CN111533915B

CN111533915B - Hybrid giant molecule and method for forming highly ordered vertical domain structure and patterning by using same

Info

Publication number: CN111533915B
Application number: CN202010340984.3A
Authority: CN
Inventors: 黄树彬; 文韬
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2021-09-21
Anticipated expiration: 2040-04-26
Also published as: CN111533915A

Abstract

The invention discloses a hybrid giant molecule and a method for forming a highly ordered vertical domain structure and patterning thereof. The hybrid giant molecule is formed by covalently linking an edge-modified polyhedral oligomeric silsesquioxane head (XPOSS) and a polymer tail chain. The invention provides a method for inducing self-assembly of hybrid giant molecules to form a highly ordered vertical phase domain structure and patterning thereof by utilizing a short-time and efficient solvent annealing and thermal annealing combined method. The self-assembly and patterning of the hybrid giant molecule are remarkably different from those of the traditional block copolymer, and the hybrid giant molecule is characterized in that the characteristic size (feature size) of the pattern is small (<5nm), a highly ordered vertical domain can be quickly formed, the Line Edge Roughness (LER) is low, the etching selectivity is high, and the requirements of half pitch (half pitch) <10nm of the next generation processing technology in the semiconductor industry are fully met.

Description

Hybrid giant molecule and method for forming highly ordered vertical domain structure and patterning by using same

Technical Field

The invention relates to the field of nano-structure manufacturing, in particular to a hybrid giant molecule and a method for forming a highly ordered vertical domain structure and patterning thereof.

Background

With the advent of the 5G and internet of things era, the demand for integrated circuits with higher integration degree is also increasing. Because the greater the number of transistors integrated on a chip per unit area, the faster the circuit operates and the lower the energy consumption. The development of the semiconductor industry has followed moore's law since the last 60 th generation: the number of transistors integrated on a semiconductor chip doubles every 18-24 months, but the transistor number density doubles only every three to four years in the time expected by the 2010 international semiconductor technology development roadmap.

The semiconductor industry has slowed down primarily because the 193nm immersion lithography technology currently leading the semiconductor industry is approaching its ultimate resolution, and a single exposure can only produce structures with half-pitches greater than 22 nm. The structure with half pitch larger than 10nm can be obtained by the multiple exposure at the lowest, and the requirement of the multiple exposure on the alignment precision is very high. For next generation sub-10 nm patterning, several emerging processes may become suitable. Extreme Ultraviolet (EUV) lithography can be processed to produce structures with dimensions less than 10nm, but one EUV lithography machine currently costs up to 1 billion dollars and is expensive. Electron beam lithography also allows smaller patterns to be obtained, but is limited by its single-thread nature, low processing efficiency, and high cost. In the semiconductor industry, the block polymer etching method is selected as an alternative scheme for preparing a half pitch less than 10nm in the last decade, and the technology can obtain a structure with a smaller size, has high processing efficiency and low cost and has high potential.

The block copolymer etching method is a technique of transferring and etching a pattern generated by phase separation of a polymer onto a substrate using a block copolymer thin film as a template. The block copolymer is formed by connecting two or more than two different homopolymers through covalent bonds, and can be self-assembled to generate a periodic nano structure of 5-100 nm through microphase separation. The diblock copolymer (A-B-B) is the block copolymer having the simplest structure. By changing the ratio of the two blocks, different phase morphologies such as a spherical phase (S), a columnar phase (C), and a lamellar phase (L) can be obtained. Block copolymer etching methods currently face several problems: two-phase interaction parameters, domain orientation, two-phase etch selectivity, and structural order. Conventional organic block polymers generally have a small value of the interaction parameter χ, such as PS-b-PMMA (χ ═ 0.039, 150 ℃, Macromolecules, 2008, 41, 9948), and can only produce structures of > 12 nm. The vertically oriented columnar phase and the single-layer spherical phase film can be used as templates for preparing the dot array structure, but the vertically oriented columnar phase has a uniform section due to a higher depth-to-width ratio, so that the transfer of patterns is facilitated; the vertically oriented lamellar phase and the parallel oriented columnar phase can be used as templates for preparing line structures, but the vertically oriented lamellar phase has high depth-to-width ratio and uniform section, and is more favorable for pattern transfer. However, since the interaction of the two phases at the film interface is usually different, the block copolymers often form a parallel oriented structure. Block polymers with high two-phase etch selectivity are also good for pattern transfer, but conventional organic block polymers also have low etch selectivity (polymer, 2013, 54, 1269). Due to the presence of chain entanglement, the structures formed by block copolymers are generally relatively disordered (science, 2000, 290, 1558; nature, 2003, 424, 411; advanced materials, 2004, 16, 1736).

