A modified silicon nitride film and its preparation method and application
Through thermal atomic layer deposition technology, metal-doped carbon doped and nitrogen source plasma gas are introduced to deposit silicon nitride layers layer by layer, solving the problem of low density caused by residual stress during DIPAS deposition, and achieving high-density and low dielectric constant silicon nitride films, enhancing its application prospects in the fields of semiconductors and microelectronics.
Patent Information
- Application Number
- CN202510050424.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-04-08
AI Technical Summary
In the existing silicon nitride thin film preparation process, the residual stress generated by the DIPAS deposition process leads to low density, limiting its application prospects.
Using thermal atomic layer deposition technology, a carbon-metal co-doped silicon nitride layer is deposited layer by layer by layer by layer by introducing silicon precursor, metal-doped carbon dots and nitrogen source plasma gas, so as to relieve residual stress and regulate the density and dielectric constant of the film.
The high density and low dielectric constant of silicon nitride film are achieved, and the quality and application prospects of the film are improved. It is suitable for the semiconductor industry and microelectronics field.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of semiconductor materials, and in particular relates to a modified silicon nitride film and a preparation method and application thereof. Background Art
[0002] Silicon nitride film refers to a film of silicon nitrogen compound, which has good chemical stability, insulation properties and high temperature resistance. It is widely used as an electrical insulation layer in the semiconductor industry, microelectronics and other fields.
[0003] At present, chemical vapor deposition is a commonly used process for preparing silicon nitride thin films. In this method, a dense silicon nitride thin film can be prepared by controlling the process parameters, and the obtained silicon nitride thin film has the advantages of small thickness deviation and stable refractive index. Among them, diisopropylaminosilane (DIPAS), as the most commonly used precursor molecule in chemical vapor deposition, can be deposited at a relatively low temperature, and the resulting silicon nitride thin film has good optical properties, dielectric insulation and chemical stability, showing good advantages in the preparation of semiconductor devices and has a wide range of applications in the semiconductor industry.
[0004] However, a certain amount of residual stress will be generated during the DIPAS deposition process, and as the chamber cleaning and coating times accumulate, the prepared silicon nitride film has the problem of low density, which has great limitations. Summary of the invention
[0005] In order to solve the problem of low density of silicon nitride films prepared by existing preparation processes, a first object of the present invention is to provide a method for preparing a modified silicon nitride film.
[0006] A second object of the present invention is to provide a modified silicon nitride film.
[0007] The third object of the present invention is to provide application of the modified silicon nitride film in the semiconductor industry and / or microelectronics field.
[0008] Specifically, the method for preparing a modified silicon nitride film provided by the present invention specifically comprises: (1) placing a substrate in a reaction chamber, introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition to chemically adsorb the silicon precursor with the substrate to obtain a first reaction product; (2) introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition to chemically adsorb the metal precursor with the first reaction product to obtain a second reaction product; (3) introducing a nitrogen source plasma gas into the reaction chamber to react with the second reaction product to obtain a carbon-metal co-doped silicon nitride layer; and repeating steps (1) to (3) for no less than 2 times in sequence to obtain a modified silicon nitride film on the substrate.
[0009] Furthermore, in step (1), the silicon precursor comprises one or more compounds represented by formula (1) to formula (4),
[0010]
[0011] In formula (1) to formula (4), R1 to R 20 Each is independently a hydrogen atom or a C1-C5 alkyl group.
[0012] Furthermore, in step (1), the method of introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition for chemical adsorption with the substrate includes: using a gas carrier to pass the silicon precursor into the reaction chamber in a pulsed manner, and the silicon precursor contacts the substrate for chemical adsorption to obtain a first reaction product.
[0013] Furthermore, in step (1), the gas carrier includes one or more of nitrogen, argon, helium and krypton.
[0014] Furthermore, in step (1), the flow rate of the gas carrier is 50 to 500 sccm.
