Regional selective deposition method for optimizing super-resolution photoetching pattern quality

Abstract

The invention provides a regioselective deposition method for optimizing super-resolution photoetching pattern quality. The regioselective deposition method comprises the following steps: preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer which are sequentially stacked on a substrate; performing super-resolution photoetching on the photosensitive film layer to enable the photosensitive film layer to form a super-resolution grating structure; the graphic structure of the super-resolution grating structure is sequentially etched and transmitted to the metal layer and the dielectric layer, and the metal layer is removed; and carrying out surface treatment on the exposed carbon-containing film layer, carrying out regioselective chemical adsorption between the carbon-containing film layer after surface treatment and the etched dielectric layer based on a precursor, and depositing film layers on the surface and the side wall of the dielectric layer.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor devices, and in particular to a regional selective deposition method for optimizing the quality of super-resolution lithography patterns. Background Art

[0002] In recent years, as the most advanced technology of semiconductor devices has entered the scale below 22 nm, the physical dimensions of transistors, such as channel length and channel width, have continued to shrink. When the feature size is reduced to less than tens of nanometers, the impact of line edge roughness (LER) and feature size deviation on device performance becomes impossible to ignore. The line edge roughness of the pattern will produce some channels in the direction of the channel length, that is, the local short channel effect, which leads to mismatch between devices. In addition, at technology nodes less than 45nm, semiconductor manufacturing usually requires many lithography and etching steps to reduce the resolution of the pattern. However, due to problems such as edge placement errors caused by multiple lithography and etching steps, device performance and yield are deteriorated, limiting the further miniaturization of the device. Summary of the invention

[0003] In view of this, an embodiment of the present invention provides a regional selective deposition method for optimizing the quality of super-resolution lithography graphics, including: preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on a substrate; performing super-resolution lithography on the photosensitive film layer to form a super-resolution grating structure in the photosensitive film layer; etching and transferring the graphic structure of the super-resolution grating structure to the metal layer and the dielectric layer in sequence, and removing the metal layer; performing surface treatment on the exposed carbon-containing film layer, and depositing a film layer on the surface and sidewall of the dielectric layer based on regional selective chemical adsorption of a precursor between the surface-treated carbon-containing film layer and the etched dielectric layer to obtain a super-resolution graphic with optimized graphic quality.

[0004] According to an embodiment of the present invention, the exposed carbon-containing film layer is subjected to surface treatment, including: chemically modifying the surface of the carbon-containing film layer by plasma treatment to reduce the oxygen content of the terminal groups on the surface of the carbon-containing film layer and increase the contact angle; the reaction gas used in the plasma treatment includes H 2 , CHF 3 , SF 6 CF 4 , C 4 F 8 At least one of the following, the reaction power is 20W to 100 W; and the processing time is 5 s to 120 s.

[0005] According to an embodiment of the present invention, based on the regional selective chemical adsorption of the precursor between the surface-treated carbon-containing film layer and the etched dielectric layer, a film layer is deposited on the surface and sidewall of the dielectric layer to obtain a super-resolution graphic with optimized graphic quality, including: using a carrier gas to introduce a first precursor into a reaction chamber, so that the first precursor is adsorbed on the surface of the dielectric layer; using a purge gas to discharge the unadsorbed first precursor in the reaction chamber; introducing a second precursor into the reaction chamber, the second precursor chemically reacts with the first precursor to form a molecular film on the surface and sidewall of the dielectric layer; using a purge gas to discharge excess second precursor and by-products in the reaction chamber, completing a deposition cycle, repeating multiple deposition cycles, and obtaining a super-resolution graphic with optimized graphic quality.

[0006] According to an embodiment of the present invention, the first precursor includes one of bis(diethylamino)silane, diisopropylamine silane, tri(dimethylamino)silane (3DMAS), trisilylamine, tetra(ethylamino)titanium, titanium tetrachloride, and trimethylaluminum; the second precursor includes O 2 Plasma, H 2 O, O 3 One of them.

[0007] According to an embodiment of the present invention, the gas flow rate of the carrier gas is 30 sccm~100 sccm, the gas flow rate of the purge gas is 100 sccm~200 sccm, the time for the first precursor to be introduced is 80 ms~200 ms, and the time for the second precursor to be introduced is 1 s~6 s; the purge time of the purge gas is 1 s~10 s; the temperature of the reaction chamber is 100 ℃~300 ℃.

