Etching device and etching method

Abstract

The present application discloses an etching device and an etching method, which relate to the technical field of semiconductor manufacturing equipment and semiconductor manufacturing methods, and in particular to an etching device and an etching method. The etching device includes: an electrostatic chuck, and at least one heater; the electrostatic chuck has: an adsorption surface; at least one vent is provided in the adsorption surface, and the vent is at least used to conduct the first gas to one side of the adsorption surface; at least one heater is provided on one side of the adsorption surface at a preset distance from the plane where the adsorption surface is located. By implementing the etching device and etching method disclosed in the embodiment of the present application, the electrostatic chuck adsorbs the etched wafer, and in combination with the reaction gas, the purge gas, and the heater, the atomic layer etching of the etched wafer can be completed in a reaction chamber, thereby improving the processing efficiency of the etched wafer.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor manufacturing equipment and semiconductor manufacturing methods, and in particular to an etching device and an etching method. Background Art

[0002] Atomic layer etching (ALE) is an important nano-level etching technology that can accurately etch an atomic layer and stop etching at the appropriate position to obtain a very high etching selectivity. Existing atomic layer etching devices use two types of process schemes: First, the wafer is placed in a low-temperature chamber for reaction to form volatile substances on the surface of the wafer; then the wafer is transferred to another high-temperature chamber to heat the wafer, so that the volatile substances evaporate to complete the etching. This scheme requires the wafer to be transferred back and forth between the two chambers, and the production capacity is low. Second, the wafer is placed on a cooling plate to react to form volatile substances; the surface of the cooling plate is provided with a liftable ejector pin, which lifts the wafer close to the heat source for baking to volatilize the volatile substances. This scheme changes the temperature of the wafer by lifting the ejector pin, which is inefficient; the lifting of the ejector pin will also cause the wafer to shake, affecting the stability of the wafer during the manufacturing process; in addition, after volatilization, byproduct particles will be formed on the cooling plate, affecting the surface performance of the wafer. The above two solutions both need to change the wafer temperature by mechanical transmission, and the temperature change efficiency is low. Therefore, in view of the above problems, an etching device and an etching method are urgently needed. Summary of the invention

[0003] In order to solve the problem of low processing efficiency and low production capacity in the existing atomic layer etching process, the position of the etched wafer is changed by mechanical transmission so that it is processed under different temperature conditions. This application provides the following technical solutions:

[0004] In a first aspect, an etching device is provided, comprising: an electrostatic chuck, at least one heater;

[0005] The electrostatic chuck has: an adsorption surface;

[0006] At least one vent hole is provided in the adsorption surface, and the vent hole is used to conduct the first gas to one side of the adsorption surface at least;

[0007] At least one heater is arranged on one side of the adsorption surface at a preset distance from the plane where the adsorption surface is located.

[0008] Furthermore, the electrostatic chuck also has a cooling pipe, which is arranged inside the electrostatic chuck, and the cooling end of the cooling pipe is connected to an external cooling source.

[0009] Furthermore, the adsorption surface is provided with protrusions, which form a closed pattern on the adsorption surface, so as to form a closed gap between the wafer surface and the electrostatic chuck when the electrostatic chuck adsorbs the wafer.

[0010] Further, at least one heater is circumferentially arranged on the heating plane;

[0011] The distance between the heating plane and the plane where the adsorption surface is located is a preset distance;

[0012] A line connecting the circumferential center of at least one heater and the center of the electrostatic chuck is perpendicular to the heating plane.

[0013] Furthermore, the etching device also includes a reaction chamber;

[0014] The electrostatic chuck and at least one heater are arranged in the reaction chamber.

[0015] Furthermore, an air inlet valve is arranged at the upper part of the reaction chamber, and an air exhaust valve is arranged at the lower part of the reaction chamber.

[0016] The gas inlet valve is used to deliver the second gas or the third gas into the reaction chamber;

[0017] The exhaust valve is used to exhaust the gas in the reaction chamber.

[0018] Further, a ventilation baffle is provided on the upper part of at least one heater, and a baffle plane of the ventilation baffle is parallel to the adsorption surface;

[0019] In the ventilation baffle, at least one through hole is arranged perpendicular to the plane of the baffle, and the through hole is used to adjust the pressure generated by the second gas or the third gas on the adsorption surface.

