Euv metal photoresist and preparation method and application thereof

Abstract

The application discloses an EUV metal photoresist, a preparation method and application thereof. The photoresist composition comprises the following components: a compound A shown in the following formula, a chrysenyl B shown in the following formula, a photoacid generator, an organic solvent and an organic base. The photoresist can be used in EUV photoetching technology, has the characteristics of high resolution, high sensitivity and high photosensitivity, and has wide application prospects.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photoresist, and particularly relates to an EUV metal photoresist as well as a preparation method and application thereof. BACKGROUND

[0002] With the continuous development of modern semiconductor technology and its wide application in various fields such as electronic equipment, communication equipment information security and entertainment equipment, it has become the most dynamic technology field in the world, and widely penetrates into various aspects of our work and life. The manufacturing of integrated circuits is the core field of the semiconductor industry, and each update of integrated circuits cannot be separated from the change of photolithography technology. The development history of photolithography technology is the development history of integrated circuits, and the level of photolithography technology determines the manufacturing level of integrated circuits.

[0003] The principle of photolithography is to cover a layer of photoresist with high photosensitivity on the surface of a silicon wafer, and then use light (generally ultraviolet light, deep ultraviolet light and extreme ultraviolet light) to irradiate the surface of the silicon wafer through a mask. The photoresist irradiated by light will react. After that, the irradiated / unirradiated photoresist is washed away with a special solvent, and the transfer of the circuit diagram from the mask to the silicon wafer is realized. Photolithography technology has undergone changes in exposure modes such as contact / proximity, equal projection, reduced step projection and scanning step projection. The exposure wavelength has changed from full-spectrum exposure of 300-450nm, to 436nm G-line, 365nm I-line, 248nm KrF laser, to the most widely used 193nm ArF laser, and to the currently widely studied 13.5nm extreme ultraviolet light, electron beam and x-ray. The manufacturing node has changed from 0.5mm, 0.1mm, 90nm to 30nm, and even lower. Extreme ultraviolet lithography is different from traditional optical lithography in that it has a very short wavelength. However, most elements have strong absorption of extreme ultraviolet, so the traditional long-wavelength photoresist is not suitable for extreme ultraviolet lithography, and therefore a new extreme ultraviolet photoresist system needs to be developed. Photolithography technology is one of the most critical technologies in integrated circuit manufacturing. The successful use of each generation of photolithography technology greatly promotes the development of integrated circuits, making the integration of integrated circuits higher and higher and the cost lower and lower. Photolithography technology is a process flow of exposing the photoresist material coated on the surface of a semiconductor substrate to transfer the fine geometric pattern on the mask to the semiconductor substrate. The higher the resolution of the photolithography pattern, the higher the integration of the integrated circuit, and the smaller the critical dimension.

[0004] At present, the semiconductor industry has reached a consensus that Extreme Ultraviolet (EUV, 13.5 nm) lithography technology is a potential next-generation lithography technology. With extremely short wavelength, the final resolution will only be limited by the material properties of the photoresist. Using EUV lithography can produce higher resolution circuit diagrams, greatly improving the integration density of integrated circuits and the performance of electronic devices. Research on photoresists and lithography processes suitable for EUV lithography technology has become a hot and difficult point in lithography research.

[0005] EUV photoresists must have low light absorption, high transparency, high etch resistance, high resolution, high sensitivity, low exposure dose, high environmental stability, low gas production, and low line edge roughness. The development of EUV photoresists has been limited by three factors: resolution, line edge roughness, and photosensitivity, which generally have a mutually restrictive relationship. In early lithography technology, high molecular photoresists are most commonly used, so high molecular photoresist systems are first applied to EUV lithography. The industry urgently needs to develop EUV photoresists that improve resolution. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the shortcomings of the existing EUV photoresist, such as few types and poor selectivity. Thus, an EUV metal photoresist composition, a preparation method and application thereof are provided. The photoresist provided by the present application has the characteristics of high resolution, high sensitivity and high photosensitivity, and has a wide application prospect.

[0007] The present application provides a photoresist composition comprising the following components: a compound A represented by the following formula, a perylene B represented by the following formula, a photoacid generator, an organic solvent and an organic base;

[0008]

[0009] The compound A is 40-60 parts by weight, and the perylene B is 40-60 parts by weight.

[0010] In the photoresist composition, the photoacid generator can be a conventional photoacid generator in the field of photoresists, for example

[0011] In the photoresist composition, the organic solvent can be a conventional organic solvent in the field of photoresists, for example an ester solvent; preferably ethyl lactate.