[0008] According to an embodiment of the present invention, a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer are prepared and stacked in sequence on a substrate, including: forming a functional layer on the substrate by thermal oxidation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition or coating; depositing a carbon-containing material on the functional layer and then baking it to form a carbon-containing film layer by magnetron sputtering, vacuum evaporation, spin coating, spraying, a combination of spin coating and spraying, or printing; forming a dielectric layer on the carbon-containing film layer by spin coating, spraying, a combination of spin coating and spraying, printing, electron beam evaporation or magnetron sputtering deposition; forming a metal layer on the dielectric layer by electron beam evaporation or magnetron sputtering deposition; forming a photosensitive film layer on the metal layer by coating, and the thickness of the photosensitive film layer is 15 nm to 40 nm.

[0009] According to an embodiment of the present invention, the baking temperature is 100° C. to 300° C., and the baking time is 10 min to 5 h.

[0010] According to an embodiment of the present invention, the material of the functional layer includes SiO 2、SiN、poly-Si、TiN、Al 2 O 3 The material of the carbon-containing film layer includes at least one of spin-coated carbon, amorphous carbon, graphene and carbon nanotubes, and the thickness of the carbon-containing film layer is 10 nm to 200 nm; the material of the dielectric layer includes SiO 2 、TiO 2 、Al 2 O 3 At least one of the above, the thickness of the dielectric layer is 10 nm to 500 nm; the material of the metal layer includes Ag and Al, and the thickness of the metal layer is 20 nm to 50 nm.

[0011] According to an embodiment of the present invention, the pattern of the super-resolution grating structure is sequentially etched and transferred to the metal layer and the dielectric layer, and the metal layer is removed, including: etching the metal layer by an ion beam etching method, transferring the pattern structure of the super-resolution grating structure to the metal layer, and the etching gas includes Ar gas; etching the dielectric layer by ion beam etching, reactive ion etching or inductively coupled plasma, transferring the pattern structure of the metal layer to the dielectric layer, and the etching gas includes SF 6 , CHF 3 and Ar; and removing the metal layer by wet etching or mechanical stripping.

[0012] According to an embodiment of the present invention, preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on a substrate also includes: alternately depositing the carbon-containing film layer and the dielectric layer on the functional layer multiple times.

[0013] The regional selective deposition method provided by the embodiment of the present invention for optimizing the quality of super-resolution lithography patterns has at least the following technical effects:

[0014] Based on the regional selective deposition method, the surface specific differences of the carbon-containing film layer and the dielectric layer are utilized, and surface plasma treatment is used to delay the start time of chemical adsorption of the non-growing film layer surface and the precursor, that is, to delay the start time of nucleation of atomic layer deposition, so that growth only occurs in specific areas, while other areas remain intact, to achieve regional selective deposition, and to achieve high-precision deposition at the atomic scale, thereby optimizing the quality of super-resolution lithography patterns. In addition, based on the micro-load effect, according to the selectivity of the deposition area, not only can the edge roughness of the super-resolution lithography pattern be regulated, but also the compensation for the etching loss of the feature size can be achieved to keep it consistent with the design value of the pattern size. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0016] Figure 1 The flowchart of the area selective deposition method for optimizing the quality of super-resolution lithography patterns according to an embodiment of the present invention is schematically shown.

[0017] Figure 2 The process flow diagram of a regional selective deposition method for optimizing the quality of super-resolution lithography patterns according to an embodiment of the present invention is schematically shown.

[0018] Figure 3 The X-ray photoelectron spectroscopy measurement results of the surface of a spin-on-carbon (SOC) film layer before and after F plasma treatment according to an embodiment of the present invention are schematically shown.

[0019] Figure 4 The diagram schematically shows the selective size and graphic feature size of a spin-on-carbon (SOC) film layer before and after plasma treatment according to an embodiment of the present invention.

[0020] Figure 5 The schematic diagram shows a method of using atomic layer deposition according to an embodiment of the present invention, wherein SiO 2 The dielectric layer and the SOC carbon-containing film layer are deposited with a certain thickness of SiO 2 Membrane layer.

[0021] Figure 6 Schematically showing the result of line edge roughness of grating patterns without applying the regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the present embodiment and using the regional selective deposition method provided by the present embodiment.

[0022] Figure 7 Schematically showing the result of line edge roughness of grating patterns without applying the regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the present embodiment and using the regional selective deposition method provided by the present embodiment. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the description of the present invention, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "rear", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the subsystem or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present invention. The shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship. In addition, in the claims, any reference symbol between brackets shall not be construed as a limitation to the claims.

