Interfacial Reaction and Electrical Properties of HfO₂ Film Gate Dielectric Prepared by Pulsed Laser Deposition in Nitrogen: Role of Rapid Thermal Annealing and Gate Electrode

Abstract

The high-k dielectric HfO(2) thin films were deposited by pulsed laser deposition in nitrogen atmosphere. Rapid thermal annealing effect on film surface roughness, structure and electrical properties of HfO(2) film was investigated. The mechanism of interfacial reaction and the annealing atmosphere effect on the interfacial layer thickness were discussed. The sample annealed in nitrogen shows an amorphous dominated structure and the lowest leakage current density. Capacitors with high-k HfO(2) film as gate dielectric were fabricated, using Pt, Au, and Ti as the top gate electrode whereas Pt constitutes the bottom side electrode. At the gate injection case, the Pt- and Au-gated metal oxide semiconductor devices present a lower leakage current than that of the Ti-gated device, as well as similar leakage current conduction mechanism and interfacial properties at the metal/HfO(2) interface, because of their close work function and chemical properties.

Evaluation of Radiation Sensor Aspects of $\text{Er}_2$$\text{O}_3$ MOS Capacitors under Zero Gate Bias

“…In some cases, the silicate formation in high-k oxide/Si or microstructural change occurring due to high annealing temperature leads to a reduction in the capacitance [22], [23]. On the other side, the capacitance-voltage (C-V) curve is affected by several parameters such as the gate electrode type and annealing condition [24]. However, remarkable studies have been performed with the aim of ameliorating the aforementioned problems in recent years.…”

Approaching Defect-free Amorphous Silicon Nitride by Plasma-assisted Atomic Beam Deposition for High Performance Gate Dielectric

“…Additionally, the gate leakage J G of the MNS structure as a function of EOT for the a -Si 3 N 4 layer thickness at 1 V is plotted in Fig. 4b with conventionally used dielectrics of SiO 2 and HfO 2 for comparison, clearly indicating that the J G value of a -Si 3 N 4 is a factor of 10 6 and 10 1 ~10 3 lower than that of SiO x 41 and HfO 2 42 43 at the same EOT, respectively. The extrapolation of leakage currents J G suggests that a -Si 3 N 4 with an EOT of 0.9 and 0.5 nm could replace SiO x for 7 nm of physical gate length (18-nm node) of low standby power and high power devices, respectively 1 44 .…”

“…The top inset is the energy band diagram of the MNS capacitor with a p -type substrate for a negative gate bias, and the bottom inset is cross sectional HR TEM image. ( b ) Plot of leakage current density at 1V of gate voltage versus EOT for SiO 2 41, HfO 2 4243, and PA-ABD a -Si 3 N 4 for comparison, and PA-ABD a -Si 3 N 4 shows a significant leakage current reduction. The criteria of low power limit and gate limit of leakage current densities are taken from previous reports144.…”

Comparison of electrical characteristics for SiONx and HfZrOx gate dielectrics of MOSFETs with decoupled plasma nitridation treatment

“…The other effects of gate oxynitride are boron penetration causing the higher interface states, V T instability and reliability concern for pMOSFETs and provide the parasitic gate capacitance at the inversion mode which decreases the drive current and increases the gate delay. Continuously, though the combination of HK/MG technology [44][45][46][47] shows the better drive current, the control of gate leakage and the optimal treatment of nitridation fixing the oxygen vacancy in HK dielectric still needs to be expectantly reformed to satisfy the portable electronic products. More adequately comprehending nitrogen concentration, thermal annealing and desired equivalent oxide thickness is very important to effectively provide the contribution in the HfO x /ZrO y /HfO x thickness and dielectric quality through DPN process.…”