Film etching method of wafer

Abstract

A thin film etching method of a wafer comprises the following steps: providing a substrate; forming a first dielectric layer on the substrate; carrying out modification treatment on the first dielectric layer so as to form a modified group on the first dielectric layer; carrying out protonation reaction on the basis of the modified group; and etching the first dielectric layer after the protonation reaction. According to the embodiment of the invention, the production efficiency of manufacturing the semiconductor device is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular to a wafer thin film etching method. Background Art

[0002] At present, Metal Oxide Semiconductor (MOS) field-effect transistors have been widely used in the semiconductor field; especially in smart cards, Radio Frequency Identification (RFID) devices, new mobile phones and other small, lightweight and powerful electronic devices, which has put forward higher requirements for the production of semiconductor devices.

[0003] However, in the actual process of manufacturing, there is a problem of low production efficiency. Therefore, how to provide a technical solution to improve production efficiency has become a technical problem that those skilled in the art need to solve urgently. Summary of the Invention

[0004] The technical problem solved by the present invention is to improve production efficiency by etching the thin film by providing a wafer thin film etching method.

[0005] To solve the above problems, an embodiment of the present invention provides a thin film etching method for a wafer, comprising: providing a substrate; forming a first dielectric layer located on the substrate; performing a modification treatment on the first dielectric layer to form modified groups on the first dielectric layer; performing a protonation reaction based on the modified groups; and etching the first dielectric layer after the protonation reaction.

[0006] Optionally, the modifying group is an amino group;

[0007] The protonation reaction occurs based on the modified group, including: a protonation reaction occurs based on hydrogen ions and the amino group, so that the surface of the modified first dielectric layer has a positive charge.

[0008] Optionally, the gas forming the amino group includes nitrogen and hydrogen.

[0009] Optionally, the step of modifying the first dielectric layer includes:

[0010] The nitrogen gas and the hydrogen gas are plasma-treated to form a plasma gas.

[0011] Optionally, after forming the first dielectric layer on the substrate and before performing the modification treatment on the first dielectric layer, the thin film etching method further includes:

[0012] forming a second dielectric layer on the first dielectric layer;

[0013] patterning the second dielectric layer to expose the first dielectric layer to be modified;

[0014] The plasma gas is used to perform a modification treatment on the first dielectric layer that is exposed and needs to be modified.

[0015] Optionally, the material of the second dielectric layer includes: one or more of: photoresist, silicon nitride, silicon carbide, and silicon carbonitride.

[0016] Optionally, the modifying group includes one or more of an amino group, a carboxyl group, a thiol group, and an alkyl group.

[0017] Optionally, the material of the first dielectric layer includes one or more of silicon oxide, silicon oxycarbide, and silicon oxynitride.

[0018] Optionally, the parameters for modifying the first dielectric layer include: the nitrogen flow rate is 50 sccm to 80 sccm, the hydrogen flow rate is 50 sccm to 80 sccm, the chamber pressure is 1.0 mtorr to 10 mtorr, the temperature is 60°C to 300°C, and the processing time is 70 seconds to 100 seconds.

[0019] Optionally, the etching gas used for etching the first dielectric layer after the protonation reaction includes one or more of the following combinations: tetracarbon octafluoride C4F8, pentacarbon octafluoride C5F8, and tetracarbon hexafluoride C4F6.

[0020] Optionally, the step of etching the first dielectric layer after the protonation reaction includes:

[0021] Based on the positive charge on the surface of the modified first dielectric layer, fluorine ions in the etching gas are attracted to react with the first dielectric layer.