[0028] Similarly, in order to simplify the present invention and help understand one or more of the various disclosed aspects, in the above description of exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In order to optimize the quality of super-resolution lithography patterns, an embodiment of the present invention provides a regional selective deposition method for optimizing the quality of super-resolution lithography patterns, which adopts a bottom-up nanomanufacturing technology of deposition in a specific area to form a film layer with precise position alignment and thickness control on the pattern structure, thereby obtaining a super-resolution pattern with optimized pattern quality.

[0031] The regional selective deposition method provided by the embodiment of the present invention will be explained in detail below with reference to specific drawings.

[0032] Figure 1 A flow chart of a method for area selective deposition for optimizing the quality of super-resolution lithography patterns according to an embodiment of the present invention is schematically shown.

[0033] like Figure 1 As shown, the area selective deposition method for optimizing the quality of super-resolution lithography patterns according to the embodiment of the present invention may include operations S110 to S130.

[0034] In operation S110 , a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer, and a photosensitive film layer stacked in sequence are prepared on a substrate.

[0035] In operation S120 , super-resolution photolithography is performed on the photosensitive film layer to form a super-resolution grating structure on the photosensitive film layer.

[0036] In operation S130, the pattern structure of the super-resolution grating structure is sequentially etched and transferred to the metal layer and the dielectric layer, and the metal layer is removed.

[0037] In operation S140, the exposed carbon-containing film layer is surface treated, and based on the regional selective chemical adsorption of the precursor between the surface-treated carbon-containing film layer and the etched dielectric layer, a film layer is deposited on the surface and sidewall of the dielectric layer to obtain a super-resolution pattern with optimized pattern quality.

[0038] According to an embodiment of the present invention, after the carbon-containing film layer exposed after etching is subjected to surface treatment, the oxygen content of the terminal groups on the surface of the carbon-containing film layer is reduced, resulting in a reduction in deposition reaction sites. Since atomic layer deposition has a strong dependence on surface chemistry, the area-selective atomic layer deposition technology (AS-ALD) is used to delay the start time of chemical adsorption between the surface of the non-growing film layer and the precursor according to the difference in the surface chemical properties of the material itself, that is, to delay the start time of nucleation of atomic layer deposition, so that it only grows in a specific area and maintains its original state in other areas. By utilizing the difference in surface properties between the growth area (dielectric layer) and the non-growth area (carbon-containing film layer), the precursor performs area-selective chemical adsorption between the dielectric layer and the exposed carbon-containing film layer, so that the atomic layer deposition process only occurs on the surface and sidewalls of the dielectric layer, thereby obtaining a super-resolution graphic with optimized graphic quality.

[0039] The regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the embodiments of the present invention is an emerging bottom-up nanopatterning solution that can significantly reduce the number of required patterning steps, making it a time- and cost-effective method. These advances have enabled more efficient device manufacturing processes and may push AS-ALD one step closer to industrial applications in the fields of electronics, catalysis, photonics, and more.

[0040] Based on the above embodiment, the step of preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer, and a photosensitive film layer stacked in sequence on a substrate in operation S110 may include:

[0041] The functional layer is formed on the substrate by thermal oxidation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition or coating.

[0042] The carbon-containing material is deposited on the functional layer by magnetron sputtering, vacuum evaporation, spin coating, spray coating, a combination of spin coating and spray coating, or printing, and then baked to form a carbon-containing film layer.

[0043] The dielectric layer is formed on the carbon-containing film layer by using a method of spin coating, spray coating, a combination of spin coating and spray coating, printing, electron beam evaporation or magnetron sputtering deposition.

[0044] forming a metal layer on the dielectric layer by electron beam evaporation or magnetron sputtering deposition;

[0045] A photosensitive film layer is formed on the metal layer by a coating method.

[0046] In some possible implementations, the material of the functional layer may include SiO 2 、SiN、poly-Si、TiN、Al 2 O3 At least one of the functional layers may have a thickness of 10 nm to 500 nm.

[0047] In some possible implementations, the material of the carbon-containing film layer may include at least one of spin-coated carbon, amorphous carbon, graphene, and carbon nanotubes, and the thickness of the carbon-containing film layer may be 10 nm to 200 nm. The temperature for baking the carbon-containing material may be 100°C to 300°C, and the baking time may be 10 min to 5 h. The thickness of the photosensitive film layer may be 15 nm to 40 nm.

