Low-frequency noise characterization of n- and p-MOSFET's with ultrathin oxynitride gate films

Abstract

Abstruct-MOSFET's with ultrathin (5 to 8.5 nm) silicon oxynitride gate film prepared by low-pressure rapid thermal chemical vapor deposition (RTCVD) using SiH4, NzO and NH3 gases, are studied by low-frequency noise measurements (1 Hz up to 5 kHz). The analysis takes into account the correlated mobility fluctuations induced by those of the interfacial oxide charge. The nitrogen concentration, determined from SIMS analysis, varies from 0 to 11% atomic percentage. A comparison of the electrical properties between thermal and silicon oxynitride films is presented. The increasing LF noise signal with nitrogen atomic percentage indicates the presence of a higher density of slow interface traps with increasing nitrogen incorporation. Besides, a higher Coulomb scattering rate due to the nitridation induced interface charge explains reasonably well the degradation of the low field mobility after nitridation.

$1/f$ Noise in Drain and Gate Current of MOSFETs With High-$k$ Gate Stacks

“…Moreover, it is worth noting that noise levels are higher in p-MOSFETs, even in the reference devices. This result is in agreement with the study of Morfouli et al [22]. They reported that in the case of SiON dielectric, p-MOSFETs show a larger trap density with respect to the n-MOSFETs.…”

“…Under this supposition, the trap density N t can be extracted by using (1), and the results are shown in Fig. 4 [22], [23]. Therefore, an increase of defectivity in the gate dielectric is observed in both high-k materials with respect to conventional SiON.…”

Silicon on Insulator Technology Review

“…• Effective [111,95] reduction of substrate coupling in RF circuits (allows higher quality inductors with increased Q factor)…”

Impact of nitridation of SiO2 gate oxide on 1/f noise in 0.18um CMOS

“…The increase is almost one order of magnitude for the PMOS and 2-3 times larger for the NMOS. This has been related to the increased near interface oxide traps density, due to the introduction of nitride in the oxide [3]. This increase is proportional to the nitride concentration and it is measured to be a factor 2 larger for PMOS with respect to NMOS, with oxide thickness in the range 5-8.5 nm [3].…”

“…This has been related to the increased near interface oxide traps density, due to the introduction of nitride in the oxide [3]. This increase is proportional to the nitride concentration and it is measured to be a factor 2 larger for PMOS with respect to NMOS, with oxide thickness in the range 5-8.5 nm [3]. One could argue that the differences we measured are due to poor description of the 1/f noise spectral density by means of an oversimplified model.…”