[0020] Furthermore, the etching device also includes a gas exchange valve;

[0021] The air exchange valve is connected to the air intake valve and is used for switching the second gas or the third gas.

[0022] In a second aspect, an etching method is provided, which is applied to the etching device described in the first aspect, comprising:

[0023] In response to the etched wafer not reaching a preset etching depth, executing:

[0024] Adsorbing the etched wafer, and introducing a first gas through the vent hole to reduce the temperature of the etched wafer;

[0025] A second gas is introduced through the gas inlet valve, so that the etched surface of the etched wafer reacts with the second gas in the reaction chamber;

[0026] Extracting air from the vent hole to form a vacuum between the etched wafer and the electrostatic chuck, and turning on at least one heater to heat the etched wafer;

[0027] A third gas is introduced through the gas inlet valve to purge reactants generated on the etched surface.

[0028] Furthermore, the first gas is helium.

[0029] The beneficial effects of the technical solution provided by the embodiment of the present application are:

[0030] By implementing the etching equipment and etching method disclosed in the embodiments of the present application, the etched wafer is adsorbed by an electrostatic chuck, and the reaction gas, purge gas, and heater are used to complete atomic layer etching of the etched wafer in a reaction chamber. When the wafer position is fixed, the wafer is heated and cooled, the etching reaction is carried out, and the by-products are purged and pumped, thereby improving the processing efficiency of the etched wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 is a schematic diagram of an etching device provided in an embodiment of the present application;

[0033] Figure 2 is a top view of an electrostatic chuck provided in an embodiment of the present application;

[0034] Figure 3 is a cross-sectional view of an electrostatic chuck provided in an embodiment of the present application;

[0035] Figure 4 is a top view of the adsorption surface provided in an embodiment of the present application;

[0036] Figure 5 is a top view of an adsorption surface with convex points provided in an embodiment of the present application;

[0037] Figure 6 It is a schematic diagram of an etching method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in the implementation mode of this application will be clearly and completely described below in conjunction with the drawings in the implementation mode of this application. Obviously, the described implementation mode is only a part of the embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantity limitation, but indicate that there is at least one. The numbers in the drawings of the specification only indicate the distinction between various functional components or modules, and do not indicate the logical relationship between components or modules. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0040] Hereinafter, various embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the accompanying drawings, the same reference numerals are given to components having substantially the same or similar structures and functions, and repeated descriptions thereof will be omitted.

[0041] In the existing atomic layer etching process, the position of the etched wafer is changed by mechanical transmission, thereby changing the temperature environment of the etched wafer, and the process flow of the corresponding process has the problem of low processing efficiency. The present application provides the following embodiments:

[0042] In some embodiments, Figure 1 As shown, an etching device includes: an electrostatic chuck 100, at least one heater 200;

[0043] The electrostatic chuck 100 has a suction surface 101 .

[0044] At least one vent hole 110 is disposed within the adsorption surface 101 , and the vent hole 110 is at least used to conduct the first gas to one side of the adsorption surface 101 .

[0045] At least one heater 200 is disposed on one side of the adsorption surface 101 at a preset distance H from the plane where the adsorption surface 101 is located.

[0046] The electrostatic chuck is used to flatly adsorb the etched wafer onto the adsorption surface, thereby improving the quality and stability of the processed wafer processing.

[0047] The heater is a non-contact heater, which can heat an object placed on the adsorption surface at a preset distance from the plane where the adsorption surface is located.

[0048] Preferably, the heater is an infrared lamp.

[0049] By setting the radiation direction of the infrared lamp, the etched wafer adsorbed on the adsorption surface 101 can be uniformly heated.

[0050] The vent hole 110 is at least used to deliver a first gas to the back side of the etched wafer. The function of the first gas is to uniformly and quickly reduce the temperature of the etched wafer.

[0051] Preferably, the vent hole 110 is also connected to the first end of the three-way pipe fitting (not shown in the figure); the second end of the three-way pipe fitting is the air inlet end of the first gas; and the third end of the three-way pipe fitting is the air outlet end of the first gas.