Disclosure of Invention

In order to overcome the above-mentioned disadvantages of the prior art, the present invention provides a hybrid giant molecule and a method for forming a highly ordered vertical domain structure and patterning thereof. The hybrid giant molecule is formed by covalently linking an edge-modified polyhedral oligomeric silsesquioxane head (XPOSS) and a polymer tail chain.

The invention provides a hybrid giant molecule aiming at the defects of a block polymer in patterning application, which can form a low-line edge roughness structure with a half pitch of less than 5nm, less chain entanglement and high two-phase etching selectivity. The invention also provides a method for simply and rapidly forming a highly ordered vertical phase domain structure.

The purpose of the invention is realized by at least one of the following technical solutions.

The invention provides a hybrid giant molecule which is a polyhedral oligomeric silsesquioxane head group (SRCH) modified by edges₂CH₂SiO_1.5)_nCovalently linked to a polymer tail chain;

wherein R is a modifying group, and is selected from one of alkyl, fluorinated alkyl, hydroxyl modified alkyl, carboxyl modified alkyl, amino modified alkyl and a polymer chain; n is the number of the head base peaks (the number of the polyhedron peaks) of the hybridized giant molecule, and the value range of n is 6-12;

the polymer tail chain is selected from one or more than two homopolymers and block copolymers of polystyrene, poly-p-methylstyrene, poly-p-trimethylsilylstyrene, poly-p-fluorostyrene, poly-2-vinylpyridine, poly-4-vinylpyridine, polymethyl acrylate, polymethyl methacrylate, polydimethylsiloxane, polyisoprene, polyethylene, polypropylene, polyacrylonitrile, polybutadiene, polyimide, polyurethane, polypropylene oxide, polyvinyl chloride and polyvinyl fluoride.

Further, the topological structure of the hybrid giant molecule is selected from one of a head group and a tail chain, a head group and p tail chains, q head groups and a tail chain, and q head groups and p tail chains; wherein the value range of p is 2-6, and the value range of q is 2-6.

Further, n has a value of 6, 8, 10 or 12.

Further, the value of n is 8, R is 2, 3-dihydroxypropyl, and the tail chain of the polymer is polystyrene; the molecular weight of the hybrid giant molecule is 1500-. The hybrid giant molecule is designated DPOSS-PS.

Further, the molecular weight of the polymer tail chain is 2.8k or 6.6 k. When the molecular weight of the polymer tail chain is 2.8k, the hybrid giant molecule is designated as DPOSS-PS_2.8k(ii) a When the molecular weight of the polymer tail chain is 6.6k, the hybrid giant molecule is designated as DPOSS-PS_6.6k。

The invention provides a method for forming a highly ordered vertical phase domain structure by using hybridized giant molecules, which comprises the following steps:

and dissolving the hybridized giant molecules in a solvent, then spin-coating the solvent on a substrate, and carrying out solvent annealing treatment and thermal annealing treatment to obtain the film with the highly ordered vertical phase domain structure.

Further, the solvent is selected from one of tetrahydrofuran, acetone, chloroform, dichloromethane, ethyl acetate and N, N' -dimethylformamide; the mass-volume ratio of the hybridized giant molecules to the solvent is 1: 1-1: 50 mg/mL.