[0022] Compared with the prior art, the technical solution of the embodiment of the present application has the following advantages:

[0023] The thin film etching method for a wafer described in the present application includes: forming a first dielectric layer located on the substrate; modifying the first dielectric layer to form modified groups on the first dielectric layer, causing the modified groups to undergo a protonation reaction, and forming positive charges on the surface of the modified first dielectric layer. The positive charges promote the etching of the first dielectric layer, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0025] Figures 1 to 5 1 is a schematic structural diagram corresponding to each step in a thin film etching method for a wafer according to an embodiment of the present invention;

[0026] Figure 6 It is a schematic structural diagram corresponding to each step in a thin film etching method for a wafer according to another embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] As can be seen from the background technology, in the actual process of manufacturing, there is a problem of low production efficiency. The reasons for the reduced production efficiency are analyzed below.

[0029] With the increasing demand for miniaturized semiconductor devices, multiple dielectric layers, including silicon oxide, are typically designed to ensure device performance. During semiconductor device manufacturing, these dielectric layers are etched. However, as the number of dielectric layers increases, simply adjusting the etching tool to optimal process parameters, such as gas ratio, pressure, and temperature, is no longer sufficient to meet the etching requirements, resulting in reduced production efficiency.

[0030] In order to solve the above technical problems, an embodiment of the present invention provides a thin film etching method for a wafer. The thin film etching method for a wafer can increase the thin film etching rate, thereby improving production efficiency.

[0031] refer to Figures 1 to 5 , which is a structural schematic diagram corresponding to each step in the thin film etching method for a wafer according to an embodiment of the present invention.

[0032] The thin film etching method includes: providing a substrate; forming a first dielectric layer on the substrate; performing a modification treatment on the first dielectric layer to form modified groups on the first dielectric layer; performing a protonation reaction based on the modified groups; and etching the first dielectric layer after the protonation reaction.

[0033] The thin film etching method for a wafer described in the present application includes: forming a first dielectric layer located on the substrate; modifying the first dielectric layer to form modified groups on the first dielectric layer, causing the modified groups to undergo a protonation reaction, and forming positive charges on the surface of the modified first dielectric layer. The positive charges promote the etching of the first dielectric layer, thereby improving production efficiency.

[0034] refer to Figure 1 , providing a substrate 100.

[0035] In this embodiment, the substrate 100 is used to provide a process platform for forming a semiconductor structure. The substrate 100 is a silicon substrate 100, and the material of the substrate 100 is single crystal silicon. In other embodiments, the material of the substrate 100 can also be one or more of germanium, silicon germanium, silicon carbide, gallium nitride, gallium arsenide, and indium gallium. The substrate 100 can also be a silicon-on-insulator substrate 100 or a germanium-on-insulator substrate 100, or other types of substrates 100. In other embodiments, an epitaxial layer (not shown) having the same crystal structure as the substrate 100 is formed on the surface of the substrate 100 to improve the quality of pattern transfer.

[0036] Continue to refer Figure 1 , forming a first dielectric layer 101 on the substrate 100;

[0037] The first dielectric layer 101 has the following functions: First, as an isolation layer, the first dielectric layer 101 is used to electrically isolate adjacent semiconductor devices, preventing electrical interference between different regions and ensuring stable operation of the devices; Second, the first dielectric layer 101 is used to isolate adjacent semiconductor film layers, reducing the coupling capacitance between adjacent film layers; Third, it regulates the performance of the semiconductor device: the thickness of the first dielectric layer 101 is used to adjust the electric field between the gate and the semiconductor channel layer to adjust the semiconductor channel current; Fourth, it is used to store charge: the first dielectric layer 101 acts as a dielectric layer of a capacitor to store charge; Fifth, it acts as a stress buffer: the first dielectric layer 101 is used to relieve stress caused by the different thermal expansion coefficients of different materials, preventing performance degradation of semiconductor devices due to long-term operation. Sixth, it has a protective function: the first dielectric layer 101 can also serve as a protective layer to prevent the surface of the semiconductor device from being contaminated or physically damaged, thereby extending the service life of the device.

[0038] The material of the first dielectric layer 101 includes one or more of silicon oxide, silicon oxycarbide, silicon oxynitride, and silicon nitride. In this embodiment, the material of the first dielectric layer 101 is silicon oxide.

