultrapure water vapor spray head arranged around the steam spray head in the reaction chamber, which can perform online high-temperature steam cleaning on the wafer surface and the inner wall of the chamber before and after the etching process, effectively removing residual etching by-products, particles and organic contaminants, ensuring the cleanliness of the chamber and improving the uniformity and repeatability of subsequent etching processes; the introduction of ultrapure water vapor during the process can play a doping role on the etching vapor, which can adjust the uniformity of etching.

[0065] In some embodiments, one end of the steam delivery pipe is connected to the steam generating unit, and the other end extends into the reaction chamber and is connected to the steam spray head; the high-temperature steam etching equipment also includes an ultrapure water vapor module, which is located outside the reaction chamber and connected to the steam delivery pipe, for generating and delivering ultrapure water vapor to the steam delivery pipe.

[0066] This application directly connects the ultrapure water vapor module to the steam delivery pipeline, sharing the same delivery and spraying path with the etching steam. This eliminates the need for additional spray heads and pipelines within the reaction chamber, simplifying the equipment structure, reducing the complexity of the chamber layout, and saving installation space. Furthermore, the ultrapure water vapor can perform online high-temperature steam cleaning of the wafer surface and the inner wall of the chamber before and after the etching process, effectively removing residual etching byproducts, particles, and organic contaminants, ensuring chamber cleanliness, and improving the uniformity and repeatability of subsequent etching processes. The introduction of ultrapure water vapor during the process can also dope the etching steam, thereby adjusting the uniformity of the etching.

[0067] In some specific embodiments, the structure of the ultrapure water vapor module is the same as that of the liquid heating element.

[0068] In some embodiments, a heating plate is provided on the inner or outer surface of the reaction chamber wall to heat the reaction chamber wall and prevent the etching vapor from condensing on the inner surface of the reaction chamber wall.

[0069] This application provides heating plates on the inner or outer surface of the reaction chamber wall for overall heating, which can maintain the temperature of the chamber wall above the etching vapor dew point. This effectively prevents the etching vapor from condensing and liquefying on the inner surface of the chamber wall, thus preventing local etching abnormalities, pattern damage, or particle contamination on the wafer caused by dripping liquid. Maintaining a constant temperature in the chamber wall can reduce the loss of etching vapor due to condensation, ensuring that the etching vapor concentration and pressure in the reaction chamber are stable and uniform, thereby improving the overall etching uniformity of the wafer.

[0070] In some specific embodiments, the heating plate is a graphene far-infrared heating plate.

[0071] In some embodiments, reference is made to Figure 1 and Figure 2Position a is the position of the wafer stage before the start of vapor etching, and position a' is the position of the wafer stage during the vapor etching process.

[0072] In some embodiments, reference is made to Figure 8 Position b represents the position of the rocker arm and the movable arm before the start of vapor etching, and position b' represents the position of the rocker arm and the movable arm during the vapor etching process.

[0073] This application also provides a control method for the aforementioned high-temperature vapor etching equipment, comprising the following steps: S1: Place the wafer on the wafer stage (at this time, the wafer stage is located at position a). S2: The lifting module reduces the distance between the wafer stage and the steam spray head (i.e., the wafer stage is raised from position a to position a'). S3: The steam generating unit generates and delivers etching steam to the steam spray head to achieve steam etching of the wafer.

[0074] In some embodiments, step S1 includes placing the wafer on the wafer stage, with the rocker arm and the movable arm located at position b, and the clamping portion abutting against the edge of the wafer to support the wafer.

[0075] In some embodiments, step S2 further includes moving the rocker arm and the movable arm to position b', whereby the clamping portion carries and clamps the wafer.

[0076] In some embodiments, step S2 further includes the heating unit heating the wafer to a preset temperature.

