The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by ...The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by solving the rate equations and Poisson's equation simultaneously, to understand threshold voltage shifts induced by TID in silicon-based metal–oxide–semiconductor(MOS) devices. The calculated charged defect distribution and corresponding electric field under different TIDs are consistent with experiments. TID changes the electric field at the Si/SiO_(2) interface by inducing the accumulation of oxide charged defects nearby, thus shifting the threshold voltage accordingly. With increasing TID, the oxide charged defects increase to saturation, and the electric field increases following the universal 2/3 power law. Through analyzing the influence of TID on the interfacial electric field by different factors, we recommend that the radiation-hardened performance of devices can be improved by choosing a thin oxide layer with high permittivity and under high gate voltages.展开更多
Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly b...Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly bonded oxygen(O)atoms exist in a-IGZO thin films deposited at high O_(2) pressures,but these can be eliminated by vacuum annealing.The threshold voltage(V_(th))of the a-IGZO TFTs is shifted under positive gate bias,and the Vth shift is positively related to the deposition pressure.A temperature variation experiment in the range of 20 K-300 K demonstrates that an activation energy of 144 meV is required for the Vth shift,which is close to the activation energy required for the migration of weakly bonded O atoms in a-IGZO thin films.Accordingly,the Vth shift is attributed to the acceptor-like states induced by the accumulation of weakly bonded O atoms at the a-IGZO/SiO_(2) interface under positive gate bias.These results provide an insight into the mechanism responsible for the Vth shift of the a-IGZO TFTs and help in the production of reliable designs.展开更多
Degradation induced by the negative bias temperature instability(NBTI)can be attributed to three mutually uncoupled physical mechanisms,i.e.,the generation of interface traps(ΔV_(IT)),hole trapping in pre-existing ga...Degradation induced by the negative bias temperature instability(NBTI)can be attributed to three mutually uncoupled physical mechanisms,i.e.,the generation of interface traps(ΔV_(IT)),hole trapping in pre-existing gate oxide defects(ΔV_(HT)),and the generation of gate oxide defects(ΔV_(OT)).In this work,the characteristic of NBTI for p-type MOSFET fabricated by using a 28-nm high-k metal gate(HKMG)process is thoroughly studied.The experimental results show that the degradation is enhanced at a larger stress bias and higher temperature.The effects of the three underlying subcomponents are evaluated by using the comprehensive models.It is found that the generation of interface traps dominates the NBTI degradation during long-time NBTI stress.Moreover,the NBTI parameters of the power-law time exponent and temperature activation energy as well as the gate oxide field acceleration are extracted.The dependence of operating lifetime on stress bias and temperature is also discussed.It is observed that NBTI lifetime significantly decreases as the stress increases.Furthermore,the decrease of charges related to interface traps and hole detrapping in pre-existing gate oxide defects are used to explain the recovery mechanism after stress.展开更多
Irradiation experiments on p-Ga N gate high-electron-mobility transistors(HEMTs) were conducted using neutrons at Back-streaming White Neutron(Back-n) facility at the China Spallation Neutron Source(CSNS).Two groups o...Irradiation experiments on p-Ga N gate high-electron-mobility transistors(HEMTs) were conducted using neutrons at Back-streaming White Neutron(Back-n) facility at the China Spallation Neutron Source(CSNS).Two groups of devices were float-biased,while one group was ON-biased.Post-irradiation analysis revealed that the electrical performance of the devices exhibited progressive degradation with increasing Back-n fluence,with the ON-biased group demonstrating the most pronounced deterioration.This degradation was primarily characterized by a negative shift in the threshold voltage,a significant increase in reverse gate leakage current,and a slight reduction in forward gate leakage.Further analysis of the gate leakage current and capacitance-voltage characteristics indicated an elevated concentration of two-dimensional electron gas(2DEG),attributed to donor-type defects introduced within the barrier layer by Back-n irradiation.These defects act as hole traps,converting into fixed positive charges that deepen the quantum-well conduction band,thereby enhancing the 2DEG density.Additionally,through the trap-assisted tunneling mechanism,these defects serve as tunneling centers,increasing the probability of electron tunneling and consequently elevating the reverse gate leakage current.展开更多
基金Project supported by the Science Challenge Project of China (Grant No.TZ2018004)the National Natural Science Foundation of China (Grant Nos.11975018 and 11775254)+1 种基金the National MCF Energy R&D Program of China (Grant No.2018YEF0308100)the outstanding member of Youth Innovation Promotion Association CAS (Grant No.Y202087)。
文摘The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by solving the rate equations and Poisson's equation simultaneously, to understand threshold voltage shifts induced by TID in silicon-based metal–oxide–semiconductor(MOS) devices. The calculated charged defect distribution and corresponding electric field under different TIDs are consistent with experiments. TID changes the electric field at the Si/SiO_(2) interface by inducing the accumulation of oxide charged defects nearby, thus shifting the threshold voltage accordingly. With increasing TID, the oxide charged defects increase to saturation, and the electric field increases following the universal 2/3 power law. Through analyzing the influence of TID on the interfacial electric field by different factors, we recommend that the radiation-hardened performance of devices can be improved by choosing a thin oxide layer with high permittivity and under high gate voltages.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51771144 and 62104189)the Natural Science Foundation of Shaanxi Province,China(Grant Nos.2021JC-06,2019TD-020,and 2019JLM-30)+1 种基金the China Postdoctoral Science Foundation(Grant No.2020M683483)the Fundamental scientific research business expenses of Xi'an Jiaotong University(Grant No.XZY022020017).
