Low-Temperature Gate Oxynitrides Formed by Radical Oxygen/Nitrogen in a Low-Biased High Density Plasma

Abstract

Low-temperature (<= 400 degrees C) ultrathin (similar to 3 nm) gate oxynitrides have been formed, without the need to post-anneal, by using radical oxygen and nitrogen in a low-biased high-density plasma utilizing a unique slot-plane-antenna technique. X-ray photoelectron and secondary-ion mass spectroscopies reveal that the high nitrogen concentrations confined within the bulk of oxynitrides stem mostly from the bonding configuration of Si - N = O-2. Compared to plasma nitrided thermal oxides, plasma oxynitrides show a better efficiency of nitridation along with the improved charge-to-breakdown and interface characteristics, which allows further scaling down of devices.