A study on the formation and characteristics of the Si-O-C-H composite thin films with low dielectric constant for advanced semiconductor devices

The Si-O-C-H composite thin films were deposited on a p-type Si(100) substr ate using bis-trimethylsilane (BTMSM) and O-2 mixture gases by an inductive ly coupled plasma chemical vapor deposition (ICPCVD). High density plasma o f approximately similar to 10(12) cm(-3) is obtained at low pressure (< 320 mtorr) with an RF power of approximately 300 W in the inductively coupled plasma source where the BTMSM and oxygen gases are greatly dissociated. Fou rier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) s pectra show that the film has Si-CH3 and O-H related bonds. The CH3 groups formed the void in the film and the Si atoms in the annealed sample have di fferent chemical states from those in the deposited sample. It means that t he void is formed due to the removing of O-H related bonds during the annea ling process. The relative dielectric constant of the annealed sample;with the flow rate ratio O-2/BTMSM as 0.3 at 500 degreesC for 30 min is approxim ately 2.5. (C) 2001 Elsevier Science B.V. All rights reserved.