[0077] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A high-temperature vapor etching apparatus, characterized in that, include: Steam module, including steam generating unit and steam spray head; The steam generating unit is located outside the reaction chamber and connected to the steam spray head, and is used to generate and deliver etching steam to the steam spray head; the steam spray head is located at the top of the reaction chamber and is used to uniformly spray the etching steam into the reaction chamber. as well as, A lifting module, connected to the wafer stage, is used to reduce the distance between the wafer stage and the vapor spray head before vapor etching begins, or to adjust the distance between the wafer stage and the vapor spray head during vapor etching.

2. The high-temperature vapor etching apparatus according to claim 1, characterized in that, The high-temperature vapor etching equipment also includes a heating unit, which is disposed on the wafer stage and is used to heat the wafer to a set temperature; The steam module also includes a steam delivery pipeline, a steam temperature regulation unit, and a steam pressure regulation unit; One end of the steam conveying pipe is connected to the steam generating unit, and the other end extends into the reaction chamber and is connected to the steam spray head; Both the steam temperature regulating unit and the steam pressure regulating unit are installed on the steam conveying pipeline. The steam temperature regulating unit is used to regulate the temperature of the etching steam in the steam conveying pipeline to prevent the temperature of the etching steam from falling below a preset temperature. The steam pressure regulating unit is used to regulate the pressure of the etching steam in the steam conveying pipeline so that the pressure of the etching steam matches the spray pressure of the steam spray head, so that it is evenly sprayed into the reaction chamber.

3. The high-temperature vapor etching apparatus according to claim 2, characterized in that, The steam module further includes a selection unit. The steam generating unit includes a liquid heating element and a gas vaporization element. The selection unit is connected to the liquid heating element, the gas vaporization element and the steam conveying pipeline respectively, and is used to select the liquid heating element to be connected to the steam conveying pipeline, or to select the gas vaporization element to be connected to the steam conveying pipeline.

4. The high-temperature vapor etching apparatus according to claim 1, characterized in that, The wafer stage has an internal gas supply cavity, and the supporting surface of the wafer stage has a plurality of gas outlet holes that communicate with the gas supply cavity, and the plurality of gas outlet holes are arranged circumferentially around the central axis of the supporting surface. The high-temperature vapor etching equipment also includes a gas supply unit, which includes a bellows, a gas supply pipe, and a gas storage unit. One end of the gas supply pipe is connected to the gas storage unit, and the other end of the gas supply pipe passes through the wall of the reaction chamber and is connected to one end of the bellows. The other end of the bellows is connected to the gas supply chamber. The gas storage unit is used to store protective gas, which is then delivered to the back side of the wafer via the gas supply pipe, the corrugated pipe, the gas supply cavity, and the gas outlet.

5. The high-temperature vapor etching apparatus according to claim 4, characterized in that, At least three lifting units are provided at the edge of the wafer stage, and each lifting unit is evenly distributed along the circumference of the wafer stage. They are used to lift the wafer during vapor etching, so that the back side of the wafer is separated from the bearing surface of the wafer stage.

6. The high-temperature vapor etching apparatus according to claim 5, characterized in that, The lifting unit includes a support body, an extension bracket, a first drive assembly, and a second drive assembly; The support includes a rocker arm and a movable arm. One end of the rocker arm and one end of the movable arm are sleeved together and form a sliding fit. The other end of the rocker arm is rotatably connected to the wafer stage. The other end of the movable arm is provided with a clamping part, which is used to support and clamp the wafer. The first driving assembly includes a first driving member and a first transmission member. The second driving assembly includes a second driving member, a second transmission member, and a reset member. The epitaxial support is fixedly disposed on the edge of the wafer stage. The first driving member is fixedly connected to the epitaxial support. The first driving member is connected to the first transmission member. The first transmission member abuts against the second driving member. The first driving member is used to drive the first transmission member to move, thereby driving the second driving member closer to the wafer stage. The second transmission member is connected to the second driving member and the movable rod respectively. The second driving member is used to drive the second transmission member to move, thereby driving the movable rod to move along its length direction. The reset member is disposed between the rocker arm and the wafer stage, and is used to drive the rocker arm away from the wafer stage.