[0015] Furthermore, in step (1), the time for the silicon precursor to be in contact with the substrate for chemical adsorption is 2 to 10 seconds.
[0016] Furthermore, in step (1), the temperature of the reaction chamber is 100-450° C., and the gas pressure is 150-550 Pa.
[0017] Furthermore, in step (2), the metal-doped carbon dots include one or more of Al-CDs, Mg-CDs, Zn-CDs, Fe-CDs and Mn-CDs.
[0018] Furthermore, in step (2), the method for preparing the metal-doped carbon dots comprises: mixing aniline, a metal inorganic salt and an organic alcohol solvent, and performing a high-temperature reaction to obtain the metal-doped carbon dots.
[0019] Furthermore, the metal inorganic salt is selected from one or more of AlCl3, MgCl2, ZnCl2, MnCl2 and FeCl2.
[0020] Furthermore, the mixing mass ratio of the aniline, the metal inorganic salt and the organic alcohol solvent is (8-12):(5-8):1.
[0021] Furthermore, the temperature of the high temperature reaction is 170-200° C., and the time is 6-24 hours.
[0022] Furthermore, in step (2), the method of introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition for chemical adsorption with the first reaction product includes: using a gas carrier to pass the metal-doped carbon dots into the reaction chamber in pulses, and the metal-doped carbon dots contact the first reaction product for chemical adsorption to obtain a second reaction product.
[0023] Furthermore, in step (2), the gas carrier includes one or more of nitrogen, argon, helium and krypton.
[0024] Furthermore, in step (2), the flow rate of the gas carrier is 50 to 500 sccm.
[0025] Furthermore, in step (2), the time for chemical adsorption of the metal-doped carbon dots and the first reaction product is 2 to 10 seconds.
[0026] Furthermore, in step (2), the temperature of the reaction chamber is 100-450° C., and the gas pressure is 150-550 Pa.
[0027] Furthermore, in step (3), the nitrogen source plasma gas is nitrogen plasma gas and / or ammonia plasma.
[0028] Furthermore, in step (3), the flow rate of the nitrogen source plasma gas is 50 to 500 sccm.
[0029] Furthermore, in step (3), the nitrogen source plasma gas reacts with the second reaction product for 10 to 60 seconds.
[0030] The modified silicon nitride film provided by the present invention is prepared by the above-mentioned method for preparing the modified silicon nitride film.
[0031] Furthermore, the dielectric constant of the modified silicon nitride film is 2 to 3, and the density is 4 to 5 g / cm 3 .
[0032] The present invention also provides application of the modified silicon nitride film in the semiconductor industry and / or microelectronics field.
[0033] Beneficial effects:
[0034] In the preparation method of the modified silicon nitride film provided by the present invention, the metal-doped carbon dots introduced during the formation of the silicon nitride film can effectively alleviate the residual stress generated during the deposition of the silicon precursor, and at the same time achieve carbon-metal co-doping of the film to regulate the content of carbon and metal elements in the obtained film, thereby obtaining a film with both a lower dielectric constant and a higher density. The modified silicon carbide film is of high quality and can be well applied in the semiconductor industry and / or the field of microelectronics, and has good application prospects. DETAILED DESCRIPTION
[0035] The method for preparing a modified silicon nitride film provided by the present invention specifically comprises: (1) placing a substrate in a reaction chamber, introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition to chemically adsorb the silicon precursor with the substrate to obtain a first reaction product; (2) introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition to chemically adsorb the metal precursor with the first reaction product to obtain a second reaction product; (3) introducing a nitrogen source plasma gas into the reaction chamber to react with the second reaction product to obtain a carbon-metal co-doped silicon nitride layer; and repeating steps (1) to (3) for no less than 2 times in sequence to obtain a modified silicon nitride film on the substrate.