[0048] In some possible implementations, the material of the dielectric layer may include SiO 2 、TiO 2 、Al 2 O 3 At least one of the above, the thickness of the dielectric layer may be 10 nm to 500 nm;

[0049] In some possible implementations, the material of the metal layer may include Ag and Al, and the thickness of the metal layer may be 20 nm to 50 nm. The purpose of depositing the metal layer on the dielectric layer is to break through the resolution diffraction limit and realize super-resolution lithography patterns using surface plasmons.

[0050] Based on the above embodiment, the step of preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on the substrate in operation S110 may further include:

[0051] Carbon-containing film layers and dielectric layers are deposited alternately on the functional layer multiple times. That is, alternately stacked carbon-containing film layers and dielectric layers can be formed on the functional layer. Multiple alternate depositions form a multilayer film structure, and a three-dimensional graphic structure is obtained after etching transfer. Selective deposition on the sidewall can expand its application range.

[0052] Based on the above embodiment, the step of etching the pattern of the super-resolution grating structure to the metal layer and the dielectric layer in sequence and removing the metal layer in operation S130 may include:

[0053] The metal layer is etched by an ion beam etching method to transfer the graphic structure of the super-resolution grating structure to the metal layer. The etching gas may include Ar gas.

[0054] The dielectric layer is etched by ion beam etching, reactive ion etching or inductively coupled plasma to transfer the pattern structure of the metal layer to the dielectric layer. The etching gas can be SF 6 , CHF 3 Or one or more of Ar.

[0055] The metal layer is removed by wet etching or mechanical stripping.

[0056] Based on the above embodiment, the film layer is deposited by using the AS-ALD deposition process, and the surface treatment of the exposed carbon-containing film layer in operation S140 may include:

[0057] The surface of the carbon-containing film layer is chemically modified by plasma to reduce the oxygen content of the terminal groups on the surface of the carbon-containing film layer and increase the contact angle. The reaction gas used in the plasma may include H 2 , CHF 3 , SF 6 CF 4 , C 4 F 8 At least one of the above, the reaction power can be 20 W to 100 W; the treatment time can be 5 s to 120 s. After plasma treatment, the contact angle of the non-growth area increases and the hydrophilicity decreases. After plasma treatment, the oxygen-containing groups in the non-growth area decrease, resulting in a decrease in the sites that react with the precursor during the AS-ALD process.

[0058] Based on the above embodiment, in operation S140, the process of depositing a film layer on the surface and sidewall of the dielectric layer based on the regional selective chemical adsorption of the precursor between the surface treated carbon-containing film layer and the etched dielectric layer to obtain a super-resolution pattern with optimized pattern quality may include:

[0059] The first precursor is introduced into the reaction chamber by using a carrier gas, so that the first precursor is adsorbed on the surface of the dielectric layer.

[0060] The first precursor that is not adsorbed in the reaction chamber is discharged by using a purge gas.

[0061] The second precursor is introduced into the reaction chamber, and the second precursor reacts chemically with the first precursor to form a molecular film on the surface and side wall of the dielectric layer.

[0062] The purge gas is used to discharge the excess second precursor and by-products in the reaction chamber to complete a deposition cycle.

[0063] Repeat multiple deposition cycles to obtain super-resolution images with optimized image quality.

[0064] According to an embodiment of the present invention, first, the graphic structure is surface treated, the natural oxide layer on the surface of the carbon-containing film layer is destroyed, and due to its lower adsorption energy, the number of oxygen-containing groups in the carbon-containing film layer is reduced, thereby reducing the reaction sites and causing nucleation delay; then, high-purity N 2 The first precursor is introduced into the reaction chamber as a carrier gas and adsorbed only in the growth area; high-purity N 2The excess first precursor is purged away; then, the second precursor is introduced into the reaction chamber and reacts chemically with the adsorbed first precursor under the action of RF power or heating to form a molecular film; finally, high-purity N 2 Excess precursors and byproducts are purged; a deposition cycle is now completed. Repeating the above steps multiple times and completing multiple deposition cycles can obtain a film layer of the desired thickness, thereby obtaining a super-resolution image with optimized image quality.