[0012] In the photoresist composition, the organic base can be a conventional organic base in the field of photoresists, preferably a weak organic base, for example trioctylamine.

[0013] In the photoresist composition, the amount of the compound A is preferably 50 parts by weight.

[0014] The portion of the leuco crystal B in the photoresist composition is preferably 50 parts by weight.

[0015] The portion of the photoacid generator in the photoresist composition can be a portion conventional in the art, for example, 1-12 parts, preferably 9 parts by weight.

[0016] The portion of the organic solvent in the photoresist composition can be a portion conventional in the art, for example, 1500-2500 parts, preferably 2000 parts by weight.

[0017] The portion of the organic base in the photoresist composition can be a portion conventional in the art, preferably 0.2-1 parts, more preferably 0.5 parts by weight.

[0018] In a specific embodiment, the photoacid generator is 1-12 parts by weight of

[0019] The organic solvent is ethyl lactate in a portion of 1500-2500 parts by weight.

[0020] The organic base is trioctylamine in a portion of 0.2-1 parts by weight.

[0021] In a specific embodiment, the photoresist composition consists of the following components: the above-mentioned compound A, the above-mentioned leuco crystal B, the above-mentioned photoacid generator, the above-mentioned organic solvent and the above-mentioned organic base.

[0022] wherein the above-mentioned compound A refers to the type and content of the above-mentioned compound A; the above-mentioned leuco crystal B refers to the type and content of the above-mentioned leuco crystal B; the above-mentioned photoacid generator refers to the type and content of the above-mentioned photoacid generator; and the above-mentioned organic base refers to the type and content of the above-mentioned organic base.

[0023] The photoresist composition preferably consists of the following components of compound A, leuco crystal B, photoacid generator, organic solvent and organic base in any one of the following groups by weight:

[0024] Photoresist composition 1: 50 parts of the above-mentioned compound A, 50 parts of the above-mentioned leuco crystal B, 9 parts of the above-mentioned photoacid generator, 2000 parts of the above-mentioned organic solvent and 0.5 parts of the above-mentioned organic base;

[0025] Photoresist composition 2: 40 parts of the above-mentioned compound A, 40 parts of the above-mentioned leuco crystal B, 3 parts of the above-mentioned photoacid generator, 1500 parts of the above-mentioned organic solvent and 0.5 parts of the above-mentioned organic base;

[0026] Photoresist composition 3: 45 parts of the above-mentioned compound A, 45 parts of the above-mentioned leuco crystal B, 5 parts of the above-mentioned photoacid generator, 1700 parts of the above-mentioned organic solvent and 0.5 parts of the above-mentioned organic base.

[0027] Photoresist composition 4: 55 parts of said compound A, 55 parts of said diene B, 7 parts of said photoacid generator, 2100 parts of said organic solvent and 0.5 parts of said organic base;

[0028] Photoresist composition 5: 60 parts of said compound A, 60 parts of said diene B, 12 parts of said photoacid generator, 2500 parts of said organic solvent and 0.5 parts of said organic base;

[0029] Photoresist composition 6: 56 parts of said compound A, 48 parts of said diene B, 9 parts of said photoacid generator, 2000 parts of said organic solvent and 0.5 parts of said organic base;

[0030] Photoresist composition 7: 52 parts of said compound A, 56 parts of said diene B, 9 parts of said photoacid generator, 2000 parts of said organic solvent and 0.5 parts of said organic base;

[0031] Photoresist composition 8: 40 parts of said compound A, 60 parts of said diene B, 9 parts of said photoacid generator, 2000 parts of said organic solvent and 0.5 parts of said organic base.

[0032] In photoresist compositions 1-8, said photoacid generator is said organic solvent is ethyl lactate and said organic base is trioctylamine.

[0033] The present application also provides a method for preparing a photoresist composition, which comprises the following steps: mixing the components of said photoresist composition uniformly, and then the preparation is completed.

[0034] After mixing, a filtration step can be further included. The filtration can be performed by conventional methods, and preferably by using an ultra-high molecular weight polyethylene membrane. The pore size of said ultra-high molecular weight polyethylene membrane is preferably 0.1 μm.

[0035] The present application also provides a method for forming a pattern by using a photoetching technique, which comprises the following steps:

[0036] Step 1: coating the photoresist composition described above on the surface of a substrate, baking, and obtaining a photoresist layer;

[0037] Step 2: exposing the photoresist layer obtained in Step 1 to light, baking, developing, and obtaining a photoresist pattern.

