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1.
对超深亚微米PMOS器件的负栅压温度不稳定性(NBTI)退化机理进行了研究.主要集中在对器件施加NBT和随后的PBT应力后器件阈值电压的漂移上.实验证明反型沟道中空穴在栅氧中的俘获以及氢分子在栅氧中的扩散是引起NBTI退化的主要原因.当应力条件变为PBT时,陷落的空穴可以快速退陷,但只有部分氢分子可以扩散回栅氧与衬底界面钝化硅悬挂键,这就导致了PBT条件下阈值电压只能部分恢复.
关键词:
超深亚微米PMOS器件
负偏压温度不稳定性
界面陷阱
氢气 相似文献
2.
研究了深亚微米PMOS器件在负偏压温度(negative bias temperature, NBT) 应力前后的电流电压特性随应力时间的退化,重点分析了NBT应力对PMOS器件阈值电压漂移的影响,通过实验证明了在栅氧化层和衬底界面附近的电化学反应和栅氧化层内与氢相关的元素的扩散,是PMOS器件中NBT效应产生的主要原因.指出NBT导致的PMOS器件退化依赖于反应机理和扩散机理两种机理的平衡.
关键词:
深亚微米PMOS器件
负偏压温度不稳定性
界面态
氧化层固定正电荷 相似文献
3.
Degradation characteristics of PMOSFETs under negative bias
temperature--positive bias temperature--negative bias temperature
(NBT--PBT--NBT) stress conditions are investigated in this paper. It
is found that for all device parameters, the threshold voltage has
the largest shift under the first NBT stress condition. When the
polarity of gate voltage is changed to positive, the shift of device
parameters can be greatly recovered. However, this recovery is
unstable. The more severe degradation appears soon after
reapplication of NBT stress condition. The second NBT stress causes
in linear drain current to degrade greatly, which is different from
that of the first NBT stress. This more severe parameter shift
results from the wear out of silicon substrate and oxide interface
during the first NBT and PBT stress due to carrier
trapping/detrapping and hydrogen related species diffusion. 相似文献
4.
Study on the drain bias effect on negative bias temperature instability degradation of an ultra-short p-channel metal-oxide-semiconductor field-effect transistor 下载免费PDF全文
This paper studies the effect of drain bias on
ultra-short p-channel metal-oxide-semiconductor field-effect
transistor (PMOSFET) degradation during negative bias temperature
(NBT) stress. When a relatively large gate voltage is applied, the
degradation magnitude is much more than the drain voltage which is
the same as the gate voltage supplied, and the time exponent gets
larger than that of the NBT instability (NBTI). With decreasing
drain voltage, the degradation magnitude and the time exponent all
get smaller. At some values of the drain voltage, the degradation
magnitude is even smaller than that of NBTI, and when the drain
voltage gets small enough, the exhibition of degradation becomes
very similar to the NBTI degradation. When a relatively large drain
voltage is applied, with decreasing gate voltage, the
degradation magnitude gets smaller. However, the time exponent
becomes larger. With the help of electric field simulation, this
paper concludes that the degradation magnitude is determined by the
vertical electric field of the oxide, the amount of hot holes
generated by the strong channel lateral electric field at the
gate/drain overlap region, and the time exponent is mainly
controlled by localized damage caused by the lateral electric
field of the oxide in the gate/drain overlap region where hot carriers
are produced. 相似文献
5.
Actions of negative bias temperature instability (NBTI) and hot carriers in ultra-deep submicron p-channel metal——oxide——semiconductor field-effect transistors (PMOSFETs) 下载免费PDF全文
Hot carrier injection (HCI) at high temperatures and different
values of gate bias Vg has been performed in order to study
the actions of negative bias temperature instability (NBTI) and hot
carriers. Hot-carrier-stress-induced damage at Vg=Vd, where Vd is the voltage of the transistor drain,
increases as temperature rises, contrary to conventional hot carrier
behaviour, which is identified as being related to the NBTI. A
comparison between the actions of NBTI and hot carriers at low and
high gate voltages shows that the damage behaviours are quite
different: the low gate voltage stress results in an increase in
transconductance, while the NBTI-dominated high gate voltage and
high temperature stress causes a decrease in transconductance. It is
concluded that this can be a major source of hot carrier damage at
elevated temperatures and high gate voltage stressing of p-channel
metal--oxide--semiconductor field-effect transistors (PMOSFETs). We
demonstrate a novel mode of NBTI-enhanced hot carrier degradation in
PMOSFETs. A novel method to decouple the actions of NBTI from that
of hot carriers is also presented. 相似文献
6.