[0052] Preferably, the first gas delivered to the back of the etched wafer is helium. Helium exhibits excellent thermal conductivity under high pressure. At room temperature, its thermal conductivity can reach 156.7mW / (m·K). Since high-pressure helium has a very high thermal conductivity, in the use scenario of the etching equipment disclosed in the embodiment of the present application, high-pressure helium can quickly and evenly reduce the temperature of the etched wafer to avoid local hot spots. In addition, as an inert gas, helium does not react chemically with other substances. It does not cause chemical reactions of the etched wafer material or other materials in the process, avoiding possible contamination and reaction by-products. Helium also has a small molecular diameter, which enables it to easily pass through tiny channels and gaps, helping helium to be evenly distributed in the tiny space between the etched wafer and the suction cup, ensuring the cooling effect of the entire etched wafer. Helium has low viscosity and can pass through a tiny space at a higher flow rate, further improving the efficiency of heat conduction. Low viscosity also reduces the resistance to gas flow, provides stable temperature control, and makes the cooling system run more efficiently.

[0053] Preferably, the electrostatic chuck 100 further has a cooling pipe 120, such as Figure 2 , 3 The cooling pipe 120 is disposed inside the electrostatic chuck 100 , and a cooling end 121 of the cooling pipe 120 is connected to an external cooling source 900 .

[0054] The cooling material is recovered at the circulation end 122 of the cooling pipe and can be injected into the cooling pipe 120 after cooling.

[0055] The cooling pipe 120 is a pipe for carrying a cooling substance, and the temperature of the etched wafer adsorbed by the electrostatic chuck can be reduced through the cooling pipe 120. The cooling substance can be a cooling gas or a cooling liquid.

[0056] Accordingly, the cooling source may provide a gas for cooling or a liquid for cooling.

[0057] Preferably, the cooling pipe is a water-cooling pipe; the cooling source provides cold water.

[0058] Preferably, the temperature of the cold water provided by the cooling source is 25°C.

[0059] The adsorption surface 101 is provided with a protrusion 130, and the protrusion 130 forms a closed pattern on the adsorption surface, which is used to form a closed gap between the wafer surface and the electrostatic chuck when the electrostatic chuck 100 adsorbs the etched wafer.

[0060] Preferably, the protrusion 130 is strip-shaped and made of an elastic material. When the electrostatic chuck 100 is used to adsorb the etched wafer, a closed gap can be formed between the adsorption surface, the back of the etched wafer, and the protrusion 130. The use of an elastic material can ensure that the closed gap formed when the etched wafer is adsorbed by the electrostatic chuck has good airtightness.

[0061] Optionally, the closed shape enclosed by the protrusions 130 may be a rectangle, a rounded rectangle, an ellipse, or the like.

[0062] Preferably, the closed figure formed by the raised portion 130 is a circle, such as Figure 4 As shown. The center of the circular protrusion coincides with the center of the position where the etched wafer is adsorbed by the electrostatic chuck. The diameter of the circular protrusion is smaller than the diameter of the etched wafer. However, there should not be too much difference between the diameter of the wafer area, so that when the closed gap is used for the process related to heat conduction, the temperature of the entire wafer can be evenly adjusted to avoid local temperature differences in the wafer. Corresponding to wafers of different sizes, the diameter of the circle enclosed by the protrusion 130 can be adjusted accordingly. Schematically, for an 8-inch wafer, the diameter of the enclosed circle can be 7 inches; for a 12-inch wafer, the diameter of the enclosed circle can be 11 inches.

[0063] Preferably, the adsorption surface 101 within the closed shape surrounded by the raised portion 130 is further provided with a convex point 131 .

[0064] Preferably, the protrusions 131 are evenly distributed in the adsorption surface area surrounded by the protrusions, such as Figure 5 It should be noted that Figure 5 It is only used to illustrate that the protrusions 131 are uniformly distributed, and is not used to limit the actual distribution positions of the protrusions 131.

[0065] Preferably, the material used to make the bumps 131 is the same elastic material as the material used to make the raised portion 130. The elastic material has heat-insulating properties. Schematically, the elastic material can be silicone, EPDM rubber, etc. The raised height of the bumps 131 relative to the adsorption surface 101 is the same as the raised height of the raised portion 130 relative to the adsorption surface 101. The evenly distributed bumps 131 can provide additional support to the central part of the etched wafer to prevent the wafer from warping due to stress, which affects the accuracy of etching or other process links.

