Chemical bonding and stability of 50 degrees C plasma-deposited silicon nitrides

Silicon nitride films have been deposited at 50 degrees C using a high-dens ity plasma (HDP) chemical vapor deposition (CVD). Electron cyclotron resona nce (ECR) plasma has been employed as a HDP source. The electrical properti es of resulting low-temperature silicon nitrides have been previously evalu ated. X-ray photoelectron spectroscopy shows that chemical bonding structur e of this low-temperature ECR nitride is very comparable to that of 250 deg rees C industry-deposited plasma-enhanced CVD (PECVD) nitride. IR absorptio n data indicate that the low-temperature ECR nitride has more Si-H bonds an d less N-H bonds than the high-temperature PECVD nitrides. These ECR films display robustness to buffered oxide etch attack with etch rates that are 2 0-50 % of a 250 degrees C-deposited PECVD nitride. ECR-nitride aged for 17 months has the leakage current of <5 x 10(-9) A/cm(2) and electrically brea ks down at 5.7 MV/cm. It is suggested that these low-temperature ECR nitrid es can be very suitable for encapsulation, passivation, and barrier layers. (C) 1999 The Electrochemical Society. S1099-0062(99)08-079-7. All rights r eserved.