Deposition characterization of low-k hybrid thin films using methyl methacrylate for ULSI applications

Hybrid low dielectric constant (low-k) materials have been emerged immensely as interlayer dielectrics (ILD). Hence, in this paper we have presented the annealing temperature effect on dielectric constant of the spin coated hybrid thin films prepared by incorporating methylmethacrylate (MMA) as organic material. The process parameters have been optimized for obtaining lower dielectric constant of hybrid thin films so as to achieve better interconnect layer characteristics in ULSI applications. The structural and electrical properties of thin films have been carried out by using, Fourier transform infrared (FTIR) spectroscopy, Ellipsometer, Energy Dispersive Spectroscopy (EDAX), Scanning Electron Microscopy (SEM) and Capacitance–Voltage (CV) analyzer. The FTIR and EDAX characterization confirms formation of hybrid thin films. The lower values of strain of the deposited films, calculated from Si–O–Si stretching peak makes them suitable for ILD application in ULSI circuits that controls extrusion of metal. The data obtained from ellipsometer and FTIR characterizations have been used to deduce the values of dielectric constant of the deposited thin films by means of novel formulation reported by Takuya Fukuda et al. The values obtained through this formulation shows that, the dielectric constant of the hybrid thin films is successfully reduced. The dielectric constants have been found to be decreased from 2.656 to 2.637 with the increase in annealing temperature from 200 to 400 °C and the dielectric constant of 2.67 determined through CV analyzer for annealing temperature of 200 °C is almost matches.