Effect of substrate bias on negative bias temperature instability of ultra-deep sub-micro p-channel metal--oxide--semiconductor field-effect transistors 下载免费PDF全文
The effect of substrate bias on the degradation during applying a
negative bias temperature (NBT) stress is studied in this paper.
With a smaller gate voltage stress applied, the degradation of
negative bias temperature instability (NBTI) is enhanced, and there
comes forth an inflexion point. The degradation pace turns larger
when the substrate bias is higher than the inflexion point. The
substrate hot holes can be injected into oxide and generate
additional oxide traps, inducing an inflexion phenomenon. When a
constant substrate bias stress is applied, as the gate voltage
stress increases, an inflexion comes into being also. The higher
gate voltage causes the electrons to tunnel into the substrate from
the poly, thereby generating the electron--hole pairs by impact
ionization. The holes generated by impact ionization and the holes
from the substrate all can be accelerated to high energies by the
substrate bias. More additional oxide traps can be produced, and
correspondingly, the degradation is strengthened by the substrate
bias. The results of the alternate stress experiment show that the
interface traps generated by the hot holes cannot be annealed, which
is different from those generated by common holes. 相似文献
7.
The study on mechanism and model of negative bias temperature instability degradation in P-channel metal-oxide-semiconductor field-effect transistors 下载免费PDF全文
Negative Bias Temperature Instability (NBTI) has become one of the most serious reliability problems of metal- oxide-semiconductor field-effect transistors (MOSFETs). The degradation mechanism and model of NBTI are studied in this paper. From the experimental results, the exponential value 0.25-0.5 which represents the relation of NBTI degradation and stress time is obtained. Based on the experimental results and existing model, the reaction-diffusion model with H+ related species generated is deduced, and the exponent 0.5 is obtained. The results suggest that there should be H+ generated in the NBTI degradation. With the real time method, the degradation with an exponent 0.5 appears clearly in drain current shift during the first seconds of stress and then verifies that H+ generated during NBTI stress. 相似文献
8.
Effects of stress conditions on the generation of negative bias temperature instability-associated interface traps 下载免费PDF全文
The exponent n of the generation of an interface trap(Nit),which contributes to the power-law negative bias temperature instability(NBTI)degradation,and the exponent’s time evolution are investigated by simulations with varying the stress voltage Vgand temperature T.It is found that the exponent n in the diffusion-limited phase of the degradation process is irrelevant to both Vgand T.The time evolution of the exponent n is affected by the stress conditions,which is reflected in the shift of the onset of the diffusion-limited phase.According to the diffusion profiles,the generation of the atomic hydrogen species,which is equal to the buildup of Nit,is strongly correlated with the stress conditions,whereas the diffusion of the hydrogen species shows Vg-unaffected but T-affected relations through the normalized results. 相似文献
9.
Evaluation of negative bias temperature instability in ultra-thin gate oxide pMOSFETs using a new on-line PDO method 下载免费PDF全文
A new on-line methodology is used to characterize the negative bias temperature
instability (NBTI) without inherent recovery. Saturation drain voltage shift and
mobility shift are extracted by ID-VD characterizations, which were
measured before stress, and after every certain stress phase, using the
proportional differential operator (PDO) method. The new on-line methodology avoids
the mobility linearity assumption as compared with the previous on-the-fly method.
It is found that both reaction--diffusion and charge-injection processes are
important in NBTI effect under either DC or AC stress. A similar activation energy,
0.15 eV, occurred in both DC and AC NBTI processes. Also degradation rate factor is
independent of temperature below 90\du\ and sharply increases above it. The
frequency dependence of NBTI degradation shows that NBTI degradation is independent
of frequencies. The carrier tunnelling and reaction--diffusion mechanisms exist
simultaneously in NBTI degradation of sub-micron pMOSFETs, and the carrier
tunnelling dominates the earlier NBTI stage and the reaction--diffusion mechanism
follows when the generation rate of traps caused by carrier tunnelling reaches its
maximum. 相似文献
10.