[0036] In the present invention, the substrate is a type of material commonly used in the semiconductor industry and the field of microelectronics. Those skilled in the art can make adaptive choices from the prior art according to actual needs. The present invention does not impose any particular limitation. Specific examples include but are not limited to: one or more of silicon wafers, quartz, glass and resin.
[0037] In the present invention, in step (1), the silicon precursor is specifically one or more compounds represented by formula (1) to formula (4),
[0038]
[0039] In formula (1) to formula (4), R1 to R 20 Each is independently a hydrogen atom or a C1-C5 alkyl group. Specific examples of the C1-C5 alkyl group include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
[0040] In some specific embodiments, specific examples of the silicon precursor include but are not limited to: methylaminosilane, ethyldiaminosilane, n-propylaminosilane, isopropylaminosilane, n-butylaminosilane, isobutylaminosilane, tert-butylaminosilane, bis(methylamino)silane, bis(methyldiamino)silane, bis(ethyldiamino)silane, bis(n-propylamino)silane, bis(isopropylamino)silane, bis(n-butylamino)silane, bis(isobutylamino)silane, bis(tert-butylamino)silane, trimethylsilane, tri(ethylamino)silane, tri(n-propylamino)silane, tri(isopropylamino)silane, tri(n-butylamino)silane, tri(isobutylamino)silane, tri(tert-butylamino)silane, tetramethylsilane and tetraethylsilane.
[0041] In the present invention, in step (2), the metal-doped carbon dots refer to a substance obtained by introducing metal ions during the preparation process of carbon dots (CDs) to modify CDs, and specific examples thereof include but are not limited to: one or more of Al-CDs, Mg-CDs, Zn-CDs, Fe-CDs and Mn-CDs.
[0042] In the present invention, in step (2), the preparation of the metal-doped carbon dots preferably includes: mixing aniline, a metal inorganic salt and an organic alcohol solvent, and reacting at high temperature to obtain the metal-doped carbon dots. The metal inorganic salt is adaptively selected according to the expected metal-doped carbon dots, and the present invention does not impose any particular limitation on it. Specific examples include but are not limited to: one or more of AlCl3, MgCl2, ZnCl2, MnCl2 and FeCl2. Specific examples of the organic alcohol solvent include but are not limited to: one or more of methanol, ethanol and propanol.
[0043] In some specific embodiments, in the preparation of the metal-doped carbon dots, the mixing mass ratio of the aniline, the metal inorganic salt and the organic alcohol solvent is preferably (8-12):(5-8):1, such as 8:5:1, 8:6:1, 10:5:1, 10:6:1, 12:8:1 or any value therebetween.
[0044] In some specific embodiments, in the preparation of the metal-doped carbon dots, the conditions of the high temperature reaction specifically include a temperature of preferably 170 to 200°C, such as 170°C, 180°C, 190°C, 200°C or any value therebetween; a time of 6 to 24h, such as 6h, 8h, 12h, 16h, 24h or any value therebetween.
[0045] In the present invention, in steps (1) and (2), thermal atomic layer deposition refers to a technology that utilizes a heat source to decompose a precursor material and deposit it on a substrate to form a single-layer structure, and specific examples thereof include but are not limited to: one or more of: thermal cathode evaporation, molecular beam evaporation, ion beam deposition, metal organic decomposition evaporation, and atomic layer chemical vapor deposition. More specifically, the process and conditions for forming the first reactant or the second reactant by thermal atomic layer deposition in steps (1) and (2) may be completely the same, partially the same, or completely different.
[0046] In the present invention, in step (1), the method of introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition for chemical adsorption with the substrate specifically includes: using a gas carrier to pass the silicon precursor into the reaction chamber in a pulsed manner, and the silicon precursor contacts the substrate for chemical adsorption to obtain a first reaction product.
[0047] In some specific embodiments, in step (1), specific examples of the gas carrier include but are not limited to: one or more of nitrogen, argon, helium and krypton.
