US-20260130142-A1 - Precursors and Flowable CVD Methods for Making Low-K Films to Fill Surface Features

US20260130142A1US 20260130142 A1US20260130142 A1US 20260130142A1US-20260130142-A1

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.

Inventors

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

Assignees

VERSUM MATERIALS US, LLC

Dates

Publication Date: 20260507
Application Date: 20251222

Claims (15)

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 400° C.; 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 an acyloxyaminoxysilane 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; 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 plasma is selected from the group consisting of an in-situ or remote plasma source based plasma comprising nitrogen, an in-situ or remote plasma source based plasma comprising nitrogen and helium, an in-situ or remote plasma source based plasma comprising nitrogen and argon, an in-situ or remote plasma source based plasma comprising ammonia, an in-situ or remote plasma source based plasma comprising ammonia and helium, an in-situ or remote plasma source based plasma comprising ammonia and argon, helium plasma, argon plasma, hydrogen plasma, an in-situ or remote plasma source based plasma comprising hydrogen and helium, an in-situ or remote plasma source based plasma comprising hydrogen and argon, an in-situ or remote plasma source based plasms comprising ammonia and hydrogen, an in-situ or remote plasma source based organic amine plasma, an in-situ or remote plasma source based plasma comprising oxygen, an in-situ or remote plasma source based plasma comprising oxygen and hydrogen, and mixtures thereof.
3 . The method of claim 1 , wherein the plasma is selected from the group consisting of an in-situ or remote plasma source based plasma comprising carbon or hydrocarbon, an in-situ or remote plasma source based plasma comprising hydrocarbon and helium, an in-situ or remote plasma source based plasma comprising hydrocarbon and argon, an in-situ or remote plasma source based plasma comprising carbon dioxide, an in-situ or remote plasma source based plasma comprising carbon monoxide, an in-situ or remote plasma source based plasma comprising a hydrocarbon and hydrogen, an in-situ or remote plasma source based plasma comprising a hydrocarbon and nitrogen, an in-situ or remote plasma source based plasma comprising hydrocarbon and oxygen, and mixture thereof.
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 acyloxyaminoxysilane is defined by 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.
8 . The method of claim 1 , wherein the at least one silicon-containing compound having at least one acetoxy group is selected from the group consisting of: diacetoxydimethylaminoxymethylsilane, diacetoxydi(methylethyl)aminoxymethylsilane, and diacetoxydiethylaminoxymethylsilane.
9 . The method of claim 1 , wherein the silicon containing film has a dielectric constant of <3.0 as determined by Capacitence-Voltage measurements, a porosity of >10% as measured by Ellipsometric Porosimetry.
10 . A silicon-containing film precursor comprising at least one silicon-containing compound is selected from the group consisting of: I(a). an acyloxysilane defined by 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=2 or 3; n=1 or 2; p=0 or 1; and m+n+p=4; I(b). an acyloxyalkoxysilane defined by 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=2 or 3; m=1 or 2; p=0 or 1; q=0 or 1 and m+n+p+q=4; and I(c). an acyloxyaminoxysilane defined by 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.
11 . The precursor of claim 10 , further comprising at least one solvent.
12 . The precursor of claim 10 , further comprising at least one of an oxygen containing source and a nitrogen containing source.
13 . The precursor of claim 12 , further comprising at least one oligomer of at least one of the silicon containing compounds.
14 . The precursor of claim 12 comprising the acyloxysilane, the acyloxyalkoxysilane, or the acyloxyaminoxysilane and at least one oxygen containing source.
