Metal-oxide-semiconductor characteristics of rapid thermal nitrided thin oxides

Abstract

The electrical properties of thin nitrided oxide (∼100 Å) formed by rapid thermal nitridation (RTN) in pure NH3 have been studied. It is found that the current-voltage characteristic of RTN oxides follows a Fowler–Nordheim tunneling behavior with modifications caused by electron trapping processes at the oxide surface and interface. The trapping density is dependent on the RTN conditions. At the interface, both fixed charge (Nf) and interface state (Dit) densities exhibit turnaround phenomena when the RTN process proceeds. The maximum values of Nf and Dit at the turnaround points are lower for the higher temperature RTN, suggesting a viscous flow related strain relieving mechanism associated with RTN of thin oxides. Films with superior endurance behavior (QBD=20.4 C/cm2 compared with QBD=5.1 C/cm2 of thermal oxide under 10 mA/cm2 constant current stress) have been obtained by RTN at 1000 °C, 10 s.

Effects of rapid thermal annealing on nitrided gate oxide grown on 4H-SiC

“…These factors accumulatively attributed to the improvement in the oxide reliability [26,28]. Similar observations have been reported in rapid thermal nitrided Si-based oxides [29,30], whereby the oxide was simultaneously grown and annealed in nitridation sources. In contrast, rapid thermal nitrided oxide on 6H-SiC demonstrated a higher interface-trap density than O 2 grown SiO 2 [31].…”

Stability of nitrided silicon dioxide deposited by reactive sputtering

“…This property is common for thermal nitrided oxides. 8,10 It is observed for both electron injection from aluminum and silicon. At higher fields ͑Ͼ11 MV/cm͒, the current rises more rapidly, which is probably related to positive charge generation and reduction of injection barrier height for electrons.…”

“…7 In order to improve thermal oxide hardness against irradiation and hot carrier injection, incorporation of nitrogen in oxide from NH 3 or N 2 O has been practiced recently. [8][9][10] It may be expected that nitrogen can play a similar role if introduced in the sputtered oxide by the reactive sputtering process, and this letter presents results on the electrical properties of such a gate oxide.…”

“…It suggests increased electron trapping, which is the usual observation for lightly nitrided oxides. 8,10 However, at higher nitrogen flow rates the electron trapping in the oxide is lowered.…”

Characterizations of Ultra-thin Dielectrics Grown by Microwave Afterglow O2/N2O Plasma Oxidation at Low Temperature with Rapid Thermal Annealing

“…Three major techniques have been developed for oxynitride formation. These techniques are ammonia annealing [I,2], N 2 0 gas annealing or oxidation [3,4] and utilization of NO gas [5,6]. However, a common disadvantage of these techniques is that the processing temperatures are high (typically above 950 °C) and thus do not meet the requirement of lowtemperature processing for ULSI devices.…”