[0039] The process for forming the first dielectric layer 101 on the substrate 100 includes one or more of an atomic layer deposition process, a chemical vapor deposition process, a physical vapor deposition process, and a combination of a plasma process and a chemical vapor deposition process. In this embodiment, the material layer of the first dielectric layer 101 is formed on the substrate 100 by a combination of a plasma process and a chemical vapor deposition process.

[0040] In this embodiment, the step of forming the first dielectric layer 101 using silicon oxide mainly includes:

[0041] placing the substrate 100 on an anti-static chuck in a deposition chamber;

[0042] A reaction gas, such as silicon tetrachloride, silane and oxygen, is introduced into the deposition chamber; a radio frequency source is turned on and low radio frequency power is used to heat the reaction gas; high radio frequency power is used to ionize the reaction gas to form plasma, and the silicon oxide film layer is formed on the substrate 100 by chemical vapor deposition.

[0043] refer to Figure 2 After forming the first dielectric layer 101 on the substrate 100 and before performing a modification treatment on the first dielectric layer 101, the thin film etching method further includes:

[0044] A second dielectric layer 102 is formed on the first dielectric layer 101 .

[0045] The material of the second dielectric layer 102 includes: one or more of photoresist, silicon nitride, silicon carbide, and silicon carbonitride. In this embodiment, the material of the second dielectric layer 102 is photoresist.

[0046] The types of photoresists include positive photoresists and negative photoresists.

[0047] The positive photoresist includes one or more of deep ultraviolet photoresist, extreme ultraviolet photoresist, electron beam photoresist, thermal curing photoresist, and water-soluble photoresist. The negative photoresist includes one or more of deep ultraviolet photoresist, extreme ultraviolet photoresist, electron beam photoresist, thermal curing photoresist, and water-soluble photoresist. In this embodiment, the photoresist is a thermally cured positive photoresist.

[0048] The photoresist is coated on the surface of the first dielectric layer 101 through a coating process.

[0049] It should be noted that the photoresist coating process includes spin coating, spray coating, and immersion coating. Spin coating can adjust the thickness of the photoresist and has advantages such as high coating efficiency and uniform photoresist thickness. In this embodiment, the photoresist is coated on the surface of the first dielectric layer 101 using a spin coating process.

[0050] Continue to refer Figure 2 , patterning the second dielectric layer 102 to expose the first dielectric layer 101 to be modified.

[0051] In this embodiment, the photoresist is patterned by processes such as exposure, development, and baking to expose the first dielectric layer 101 to be modified, that is, to expose the silicon oxide to be modified.

[0052] In other embodiments, the second dielectric layer 102 is made of silicon nitride. The second dielectric layer 102 is patterned to expose the first dielectric layer 101 to be modified, that is, the silicon nitride is exposed, developed, etched, and other processes to expose the first dielectric layer 101 to be modified.

[0053] refer to Figure 3 , performing a modification treatment on the first dielectric layer 101 to form a modified group 103 on the first dielectric layer 101 .

[0054] By modifying the first dielectric layer 101 , the etching rate of the first dielectric layer 101 in the etching process can be increased, thereby improving production efficiency.

[0055] The modifying group 103 includes one or more of an amino group, a carboxyl group, a thiol group, and an alkyl group. In this embodiment, the modifying group 103 is an amino group (-NH2). Compared to other modifying groups, the amino group has a stronger ability to regulate the surface charge of the first dielectric layer 101, thereby increasing the etching rate of the first dielectric layer 101 during the etching process, thereby improving production efficiency.

[0056] In this embodiment, the gas forming the amino group includes nitrogen and hydrogen.

[0057] The step of modifying the first dielectric layer 101 includes: plasma-treating the nitrogen and hydrogen to form plasma gas, and modifying the exposed first dielectric layer to be modified using the plasma gas.

[0058] In this embodiment, the nitrogen and hydrogen are treated by plasma treatment to form ammonia (NH 3 ) plasma gas.