[0048] In some specific embodiments, in step (1), the flow rate of the gas carrier is preferably 50-500 sccm, such as 50 sccm, 80 sccm, 115 sccm, 200 sccm, 250 sccm, 300 sccm, 500 sccm or any value therebetween.
[0049] In some specific embodiments, in step (1), the time for the silicon precursor to be in contact with the substrate for chemical adsorption is preferably 2 to 10 seconds, such as 2 seconds, 3 seconds, 5 seconds, 7 seconds, 9 seconds, 10 seconds or any value therebetween.
[0050] In some specific embodiments, in step (1), when the silicon precursor contacts the substrate for chemical adsorption, the temperature of the reaction chamber is preferably 100-450°C, such as 100°C, 150°C, 200°C, 300°C, 450°C or any value therebetween; the gas pressure is preferably 150-550Pa, such as 150Pa, 200Pa, 250Pa, 300Pa, 400Pa, 500Pa, 550Pa or any value therebetween.
[0051] In the present invention, step (1) preferably also includes: taking the gas carrier to purge the first reaction product; more specifically, the purge time is preferably 10 to 60 s, such as 10 s, 15.5 s, 18 s, 30 s, 45 s, 50 s, 60 s or any value therebetween.
[0052] In the present invention, in step (2), the method of introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition for chemical adsorption with the first reaction product specifically includes: using a gas carrier to pass the metal-doped carbon dots into the reaction chamber in pulses, and the metal-doped carbon dots contact the first reaction product for chemical adsorption to obtain a second reaction product.
[0053] In some specific embodiments, in step (2), specific examples of the gas carrier include but are not limited to: one or more of nitrogen, argon, helium and krypton.
[0054] In some specific embodiments, in step (2), the flow rate of the gas carrier is preferably 50-500 sccm, such as 50 sccm, 80 sccm, 115 sccm, 200 sccm, 250 sccm, 300 sccm, 500 sccm or any value therebetween.
[0055] In some specific embodiments, in step (2), the time for chemical adsorption of the metal-doped carbon dots and the first reaction product is preferably 2 to 10 s, such as 2 s, 3 s, 4 s, 5 s, 6 s, 7 s, 8 s, 9 s, 10 s or any value therebetween.
[0056] In some specific embodiments, in step (2), when the metal-doped carbon dots contact the first reaction product for chemical adsorption, the temperature of the reaction chamber is preferably 100-450°C, such as 100°C, 150°C, 200°C, 300°C, 450°C or any value therebetween; the gas pressure is preferably 150-550Pa, such as 150Pa, 200Pa, 250Pa, 300Pa, 400Pa, 500Pa, 550Pa or any value therebetween.
[0057] In the present invention, step (2) preferably also includes: taking the gas carrier to purge the second reaction product; more specifically, the purge time is preferably 10 to 60 s, such as 10 s, 15.5 s, 18 s, 30 s, 45 s, 50 s, 60 s or any value therebetween.
[0058] In the present invention, in step (3), the nitrogen source plasma refers to a reactive nitrogen-containing gas generated in situ or remotely by a plasma generator, and specific examples thereof include but are not limited to: nitrogen plasma gas and / or ammonia plasma.
[0059] In some specific embodiments, in step (3), the flow rate of the nitrogen source plasma gas is preferably 50-500 sccm, such as 50 sccm, 75 sccm, 100 sccm, 200 sccm, 300 sccm, 500 sccm or any value therebetween.
[0060] In some specific embodiments, in step (3), the time for the nitrogen source plasma gas to react with the second reaction product is preferably 10 to 60 s, such as 10 s, 15 s, 18 s, 20 s, 50 s, 60 s or any value therebetween.
[0061] In some specific embodiments, in step (3), when the nitrogen source plasma gas reacts with the second reaction product, the temperature of the reaction chamber is preferably 100-450°C, such as 100°C, 150°C, 200°C, 300°C, 400°C, 450°C or any value therebetween; the gas pressure is preferably 150-550Pa, such as 150Pa, 200Pa, 250Pa, 400Pa, 550Pa or any value therebetween.