[0038] In Step 1, the substrate can be conventional substrates in the art, and preferably is a wafer, such as an 8-inch wafer.

[0039] In Step 1, the coating method can be conventional methods in the art, and preferably is spin coating by using a spin coater.

[0040] In step 1, when spin-coating is selected, the number of rotations of the spin coater is preferably 2000-3000 rpm, for example 2500 rpm.

[0041] In step 1, the thickness of the photoresist layer can be a conventional thickness in the art, preferably 40-60 nm, for example 50 nm.

[0042] In step 1, the baking temperature can be a conventional baking temperature in the art, preferably 70-90°C, for example 80°C.

[0043] In step 1, the baking time can be a conventional baking time in the art, preferably 50-70 seconds, for example 60 seconds.

[0044] In step 2, the baking temperature can be a conventional baking temperature in the art, preferably 120-140°C, for example 130°C.

[0045] In step 2, the baking time can be a conventional baking time in the art, preferably 50-70 seconds, for example 60 seconds.

[0046] In step 2, the development can be a conventional operation in the art, and the developer generally used is aqueous tetramethylammonium hydroxide, for example aqueous tetramethylammonium hydroxide having a mass fraction of 2.38%.

[0047] Without departing from the common general knowledge in the art, the above-mentioned preferred conditions can be combined in any manner, thereby obtaining various preferred examples of the present application.

[0048] The resin of the present application is self-made, and the other reagents and materials used are commercially available.

[0049] The positive progress effect of the present application is that the photoresist provided by the present application has the characteristics of high resolution, photosensitivity and low line edge roughness. Therefore, the EUV metal photoresist composition of the present application has good performance. DETAILED DESCRIPTION

[0050] The present application will be further illustrated by the following examples, but the present application is not limited to the scope of the examples. The experimental methods in the following examples, for which no specific conditions are indicated, are selected according to conventional methods and conditions, or according to the instructions of the goods.

[0051] Preparation of photoresist compositions Examples 1-8 and Comparative Examples 1-8

[0052] The components were mixed uniformly according to the combination and content shown in Table 1, filtered using a 0.1 μm ultra-high molecular weight polyethylene film, and photoresist compositions were obtained;

[0053] Compound A is

[0054] wherein the photolatent acid is

[0055] wherein wherein the photolatent acid is The organic solvent is ethyl lactate; the organic base is trioctylamine.

[0056] Table 1

[0057]

[0058] Effect Examples

[0059] 1. EUV exposure and detection

[0060] Preparation of photoresist film and exposure: The prepared photoresist was coated on an 8-inch wafer using a spin coater at a rotation speed of 2500 RPM, and heated on a hot plate at 80°C for 60 seconds to obtain a photoresist film. The average film thickness was measured to be 50 nm by measuring 25 points using an optical film thickness measurement system F50 (Filmetrics). Extreme ultraviolet exposure was performed on the Shanghai Synchrotron Radiation Facility Interference Lithography Line (BL08U1B), followed by baking at 130°C for 60 seconds. Finally, development was performed in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH), thereby obtaining a pattern.

[0061] LER measurement: The LER of the 50-nm LS pattern was measured under FE-SEM (Hitachi SU9000).

[0062] LWR measurement: The LWR of the 50-nm LS pattern was measured under CD-SEM (HITACHI, CD-SEM, CG5000).

[0063] Sensitivity detection: The Eth value was used as an index for sensitivity. Stepwise 25-point exposure was performed on an 8-inch wafer at different energies (e.g., 0.5 mJ / cm 2 , 1 mJ / cm 2 , 1.5 mJ / cm 2 ...), followed by post-exposure baking (PEB), development, and measurement of the film thickness. The film thickness just reaching 0 nm was recorded as Eth.

[0064] Resolution detection: Under the conditions given above for sensitivity, the limiting resolution (the minimum limit width when separating and resolving lines and spaces) at the exposure dose (the dose of electron beam irradiation) was taken as the LS resolution.

[0065] Table 2

[0066]

[0067]

[0068] 2. EB exposure and detection

[0069] Photoresist film preparation and exposure: The photoresist was coated on an 8-inch wafer using a spin coater at a rotation speed of 2500 RPM and heated on a hot plate at 80°C for 60 seconds to obtain a photoresist film. The average film thickness was measured to be 50 nm by measuring 25 points using an optical film thickness measurement system F50 (Filmetrics). The photoresist was exposed to an electron beam using an EB writing system Elionix ELS-G100 (elionix, acceleration voltage 100 KeV) and then baked at 130°C for 60 seconds under conditioning. Finally, it was developed in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH), thereby obtaining a pattern.