Preferably, the solvent is tetrahydrofuran.

Further, the substrate is selected from one of silicon wafer, mica, metal, indium tin oxide glass, carbon-plated silicon wafer, carbon-plated mica, carbon-plated metal and carbon-plated indium tin oxide glass.

Preferably, the substrate is carbon-coated mica.

Further, the solvent for annealing treatment of the solvent is selected from one of chloroform, tetrahydrofuran, toluene and acetone; the temperature of the solvent annealing treatment is 10-50 ℃, and the time of the solvent annealing treatment is 20min-2 h; the temperature of the thermal annealing treatment is 100-180 ℃, and the time of the thermal annealing treatment is 1-10 min.

The invention also provides a method for patterning the hybrid giant molecule. The method comprises the following steps: performing reactive ion etching on the hybridized giant molecule to obtain a patterned hybridized giant molecule; parameters of the reactive ion etching: CF (compact flash)₄Gas flow rate and O₂The gas flow rate ratio was 6: 2-10: 2 SCCM; the pressure is 5-15 mT; the power is 30-40W, and the time is 40-80 s; the temperature was room temperature.

The self-assembly and patterning of the hybrid giant molecule provided by the invention are remarkably different from those of the traditional block copolymer, and the hybrid giant molecule is characterized in that the characteristic size (feature size) of the pattern is very small (<5nm), a highly ordered vertical domain can be quickly formed, the Line Edge Roughness (LER) is low, the etching selectivity is high, and the requirements of half pitch (half pitch) of the next generation processing technology in the semiconductor industry <10nm are fully met.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention breaks the situation of patterning by using the traditional block polymer, provides a novel hybridized giant molecule and obtains a low-line edge roughness structure with the half pitch less than 5 nm;

(2) compared with a template method, the invention provides a method for simply and efficiently obtaining the highly ordered vertical domain structure without external template induction;

(3) the present invention obtains patterns by reactive ion etching methods commonly used in the semiconductor industry.

Drawings

FIG. 1 is DPOSS-PS_2.8kTEM electron micrograph of the body section;

FIG. 2 is a TEM micrograph of the sample obtained in example 1 of the present invention;

FIGS. 3a, 3b, 3c and 3d are TEM images of thin film structures obtained by solvent annealing with tetrahydrofuran, acetone, toluene and chloroform in example 2 of the present invention, respectively;

FIG. 4 is a TEM image at different magnifications provided by example 3 of the present invention;

FIG. 5a shows an area of 2.6X 2.6 μm in example 3 of the present invention²Fig. 5b is the fast fourier transform of fig. 5a, and fig. 5c is an enlarged view of the area within the dashed box of fig. 5 a;

FIG. 6 is DPOSS-PS_6.6kA small angle X-ray scattering curve of (a);

FIGS. 7a and 7b are TEM photographs provided in example 4 of the present invention;

FIGS. 8a and 8b are a height diagram and a phase diagram of an AFM provided in example 11 of the present invention, respectively;

FIG. 9 is a TEM photograph provided by comparative example 1 of the present invention;

FIGS. 10a and 10b are a height diagram and a phase diagram of an AFM provided by comparative example 2 of the present invention, respectively;

fig. 11a and 11b are a height diagram and a phase diagram of the AFM provided by comparative example 3 of the present invention, respectively.

Detailed Description

The following examples are presented to further illustrate the practice of the invention, but the practice and protection of the invention is not limited thereto. It is noted that the processes described below, if not specifically described in detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are not indicated to the manufacturer, and are considered to be conventional products available by commercial purchase.

Example 1

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL tetrahydrofuran solvent; after being fully dissolved, the mixture is coated on a carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. The film was annealed at 120 ℃ for 15 min.

