Precursors and Flowable CVD Methods for Making Low-K Films to Fill Surface Features

Patent metadata

Field	Value
Publication number	US-2018315598-A1
Application number	US-201816004907-A
Country	US
Kind code	A1
Filing date	Jun 11, 2018
Priority date	Aug 30, 2016
Publication date	Nov 1, 2018
Grant date	—

Abstract

A method for depositing a silicon-containing film, the method comprising: placing a substrate comprising at least one surface feature into a flowable CVD reactor which is at a temperature of from about −20° C. to about 100° C.; increasing pressure in the reactor to at least 10 torr; and introducing into the reactor at least one silicon-containing compound having at least one acetoxy group to at least partially react the at least one silicon-containing compound to form a flowable liquid oligomer wherein the flowable liquid oligomer forms a silicon oxide coating on the substrate and at least partially fills at least a portion of the at least one surface feature. Once cured, the silicon oxide coating has a low k and excellent mechanical properties.

First claim

1 . A method for depositing a silicon-containing film, the method comprising:
placing a substrate comprising at least one surface feature into a reactor which is at a temperature of from about −20° C. to about 100° C.; introducing into the reactor at least one oxygen source; introducing into the reactor at least one silicon-containing compound having at least one acetoxy group, wherein the at least one silicon-containing compound is selected from the group consisting of: I(a). Acyloxysilanes with a formula of (RCOO) m R 1 n SiH p wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; m=1, 2, or 3; n=1, 2, or 3; p=0, 1, or 2; and m+n+p=4; I(b). Acyloxyalkoxysilanes with a formula of (RCOO) m (R 2 O) n SiH p R 1 q wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; R 2 is selected from a linear or branched C 1 to C 6 alkyl group; m=1, 2, or 3; n=1, 2, or 3; p=0 or 1; q=0 or 1 and m+n+p+q=4; and I(c). Acyloxyaminoxysilanes with a formula of (RCOO) m (R 3 R 4 NO) n SiH p R 1 q wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; and R 3 is selected from hydrogen, a linear or branched C 1 to C 10 alkyl group; R 4 is selected from a linear or branched C 1 to C 6 alkyl group; m=2 or 3; n=1 or 2; p=0 or 1; q=0 or 1 and m+n+p+q=4; increasing pressure in the reactor to at least 10 torr; and providing an in-situ plasma or remote plasma source to the reactor to at least partially react the at least one silicon-containing compound to form a flowable liquid oligomer wherein the flowable liquid oligomer forms a coating on the substrate and at least partially fills at least a portion of the at least one surface feature.

2 . The method of claim 1 wherein the pressure in the reactor is 12 Torr.

3 . The method of claim 1 wherein the plasma is in-situe plasma.

4 . The method of claim 1 further comprising the step of subjecting the coating to a thermal treatment at one or more temperatures between about 100° C. to about 1000° C. to densify at least a portion of the coating and form a hardened layer.

5 . The method of claim 4 further comprising the step of exposing the hardened layer to energy selected from the group consisting of a plasma, infrared light, chemical treatment, an electron beam, or UV light to form the final silicon-containing film.

6 . The method of claim 5 wherein the above steps define one cycle for the method and the cycle can be repeated until the desired thickness of the silicon-containing film is obtained.

7 . The method of claim 1 wherein the at least one silicon-containing compound having at least one acetoxy group comprises diacetoxydimethylsilane.

8 . The method of claim 1 wherein the acyloxysilane having the Formula I(a) is selected from the group consisting of:

wherein R is selected from the group consisting of methyl, ethyl, n-propyl, iso-propyl, tert-butyl, n-butyl, sec-butyl, and iso-butyl; and R 1 is selected from the group consisting of methyl, ethyl, vinyl, allyl, and ethynyl.

9 . The method of claim 1 wherein the acyloxyalkoxysilane having the Formula I(b) is selected from the group consisting of:

wherein R is selected from the group consisting of methyl, ethyl, n-propyl, iso-propyl, tert-butyl, n-butyl, sec-butyl, and iso-butyl; R 1 is selected from the group consisting of methyl, ethyl, vinyl, allyl, and ethynyl; and R 2 is selected from the group consisting of methyl, ethyl, n-propyl, iso-propyl, tert-butyl, n-butyl, sec-butyl, and iso-butyl.

10 . The method of claim 1 wherein the acyloxyaminoxysilane having the Formula I(c):

wherein R and R 1 are independently selected from the group consisting of methyl, ethyl, n-propyl, iso-propyl, tert-butyl, n-butyl, sec-butyl, and iso-butyl; R 1 is selected from the group consisting of methyl, ethyl, vinlyl, allyl, and ethynyl; and R 3 and R 4 are independently selected from the group consisting of methyl and ethyl.

11 . The method of claim 1 wherein the silicon containing film has a dielectric constant of between 2.8 and 3.6 as determined by Capacitence-Voltage measurements, and a porosity of <10% as measured by Ellipsometric Porosimetry.

12 . A silicon-containing film precursor comprising at least one silicon-containing compound is selected from the group consisting of:
I(a). Acyloxysilanes with a formula of (RCOO) m R 1 n SiH p wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; m=1, 2, or 3; n=1, 2, or 3; p=0, 1, or 2; and m+n+p=4; I(b). Acyloxyalkoxysilanes with a formula of (RCOO) m (R 2 O) n SiH p R 1 q wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; R 2 is selected from a linear or branched C 1 to C 6 alkyl group; m=1, 2, or 3; n=1, 2, or 3; p=0 or 1; q=0 or 1 and m+n+p+q=4; and I(c). Acyloxyaminoxysilanes with a formula of (RCOO) m (R 3 R 4 NO) n SiH p R 1 q wherein R is selected from hydrogen, a linear or branched C 1 to C 6 alkyl group; R 1 is selected from a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, a linear or branched C 2 to C 6 alkynyl group; and R 3 is selected from hydrogen, a linear or branched C 1 to C 10 alkyl group; R 4 is selected from a linear or branched C 1 to C 6 alkyl group; m=2 or 3; n=1 or 2; p=0 or 1; q=0 or 1 and m+n+p+q=4; wherein the silicon-containing compound reacts with a plasma to form the silicon containing film.

13 . The precursor of claim 12 further comprising at least one solvent.

14 . The precursor of claim 12 further comprising at least one of an oxygen containing source and a nitrogen containing source.

15 . The precursor of claim 12 further comprising at least one oligomer of at least one of the silicon containing compounds.

16 . The precursor of claim 14 comprising diacetoxydimethylsilane and at least one oxygen containing source.

17 . A silicon containing film obtained by the method of claim 1 having a dielectric constant of from 2.8 to 3.6 as determined by Capacitence-Voltage measurements, and a porosity of <10 volume % as measured by Ellipsometric Porosimetry upon a substrate having at least one surface feature.

Assignees

• Versum Mat Us Llc

Inventors

• Li Jianheng
• Vrtis Raymond Nicholas
• Ridgeway Robert Gordon
• Xiao Manchao
• Lei Xinjian

Classifications

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6928

  the material containing silicon and at least one metal element, e.g. metal silicate based insulators or metal silicon oxynitrides · CPC title

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/6687

  the compound comprising silicon and nitrogen · CPC title

• H10P14/6682

  the compound being a silane, e.g. disilane, methylsilane or chlorosilane · CPC title