[0059] The use of plasma gas ammonia (NH3) to form the modified amino groups on the surface of the first dielectric layer 101 has the following advantages: first, the formation of plasma gas ammonia (NH3) can be carried out at a lower temperature, reducing energy consumption; second, the high-energy environment provided by the plasma gas ammonia (NH3) promotes the rapid progress of the reaction; third, the formation of amino groups by plasma gas ammonia (NH3) does not require high-voltage equipment, reducing safety risks; fourth, the density of amino groups formed by plasma gas ammonia NH3 is controllable; and fifth, plasma gas ammonia (NH3) can achieve uniform surface modification.

[0060] In this embodiment, the steps of forming the plasma gas ammonia (NH3) include:

[0061] The mixed gas of hydrogen and nitrogen is introduced into the reaction chamber.

[0062] The plasma generator in the reaction chamber emits arc, microwave or radio frequency to excite the hydrogen gas to ionize and form the hydrogen plasma. The hydrogen plasma includes hydrogen ions (H + ), activated hydrogen atoms (H) and electrons (e - ) and other mixed plasma states.

[0063] The plasma generator in the reaction chamber emits arc, microwave or radio frequency, and simultaneously excites the nitrogen gas to ionize, thereby forming the nitrogen plasma. The nitrogen plasma includes a mixed plasma state of activated nitrogen atoms (N), nitrogen ions (N-), etc.

[0064] Since hydrogen plasma and nitrogen plasma have high energy, ammonia (NH3) is formed according to the following reaction equation (1).

[0065] N+ 3H → NH3 (1)

[0066] The activated hydrogen atoms (H) and the activated nitrogen atoms (N) generate ammonia (NH3); when the plasma generator emits an arc, microwave or radio frequency, the ammonia (NH3) is ionized to form an amino group (-NH2), that is, the modified group is formed on the surface of the first dielectric layer 101, so as to achieve the modification treatment of the first dielectric layer 101 exposed to be modified by using the plasma gas.

[0067] The principle of using the plasma gas ammonia (NH 3 ) to modify the exposed first dielectric layer 101 that needs to be modified is as follows.

[0068] Physics principle: Van der Waals forces exist between all molecules. When polar and non-polar molecules approach each other, the non-polar molecules become polarized under the influence of the polar molecules' intrinsic dipoles, generating an induced dipole. The induced dipole and the intrinsic dipole then attract each other, generating intermolecular forces. Amino groups, as polar groups, induce this force when interacting with the non-polar first dielectric layer 101. Specifically, van der Waals forces exist between the amino groups (-NH2) and the surface of the first dielectric layer 101. These van der Waals forces adhere the amino groups (-NH2) to the surface of the first dielectric layer 101, resulting in a certain number of amino groups (-NH2) on the surface of the first dielectric layer 101.

[0069] Chemical principle: Under high energy conditions, nitrogen atoms and hydrogen atoms in the plasma gas ammonia react with silicon atoms on the surface of the first dielectric layer 101, which is silicon oxide, to form a silicon-amino group structure (Si-NH2).

[0070] The greater the number of amino groups (-NH2) attached to the surface of the first dielectric layer 101 exposed to modification, the higher the etching rate of the first dielectric layer 101. The number of amino groups (-NH2) attached to the surface of the first dielectric layer 101 exposed to modification depends on the parameters of the modification process for the first dielectric layer 101. In this embodiment, the nitrogen flow rate is 50 sccm to 80 sccm, the hydrogen flow rate is 50 sccm to 80 sccm, the chamber pressure is 1.0 mtorr to 10 mtorr, the temperature is 60°C to 300°C, and the treatment time is 70 seconds to 100 seconds. In a specific embodiment, the nitrogen flow rate is 70 sccm, the hydrogen flow rate is 60 sccm, the chamber pressure is 3.0 mtorr, the temperature is 200°C, and the treatment time is 80 seconds.