H. Hussin N. Soin N.M. Karim S.F. Wan Muhamad Hatta 《Physica B: Condensed Matter》2012,407(15):3031-3033
This paper presents the effects of interface trap concentration and threshold voltage shift on NBTI degradation in p-MOSFETs. To explore the degradation mechanisms, transistors having an EOT of 1.1 nm and 5 nm were simulated by applying various stress conditions. The NBTI degradation mechanism was studied by varying the gate voltage, temperature and substrate doping level. The simulations show NBTI degradation in terms of the threshold voltage shift, ΔVth and number of interface traps, ΔNit. The simulation results show an improved degradation trend in terms of ΔVth and ΔNit when the substrate doping level is increased. 相似文献
11.
Negative bias temperature instability (NBTI) and stress-induced leakage current (SILC) both are more serious due to the aggressive scaling lowering of devices. We investigate the SILC during NBTI stress in PMOSFETs with ultra-thin gate dielectrics. The SILC sensed range from -1 V to 1 V is divided into four parts: the on-state SILC, the near-zero SILC, the off-state SILC sensed at lower positive voltages and the one sensed at higher positive voltages. We develop a model of tunnelling assisted by interface states and oxide bulk traps to explain the four different parts of SILC during NBTI stress. 相似文献
12.
Recovery phenomenon is observed under negative gate voltage stress which is smaller than the previous degradation stress. We focus on the drain current to study the degradation and recovery of negative bias temperature instability (NBTI) with a real-time method. By this method, different recovery phenomena among different size devices are observed. Under negative recovery stress, the drain current gradually recovers for the large size devices and gets into recovery saturation when long recovery time is involved. For small-size devices, a step-like recovery of drain current is observed. The recovery of the drain current is mainly caused by the holes detrapping and tunnelling back to the channel surface which are trapped in oxide. The model of hole detrapping explains the recovery under negative voltage stress reasonably. 相似文献
13.
Study on the degradation of NMOSFETs with ultra-thin gate oxide under channel hot electron stress at high temperature 下载免费PDF全文
This paper studies the degradation of device parameters
and that of stress induced leakage current (SILC) of thin tunnel
gate oxide under channel hot electron (CHE) stress at high
temperature by using n-channel metal oxide semiconductor field
effect transistors (NMOSFETs) with 1.4-nm gate oxides. The
degradation of device parameters under CHE stress exhibits
saturating time dependence at high temperature. The emphasis of this
paper is on SILC of an ultra-thin-gate-oxide under CHE stress at high
temperature. Based on the experimental results, it is found that
there is a linear correlation between SILC degradation and Vh
degradation in NMOSFETs during CHE stress. A model of
the combined effect of oxide trapped negative charges and interface
traps is developed to explain the origin of SILC during CHE stress. 相似文献
14.
Hot-carrier degradation for 90nm gate length LDD-NMOSFET with ultra-thin gate oxide under low gate voltage stress 下载免费PDF全文
The hot-carrier degradation for 90~nm gate length lightly-doped drain
(LDD) NMOSFET with ultra-thin (1.4~nm) gate oxide under the low gate
voltage (LGV) (at Vg=Vth, where Vth is the
threshold voltage) stress has been investigated. It is found that the
drain current decreases and the threshold voltage increases after the
LGV (Vg=Vth stress. The results are opposite to the
degradation phenomena of conventional NMOSFET for the case of this
stress. By analysing the gate-induced drain leakage (GIDL) current
before and after stresses, it is confirmed that under the LGV stress
in ultra-short gate LDD-NMOSFET with ultra-thin gate oxide, the hot
holes are trapped at interface in the LDD region and cannot shorten
the channel to mask the influence of interface states as those in
conventional
NMOSFET do, which leads to the different degradation phenomena from those of the
conventional NMOS devices. This paper also discusses the degradation in the
90~nm gate length LDD-NMOSFET with 1.4~nm gate oxide under the LGV stress at
Vg=Vth with various drain biases. Experimental results show that
the degradation slopes (n) range from 0.21 to 0.41. The value of
n is
less than that of conventional MOSFET (0.5-0.6) and also that of the long gate
length LDD MOSFET (\sim0.8). 相似文献
15.