[0062] In the present invention, step (3) preferably also includes: taking the gas carrier to purge the carbon-metal co-doped silicon nitride layer; more specifically, the purge time is preferably 10 to 60 s, such as 10 s, 15.5 s, 18 s, 30 s, 45 s, 50 s, 60 s or any value therebetween.
[0063] The present invention also provides a modified silicon nitride film, which is prepared by the above-mentioned method for preparing the modified silicon nitride film.
[0064] In the present invention, the dielectric constant of the modified silicon nitride film is preferably 2 to 3, such as 2, 2.04, 2.15, 2.3, 2.5, 2.8, 3 or any value therebetween; the density is preferably 4 to 5 g / cm 3 , such as 4g / cm 3 4.017g / cm 3 , 4.25g / cm 3 4.38g / cm 3 4.5g / cm 3 , 4.97g / cm 3 , 5g / cm 3 or any value in between.
[0065] The present invention also provides application of the modified silicon nitride film in the semiconductor industry and / or microelectronics field.
[0066] Embodiments of the present invention are described in detail below, and the examples of the embodiments are intended to be used to explain the present invention, but should not be construed as limiting the present invention. In the embodiments, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not specified for reagents or instruments used, they are all conventional products that can be obtained commercially.
[0067] Preparation Example 1
[0068] This preparation example is used to illustrate the preparation of Al-CDs, which specifically includes: mixing aniline, AlCl3 and anhydrous ethanol in a mass ratio of 10:6:1, adding the mixture to a reaction kettle, and performing a high temperature reaction at 180°C for 12 hours to obtain Al-CDs.
[0069] Preparation Example 2
[0070] This preparation example adopts the method provided in Preparation Example 1 to prepare Mg-CDs, except that MgCl2 is used instead of AlCl3 in equal parts by mass, and other conditions are the same to obtain Mg-CDs.
[0071] Comparative Preparation Example
[0072] This comparative preparation example adopts the method provided in Preparation Example 1 to prepare CDs, except that anhydrous ethanol is used instead of AlCl3 in equal parts by mass, and other conditions are the same to obtain CDs.
[0073] Example 1
[0074] This embodiment is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0075] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0076] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the Al-CDs provided in Preparation Example 1 were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove unadsorbed Al-CDs;
[0077] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon and aluminum co-doped silicon nitride layer;
[0078] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0079] Example 2
[0080] This embodiment is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0081] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 400° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0082] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the Al-CDs provided in Preparation Example 1 were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove unadsorbed Al-CDs;
[0083] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon and aluminum co-doped silicon nitride layer;
[0084] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0085] Example 3
[0086] This embodiment is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0087] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing tri(isopropylamino)silane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed tri(isopropylamino)silane;
[0088] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the Al-CDs provided in Preparation Example 1 were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove unadsorbed Al-CDs;
[0089] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon and aluminum co-doped silicon nitride layer;
[0090] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0091] Example 4
[0092] This embodiment is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0093] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0094] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the Mg-CDs provided in Preparation Example 2 were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove the unadsorbed Mg-CDs;
[0095] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon-magnesium co-doped silicon nitride layer;
[0096] Repeat the above steps (1) to (3) 200 times to obtain a film with a thickness of Modified silicon nitride film.
[0097] Example 5
[0098] This embodiment is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0099] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing tri(isopropylamino)silane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed tri(isopropylamino)silane;
[0100] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the Mg-CDs provided in Preparation Example 2 were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove the unadsorbed Mg-CDs;
[0101] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon-magnesium co-doped silicon nitride layer;
[0102] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0103] Comparative Example 1
[0104] This comparative example is used to illustrate a method for preparing a silicon nitride film, which specifically includes the following steps:
[0105] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0106] (2) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a silicon nitride layer;
[0107] Repeat the above steps (1) and (2) 200 times to obtain a film with a thickness of of silicon nitride film.