DPOSS-PS is known_2.8kThe bulk self-assembles to form a lamellar phase, d is 8.9nm as measured by small angle X-ray scattering, so its half pitch is 4.5nm<5nm, FIG. 1 is a TEM image of a bulk section thereof. As can be seen from the transmission electron microscope photographs shown in FIGS. 2a and 2b, a large-area continuous linear structure is generated after short-time thermal annealing, but the structural order degree is poor, and the line pattern indicates that a vertical phase domain structure is formed.

The DPOSS-PS_2.8kThe structural formula of (A) is as follows:

example 2

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And respectively placing the films on platforms of closed tanks which are filled with 10mL of tetrahydrofuran, acetone, toluene and chloroform and have the capacity of 200mL at room temperature for annealing for 30min to obtain the annealed films.

The morphology after annealing with tetrahydrofuran, acetone, toluene and chloroform is shown in the TEM photographs of fig. 3a, 3b, 3c and 3d, respectively. Through comparison, the film annealed by toluene has the most disordered structure and simultaneously has linear and dot structures, and the films annealed by other three solvents only have the linear structure, wherein the film annealed by acetone and chloroform has the highest degree of order, and the film annealed by tetrahydrofuran has the next highest degree of order.

Example 3

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 3min at 120 ℃ to obtain the annealed film.

As can be seen from fig. 4a and 4bAnnealing under the condition forms a highly ordered vertical phase domain structure, the defect density is extremely low, the edge roughness of lines is extremely low as can be clearly seen from fig. 4b, and the half pitch obtained by measurement is 4.9 nm. From FIGS. 5a, 5b and 5c, it can be seen that the film has a relatively large area (at least 2.6X 2.6 μm)²) All forming such a highly ordered structure.

Example 4

5mg of DPOSS-PS was taken_6.6kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 3min at 120 ℃ to obtain the annealed film.

The DPOSS-PS_6.6kThe structural formula of (A) is as follows:

FIG. 6 is a DPOSS-PS_6.6kSAXS curve of (A), DPOSS-PS from FIG. 6_6.6kThe bulk structure is hexagonal columnar phase, d is 10.8nm as measured by small angle X-ray scattering, so its half pitch is 5.4 nm. From the TEM photographs shown in fig. 7a and 7b, it can be seen that the highly ordered vertical domains, i.e., dot-shaped array structures, can also be induced by the chloroform solvent annealing for 30min and 120 ℃ annealing for 3 min.

Example 5

Taking 1mg of DPOSS-PS_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 3min at 120 ℃ to obtain the annealed film. The thin film prepared in example 5 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 6

Taking 50mg of DPOSS-PS_2.8kDissolved in 1mL of tetrahydroAnd (3) a furan solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 3min at 120 ℃ to obtain the annealed film. The thin film prepared in example 6 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 7

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform at the temperature of 10 ℃ for 2h, taking out the film, and then annealing the film at the temperature of 120 ℃ for 3min to obtain the annealed film. The thin film prepared in example 7 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 8

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform at the temperature of 50 ℃ for 20min, taking out the film, and then annealing the film at the temperature of 120 ℃ for 3min to obtain the annealed film. The thin film prepared in example 8 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 9

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 10min at the temperature of 100 ℃ to obtain the annealed film. The thin film prepared in example 9 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 10

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of tetrahydrofuran solutionAnd (3) preparing. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. And (3) annealing the film on a platform of a closed tank with the capacity of 200mL and containing 10mL of chloroform for 30min at room temperature, taking out the film, and then annealing the film for 1min at 180 ℃ to obtain the annealed film. The thin film prepared in example 10 also has a highly ordered vertical domain structure, as can be seen in fig. 4a and 4 b.

Example 11

Etching DPOSS-PS by reactive ion etching_2.8kThe parameters of the reactive ion etching method: flow rate CF₄:O₂When the ratio is 8: 2(SCCM), pressure 10mT, temperature room temperature, power 35W, duration 60 s.

As can be seen from the AFM photographs shown in fig. 8a and 8b, the method can etch a pattern.