[0071] In other embodiments, aminosilane coupling agent method is used to form amino groups on the surface of the first dielectric layer 101. Aminosilane coupling agent molecules have silane groups and amino groups. The silane groups are combined with the surface of the first dielectric layer 101, while the amino groups are exposed on the surface.

[0072] In this embodiment, the first dielectric layer 101 is described as silicon oxide, and the main steps include:

[0073] Cleaning removes contaminants on the surface of the silicon oxide.

[0074] The silicon oxide is immersed in a solution of an aminosilane coupling agent. Hydroxyl groups exist on the surface of the silicon oxide. The silane groups react with the hydroxy groups on the surface of the silicon oxide to expose amino groups on the surface of the silicon oxide.

[0075] The soaked silicon oxide is baked to expose and fix the amino groups on the surface of the silicon oxide.

[0076] The silicon oxide surface is cleaned to remove unreacted coupling agent.

[0077] It should be noted that the types of the aminosilane coupling agent include: one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

[0078] It should be noted that the sources of the hydroxyl groups on the silicon oxide surface are as follows:

[0079] First, surface defects of silicon oxide; during the formation process of silicon oxide, its surface is usually not completely flat and perfect, and there will be missing silicon atoms or oxygen atoms on the surface. These defective positions will form silicon dangling bonds or oxygen dangling bonds, and oxygen dangling bonds can react with water molecules to form hydroxyl groups.

[0080] Second, the breaking of silicon-oxygen bonds: On the surface of silicon oxide, some silicon-oxygen bonds break, forming silicon dangling bonds and oxygen dangling bonds. The oxygen dangling bonds react with water molecules to form hydroxyl groups.

[0081] Third, hydrolysis reaction; when the silicon oxide surface comes into contact with water, a hydrolysis reaction can occur, in which the silicon-oxygen bonds on the surface react with water molecules to generate hydroxyl groups.

[0082] Fourth, adsorption of water molecules: The surface of silicon oxide is hydrophilic and can adsorb water molecules in the environment. The adsorbed water molecules can interact with the oxygen atoms on the surface of silicon oxide through hydrogen bonds to form hydroxyl groups.

[0083] It should be noted that, in other embodiments, the substance that forms the amino group further includes: one or more of amine compounds, diamines and urea.

[0084] The amine compounds include:

[0085] Primary amines: such as ethylamine (EtNH), n-propylamine (n-PrNH), n-butylamine (n-BuNH), etc., which contain an amino group.

[0086] Secondary amines: such as diethylamine (EtNH) and di-n-propylamine (n-PrNH), which contain two amino groups.

[0087] Tertiary amines: such as triethylamine (EtN), tri-n-propylamine (n-PrN), etc., which contain three amino groups.

[0088] The diamines include ethylenediamine (EDA), hexamethylenediamine, etc., which contain two amino groups.

[0089] The urea ((NH)CO) can release amino groups under specific conditions.

[0090] In other embodiments, the amino groups are formed on the surface of the first dielectric layer 101 by the photochemical reaction method, which mainly includes the following steps:

[0091] Cleaning removes contaminants on the surface of the silicon oxide.

[0092] A layer of photosensitizer is coated on the surface of the first dielectric layer 101 , and the photosensitizer is a photosensitizer compound containing an amino group.

[0093] The coated first dielectric layer 101 is exposed to ultraviolet light to cause the photosensitizer to undergo a photochemical reaction to form amino groups.

[0094] refer to Figure 4 , a protonation reaction occurs based on the modified group 103.

[0095] The protonation reaction occurs based on the modified groups 103 so that the surface of the modified first dielectric layer 101 has positive charges, thereby increasing the etching rate of the first dielectric layer 101 and improving production efficiency.

[0096] In this embodiment, the main steps of the protonation reaction of the modified group 103 include:

[0097] The hydrogen plasma, nitrogen plasma and ammonia plasma in the reaction chamber are sucked out by a vacuum pumping system.