7. The high-temperature vapor etching apparatus according to claim 6, characterized in that, The first driving component includes a first pneumatic motor and a first transmission gear. The first transmission component includes a first transmission rod, a first rack, and an angle fixing frame. The angle fixing frame is fixedly mounted on the first pneumatic motor. The first transmission rod is slidably connected to the angle fixing frame, and the angle fixing frame defines the sliding direction of the first transmission rod. The first rack is disposed at one end of the first transmission rod and extends along the length of the first transmission rod. The first transmission gear is mounted on the output shaft of the first pneumatic motor and meshes with the first rack. The other end of the first transmission rod abuts against the second driving component. And / or, The second driving component includes a second pneumatic motor, a second transmission gear, and a positioning frame. The second transmission component includes a second rack. The positioning frame is fixedly connected to the second pneumatic motor and the rocker arm, respectively. The second rack is disposed on the movable rod and extends along the length direction of the movable rod. The second transmission gear is mounted on the output shaft of the second pneumatic motor and meshes with the second rack.

8. The high-temperature vapor etching apparatus according to any one of claims 1-7, characterized in that, The high-temperature vapor etching equipment also includes a vacuum module, which comprises a vacuum generating unit, a pressure sensing unit, a liquid collecting unit, and a vacuum pipeline. The pressure sensing unit is disposed in the reaction chamber and is used to detect the pressure in the reaction chamber; one end of the vacuum pipe is connected to the reaction chamber, and the other end of the vacuum pipe is connected to the vacuum generating unit. The vacuum generating unit is connected to the pressure sensing unit and is used to adjust the pressure in the reaction chamber to the target pressure according to the pressure detected by the pressure sensing unit; the liquid collecting unit is disposed on the vacuum pipe and is used to condense the etching vapor.

9. The high-temperature vapor etching apparatus according to claim 8, characterized in that, The liquid collection unit includes a spiral condenser pipe, a straight condenser pipe, an anti-sucking pipe, and a condensate storage container. The spiral condenser pipe surrounds the outside of the straight condenser pipe. One end of the spiral condenser pipe is connected to the first interface of the condensate storage container, and one end of the straight condenser pipe is connected to the second interface of the condensate storage container. The other ends of the spiral condenser pipe and the straight condenser pipe are both connected to the vacuum pipe. One end of the anti-sucking pipe is connected to the other end of the spiral condenser pipe, and the other end of the anti-sucking pipe is connected to the other end of the straight condenser pipe.

10. The high-temperature vapor etching apparatus according to any one of claims 1-7, characterized in that, The high-temperature vapor etching equipment also includes an ultrapure water vapor module and an ultrapure water vapor spray head. The ultrapure water vapor module is located outside the reaction chamber and is connected to the ultrapure water vapor spray head. It is used to generate and deliver ultrapure water vapor to the ultrapure water vapor spray head. The ultrapure water vapor spray head is located at the top of the reaction chamber and surrounds the vapor spray head. or, The steam module also includes a steam delivery pipe, one end of which is connected to the steam generating unit, and the other end extends into the reaction chamber and is connected to the steam spray head; the high-temperature steam etching equipment also includes an ultrapure water vapor module, which is located outside the reaction chamber and connected to the steam delivery pipe, for generating and delivering ultrapure water vapor to the steam delivery pipe.

11. The high-temperature vapor etching apparatus according to any one of claims 1-7, characterized in that, The inner or outer surface of the reaction chamber wall is covered with a heating plate to heat the reaction chamber wall and prevent the etching vapor from condensing on the inner surface of the reaction chamber wall.

12. A control method for a high-temperature vapor etching apparatus as described in any one of claims 1-11, characterized in that, Includes the following steps: Place the wafer on the wafer carrier; The lifting module reduces the distance between the wafer stage and the steam spray head; The steam generating unit generates and delivers etching steam to the steam spray head to achieve steam etching of the wafer.

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