Thin films and methods for the preparation thereof

A method of forming a thin film having a dielectric constant of 2.9 or less, comprising

• hydrolyzing a first silicon compound having the general formula I
• X13-a—SiR1bR2cR3d I
• wherein X1 represents a hydrolyzable group;
• R1 is an alkenyl or alkynyl group, which optionally bears one or more substituents;
• R2 and R3 are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non-substituted alkenyl and alkynyl groups, and substituted or nonsubstituted aryl groups;
• a is an integer 0, 1 or 2;
• b is an integer a+1;
• c is an integer 0, 1 or 2;
• d is an integer 0 or 1;
• and
• b+c+d=3
• with a second silicon compound having the general formula II
• X23-e—SiR4fR5gR6h II
• wherein X2 represents a hydrolyzable group;
• R4 is an aryl group, which optionally bears one or more substituents;
• R5 and R6 are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non-substituted alkenyl and alkynyl groups, and substituted or non-substituted aryl groups;
• e is an integer 0, 1 or 2;
• f is an integer e+1;
• g is an integer 0, 1 or 2;
• h is an integer 0 or 1;
• and
• f+g+h=3
• and optionally with a third silicon compound having the general formula III
• X33-i—SiR7jR8kR9l III
• wherein X3 represents a hydrolyzable group;
• R7 is an alkyl group, which optionally bears one or more substituents;
• R8 and R9 are independently selected from hydrogen, substituted or non-substituted alkyl groups, substituted or non-substituted alkenyl or alkynyl groups, and substituted or nonsubstituted aryl groups;
• i is an integer 0, 1 or 2;
• j is an integer i+1;
• k is an integer 0, 1 or 2;
• l is an integer 0 or 1;
• and
• j+k+l=3
• to produce a siloxane material;
• depositing the siloxane material in the form of a thin layer;
• and
• curing the thin layer to form a film.