CHARACTERIZATION OF THIN SILICON OXYNITRIDE FILMS PREPARED BY LOW-PRESSURE RAPID THERMAL CHEMICAL-VAPOR-DEPOSITION

Thin silicon oxynitride (Si-N-0) films have been deposited using low p ressure rapid thermal chemical vapor deposition (RTCVD), with silane ( SiH4), nitrous oxide (N2O), and ammonia (NH3) as the reactive gases. S tructural and kinetic studies indicate that an increase in the NH3/N2O floW rate ratio leads to an increased N/O atomic ratio and a decrease d Si-N-O deposition rate for constant SiH4 and N2O flow rates. Experim ental results show that RTCVD Si-N-O films with high throughput at low thermal budget, uniform composition, and atomically flat interface ca n be achieved using a SiH4/NH3/N2O gas mixture. Electrical characteriz ation of polySi/Si-N-O/Si capacitors demonstrates that for NH3/N2O flo w rate ratios ranging from 20 to 100%, the mid-gap interface trap dens ities (D(it)) of the deposited Si-N-0 films are less-than-or-equal-to 2 x 10(10) eV-1 cm-2 and Fowler-Nordheim electron-tunneling rather tha n Frenkel-Poole thermal-emission is the dominant conduction mechanism in the thin RTCVD Si-N-O films.