[0108] Comparative Example 2
[0109] This comparative example is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0110] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0111] (2) introducing nitrogen gas as a carrier gas at a flow rate of 250 sccm, and continuously introducing triethylamine into the reaction chamber in a pulsed manner to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and continuing to introduce nitrogen gas for purging to remove unadsorbed triethylamine;
[0112] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon-doped silicon nitride layer;
[0113] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0114] Comparative Example 3
[0115] This comparative example is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0116] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0117] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and the CDs provided in the comparative preparation example were continuously introduced into the reaction chamber using a Y94 series pulsed pneumatic conveying device to contact the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continuously introduced for purging to remove unadsorbed CDs;
[0118] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain a carbon-doped silicon nitride layer;
[0119] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0120] Comparative Example 4
[0121] This comparative example is used to illustrate a method for preparing a modified silicon nitride film, which specifically includes the following steps:
[0122] (1) placing a substrate in a reaction chamber of an atomic layer deposition device, setting the temperature of the reaction chamber to 300° C. and the pressure to 250 Pa, introducing nitrogen as a carrier gas at a flow rate of 250 sccm, and continuously introducing diisopropylaminosilane into the reaction chamber in a pulsed manner to contact the substrate for chemical adsorption for 6 seconds to obtain a first reaction product, and continuing to introduce nitrogen for purging to remove unadsorbed diisopropylaminosilane;
[0123] (2) nitrogen gas was introduced as a carrier gas at a flow rate of 250 sccm, and AlCl3 was continuously introduced into the reaction chamber in a pulsed manner to contact with the first reaction product for chemical adsorption for 6 seconds to obtain a second reaction product, and nitrogen gas was continued to be introduced for purging to remove unadsorbed Al;
[0124] (3) continuously introducing nitrogen plasma gas into the reaction chamber at a flow rate of 250 sccm for 50 seconds to obtain an aluminum-doped silicon nitride layer;
[0125] Repeat the above steps (1) to (3) 200 times to prepare a film with a thickness of Modified silicon nitride film.
[0126] Test Case
[0127] This test example is used to illustrate the relevant properties of the modified silicon nitride film and the silicon nitride film provided in the above embodiments and comparative examples. The test specifically includes:
[0128] (1) Dielectric constant test: The test method is the resonant cavity method. The substrate deposited with the modified silicon nitride film or the silicon nitride film is cut into 80 mm × 80 mm squares, and the dielectric constant of the film is measured using a dielectric constant tester at 0.6 GHz.
[0129] (2) Density test: The density of the film was tested using an X-ray reflectometer (XRR, model Malvern Panalytical X'PertPRO);
[0130] (3) Element content test: The element content of the film was tested using an XPS tester (ThermoFisher EscaLab Xi+). The test results are shown in Table 1.
[0131] (4) Insulation test: The resistance of the film was tested using a HTIM-300 high temperature resistance insulation tester. The test results are shown in Table 1.
[0132] Table 1.
[0133]
[0134] It can be seen from the test results shown in Table 1 that, compared with Comparative Examples 1 to 4, the modified silicon nitride films provided by Examples 1 to 5 of the present invention are of high quality, have a lower dielectric constant, a higher density and good insulation, and still have a large resistance when containing a higher content of carbon and metal, and can be well used as an electrical insulation layer of semiconductor devices, and have good application prospects.
[0135] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.
Claims
1. A method for preparing a modified silicon nitride film, characterized in that: The preparation method comprises: (1) placing a substrate in a reaction chamber, introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition to chemically adsorb the silicon precursor onto the substrate to obtain a first reaction product; (2) introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition to chemically adsorb the metal-doped carbon dots to the first reaction product to obtain a second reaction product; (3) introducing a nitrogen source plasma gas into the reaction chamber to react with the second reaction product to obtain a carbon-metal co-doped silicon nitride layer; Repeat steps (1) to (3) for no less than 2 times to prepare a modified silicon nitride film on the substrate.