文摘Amorphous indium-gallium-zinc oxide(a-IGZO)thin films are prepared by pulsed laser deposition and fabricated into thin-film transistor(TFT)devices.In-situ x-ray photoelectron spectroscopy(XPS)illustrates that weakly bonded oxygen(O)atoms exist in a-IGZO thin films deposited at high O_(2) pressures,but these can be eliminated by vacuum annealing.The threshold voltage(V_(th))of the a-IGZO TFTs is shifted under positive gate bias,and the Vth shift is positively related to the deposition pressure.A temperature variation experiment in the range of 20 K-300 K demonstrates that an activation energy of 144 meV is required for the Vth shift,which is close to the activation energy required for the migration of weakly bonded O atoms in a-IGZO thin films.Accordingly,the Vth shift is attributed to the acceptor-like states induced by the accumulation of weakly bonded O atoms at the a-IGZO/SiO_(2) interface under positive gate bias.These results provide an insight into the mechanism responsible for the Vth shift of the a-IGZO TFTs and help in the production of reliable designs.
文摘Degradation induced by the negative bias temperature instability(NBTI)can be attributed to three mutually uncoupled physical mechanisms,i.e.,the generation of interface traps(ΔV_(IT)),hole trapping in pre-existing gate oxide defects(ΔV_(HT)),and the generation of gate oxide defects(ΔV_(OT)).In this work,the characteristic of NBTI for p-type MOSFET fabricated by using a 28-nm high-k metal gate(HKMG)process is thoroughly studied.The experimental results show that the degradation is enhanced at a larger stress bias and higher temperature.The effects of the three underlying subcomponents are evaluated by using the comprehensive models.It is found that the generation of interface traps dominates the NBTI degradation during long-time NBTI stress.Moreover,the NBTI parameters of the power-law time exponent and temperature activation energy as well as the gate oxide field acceleration are extracted.The dependence of operating lifetime on stress bias and temperature is also discussed.It is observed that NBTI lifetime significantly decreases as the stress increases.Furthermore,the decrease of charges related to interface traps and hole detrapping in pre-existing gate oxide defects are used to explain the recovery mechanism after stress.
基金supported by the National Natural Science Foundation of China (Grant Nos.12120101005,U2030104,12175174,11975174,and 12105229)State Key Laboratory Foundation of Laser Interaction with Matter (Grant Nos.SKLLIM1807 and SKLLIM2106)+1 种基金the Postdoctoral Fellowship Program of CPSF (Grant No.GZC20241372)National Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Grant No.NKLIPR2419)。
文摘Irradiation experiments on p-Ga N gate high-electron-mobility transistors(HEMTs) were conducted using neutrons at Back-streaming White Neutron(Back-n) facility at the China Spallation Neutron Source(CSNS).Two groups of devices were float-biased,while one group was ON-biased.Post-irradiation analysis revealed that the electrical performance of the devices exhibited progressive degradation with increasing Back-n fluence,with the ON-biased group demonstrating the most pronounced deterioration.This degradation was primarily characterized by a negative shift in the threshold voltage,a significant increase in reverse gate leakage current,and a slight reduction in forward gate leakage.Further analysis of the gate leakage current and capacitance-voltage characteristics indicated an elevated concentration of two-dimensional electron gas(2DEG),attributed to donor-type defects introduced within the barrier layer by Back-n irradiation.These defects act as hole traps,converting into fixed positive charges that deepen the quantum-well conduction band,thereby enhancing the 2DEG density.Additionally,through the trap-assisted tunneling mechanism,these defects serve as tunneling centers,increasing the probability of electron tunneling and consequently elevating the reverse gate leakage current.
