Preparation and Characterization of Low-k Silica Film Incorporated with Methylene Groups

Abstract

We have successfully demonstrated chemical vapor deposition of a silica film in which some of oxygen atoms of the pure silica network are replaced to methylene (-CH 2 -) groups. The as-deposited film was thermally unstable owing to the unwanted decomposition reaction of the methylene group with the dense H 2 O in the film. It was found that the film could be dehydrated without decomposition of the methylene group by low temperature annealing in a XeF 2 ambient. The dehydrated film showed not only good insulating and low-k characteristics ͑resistivity of 10 15 ⍀ cm, breakdown field of 3.3 MV/cm, and k of 2.8͒, but also good thermal properties, such as good thermal stability and high thermal conductivity.

Study on the synthesis and thermal degradation of silicone resin containing silphenylene units

“…This is also the evidence of the scission of Si-CH 3 and C-H bonds. Additionally, the appearance of peak at around 1360 cm −1 indicates the formation of Si-CH 2 -Si structure [25]. As previously reported [18,19,24], the formation of Si-CH 2 -Si structure is a radical reaction through the cleavage of Si-C and C-H bonds.…”

A Chemical Study of Plasma‐Deposited Organosilicon Thin Films as Low‐k Dielectrics

“…Other authors have reported that methylene bridges [i.e. SiCH 2 Si and Si(CH 2 ) 2 Si] improve film mechanical strength and thermal stability 14–17…”

Rapid thermal annealing effect on amorphous hydrocarbon film deposited by CH4/Ar dielectric barrier discharge plasma on Si wafer: Surface morphology and chemical evaluation

“…8, the vibrational spectrum of the asdeposited samples exhibits several peaks. 34 Stapinski et al 1,10 mentioned that the in case of low concentration of carbon the appearing band at 682 cm −1 ͑in the case of 600°C annealed sample͒ is due to the SiH x wagging mode and the bands at 742 cm −1 , which are assigned to Si-CH 3 rocking/wagging mode or to Si-C stretching mode 41,42 has the tendency to shift toward the higher wave number as the carbon concentration increases in the deposited film. On the other hand the most of the corresponding peaks disappeared after annealing of the sample at 600°C.…”