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 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.
1 . 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.
2 . The precursor of claim 1 further comprising at least one solvent.
3 . The precursor of claim 1 further comprising at least one of an oxygen containing source and a nitrogen containing source.
4 . The precursor of claim 1 further comprising at least one oligomer of at least one of the silicon containing compounds.
5 . The precursor of claim 3 comprising diacetoxydimethylsilane and at least one oxygen containing source.