2. The method for preparing a modified silicon nitride film according to claim 1, characterized in that: In step (1), the silicon precursor comprises one or more compounds represented by formula (1) to formula (4), In formula (1) to formula (4), R1 to R 20 Each is independently a hydrogen atom or a C1-C5 alkyl group.
3. The method for preparing a modified silicon nitride thin film according to claim 1, characterized in that: In step (1), the method of introducing a silicon precursor into the reaction chamber by thermal atomic layer deposition for chemical adsorption with the substrate comprises: using a gas carrier to pass the silicon precursor into the reaction chamber in a pulsed manner, and the silicon precursor contacts the substrate for chemical adsorption to obtain a first reaction product; Optionally, the gas carrier includes one or more of nitrogen, argon, helium and krypton; Optionally, the flow rate of the gas carrier is 50 to 500 sccm; Optionally, the silicon precursor is in contact with the substrate for chemical adsorption for 2 to 10 seconds; Optionally, the temperature of the reaction chamber is 100-450° C., and the gas pressure is 150-550 Pa.
4. The method for preparing a modified silicon nitride thin film according to claim 1, characterized in that: In step (2), the metal-doped carbon dots include one or more of Al-CDs, Mg-CDs, Zn-CDs, Fe-CDs and Mn-CDs.
5. The method for preparing a modified silicon nitride film according to claim 1, characterized in that: In step (2), the preparation method of the metal-doped carbon dots comprises: mixing aniline, a metal inorganic salt and an organic alcohol solvent, and performing a high temperature reaction to obtain the metal-doped carbon dots; Optionally, the metal inorganic salt is selected from one or more of AlCl3, MgCl2, ZnCl2, MnCl2 and FeCl2; Optionally, the mixing mass ratio of the aniline, the metal inorganic salt and the organic alcohol solvent is (8-12):(5-8):1; Optionally, the high temperature reaction is carried out at a temperature of 170 to 200° C. and for a time of 6 to 24 hours.
6. The method for preparing a modified silicon nitride film according to claim 1, characterized in that: In step (2), the method of introducing metal-doped carbon dots into the reaction chamber by thermal atomic layer deposition to chemically adsorb the metal-doped carbon dots and the first reaction product comprises: using a gas carrier to pass the metal-doped carbon dots into the reaction chamber in a pulsed manner, and the metal-doped carbon dots contact the first reaction product to chemically adsorb the metal-doped carbon dots to obtain a second reaction product; Optionally, the gas carrier includes one or more of nitrogen, argon, helium and krypton; Optionally, the flow rate of the gas carrier is 50 to 500 sccm; Optionally, the time for the metal-doped carbon dots to chemically adsorb with the first reaction product is 2 to 10 seconds; Optionally, the temperature of the reaction chamber is 100-450° C., and the gas pressure is 150-550 Pa.
7. The method for preparing a modified silicon nitride film according to claim 1, characterized in that: In step (3), the nitrogen source plasma gas is nitrogen plasma gas and / or ammonia plasma; Optionally, the flow rate of the nitrogen source plasma gas is 50 to 500 sccm; Optionally, the nitrogen source plasma gas reacts with the second reaction product for 10 to 60 seconds; Optionally, the temperature of the reaction chamber is 100-450° C., and the gas pressure is 150-550 Pa.
8. A modified silicon nitride film, characterized in that: The modified silicon nitride film is prepared by the method for preparing a modified silicon nitride film according to any one of claims 1 to 7.
9. The modified silicon nitride film according to claim 8, characterized in that: The dielectric constant of the modified silicon nitride film is 2-3, and the density is 4-5 g / cm 3 .
10. Use of the modified silicon nitride film according to claim 8 or 9 in the semiconductor industry and / or microelectronics field.