Ultralow dielectric mesoporous organosilicon film and preparation method thereof

Abstract

The present invention relates to the field of chemical industry, and discloses organosilicone micro-mesoporous ultra-low dielectric thin films and preparation methods therefor. A structural formula of a POSS-based organosilane precursor in the thin film is as follows: ##STR00001## where n is 12, 16, 18, 20, or 22, and X is CH.sub.3 or CH.sub.2CH.sub.3. The preparation method includes the following steps: dissolving a certain amount of the POSS-based precursor in an organic solvent at a room temperature; adding an appropriate amount of a photoacid generator, after uniformly stirring, spraying a mixed liquid to form a film on a substrate; placing the substrate under a light-emitting diode lamp for irradiating for a preset time after the organic solvent is completely evaporated; then placing the substrate in N,N-dimethylformamide for undergoing a transesterification reaction with fluoroalkyl alcohol for 24-72 h; and washing and drying to obtain the organosilicone micro-mesoporous ultra-low dielectric thin film. Compared with existing ultra-low dielectric thin films, the obtained thin film has a lower dielectric constant (1.89), and is better in dielectric stability in a humid environment, simple to operate, and high in polymerization speed.

Claims

1. A preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film, wherein a structural formula of a POSS-based organosilane precursor in the thin film is as follows: ##STR00003## wherein n is 12, 16, 18, 20, or 22, and X is CH.sub.3 or CH.sub.2CH3, comprising the following steps: dissolving a POSS-based precursor in an organic solvent at a room temperature; adding an appropriate amount of a photoacid generator; after uniformly stirring, spraying a mixed liquid to form a film on a substrate; placing the substrate under a light-emitting diode lamp for irradiating for a preset time after the organic solvent is completely evaporated; then placing the substrate in N,N-dimethylformamide for undergoing a transesterification reaction with short-chain fluoroalkyl alcohol for 24-72 h; and washing and drying to obtain the organosilicone micro-mesoporous ultra-low dielectric thin film.

2. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein the substrate is conductive glass or a silicon wafer.

3. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein a mass ratio of the POSS-based precursor to the photoacid generator is 10:0.05-1.

4. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein a molar concentration of the short-chain fluoroalkyl alcohol is 0.01-0.05 mol/L.

5. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein placing the substrate under a light-emitting diode lamp further comprises placing the substrate under a light emitting diode lamp emitting a specific wavelength of 320 nm, 365 nm, or 405 nm.

6. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein placing the substrate under a light-emitting diode lamp further comprises placing the substrate under a light emitting diode lamp having a power of 0.1-20 mW/cm.sup.2.

7. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein the preset time is 30-60 min.

8. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein the photoacid generator is 4-isobutyl phenyl-4′-methyl phenyl iodohexafluorophosphate, 2-methyl-α-[2-[[propylsulfonyl]imine]-3(2H)-thiophen-methylene-phenylacetonitrile, or 4-octyloxy diphenyl iodonium hexaflurorantimonate.

9. The preparation method for the organosilicone micro-mesoporous ultra-low dielectric thin film according to claim 1, wherein the fluoroalkyl alcohol is 2,2,2-trifluoroethanol, 3,3,3-trifluoro-1-propanol, 4,4,4-trifluoro-1-butanol, or 1H,1H,2H,2H-perfluorohexan-1-ol.

Description

DETAILED DESCRIPTION

(1) The present invention is described in details below with reference to specific embodiments.

Embodiment 1

(2) At a room temperature, 0.5 g of a POSS-based precursor (as shown in FIG. 1, n=12, X═CH.sub.2CH.sub.3) is dissolved in 5 mL of a tetrahydrofuran solvent; 0.005 g of 4-isobutyl phenyl-4′-methyl phenyl iodohexafluorophosphate (1250) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 320 nm and 0.1 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 10 mL of an N,N-DMF solution having 0.05 mol/L of 2,2,2-trifluoroethanol for undergoing a transesterification reaction for 24 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