Example 12

Etching DPOSS-PS by reactive ion etching_2.8kIs sliced into slices at a gas flow rate CF₄:O₂6: 2(SCCM), pressure 15mT, temperature room temperature, power 40W, duration 80 s. Example 12 was also patterned as shown in fig. 8a and 8 b.

Example 13

Etching DPOSS-PS by reactive ion etching_2.8kIs sliced into slices at a gas flow rate CF₄:O₂10: 2(SCCM), pressure 5mT, temperature room temperature, power 30W, duration 40 s. Example 13 was also patterned as shown in fig. 8a and 8 b.

Comparative example 1

5mg of DPOSS-PS was taken_2.8kDissolved in 1mL of toluene solvent. After the materials are fully dissolved, the materials are coated on the carbon-plated mica substrate in a rotating speed of 1500rpm to prepare a film. The film was annealed at 120 ℃ for 15 min.

Comparing fig. 2a and fig. 2b, it can be seen from fig. 9 that the sample prepared by spin coating with toluene-dissolved DPOSS-PS does not form a significant microphase separation after 15min thermal annealing.

Comparative example 2

Etching DPOSS-PS by reactive ion etching_2.8kSlicing the body of (1), gas flow rate O₂10(SCCM), pressure 10mT, temperature room temperature, power 35W, duration 60 s.

As can be seen from the AFM photographs shown in fig. 10a and 10b, this method cannot etch a pattern.

Comparative example 3

Etching DPOSS-PS by reactive ion etching_2.8kIs sliced into slices at a gas flow rate CF₄:O₂10: 1(SCCM), pressure 10mT, temperature room temperature, power 35W, duration 60 s.

As can be seen from the AFM photographs shown in fig. 11a and 11b, this method cannot etch a pattern.

The above examples are only preferred embodiments of the present invention, which are intended to be illustrative and not limiting, and those skilled in the art should understand that they can make various changes, substitutions and alterations without departing from the spirit and scope of the invention.

Claims

1. A method for forming a highly ordered vertical domain structure from a hybrid giant molecule, comprising the steps of:

dissolving the hybridized giant molecules in a solvent, then spin-coating the solvent on a substrate, and carrying out solvent annealing treatment and thermal annealing treatment to obtain a film forming a highly ordered vertical phase domain structure;

the solvent is one selected from tetrahydrofuran, acetone, chloroform, dichloromethane, ethyl acetate and N, N' -dimethylformamide; the mass-volume ratio of the hybridized giant molecules to the solvent is 1: 1-50: 1 mg/mL;

the solvent for annealing treatment is selected from one of chloroform, tetrahydrofuran and acetone; the temperature of the solvent annealing treatment is 10-50 ℃, and the time of the solvent annealing treatment is 20min-2 h; the temperature of the thermal annealing treatment is 100-180 ℃, and the time of the thermal annealing treatment is 1-10 min;

the hybrid giant molecule consists of an edge-modified polyhedral oligomeric silsesquioxane head group (SRCH)₂CH₂SiO_1.5)_nCovalently linked to a polymer tail chainForming;

wherein R is a modifying group, and is selected from one of alkyl, fluorinated alkyl, hydroxyl modified alkyl, carboxyl modified alkyl and amino modified alkyl; n is the number of head base vertices of the hybridized giant molecule, and the value range of n is 6-12;

the polymer tail chain is selected from polystyrene;

the molecular weight of the hybrid giant molecule is 1500-.

2. The method of claim 1, wherein the topological structure of the hybrid giant molecule is selected from one of a head group and a tail chain, a head group and p tail chains, q head groups and a tail chain, and q head groups and p tail chains; wherein the value range of p is 2-6, and the value range of q is 2-6.

3. The method of claim 1, wherein n is 6, 8, 10 or 12.

4. The method of claim 1, wherein n is 8, R is 2, 3-dihydroxypropyl, and the polymer tail is polystyrene.

5. The method of claim 4, wherein the molecular weight of the polymer tail chain is 2.8k or 6.6 k.