Effect of Nitrogen on the Physical Properties and Work Function of MoN_xCap Layers on HfO₂Gate Dielectrics

Abstract

In this work, MoNx films deposited by reactive sputtering are investigated as cap layers on HfO2 gate dielectrics. A phase transition from body-centered-cubic Mo phase to face-centered-cubic (FCC) γ − Mo2N phase is found with increasing nitrogen content and causes a morphology change. It is found that the crystallinity and grain size decrease when MoNx films are subjected to phase transition. The Mo 3d core levels shift toward higher binding energy due to increments of nitrogen in the MoNx films. The resistivity and work function are also seen to have positive dependence on the nitrogen content. The work functions extracted from the capacitance vs. voltage curves are 4.58 eV for Mo films and 5.10 eV–5.23 eV for MoNx films on HfO2 gate dielectrics, respectively.

A study of highly activated hydrogen evolution reaction performance in acidic media by 2D heterostructure of N and S doped graphene on MoOx

“…Since these two N structures are relatively more defective structure than graphitic N, they will be an effective pathway for adsorbing H + ions. In addition to these, the absence of a Mo 3p 3/2 peak around 394 eV in the N 1s spectrum indicates that N atoms do not penetrate the MoO x layer 49 . The absence of this peak indicates that only the graphene structure is doped.…”

“…In addition to these, the absence of a Mo 3p 3/2 peak around 394 eV in the N 1s spectrum indicates that N atoms do not penetrate the MoO x layer. 49 The absence of this peak indicates that only the graphene structure is doped. Further, the addition of nitrogen to the graphene structure is shown in detail in Scheme S1.…”

Hafnia-Based Ferroelectric Memory: Device Physics Strongly Correlated with Materials Chemistry

“…To suppress the nonideal leakage current from the direct of F–N tunneling, implementing high work-function electrodes such as Au or Pt is expected to lower the effect of those mechanisms, because the tunneling probability would decrease with increasing potential barrier height between top and bottom electrodes . However, when the high price and difficulties in the fabrication process such as etching are considered, other electrode materials such as Ru, RuO 2 , MoO 2 , and Mo 3 N 4 would be plausible alternatives, although the work function of these electrode materials is lower than those of Au or Pt. − Moreover, a defect-related conduction mechanism such as trap-assisted tunneling would be another conduction mechanism that should be prevented. Decreasing trap concentration by decreasing chemical impurities and crystallographic defect concentration by optimizing the deposition and fabrication process would be a possible solution to decrease the leakage current by trap-assisted tunneling .…”