[0066] When the electrostatic chuck is used to absorb the etched wafer, helium is injected into the closed gap through the vent hole 110, so that high-pressure helium can be formed in the space of the closed gap. The high thermal conductivity of high-pressure helium can be used to quickly reduce the temperature of the wafer. When the electrostatic chuck absorbs the etched wafer, the closed gap is evacuated through the vent hole 110, so that a near-vacuum environment can be formed in the closed gap. When the heater 200 is used to heat the etched wafer, the heat transfer between the etched wafer and the electrostatic chuck 100 is isolated, so that the temperature of the etched wafer rises rapidly.

[0067] Preferably, if Figure 1 As shown, at least one heater 200 is circumferentially arranged on the heating plane, and the distance between the heating plane and the plane where the adsorption surface is located is a preset distance H.

[0068] The at least one heater 200 is arranged circumferentially, that is, the at least one heater 200 is arranged at at least one point on a circumference. The center of the circumference is the center of the circumference.

[0069] A line connecting the circumferential center of at least one heater 200 and the center of the electrostatic chuck is perpendicular to the heating plane.

[0070] The heater 200 circumferentially arranged in a heating plane can uniformly heat the etched wafer, so that the volatile reactants generated on the surface of the etched wafer are uniformly volatilized and separated from the surface of the etched wafer.

[0071] The etching equipment further includes a reaction chamber 300 .

[0072] The electrostatic chuck 100 and at least one heater 200 are disposed in the reaction chamber 300 .

[0073] Optionally, at least one heater 200 is arranged along the inner wall circumference of the reaction chamber 300. The heat radiation direction of the at least one heater 200 is evenly distributed toward the adsorption surface of the electrostatic chuck 100. When the etched wafer is adsorbed by the electrostatic chuck 100, the at least one heater 200 arranged in this way can evenly heat the etched wafer.

[0074] Preferably, an air inlet valve 400 is provided at the upper portion of the reaction chamber, and an air exhaust valve 500 is provided at the lower portion of the reaction chamber.

[0075] Preferably, the exhaust valve 500 is disposed below a horizontal position below the surface of the electrostatic chuck 100 .

[0076] The gas inlet valve 400 is used to deliver the second gas or the third gas into the reaction chamber 300 .

[0077] The exhaust valve 500 is used to exhaust the gas in the reaction chamber.

[0078] Preferably, a ventilation baffle 600 is disposed on the top of at least one heater 200 , and a baffle plane of the ventilation baffle 600 is parallel to the adsorption surface 101 .

[0079] In the ventilation baffle 600 , at least one through hole 610 is arranged perpendicular to the plane of the baffle, and the through hole 610 is used to adjust the pressure generated by the second gas or the third gas on the adsorption surface 101 .

[0080] The second gas refers to a reaction gas, which can react with the surface atomic layer of the etched wafer to generate a volatile ammonium salt.

[0081] The reaction gas is NF 3 With NH 3 Gas with 20% as the main component. According to the reaction:

[0082] ,

[0083] Chemical reactions occur in the plasma environment to produce NH 4 F and the by-product NH 4 F·HF. The reaction product serves as a reactant in the subsequent etching process.

[0084] During the etching process, at a temperature of 20-30°C, the reactant NH 4 F (or NH 4 F·HF) reacts with the native oxide on the substrate (the native oxide here refers to silicon dioxide) to generate fluoride containing silicon and other by-products.

[0085] The reaction equation is:

[0086] ,

[0087] or:

[0088] .

[0089] The third gas refers to a purge gas, which removes the volatile ammonium salt generated on the surface of the etched wafer to the surface of the etched wafer so as to etch the next atomic layer.

[0090] At higher temperatures, usually above 100°C, the solid byproduct (NH 4 ) 2 SiF 6 The gas phase byproducts are pumped out of the reaction chamber by:

[0091] .

[0092] By purging gas, solid waste generated during the etching process is removed to ensure the cleanliness of the etching chamber and maintain the effectiveness of the etching process.

[0093] The whole process is a cyclic process, which precisely controls the depth of material etching to achieve the desired structure. The above equation is the main chemical reaction equation of the etching process. The actual chemical reaction will be more complicated and contain intermediates or by-products, which are not limited in this application.

[0094] During the etching process, the second gas is introduced from the upper part of the reaction chamber 300 through the gas inlet valve 400. The pressure of the second gas is adjusted through the through hole 610 to optimize the gas pressure on the surface of the etched wafer to achieve a higher reaction efficiency.