[0098] The hydrogen gas is introduced into the reaction chamber.

[0099] The plasma generator in the reaction chamber emits an arc, microwave, or radio frequency to ionize the hydrogen gas, forming the hydrogen plasma. The hydrogen plasma includes hydrogen ions (H+). According to the following chemical reaction equation (2), the hydrogen ions (H+) undergo a protonation reaction with the amino groups (-NH2) on the surface of the first dielectric layer 101.

[0100] -NH2+H + →-NH3 + (2)

[0101] The surface of the modified first dielectric layer 101 has a positive charge due to the protonation reaction between hydrogen ions and the amino groups. The principle is as follows: the amino groups (-NH2) are neutral, and the hydrogen ions combine with the amino groups (-NH2) to form positively charged ammonium ions 104 (-NH3 + ).

[0102] In this embodiment, the surface of the modified first dielectric layer 101 has positive charges of ammonium ions 104 (-NH3 + ).

[0103] It should be noted that, in the process step of the protonation reaction of the modified group 103, the hydrogen plasma can be the hydrogen plasma that forms the amino group, and there is no need to re-introduce hydrogen into the reaction chamber, thus saving the process production cycle.

[0104] refer to Figure 5 , etching the first dielectric layer 101 after the protonation reaction.

[0105] In this embodiment, the main step of etching the first dielectric layer 101 after the protonation reaction includes: introducing an etching gas used to etch the modified first dielectric layer 101 into the reaction chamber. The etching gas used to etch the first dielectric layer 101 after the protonation reaction includes one or more of the following: tetracarbon octafluoride (C4F8), pentacarbon octafluoride (C5F8), and tetracarbon hexafluoride (C4F6). The high F content in the tetracarbon octafluoride (C4F8) can further increase the etching rate of the first dielectric layer 101. In this embodiment, the etching gas is tetracarbon octafluoride (C4F8).

[0106] In this embodiment, the plasma generator in the reaction chamber emits arc, microwave or radio frequency to excite the tetracarbon octafluoride C4F8 to form fluoride ions.

[0107] The positive charge on the surface of the modified first dielectric layer 101 attracts fluoride ions in the etching gas to react with the first dielectric layer 101. The principle is as follows: due to the mutual attraction between positive and negative charges, the surface of the modified first dielectric layer 101 has a large amount of positive charge, causing the fluoride ions to quickly move to the surface of the first dielectric layer 101.

[0108] In this embodiment, the positively charged ammonium ions 104 (-NH3 + ), attracting fluorine ions in the etching gas to react with the first dielectric layer 101 to etch the first dielectric layer 101, thereby increasing the etching rate of the first dielectric layer 101 and thus improving production efficiency.

[0109] The mechanism for improving the etching rate of the first dielectric layer 101 after the protonation reaction is as follows: a large amount of positive charges accumulate on the surface of the first dielectric layer 101 after the protonation reaction. First, under the attractive force of the large amount of positive charges, the rate at which fluoride ions in the etching gas flow toward the first dielectric layer 101 is accelerated, reducing the time the fluoride ions spend flowing toward the surface of the first dielectric layer 101, thereby improving the etching efficiency of the first dielectric layer 101 by the fluoride ions. Second, under the attractive force of the large amount of positive charges, the kinetic energy of the fluoride ions bombarding the first dielectric layer 101 is increased, thereby accelerating the etching rate of the first dielectric layer 101 by the fluoride ions. Third, under the attractive force of the large amount of positive charges, the fluoride ions bombard the first dielectric layer 101 in a direction perpendicular or nearly perpendicular to the surface of the first dielectric layer 101, maximizing the conversion of the kinetic energy of the fluoride ions into etching of the first dielectric layer 101, thus also improving the etching rate of the first dielectric layer 101 by the fluoride ions.