[0065] Nucleation delay refers to the phenomenon that at the beginning of the atomic layer deposition process, the first precursor is not chemically adsorbed due to the lack of reaction sites on the surface of the substrate material, and thus cannot react with the second precursor to deposit a film layer; however, in a certain AS-ALD cycle process, the substrate is oxidized on the surface under the action of the second precursor and begins to chemically adsorb the first precursor to deposit the film layer material. This phenomenon is called nucleation delay.

[0066] The regional selective deposition caused by nucleation delay is generally evaluated by selectivity (S) for the AS-ALD process, which is expressed as the difference in the thickness of the deposited film layer between the growth area and the non-growth area. A highly selective AS-ALD process is crucial for the engineering application of this technology. The selectivity of atomic layer deposition achieved by this technology can be 2 nm ~12 nm.

[0067] Based on the above embodiment, the first precursor may include bis(diethylamino)silane (BDEAS), diisopropylamine silane (DIPAS), tris(dimethylamino)silane (3DMAS), trimethylsilylamine (TSA), tetra(ethylamino)titanium (TDEAT), titanium tetrachloride (TiCl 4 ), trimethylaluminum (TMA); the second precursor may include O 2 Plasma, H 2 O, O 3 One of them.

[0068] Based on the above embodiments, the gas flow rate of the carrier gas can be 30 sccm~100 sccm, the gas flow rate of the purge gas can be 100 sccm~200 sccm, the time for the first precursor to be introduced can be 80 ms~200 ms, and the time for the second precursor to be introduced can be 1 s~6 s; the purge time of the purge gas can be 1 s~10 s; the temperature of the reaction chamber can be 100 ℃~300 ℃.

[0069] In order to more clearly illustrate the regional selective deposition method provided by the embodiment of the present invention, Figure 2-Figure 7Several embodiments are listed for detailed description. It should be understood that the following embodiments are only exemplary and are not intended to limit the present invention.

[0070] Figure 2 The process flow diagram of a regional selective deposition method for optimizing the quality of super-resolution lithography patterns according to an embodiment of the present invention is schematically shown.

[0071] Example 1

[0072] The implementation steps of a regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by an embodiment of the present invention are as follows:

[0073] Step 1-1: Deposit a functional layer 5 on a substrate 6 by magnetron sputtering deposition. The functional layer 5 is a Si layer with a thickness of 50 nm. 3 N 4 .

[0074] Step 1-2: Spin-coat a carbon-containing hard mask layer 4, wherein the carbon-containing hard mask layer 4 is a SOC material, with a rotation speed of 4000 rpm and a spin coating time of 30 s at 240 o C for 15 min to form a SOC layer with a thickness of 60 nm.

[0075] Step 1-3: Prepare the dielectric layer 3 by magnetron sputtering. The dielectric layer 3 is 40 nm thick SiO 2 , the RF power is 400W and the time is 400s.

[0076] Step 1-4: Deposit the metal layer 2 by magnetron sputtering. The material of the metal layer 2 is Ag, the thickness is 40 nm, and the DC power is 50 W.

[0077] Step 1-5: Prepare the photosensitive film layer 1 by spin coating. The material of the photosensitive film layer 1 is photoresist. The rotation speed is 4000 rpm, the spin coating time is 40 s, and it is baked on a hot plate at 100°C for 3 minutes to form a photoresist layer with a thickness of 30 nm.

[0078] The structure prepared by steps 1-1 to 1-5 is as follows Figure 2 As shown in a in .

[0079] Step 1-6: Perform super-resolution lithography exposure and development on the photosensitive film layer 1, with an exposure dose of 200 mJ to obtain a grating structure with a period of 105 nm. The prepared structure is as follows Figure 2 As shown in b.

[0080] Step 1-7: Use IBE etching to transfer the photolithographic pattern structure of the photosensitive film layer 1 to the Ag layer, select an ion beam current of 260 mA, an incident angle of 10° (the angle between the normal line of the substrate and the ion beam current), and use 14 sccm of Ar gas for etching. The prepared structure is as follows Figure 2 As shown in c.

[0081] Step 1-8: Transfer the photolithographic pattern structure to SiO by RIE etching 2 layer, using 20 W RF power, 20 sccm CHF 3 The prepared structure is as follows Figure 2 As shown in d.

[0082] Step 1-9: Prepare 1:1 HNO 3 : DI aqueous solution, soak the above samples for 30 s to remove the Ag layer, then rinse and 2 Blow dry. The prepared structure is as follows Figure 2 As shown in e.

[0083] Step 1-10: Use ICP to treat the SOC in the groove, using 100W ICP RF power and 10W lower electrode power, 20 sccm C 4 F 8 gas.