[0095] Similarly, the third gas is also introduced from the upper part of the reaction chamber 300 through the gas inlet valve 400. The pressure of the third gas is adjusted through the through hole 610 to optimize the purging effect of the volatile substances on the surface of the etched wafer.

[0096] Furthermore, the etching device also includes a gas exchange valve (not shown in the figure).

[0097] The ventilation valve is connected to the air intake valve 400 and is used to switch between the second gas and the third gas.

[0098] Optionally, the air exchange valve is a triangular valve. The three ends of the triangular valve are connected to the air intake valve 400, the second gas source, and the third gas source respectively. By switching the position of the valve, the air intake valve is switched between a closed state, a state in which the second gas is introduced, or a state in which the third gas is introduced.

[0099] In some other embodiments, an etching method, such as Figure 6 As shown, the etching equipment used in the above-mentioned text includes:

[0100] In response to the etched wafer not reaching a preset etching depth, executing:

[0101] S100: adsorbing the etched wafer and introducing a first gas through the vent hole 110 to reduce the temperature of the etched wafer;

[0102] S200: introducing a second gas through the gas inlet valve 400, so that the etched surface of the etched wafer reacts with the second gas in the reaction chamber;

[0103] S300: exhausting air from the vent hole 110 to form a vacuum between the etched wafer and the electrostatic chuck, and turning on at least one heater 200 to heat the etched wafer;

[0104] S400: A third gas is introduced through the gas inlet valve 400 to purge reactants generated on the etched surface.

[0105] The preset etching depth refers to a preset target depth, which indicates the depth requirement of etching from the surface of the etched wafer to the vertical direction of the wafer. The preset etching depth is obtained by presetting.

[0106] The etched wafer is in contact with the electrostatic chuck 100 through the protrusion 130, or the protrusion 130 and the bump 131, and there is a tiny gap between the etched wafer and the electrostatic chuck. When the vent 110 is used to evacuate the adsorption surface, the back of the etched wafer and the closed gap formed by the protrusion, the heat conduction between the etched wafer and the electrostatic chuck is suppressed. At this time, at least one heater is turned on to quickly heat the etched wafer, usually to more than 100°C. Since the vacuum environment formed in the gap isolates heat conduction, it is beneficial for the temperature of the etched wafer to rise quickly and evenly, and it is beneficial for the volatilization of volatile reactants.

[0107] At higher temperatures, usually above 100°C, the solid byproduct (NH 4 ) 2 SiF 6 will transform into the gas phase:

[0108] .

[0109] Before the reaction starts, the surface of the wafer is purged to clean the surface of the etched wafer.

[0110] During the reaction process, blowing the surface of the wafer can remove the reactants generated on the surface of the wafer and allow the etching process to continue.

[0111] After purging the reactants generated on the etched surface, it also includes:

[0112] Since the byproducts generated by the reaction are converted into gas phase in a high temperature environment, when the reaction chamber is exhausted through the exhaust valve 500, the gas phase byproducts generated by the reaction can be simultaneously exhausted from the reaction chamber to facilitate subsequent etching reactions.

[0113] Preferably, the first gas is helium. Helium has good thermal conductivity under high pressure and can evenly and quickly reduce the temperature of the etched wafer. When the electrostatic chuck adsorbs the wafer, high-pressure helium is introduced to the back of the wafer. Since high-pressure helium has good thermal conductivity, the temperature of the wafer can be rapidly reduced. In conjunction with the cooling pipe, the temperature of the etched wafer can be stabilized at the temperature condition where the surface atoms react with the reaction gas. Here, the temperature range for the reaction between the reactant and the wafer surface is 20~30°C. By introducing high-pressure helium to the back of the wafer, the temperature of the wafer can be quickly reduced from the temperature environment of high-temperature volatilization to the temperature environment of the etching reaction. That is, the temperature environment above 100°C is reduced to a temperature environment of 20~30°C.

[0114] The second gas refers to the reaction gas. Under the reaction temperature conditions, the reaction gas reacts with the surface atoms of the etched wafer to generate volatile reactants.

[0115] During the etching process, at a temperature of 20-30°C, the reactant NH 4 F (or NH 4 F·HF) reacts with the native oxide on the substrate (the native oxide here refers to silicon dioxide) to generate fluoride containing silicon and other by-products.