[0070] Eop: The optimal exposure (Eop) was defined as an exposure dose that provides 1:1 resolution at the top and bottom of a 50-nm 1:1 line-and-space (LS) pattern.

[0071] LER measurement: The LER of a 50-nm LS pattern was measured under FE-SEM (Hitachi SU9000).

[0072] LWR measurement: The LWR of a 50-nm LS pattern was measured under CD-SEM (HITACHI, CD-SEM, CG5000).

[0073] Resolution detection: Under the conditions given above Eop, the limit resolution (the minimum limit width when separating and resolving lines and spaces) at the exposure dose (the dose of electron beam irradiation) was taken as the LS resolution.

[0074] Table 3

[0075]

[0076]

Claims

1. A photoresist composition characterized by comprising: A compound A represented by the following formula, a pyrene B represented by the following formula, a photoacid generator, an organic solvent, and an organic base; The compound A is in a proportion of 40-60 parts by weight, and the pyrene B is in a proportion of 40-60 parts by weight.

2. The photoresist composition of claim 1, wherein The photoresist composition satisfies one or more of the following conditions; (1) the photoacid generator is (2) The organic solvent is an ester solvent; (3) The organic base is an organic weak base.

3. The photoresist composition of claim 1, wherein The organic solvent is ethyl lactate; And / or, the organic base is trioctylamine.

4. The photoresist composition of claim 1, wherein The photoresist composition satisfies one or more of the following conditions; (1) The compound A is in a proportion of 50 parts by weight; (2) The pyrene B is in a proportion of 50 parts by weight; (3) The photoacid generator is in a proportion of 1-12 parts by weight; (4) The organic solvent is in a proportion of 1500-2500 parts by weight; (5) The organic base is in a proportion of 0.2-1 parts by weight.

5. The photoresist composition of claim 4, wherein The photoresist composition satisfies one or more of the following conditions; (1) The photoacid generator is in a proportion of 9 parts by weight; (2) The organic solvent is in a proportion of 2000 parts by weight; (3) The organic base is in a proportion of 0.5 parts by weight.

6. The photoresist composition of claim 1, wherein said photoacid generator is 1-12 parts by weight of The organic solvent is ethyl lactate in a proportion of 1500-2500 parts by weight; The organic base is trioctylamine in a proportion of 0.2-1 parts by weight.

7. The photoresist composition of any one of claims 1 to 6, wherein the photoresist composition is a negative photoresist composition. It is composed of the compound A, the pyrene B, the photoacid generator, the organic solvent, and the organic base.

8. The photoresist composition of claim 1, wherein It is composed of the compound A, the pyrene B, the photoacid generator, the organic solvent, and the organic base. Photoresist composition 1: 50 parts of the compound A, 50 parts of the pyrene B, 9 parts of the photoacid generator, 2000 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 2: 40 parts of the compound A, 40 parts of the pyrene B, 3 parts of the photoacid generator, 1500 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 3: 45 parts of the compound A, 45 parts of the pyrene B, 5 parts of the photoacid generator, 1700 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 4: 55 parts of the compound A, 55 parts of the pyrene B, 7 parts of the photoacid generator, 2100 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 5: 60 parts of the compound A, 60 parts of the pyrene B, 12 parts of the photoacid generator, 2500 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 6: 56 parts of the compound A, 48 parts of the pyrene B, 9 parts of the photoacid generator, 2000 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 7: 52 parts of the compound A, 56 parts of the pyrene B, 9 parts of the photoacid generator, 2000 parts of the organic solvent, and 0.5 parts of the organic base; Photoresist composition 8: 40 parts of the compound A, 60 parts of the pyrene B, 9 parts of the photoacid generator, 2000 parts of the organic solvent, and 0.5 parts of the organic base; In the photoresist compositions 1-8, the photoacid generator is The organic solvent is ethyl lactate and the organic base is trioctylamine.

9. A method for producing the photoresist composition according to any one of claims 1 to 8, characterized by, The components of the photoresist composition are mixed uniformly, and then the photoresist composition is ready.

10. A method of patterning by photolithography, characterized by, The method comprises the following steps: Step 1: coating the photoresist composition according to any one of claims 1-8 on the surface of a substrate, baking to obtain a photoresist layer; Step 2: exposing the photoresist layer obtained in step 1, baking, developing to obtain a photoresist pattern.

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