A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of n MOSFET during positive bias temperature instability(PBTI) stress ba...A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of n MOSFET during positive bias temperature instability(PBTI) stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy,and the energy level of the largest energy density of negative charges is 0.01 e V above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage.展开更多
The positive bias temperature instability(PBTI) degradations of high-k/metal gate(HK/MG) n MOSFETs with thin Ti N capping layers(1.4 nm and 2.4 nm) are systemically investigated. In this paper, the trap energy distrib...The positive bias temperature instability(PBTI) degradations of high-k/metal gate(HK/MG) n MOSFETs with thin Ti N capping layers(1.4 nm and 2.4 nm) are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI(90?C,125?C, 160?C) are studied and activation energy(Ea) values(0.13 e V and 0.15 e V) are extracted. Although the equivalent oxide thickness(EOT) values of two Ti N thickness values are almost similar(0.85 nm and 0.87 nm), the 2.4-nm Ti N one(thicker Ti N capping layer) shows better PBTI reliability(13.41% at 0.9 V, 90?C, 1000 s). This is due to the better interfacial layer/high-k(IL/HK) interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer.展开更多
Positive bias temperature instability(PBTI) characteristics and degradation mechanisms of NMOSFET with high-k/metal gate last process have been systematically investigated. The time evolution of threshold voltage shif...Positive bias temperature instability(PBTI) characteristics and degradation mechanisms of NMOSFET with high-k/metal gate last process have been systematically investigated. The time evolution of threshold voltage shift during PBTI stress still follows a power law. However, the exponent n decreases from 0.26 to 0.16 linearly as the gate stress voltage increases from 0.6 to 1.2 V. There is no interface state generation during stress because of the negligible sub-threshold swing change. Moreover, the activation energy is 0.1 e V, which implies that electrons directly tunnel into high-k bulk and are trapped by pre-existing traps resulting into PBTI degradation. During recovery the threshold voltage shift is linear in lgt, and a mathematical model is proposed to express threshold voltage shift.展开更多
The time zero dielectric breakdown characteristics of MOSCAP with ultra-thin EOT high-k metal gate stacks are studied. The TZDB results show an abnormal area dependence due to the series resistance effect. The series ...The time zero dielectric breakdown characteristics of MOSCAP with ultra-thin EOT high-k metal gate stacks are studied. The TZDB results show an abnormal area dependence due to the series resistance effect. The series resistance components extracted from the Fowler–Nordheim tunneling relation are attributed to the spreading resistance due to the asymmetry electrodes. Based on a series model to eliminate the series resistance effect, an area acceleration dependence is obtained by correcting the TZDB results. The area dependence follows Poisson area scaling rules, which indicates that the mechanism of TZDB is the same as TDDB and could be considered as a trap generation process.展开更多
基金Project supported by the National Science&Technology Major Projects of the Ministry of Science and Technology of China(Grant No.2009ZX02035)the National Natural Science Foundation of China(Grant Nos.61176091 and 61306129)
文摘A new method is proposed to extract the energy distribution of negative charges, which results from electron trapping by traps in the gate stack of n MOSFET during positive bias temperature instability(PBTI) stress based on the recovery measurement. In our case, the extracted energy distribution of negative charges shows an obvious dependence on energy,and the energy level of the largest energy density of negative charges is 0.01 e V above the conduction band of silicon. The charge energy distribution below that energy level shows strong dependence on the stress voltage.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.SS2015AA010601)the National Natural Science Foundation of China(Grant Nos.61176091 and 61306129)
文摘The positive bias temperature instability(PBTI) degradations of high-k/metal gate(HK/MG) n MOSFETs with thin Ti N capping layers(1.4 nm and 2.4 nm) are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI(90?C,125?C, 160?C) are studied and activation energy(Ea) values(0.13 e V and 0.15 e V) are extracted. Although the equivalent oxide thickness(EOT) values of two Ti N thickness values are almost similar(0.85 nm and 0.87 nm), the 2.4-nm Ti N one(thicker Ti N capping layer) shows better PBTI reliability(13.41% at 0.9 V, 90?C, 1000 s). This is due to the better interfacial layer/high-k(IL/HK) interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer.
基金Project supported by the Important National Science&Technology Specific Projects(No.2009ZX02035)the National Natural Science Foundation of China(Nos.61176091,61306129)
文摘Positive bias temperature instability(PBTI) characteristics and degradation mechanisms of NMOSFET with high-k/metal gate last process have been systematically investigated. The time evolution of threshold voltage shift during PBTI stress still follows a power law. However, the exponent n decreases from 0.26 to 0.16 linearly as the gate stress voltage increases from 0.6 to 1.2 V. There is no interface state generation during stress because of the negligible sub-threshold swing change. Moreover, the activation energy is 0.1 e V, which implies that electrons directly tunnel into high-k bulk and are trapped by pre-existing traps resulting into PBTI degradation. During recovery the threshold voltage shift is linear in lgt, and a mathematical model is proposed to express threshold voltage shift.
基金Project supported by the National High Technology Research and Development Program(863 Program)of China(No.SS2015AA010601)the National Natural Science Foundation of China(Nos.61176091+1 种基金61306129)the Opening Project of the Key Laboratory of Microelectronics Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences
文摘The time zero dielectric breakdown characteristics of MOSCAP with ultra-thin EOT high-k metal gate stacks are studied. The TZDB results show an abnormal area dependence due to the series resistance effect. The series resistance components extracted from the Fowler–Nordheim tunneling relation are attributed to the spreading resistance due to the asymmetry electrodes. Based on a series model to eliminate the series resistance effect, an area acceleration dependence is obtained by correcting the TZDB results. The area dependence follows Poisson area scaling rules, which indicates that the mechanism of TZDB is the same as TDDB and could be considered as a trap generation process.