[0116] The reaction equation is:

[0117] ,

[0118] or:

[0119] .

[0120] After purging the reactants generated on the etched surface, it also includes:

[0121] S500: The gas in the reaction chamber and the purged reactant particles are exhausted through the exhaust valve 500.

[0122] Repeat the above steps until the etched wafer is etched to the preset etching depth. The temperature of the etched wafer can be quickly reduced by high-pressure helium, and the temperature of the etched wafer can be quickly increased by heating the etched wafer in an insulating environment by a heater. Rapid heating and cooling within a limited time can improve etching efficiency.

[0123] It should be understood that although Figure 6 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 6At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0124] By implementing the etching equipment and etching method disclosed in the embodiments of the present application, an electrostatic chuck is used to adsorb the etched wafer, and in combination with the reaction gas, the purge gas, and the heater, atomic layer etching of the etched wafer can be completed in a reaction chamber. When the wafer position is fixed, the wafer is heated and cooled, the etching reaction is carried out, and the purge pumping of the by-products is completed, thereby improving the processing efficiency of the etched wafer; the electrostatic chuck is used to fix the etched wafer, so that the position of the etched wafer can be stabilized during the atomic layer etching process, which is conducive to precise processing; the high-pressure helium gas introduced between the electrostatic chuck and the etched wafer is combined with water cooling to uniformly cool the etched wafer, so that the reaction gas can uniformly and fully react at the atomic layer on the surface of the etched wafer to generate volatile substances; the circumferentially distributed heater can uniformly increase the wafer temperature, so that the volatile substances on the etched surface can be uniformly and completely volatilized; by timely exhausting the reaction gas and the by-products of the gas phase reaction, the cleanliness of the process environment is guaranteed and the etching quality is improved.

[0125] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0126] Embodiment 1

[0127] An etching device, such as Figure 1 As shown, it includes: an electrostatic chuck 100 and at least one heater 200 ; the electrostatic chuck has: an adsorption surface 101 .

[0128] At least one vent hole 110 is disposed within the adsorption surface 101 , and the vent hole 110 is at least used to conduct the first gas to one side of the adsorption surface 101 .

[0129] At least one heater 200 is disposed on one side of the adsorption surface 101 at a preset distance from the plane where the adsorption surface 101 is located.

[0130] Embodiment 2

[0131] On the basis of the first embodiment, the electrostatic chuck 100 further has a cooling pipe 120 inside. The cooling pipe 120 is arranged inside the electrostatic chuck 100 , and a cooling end 121 of the cooling pipe 120 is connected to an external cooling source 900 .

[0132] The adsorption surface 101 is provided with a closed protrusion 130, which is used to form a closed gap between the wafer surface and the electrostatic chuck when the electrostatic chuck 100 adsorbs the wafer.

[0133] At least one heater 200 is circumferentially disposed on the heating plane.

[0134] The distance between the heating plane and the plane where the adsorption surface is located is a preset distance.

[0135] The line connecting the center of the circle where at least one heater 200 is located and the center of the electrostatic chuck is perpendicular to the heating plane.

[0136] The etching equipment further includes a reaction chamber 300 .

[0137] The electrostatic chuck 100 and at least one heater 200 are disposed in the reaction chamber 300 .

[0138] An air inlet valve 400 is disposed at the upper portion of the reaction chamber, and an air exhaust valve 500 is disposed at the lower portion of the reaction chamber.

[0139] The gas inlet valve 400 is used to deliver the second gas or the third gas into the reaction chamber 300 .

[0140] The exhaust valve 500 is used to exhaust the gas in the reaction chamber.

[0141] A ventilation baffle 600 is disposed on the top of at least one heater 200, and the baffle plane of the ventilation baffle 600 is parallel to the adsorption surface 101. In the ventilation baffle 600, at least one through hole 610 is disposed perpendicular to the baffle plane, and the through hole 610 is used to adjust the pressure generated by the second gas or the third gas on the adsorption surface 101.

[0142] The etching device also includes a gas exchange valve.

[0143] The ventilation valve is connected to the air intake valve 400 and is used to switch between the second gas and the third gas.

[0144] The contents described in Example 1 will not be repeated here.