Embodiment 2

(3) At a room temperature, 0.5 g of a POSS-based precursor (as shown in FIG. 1, n=16, X═CH.sub.3) is dissolved in 7 mL of a tetrahydrofuran solvent; 0.01 g of 4-octyloxy diphenyl iodonium hexaflurorantimonate (OPHA) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 365 nm and 0.5 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 10 mL of an N,N-DMF solution having 0.05 mol/L of 2,2,2-trifluoroethanol for undergoing a transesterification reaction for 24 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

Embodiment 3

(4) At a room temperature, 0.5 g of a POSS-based precursor (as shown in FIG. 1, n=18, X═CH.sub.3) is dissolved in 7 mL of a tetrahydrofuran solvent; 0.0025 g of 2-methyl-α-[2-[[propylsulfonyl]imine]-3(2H)-thiophen-methylene-phenylacetonitrile (PAG103) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 405 nm and 2 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 10 mL of an N,N-DMF solution having 0.02 mol/L of 4,4,4-trifluoro-1-butanol for undergoing a transesterification reaction for 24 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

Embodiment 4

(5) At a room temperature, 0.5 g of a POSS-based precursor (as shown in FIG. 1, n=18, X═CH.sub.3) is dissolved in 7 mL of a tetrahydrofuran solvent; 0.0025 g of 2-methyl-α-[2-[[propylsulfonyl]imine]-3(2H)-thiophen-methylene-phenylacetonitrile (PAG103) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 405 nm and 2 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 10 mL of an N,N-DMF solution having 0.01 mol/L of 3,3,3-trifluoro-1-propanol for undergoing a transesterification reaction for 48 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

Embodiment 5

(6) At a room temperature, 0.5 g of a POSS-based precursor (as shown in FIG. 1, n=20, X═CH.sub.3) is dissolved in 7 mL of a tetrahydrofuran solvent; 0.02 g of 2-methyl-α-[2-[[propylsulfonyl]imine]-3(2H)-thiophen-methylene-phenylacetonitrile (PAG103) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 405 nm and 5 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 10 mL of an N,N-DMF solution having 0.01 mol/L of 3,3,3-trifluoro-1-propanol for undergoing a transesterification reaction for 48 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

Embodiment 6

(7) At a room temperature, 0.3 g of a POSS-based precursor (as shown in FIG. 1, n=22, X═CH.sub.3) is dissolved in 7 mL of a tetrahydrofuran solvent; 0.03 g of 2-methyl-α-[2-[[propylsulfonyl]imine]-3(2H)-thiophen-methylene-phenylacetonitrile (PAG103) is added; after uniformly stirring, a mixed liquid is sprayed to form a film on a substrate; the substrate is placed under a 405 nm and 20 mW/cm.sup.2 light-emitting diode lamp for irradiating for 30 min after tetrahydrofuran is completely evaporated; then the substrate is placed in 6 mL of an N,N-DMF solution having 0.05 mol/L of 1H,1H,2H,2H-perfluorohexan-1-ol for undergoing a transesterification reaction for 72 h; and washing and drying are performed to obtain an organosilicone micro-mesoporous ultra-low dielectric thin film. See Table 1 for the result.

(8) TABLE-US-00001 TABLE 1 Test results of water contact angles of organopolysiloxane superhydrophobic coatings Dielectric Water contact Tensile modulus Sample constant angle (°) (GPa) Embodiment 1 2.21 85 2.44 Embodiment 2 2.07 89 2.47 Embodiment 3 1.99 96 2.36 Embodiment 4 1.89 94 2.38 Embodiment 5 1.96 93 2.24 Embodiment 6 2.02 106 2.18

(9) Note: measurement of a dielectric constant test is implemented by using an HP4194A-type dielectric frequency spectrograph; a water contact angle test is implemented by using a DSA25-type full-automatic video contact angle measurement instrument produced by Germany Kriss company, and three parallel tests are averaged; and the tensile modulus is tested according to GB/T1040-92.

(10) The implementations are only for describing technical concepts and features of the present invention, are for the purpose of enabling people familiar with the technology to understand and implement the content of the present invention, but are not intended to limit the scope of protection of the present invention. Equivalent variations or modifications made according to the essence of the present invention all shall fall within the scope of protection of the present invention.