15 . A silicon containing film obtained by the method of claim 1 having a dielectric constant of <3.0 as determined by Capacitence-Voltage measurements, a porosity of >10 volume % as measured by Ellipsometric Porosimetry upon a substrate having at least one surface feature.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 17/586,405, filed Jan. 27, 2022, which was a divisional of U.S. patent application Ser. No. 16/580,880, filed Sep. 24, 2019, which was a divisional of Ser. No. 15/681,102, filed on Aug. 8, 2017, and is now U.S. Pat. No. 10,468,244. application Ser. No. 15/681,102 claims the benefit of priority under 35 U.S.C. § 119(e) of provisional patent application Ser. No. 62/381,222, filed on Aug. 30, 2016, the disclosures of which are hereby incorporated by reference in their entireties. BACKGROUND Described herein is a process for the fabrication of an electronic device. More specifically, described herein are compositions for forming a silicon-containing film in a deposition process, such as, for example, a flowable chemical vapor deposition. Exemplary silicon-containing films that can be deposited using the compositions and methods described herein include silicon oxide, silicon nitride, silicon oxynitride or carbon-doped silicon oxide or carbon-doped silicon nitride films. Flowable oxide deposition methods typically use alkoxysilane compounds as precursors for silicon-containing films which are deposited by controlled hydrolysis and condensation reactions. Such films can be deposited onto a substrate, for example, by applying a mixture of water and alkoxysilanes, optionally with solvent and/or other additives such as surfactants and porogens, onto a substrate. Typical methods for the application of these mixtures include spin coating, dip coating, spray coating, screen printing, co-condensation, and ink jet printing. After application to the substrate and upon application of one or more energy sources such as, for example, thermal, plasma, and/or other sources, the water within the mixture can react with the alkoxysilanes to hydrolyze the alkoxide and/or aryloxide groups and generate silanol species, which further condense with other hydrolyzed molecules and form an oligomeric or network structure. Besides physical deposition or application of the precursor to the substrate, vapor deposition processes using water and a silicon containing vapor source for flowable dielectric deposition (FCVD) have been described, for instance, in U.S. Pat. Nos. 7,541,297; 8,449,942; 8,629,067; 8,741,788; 8,481,403; 8,580,697; 8,685,867; 7,498,273; 7,074,690; 7,582,555; 7,888,233, and 7,915,131, as well as U.S. Publ. No. 2013/0230987 A1, the disclosures of which are incorporated herein by reference. Typical methods generally relate to filling gaps on substrates with a solid dielectric material by forming a flowable liquid film in the gap. The flowable film is formed by reacting a dielectric precursor which may have a Si—C bond with an oxidant to form the dielectric material. In certain embodiments, the dielectric precursor condenses and subsequently reacts with the oxidant to form dielectric material. In certain embodiments, vapor phase reactants react to form a condensed flowable film. Since the Si—C bond is relatively inert towards reaction with water, the resultant network may be beneficially functionalized with organic functional groups which impart desired chemical and physical properties to the resultant film. For example, the addition of carbon to the network may lower the dielectric constant of the resultant film. Another approach to depositing a silicon oxide film using flowable chemical vapor deposition process is gas phase polymerization. For example, the prior art has focused on using compounds such as trisilylamine (TSA) to deposit Si, H, N containing oligomers that are subsequently oxidized to SiOx films using ozone exposure. Examples of such approaches include: U.S. Publ. No. 2014/0073144; U.S. Publ. No. 2013/230987; U.S. Pat. Nos. 7,521,378, 7,557,420, and 8,575,040; and 7,825,040, the disclosures of which are incorporated herein by reference. Regarding the processes that employ trisilylamine (TSA), TSA is typically delivered into the reaction chamber as a gas, mixed with ammonia, and activated in a remote plasma reactor to generate NH2, NH, H and or N radicals or ions. The TSA reacts with the plasma activated ammonia and begins to oligomerize to form higher molecular weight TSA dimers and trimers or other species which contain Si, N and H. The substrate is placed in the reactor and cooled to one or more temperatures ranging from about 0 to about 50° C. at a certain chamber pressures and TSA/activated ammonia mixtures the oligomers begin to condense on the wafers surface in such a way that they can “flow” to fill the trench surface feature. In this way, a material which contains Si, N and H is deposited onto the wafer and fills the trench. In certain embodiments, a pre-anneal step is performed to allow the film to be more SiN-like. It is desirable to have a SiN material because the next process step is oxidation at one or more temperatures ranging from 100-700° C. using ozone or water. Because of the SiN bond