[0145] Embodiment 3

[0146] An etching method is suitable for performing atomic layer etching on a wafer using the etching equipment described in the first or second embodiment. Figure 6 As shown, including:

[0147] In response to the etched wafer not reaching a preset etching depth, executing:

[0148] S100: adsorbing the etched wafer and introducing a first gas through the vent hole 110 to reduce the temperature of the etched wafer;

[0149] S200: introducing a second gas through the gas inlet valve 400, so that the etched surface of the etched wafer reacts with the second gas in the reaction chamber;

[0150] S300: exhausting air from the vent hole 110 to form a vacuum between the etched wafer and the electrostatic chuck, and turning on at least one heater 200 to heat the etched wafer;

[0151] S400: A third gas is introduced through the gas inlet valve 400 to purge reactants generated on the etched surface.

[0152] The contents described in Example 1 or Example 2 are not repeated here.

[0153] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An etching device, characterized in that: include: an electrostatic chuck, at least one heater; The electrostatic chuck has: an adsorption surface; At least one vent hole is provided in the adsorption surface, and the vent hole is at least used to conduct the first gas to one side of the adsorption surface; The at least one heater is disposed on one side of the adsorption surface at a preset distance from the plane where the adsorption surface is located; The adsorption surface is provided with raised portions and convex points, the raised portions form a closed figure on the adsorption surface, and the convex points are arranged within the range of the closed figure formed by the raised portions; wherein the raised portions are made of elastic material, so that when the etched wafer is adsorbed by the electrostatic suction cup, the closed gap formed has good air tightness, and when the closed gap formed by the adsorption surface, the back of the etched wafer and the raised portions is evacuated using the vent hole, heat conduction between the etched wafer and the electrostatic suction cup is suppressed.

2. The etching device according to claim 1, characterized in that: The electrostatic chuck also has a cooling pipeline, which is arranged inside the electrostatic chuck, and the cooling end of the cooling pipeline is connected to an external cooling source.

3. The etching device according to claim 1, characterized in that: The at least one heater is circumferentially disposed on the heating plane; The distance between the heating plane and the plane where the adsorption surface is located is a preset distance; A line connecting the circumferential center of the at least one heater and the center of the electrostatic chuck is perpendicular to the heating plane.

4. The etching device according to claim 1, characterized in that: The etching equipment also includes a reaction chamber; The electrostatic chuck and the at least one heater are disposed in the reaction chamber.

5. The etching device according to claim 4, characterized in that: An air inlet valve is arranged at the upper part of the reaction chamber; An exhaust valve is provided at the lower part of the reaction chamber; The gas inlet valve is used to deliver the second gas or the third gas into the reaction chamber; The exhaust valve is used to exhaust the gas in the reaction chamber.

6. The etching device according to claim 4, characterized in that: A ventilation baffle is disposed on the upper portion of the at least one heater, and a baffle plane of the ventilation baffle is parallel to the adsorption surface; In the ventilation baffle, at least one through hole is arranged perpendicular to the plane of the baffle, and the through hole is used to adjust the pressure generated by the second gas or the third gas on the adsorption surface.

7. The etching device according to claim 4, characterized in that: The etching equipment also includes a gas exchange valve; The air exchange valve is connected to the air intake valve and is used for switching the second gas or the third gas.

8. An etching method, characterized in that: The etching device according to any one of claims 1 to 7, further comprising: an air inlet valve and a reaction chamber, including: In response to the etched wafer not reaching a preset etching depth, executing: A first gas is introduced through the vent hole to reduce the temperature of the etched wafer; A second gas is introduced through the gas inlet valve, so that the etched surface of the etched wafer reacts with the second gas in the reaction chamber; Extracting air from the vent hole to form a vacuum between the etched wafer and the electrostatic chuck, and turning on at least one heater to heat the etched wafer; A third gas is introduced through the gas inlet valve to purge reactants generated on the etched surface; Wherein, the second gas is a reaction gas, which is used to react with the atomic layer on the surface of the etched wafer to generate a volatile ammonium salt, and the reaction gas is a gas with NF3 and NH3 as main components; according to: NF3 + NH3 → NH4F + NH4F·HF, Generates reactants in the etching process; according to: NH4F + SiO2 → (NH4)2SiF6, or NH4F·HF + SiO2 → (NH4)2SiF6, This produces volatile ammonium salt.

9. The etching method according to claim 8, characterized in that: The first gas is helium.

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