The characteristics of organic–inorganic hybrid low-k thin films by PECVD

Abstract

Organic–Inorganic hybrid-polymer thin films were deposited on silicon(100) substrates by plasma enhanced chemical vapor deposition (PECVD) method using monomer precursors of the organic–inorganic hybrid polymers. Ethylcyclohexane (ECH) and tetraethoxysilane (TEOS) were utilized as organic and inorganic precursors, and hydrogen and argon were used as a bubbler and carrier gases, respectively. To compare the difference of the electrical and the mechanical properties of the plasma polymerized thin films, we grew the hybrid-polymer thin films under the conditions of various RF (radio frequency using 13.56 MHz) powers in the range of 20–60 W, and then thin films were annealed at 200–500 °C. The as-grown hybrid-polymer thin films were in first analyzed by FT-IR (Fourier Transform–Infrared Spectroscopy), and AFM (Atomic Force Microscopy). The result of FT-IR showed some changing of functional groups such as –CHx, CC, and Si–Ox with changing RF power and annealing temperature. AFM showed that the hybrid-polymer films with smooth surface could be grown uniformly by PECVD. Also, thermal-shrinkage of thickness was measured by cross-sectional SEM. Impedance analyzer was utilized for the measurements of capacitance and I–V curves. From the electrical properties measurements, the lowest dielectric constant and best leakage constant were obtained to be 1.82 and 10−8 A/cm2 at 1 MV/cm, respectively.