[0084] Step 1-11: Use an atomic layer deposition system (ALD) to deposit a layer of SiO with a thickness of about 10 nm on the surface of the structure. 2 Due to the reduction of oxygen-containing groups on the SOC surface and the lack of precursor reaction sites, it is difficult to chemically adsorb SiO in the first few cycles. 2 , thus achieving selective deposition between the two materials. The prepared structure is as follows Figure 2 As shown in f.

[0085] The above AS-ALD process deposits SiO 2 The process temperature is set to 100 o C, using bis(diethylamino)silane (BDEAS) as the Si precursor, with 80 sccm high-purity N 2 As carrier gas, 200 sccm of high-purity N 2 Purge away excess precursor; O 2 Plasma was used as the second precursor by 80 sccm high purity N 2 As a carrier gas, it is introduced into the reaction chamber and reacts chemically with the adsorbed BDEAS under the action of a 200 W RF power source to form a layer of SiO 2 Molecular membrane; 200 sccm high purity N 2Purge the excess precursor and by-products. Repeat the above steps to 2 The surface thickness of SiO is about 10nm. 2 Membrane layer.

[0086] Figure 3 The X-ray photoelectron spectroscopy measurement results of the surface of a spin-on-carbon (SOC) film layer before and after F plasma treatment according to an embodiment of the present invention are schematically shown.

[0087] like Figure 3 As shown in the figure, the changes in oxygen and F content before and after SOC surface treatment are shown. After SOC is treated with F plasma, the number of O-containing groups on the surface is significantly reduced, while F radicals react with the SOC surface to form hydrophobic −CFx groups. Such chemical changes are expected to hinder the nucleation of ALD precursors during deposition.

[0088] Figure 4 The diagram schematically shows the selective size and graphic feature size of a spin-on-carbon (SOC) film layer before and after plasma treatment according to an embodiment of the present invention.

[0089] like Figure 4 As shown, the surface of the SOC film layer is treated with F-containing plasma. After the treatment, the selective deposition is about 10 nm and the graphic feature size is increased by about 20 nm.

[0090] Figure 5 The method for optimizing the quality of super-resolution lithography patterns by using atomic layer deposition according to an embodiment of the present invention is schematically shown, wherein the SiO 2 The dielectric layer and the SOC carbon-containing film layer are deposited with a certain thickness of SiO 2 Membrane layer.

[0091] like Figure 5 As shown, a to c are respectively 2 No film layer is deposited on the substrate, and 10 nm SiO is deposited 2 , deposit 20nm SiO 2 Thickness morphology; d to f are respectively the SOC substrate without film deposition and the SOC substrate with 10 nm SiO deposition. 2 , deposit 20 nmSiO 2 The results show that SiO 2 There was no deposition delay on the substrate, but there was a deposition delay on the SOC substrate, and deposition only started after the 10nm ALD process.

[0092] Figure 6Schematically showing the result of line edge roughness of grating patterns without applying the regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the present embodiment and using the regional selective deposition method provided by the present embodiment.

[0093] like Figure 6 As shown, the regional selective atomic layer deposition process for optimizing the quality of super-resolution lithography patterns provided in this embodiment is applied to grating patterns. After selective deposition of about 10 nm, the pattern edge roughness is significantly improved, and the line edge roughness (LER) is reduced from the original 6.7 nm to 4.9 nm.

[0094] Example 2

[0095] The implementation steps of a regional selective deposition method for optimizing the quality of super-resolution lithography patterns in this embodiment are as follows:

[0096] Step 2-1: Deposit a functional layer 5 on a substrate 6 by magnetron sputtering. The functional layer 5 is poly-Si with a thickness of 40 nm.

[0097] Step 2-2: Spin-coat a carbon-containing hard mask layer 4, wherein the carbon-containing hard mask layer 4 is a SOC material, with a rotation speed of 4000 rpm, a spin coating time of 30 s, and a spin coating time of 240 o C for 15 min to form a SOC layer with a thickness of 60 nm.

[0098] Step 2-3: Prepare the dielectric layer 3 by magnetron sputtering. The dielectric layer 3 is 40 nm thick Si 3 N 4 , the RF power is 400W.

[0099] Step 2-4: Deposit the metal layer 2 by magnetron sputtering. The material of the metal layer 2 is Ag, the thickness is 40 nm, and the DC power is 50 W.

