Tatsuru Shirafuji

Plasma enhanced chemical vapor deposition of thermally stable and low-dielectric-constant fluorinated amorphous carbon films using low-global-warming-potential gas C5F8

Abstract Low-dielectric-constant fluorinated amorphous carbon films have been prepared from the low global-warming-potential gas of C5F8 by a capacitively coupled plasma enhanced chemical vapor deposition method. Films were prepared at substrate temperatures as high as 400°C. The obtained deposition rate of 15–65 nm/min was higher than that of conventional C4F8 plasma at the same substrate temperature. The dielectric constant of the films varied from 2.1 to 2.5 with increasing RF power from 10 to 100 W. The residual thickness of the films after 400°C-thermal treatment was higher than 98%. At an RF power higher than 50 W, cracks appeared in the films that were rapidly cooled from 400°C to room temperature, and poor adhesion characteristics were obtained even for the samples without cracks after gradual cooling. On the other hand, the samples prepared at 10 W showed no cracks and good adhesion on a crystalline silicon substrate regardless of the cooling rate.

PE-CVD of Fluorocarbon/SiO Composite Thin Films Using C4F8 and HMDSO

Plasma copolymerization of hexamethyldisiloxane (HMDSO,(CH3)3-Si-O-Si-(CH3)3) and C4F8 was performed using an RF plasma enhanced chemical vapor deposition method for application to low dielectric constant intermetal dielectrics. Structure of the films was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The film composition was controlled gradually from fluorinated carbon to organic siloxane by changing the mixing ratio of HMDSO/Ar. Dielectric constant of the films ranged from 2–3.3. Thermal stability of the films, which was characterized by intensity loss of IR absorbance peak around 1000–1500 cm−1 corresponding to C-Fn, Si-O-Si and Si-(CH2)n-Si bonds, was inferior to that from C2F4/HMDSO/Ar. In situ gasphase FT-IR spectroscopy revealed that there was a marked difference between the gas phase of C4F8/HMDSO/Ar and that of C2F4/HMDSO/Ar discharges. The IR spectrum of the former combination plasma contained a peak at 1250 cm−1 with full width at half maximum as large as 150 cm−1, which suggests that fluorocarbon particles and/or dusts are formed in the plasma. This suggests also that deposition precursors are not only CFn (n = 1, 2, and 3) but also larger precursors such as CxFy (x > 1, y < 2x + 2) in C4F8/HMDSO/Ar discharges, which is presumably the cause of difference in thermal stability of the films prepared from C4F8/HMDSO/Ar and C2F4/HMDSO/Ar mixtures.

Plasma enhanced chemical vapor deposition of fluorinated amorphous carbon thin films from tetrafluoroethylene and tetraisocyanatesilane

AbstractFluorinated amorphous carbon films were prepared from tetrafluoroethylene (TFE; C2F4) and tetraisocyanatesilane (TICS; Si(NCO)4) using an RF plasma enhanced chemical vapor deposition method for the purpose of application to inter layer low permittivity films used in large scale integrated circuits. Structure of the deposited films was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Adhesion characteristics were examined by a tape-peel method. Permittivity of the films was investigated from capacitance measurement on metal-insulator-semiconductor structure. The structural analysis revealed that the deposited films contained imide-like group n

Construction and Performance of a Fourier-Transform Infrared Phase-Modulated Ellipsometer for In-Process Surface Diagnostics

( = N---C = {text{O}})

THIN FILM FORMED FROM POLYCYCLIC ALICYCLIC COMPOUND AS PRECUSER AND PRODUCTION METHOD THEREOF

n in spite of the fact that TICS molecules contained isocyanate group n

Low-Temperature Growth Process of Polycrystalline Silicon for Thin Film Transistors

(---N = C = {text{O}})