研究了HfN/HfO2高K栅结构p型金属-氧化物-半导体(MOS)晶体管(MOSFET)中,负 偏置-温度应力引起的阈值电压不稳定性(NBTI)特征.HfN/HfO2高K栅结构的等效 氧化层厚度(EOT)为1.3nm,内含原生缺陷密度较低.研究表明,由于所制备的HfN/HfO2 高K栅结构具有低的原生缺陷密度,因此在p-MOSFET器件中观察到的NBTI属HfN/HfO2高K栅结构的本征特征,而非工艺缺陷引起的;进一步研究表明,该HfN/HfO2高K栅结构中观察到的NBTI与传统的SiO2基栅介质p-MOSFET器件中观察 到的NBTI具有类似的特征,可以被所谓的反应-扩散(R-D)模型表征: HfN/HfO2 栅结构p-MOSFET器件的NBTI效应的起源可以归为衬底注入空穴诱导的界面反应机理,即在负 偏置和温度应力作用下,从Si衬底注入的空穴诱导了Si衬底界面Si-H键断裂这一化学反应的 发生,并由此产生了Si+陷阱在Si衬底界面的积累和H原子在介质层内部的扩散 ,这种Si+陷阱的界面积累和H原子的扩散导致了器件NBTI效应的发生.
关键词:
高K栅介质
负偏置-温度不稳定性(NBTI)
反应-扩散(R-D)模型 相似文献
16.
AlGaN/GaN MIS-HEMTs with adjusted VT were fabricated using a recess gate to investigate the effect on actual operation when the polarity of the gate voltage is opposite in the on- and off-state. The direction and time exponents of VT shift depend on the polarity of the gate bias stress. Electrons detrapping from the Al2O3/AlGaN interface trap site to AlGaN under negative gate bias stress has to overcome the energy barrier, resulting in a higher temperature dependence. In addition, the unaffected gm and SS show that the degradation occurred primarily at the Al2O3/AlGaN interface rather than channel or mobility degradation. For unipolar and bipolar AC stresses, the time exponent of the VT shift during stress time has two values, and a relatively low value during relaxation after bipolar AC stress. These results may be due to the further degradation by Vmin at the broader energy levels of the Al2O3/AlGaN interface. 相似文献
17.
E. Martinez C. GaumerS. Lhostis C. LicitraM. Silly F. SirottiO. Renault 《Applied Surface Science》2012,258(6):2107-2112
The impact of HfO:N post nitridation anneal (PNA) and gate fabrication on the physico-chemical properties of the TiN/HfO:N/SiO2/Si stack are investigated using Soft X-ray Photoelectron Spectroscopy (S-XPS) and Vacuum UltraViolet Spectroscopic Ellipsometry (VUV-SE). Defects created in the high-k during plasma nitridation are passivated by PNA under O2. Both oxygen and nitrogen diffusion is observed towards the bottom SiO2/Si interface together with a regrowth of the SiO2. These defects play a major role regarding nitrogen diffusion during gate fabrication. Without PNA, no diffusion is observed because O and N atoms are trapped inside the high-k. With PNA and simultaneous defects passivation, nitrogen from both metal gate and high-k diffuses towards the bottom SiO2/Si interface. 相似文献
18.
采用不同的高场应力和栅应力对AlGaN/GaN HEMT器件进行直流应力测试,实验发现:应力后器件主要参数如饱和漏电流,跨导峰值和阈值电压等均发生了明显退化,而且这些退化还是可以完全恢复的;高场应力下,器件特性的退化随高场应力偏置电压的增加和应力时间的累积而增大;对于不同的栅应力,相对来说,脉冲栅应力和开态栅应力下器件特性的退化比关态栅应力下的退化大.对不同应力前后器件饱和漏电流,跨导峰值和阈值电压的分析表明,AlGaN势垒层陷阱俘获沟道热电子以及栅极电子在栅漏间电场的作用下填充虚栅中的表面态是这些不同应
关键词:
AlGaN/GaN HEMT器件
表面态(虚栅)
势垒层陷阱
应力 相似文献
19.
Hot-carrier degradation for 90 nm gate length lightly-doped drain (LDD) NMOSFET with ultra-thin (1.4 nm) gate oxide is investigated under the low gate voltage stress (LGVS) and peak substrate current (Isub max) stress. It is found that the degradation of device parameters exhibits saturating time dependence under the two stresses. We concentrate on the effect of these two stresses on gate-induced-drain leakage (GIDL) current and stress induced leakage current (SILC). The characteristics of the GIDL current are used to analyse the damage generated in the gate-to-LDD region during the two stresses. However, the damage generated during the LGVS shows different characteristics from that during Isub stress. SILC is also investigated under the two stresses. It is found experimentally that there is a linear correlation between the degradation of SILC and that of threshold voltage during the two stresses. It is concluded that the mechanism of SILC is due to the combined effect of oxide charge trapping and interface traps for the ultra-short gate length and ultra-thin gate oxide LDD NMOSFETs under the two stresses. 相似文献