[0110] refer to Figure 6 , is a schematic structural diagram corresponding to each step in a thin film etching method for wafers according to another embodiment of the present invention. Figure 6 and Figure 2 It can be seen from the comparison that the only difference between this embodiment and the aforementioned embodiment is that the second dielectric layer 200 exposed on both sides of the first dielectric layer 101 to be modified is designed to be in the shape of a staircase 300 .

[0111] Relative to Figure 2 The vertical sidewall 400 of the second dielectric layer 102 in the stair-shaped structure 300 increases the attachment area of ​​the modified group to the second dielectric layer 200, that is, the modified group can attach to the step 301 and the sidewall 302 of the second dielectric layer 200, so that the concentration of the modified group near the first dielectric layer 101 to be modified is increased, which can attract more fluorine ions to gather, thereby increasing the etching rate of the first dielectric layer 101 and improving production efficiency.

[0112] In this embodiment, different light transmittances are designed on a mask, and a photolithography process is performed on the second dielectric layer using the mask to form the staircase shape 300 .

[0113] It should be noted that, according to the above principle, the modified groups are also attached to the surface of the second dielectric layer. However, for the sake of simplicity and clarity of the drawings, the modified groups and ammonium ions are not shown on the surface of the second dielectric layer.

[0114] It should be noted that the above etching method can be used for other dielectric layers of semiconductor devices, thereby increasing the etching rate of the dielectric layer and thus improving production efficiency.

[0115] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A wafer thin film etching method, characterized in that: include: providing a substrate; forming a first dielectric layer on the substrate; performing a modification treatment on the first dielectric layer to form a modified group on the first dielectric layer; Protonation reaction occurs based on the modifying group; The first dielectric layer after the protonation reaction is etched.

2. The thin film etching method according to claim 1, wherein: The modified group is an amino group; The protonation reaction occurs based on the modified group, including: a protonation reaction occurs based on hydrogen ions and the amino group, so that the surface of the modified first dielectric layer has a positive charge.

3. The thin film etching method according to claim 2, wherein: Gases that form the amino groups include nitrogen and hydrogen.

4. The thin film etching method according to claim 3, wherein: The step of modifying the first dielectric layer comprises: The nitrogen gas and the hydrogen gas are plasma-treated to form a plasma gas.

5. The thin film etching method according to claim 4, wherein: After forming the first dielectric layer on the substrate and before performing a modification treatment on the first dielectric layer, the thin film etching method further includes: forming a second dielectric layer on the first dielectric layer; patterning the second dielectric layer to expose the first dielectric layer to be modified; The plasma gas is used to perform a modification treatment on the first dielectric layer that is exposed and needs to be modified.

6. The thin film etching method according to claim 5, wherein: The material of the second dielectric layer includes: one or more of photoresist, silicon nitride, silicon carbide, and silicon carbonitride.

7. The thin film etching method according to claim 1, wherein: The modified group includes one or more of an amino group, a carboxyl group, a thiol group, and an alkyl group.

8. The thin film etching method according to claim 1, wherein: The material of the first dielectric layer includes one or more of silicon oxide, silicon oxycarbide, and silicon oxynitride.

9. The thin film etching method according to claim 3, wherein: The parameters for modifying the first dielectric layer include: the nitrogen flow rate is 50 sccm to 80 sccm, the hydrogen flow rate is 50 sccm to 80 sccm, the chamber pressure is 1.0 mtorr to 10 mtorr, the temperature is 60°C to 300°C, and the processing time is 70 seconds to 100 seconds.

10. The thin film etching method according to claim 2, wherein: The etching gas used for etching the first dielectric layer after the protonation reaction includes one or more of the following: tetracarbon octafluoride C4F8, pentacarbon octafluoride C5F8, and tetracarbon hexafluoride C4F6.

11. The thin film etching method according to claim 10, wherein: The step of etching the first dielectric layer after the protonation reaction includes: Based on the positive charge on the surface of the modified first dielectric layer, fluorine ions in the etching gas are attracted to react with the first dielectric layer.

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