Evaluation of the positive biased temperature stress stability in HfSiON gate dielectrics

Characteristics and physical mechanisms of positive bias and temperature stress-induced drain current degradation in HfSiON nMOSFETs

“…2, accelerated degradation is observed. The acceleration was also observed in literature [11,Figs. 4 and 5], whereas the authors attributed the imperfect log-time dependence to a nonuniform initial trap distribution.…”

“…The log(t) degradation rate in the first stage suggests that charging [11] and concomitant discharging [12] of preexisting high-k traps dominate the first-stage I d degradation. A higher V g induces a larger electron density in the inversion channel readily for trapping, thus causing a more severe I d degradation.…”

Time Dependent Vccmin Degradation of SRAM Fabricated with High-k Gate Dielectrics

“…On the other hand, Shanware et al 4 found that V t shift of HfSiON has a log-time dependence due to electron tunneling into high-k traps with a continuous distribution in space. The time dependence of PBTI has been reported to follow either a log or a saturated exponential time dependence [2][3][4] . The choice of model does not significantly influence the results presented here since at relatively short stress times these models are similar.…”

Exchange-diffusion reactions in HfSiON during annealing studied by Rutherford backscattering spectrometry, nuclear reaction analysis and narrow resonant nuclear reaction profiling

“…Some of the key topics of concern are: density of interface states, reliability, chemical and structural stability, oxidation of the Si substrate, diffusion of metallic species into the active semiconductor region and transport of Si into the high-k film. 1-3 Recent investigations [4][5][6][7][8][9] indicate that incorporation of nitrogen into the hafnium oxide and silicate films either during or after deposition, by plasma or thermal treatments, leads to superior thermal stability, overcoming many of the abovementioned difficulties. However, since N is mainly incorporated into metastable configurations in the oxide and silicate films [9][10][11] (pseudo-ternary character, ͓HfO 2 ͔ x ͓͑SiO 2 ͒ 1−y ͑Si 3 N 4 ͒ y ͔ 1−x ), the integration of N containing high-k dielectrics into the metal oxide semiconductor field effect transistor fabrication flow relies on the stability of N during further high temperature processing steps.…”