Precursors and flowable CVD methods for making low-K films to fill surface features
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 400° C.; 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.
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 acyloxy group, wherein the at least one silicon-containing compound is an acyloxysilane having a structure:
wherein R is selected from the group consisting of hydrogen, and a linear or branched C 1 to C 6 alkyl group; R 1 is selected from the group consisting of a linear or branched C 1 to C 6 alkyl group, a linear or branched C 2 to C 6 alkenyl group, and a linear or branched C 2 to C 6 alkynyl group; 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 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.
4. The method of claim 3 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.
5. The method of claim 4 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.
6. The method of claim 1 wherein the at least one silicon-containing compound having at least one acetoxy group comprises diacetoxydimethylsilane.
7. The method of claim 1 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.
8. The method of claim 1 wherein the silicon containing film has a dielectric constant of <3.0 as determined by Capacitance-Voltage measurements, a porosity of >10% as measured by Ellipsometric Porosimetry.
9. A silicon containing film obtained by the method of claim 1 having a dielectric constant of <3.0 as determined by Capacitance-Voltage measurements, a porosity of >10 volume % as measured by Ellipsometric Porosimetry upon a substrate having at least one surface feature.