[0100] Step 2-5: Prepare the photosensitive film layer 1 by spin coating. The material of the photosensitive film layer 1 is photoresist. The rotation speed is 4000 rpm, the spin coating time is 40 s, and it is baked on a hot plate at 100°C for 3 minutes to form a photoresist layer with a thickness of 30 nm.

[0101] The structure prepared by steps 2-1 to 2-5 is as follows Figure 2 As shown in a in .

[0102] Step 2-6: Expose and develop the photosensitive film layer 1, with an exposure dose of 150 mJ to obtain a grating structure with a period of 200 nm. Figure 2 As shown in b.

[0103] Step 2-7: Use IBE etching to transfer the photolithographic pattern structure of the photosensitive film layer 1 to the Ag layer, select an ion beam current of 260 mA, an incident angle of 10° (the angle between the normal line of the substrate and the ion beam current), and use 14 sccm Ar gas for etching. The prepared structure is as follows Figure 2 As shown in c.

[0104] Step 2-8: Transfer the photolithographic pattern structure to Si by RIE etching 3 N 4 layer, using 40 W RF power, 20 sccm CHF 3 and O 2 The prepared structure is as follows Figure 2 As shown in d.

[0105] Step 2-9: Prepare 1:1 HNO 3 : DI aqueous solution, soak the above samples for 30 s to remove the Ag layer, then rinse and 2 Blow dry. The prepared structure is as follows Figure 2 As shown in e.

[0106] Step 2-10: Use ICP to treat the SOC in the groove, using 100W ICP RF power and 10W lower electrode power, 20 sccm CF 4 gas.

[0107] Step 2-11: Use the atomic layer deposition system (ALD) to deposit a certain thickness of SiO on the surface of the structure. 2 Due to the reduction of oxygen-containing groups on the SOC surface and the lack of precursor reaction sites, it is difficult to chemically adsorb SiO in the first few cycles. 2 , thus achieving selective deposition between the two materials. The prepared structure is as follows Figure 2 As shown in f.

[0108] The above-mentioned ALD process deposits SiO 2 The process temperature is set to 100 o C, using bis(diethylamino)silane (BDEAS) as the Si precursor, with 80 sccm high-purity N 2 As carrier gas, 200 sccm of high-purity N 2 Purge away excess precursor; O 2 Plasma was used as the second precursor by 80 sccm high purity N 2 As a carrier gas, it is introduced into the reaction chamber and reacts chemically with the adsorbed BDEAS under the action of a 200 W RF power source to form a layer of SiO 2Molecular membrane; 200sccm high purity N 2 Purge the excess precursor and by-products. Repeat the above steps to obtain the desired thickness of SiO 2 Membrane layer.

[0109] The preparation method of regional selective atomic layer deposition for optimizing the quality of super-resolution lithography patterns provided in this embodiment uses F-containing plasma to treat the surface of the film layer. After the treatment, SiO 2 Deposited film on Si 3 N 4 The selectivity between the two substrates is about 9nm.

[0110] Figure 7 Schematically shows the result of line edge roughness of grating patterns without applying the regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the present embodiment and using the regional selective deposition method for optimizing the quality of super-resolution lithography patterns provided by the present embodiment.

[0111] like Figure 7 As shown, the regional selective atomic layer deposition process for optimizing the quality of super-resolution lithography patterns provided in this embodiment is applied to grating patterns. After selective deposition of about 9 nm, the CD increases by about 18 nm; the pattern edge roughness is significantly improved, and the LER is reduced from the original 6.5 nm to 4.9 nm.

[0112] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood 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, all of which belong to the scope of protection of the present invention.

Claims

1. A method for optimizing the quality of super-resolution lithography patterns by area selective deposition, characterized in that: include: Preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on a substrate; Performing super-resolution photolithography on the photosensitive film layer to form a super-resolution grating structure on the photosensitive film layer; Sequentially etching and transferring the graphic structure of the super-resolution grating structure to the metal layer and the dielectric layer, and removing the metal layer; The exposed carbon-containing film layer is surface treated, and based on the regional selective chemical adsorption of the precursor between the surface-treated carbon-containing film layer and the etched dielectric layer, a film layer is deposited on the surface and sidewall of the dielectric layer to obtain a super-resolution graphic with optimized graphic quality.

2. The method according to claim 1, characterized in that The surface treatment of the exposed carbon-containing film layer comprises: Chemically modifying the surface of the carbon-containing film layer by plasma treatment to reduce the oxygen content of the terminal groups on the surface of the carbon-containing film layer and increase the contact angle; The reaction gas used in the plasma treatment includes at least one of H2, CHF3, SF6, CF4, and C4F8, and the reaction power is 20 W to 100 W; the treatment time is 5 s to 120 s.

3. The method according to claim 1, characterized in that The method is based on the region-selective chemical adsorption of the precursor between the surface-treated carbon-containing film layer and the etched dielectric layer, depositing a film layer on the surface and sidewall of the dielectric layer to obtain a super-resolution pattern with optimized pattern quality, including: Using a carrier gas to introduce a first precursor into the reaction chamber, so that the first precursor is adsorbed on the surface of the dielectric layer; Using a purge gas to discharge the unadsorbed first precursor in the reaction chamber; Passing a second precursor into the reaction chamber, the second precursor reacts chemically with the first precursor to form a molecular film on the surface and sidewall of the dielectric layer; Excess second precursor and by-products in the reaction chamber are discharged by using purge gas to complete a deposition cycle; Repeat multiple deposition cycles to obtain super-resolution images with optimized image quality.

4. The method according to claim 3, characterized in that The first precursor includes one of bis(diethylamino)silane, diisopropylamine silane, tri(dimethylamino)silane (3DMAS), trisilylamine, tetra(ethylamino)titanium, titanium tetrachloride, and trimethylaluminum; the second precursor includes one of O2 plasma, H2O, and O3.

5. The method according to claim 3, characterized in that: The gas flow rate of the carrier gas is 30 sccm~100 sccm, the gas flow rate of the purge gas is 100 sccm~200 sccm, the introduction time of the first precursor is 80ms~200 ms, and the introduction time of the second precursor is 1 s~6 s; the purge time of the purge gas is 1 s~10 s; the temperature of the reaction chamber is 100 ℃~300 ℃.

6. The method according to claim 1, characterized in that The method of preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on a substrate comprises: forming the functional layer on the substrate by thermal oxidation, electron beam evaporation, magnetron sputtering deposition, chemical vapor deposition or coating; Depositing a carbon-containing material on the functional layer by magnetron sputtering, vacuum evaporation, spin coating, spray coating, a combination of spin coating and spray coating, or printing, and then baking to form the carbon-containing film layer; Forming the dielectric layer on the carbon-containing film layer by spin coating, spray coating, a combination of spin coating and spray coating, printing, electron beam evaporation or magnetron sputtering deposition; Forming the metal layer on the dielectric layer by electron beam evaporation or magnetron sputtering deposition; The photosensitive film layer is formed on the metal layer by a coating method, and the thickness of the photosensitive film layer is 15 nm to 40 nm.

7. The method according to claim 6, characterized in that The baking temperature is 100°C to 300°C, and the baking time is 10 min to 5 h.

8. The method according to claim 1 or 6, characterized in that: The material of the functional layer includes at least one of SiO2, SiN, poly-Si, TiN, and Al2O3, and the thickness of the functional layer is 10 nm to 500 nm; The material of the carbon-containing film layer includes at least one of spin-coated carbon, amorphous carbon, graphene and carbon nanotubes, and the thickness of the carbon-containing film layer is 10 nm to 200 nm; The material of the dielectric layer includes at least one of SiO2, TiO2, and Al2O3, and the thickness of the dielectric layer is 10 nm to 500 nm; The material of the metal layer includes Ag and Al, and the thickness of the metal layer is 20 nm to 50 nm.

9. The method according to claim 1, characterized in that: The step of sequentially etching the pattern of the super-resolution grating structure to the metal layer and the dielectric layer, and removing the metal layer, comprises: The metal layer is etched by an ion beam etching method to transfer the graphic structure of the super-resolution grating structure to the metal layer, and the etching gas includes Ar gas; Etching the dielectric layer by ion beam etching, reactive ion etching or inductively coupled plasma to transfer the graphic structure of the metal layer to the dielectric layer, wherein the etching gas includes at least one of SF6, CHF3 and Ar; The metal layer is removed by wet etching or mechanical stripping.

10. The method according to claim 1 or 6, characterized in that: The method of preparing a functional layer, a carbon-containing film layer, a dielectric layer, a metal layer and a photosensitive film layer stacked in sequence on a substrate further includes: The carbon-containing film layer and the dielectric layer are alternately deposited multiple times on the functional layer.

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