共查询到20条相似文献,搜索用时 125 毫秒
1.
Ge has been an alternative channel material for the performance enhancement of complementary metal-oxide-semiconductor(CMOS)technology applications because of its high carrier mobility and superior compatibility with Si CMOS technology.The gate structure plays a key role on the electrical property.In this paper,the property of Ge MOSFET with Al2O3/GeOx/Ge stack by ozone oxidation is reviewed.The GeOxpassivation mechanism by ozone oxidation and band align-ment of Al2O3/GeOx/Ge stack is described.In addition,the charge distribution in the gate stack and remote Coulomb scatter-ing on carrier mobility is also presented.The surface passivation is mainly attributed to the high oxidation state of Ge.The en-ergy band alignment is well explained by the gap state theory.The charge distribution is quantitatively characterized and it is found that the gate charges make a great degradation on carrier mobility.These investigations help to provide an impressive un-derstanding and a possible instructive method to improve the performance of Ge devices. 相似文献
2.
Solar cell grade crystalline silicon with very low reflectivity has been obtained by electrochemically selective erosion.The porous silicon(PS) structure with a mixture of nano-and micro-crystals shows good antireflection properties on the surface layer, which has potential for application in commercial silicon photovoltaic devices after optimization.The morphology and reflectivity of the PS layers are easily modulated by controlling the electrochemical formation conditions(i.e., the current density and the anodization time).It has been shown that much a lower reflectivity of approximately 1.42% in the range 380-1100 nm is realized by using optimized conditions.In addition, the minority carrier lifetime of the PS after removing the phosphorus silicon layer is measured to be ~3.19 μs.These values are very close to the reflectivity and the minority carrier lifetime of Si3N4 as a passivation layer on a bulk silicon-based solar cell(0.33% and 3.03 μs, respectively). 相似文献
3.
RenHongxia ZhangXiaoju HaoYue XuDonggang 《电子科学学刊(英文版)》2003,20(3):202-208
Grooved gate structure Metal-Oxide-Semiconductor(MOS) device is considered as the most promising candidate used in deep and super-deep sub-micron region,for it can suppress hot carrier effect and short channel effect deeply.Based on the hydrodynamic energy transoprt model,using two-dimensional device simulator Medici,the relation between structure parameters and hot carrier effect immunity for deep-sub-micron N-channel Mosfet‘s is studied and compared with that of counterpart conventional planar device in this paper.The examined structure parameters include negative junction depth,conventinal planar device in this paper.The examined structure parameters include negative junction depth,concave corner and effective channel length.Simulation results show that grooved gate device can suppress hot carrier effect is strongly influenced by the concave corner and channel length for grooved gate device.With the increase of concave corner,the hot carrier effect in groovd gate MOSFET decreases sharply,and with the reducing of effective channel length,the hot carrier effect becomes large. 相似文献
4.
The effect of carrier phase error in digital image transmission system is discussed.Code error rate and SNR with carrier phase error in Gauss white noise channel are calculated,and the transmission system is simuated on computer. 相似文献
5.
Sub-10-nm bulk n-MOSFET(metal-oxide-semiconductor field effect transistor) direct source-todrain tunneling current density using Wentzel-Krammers-Brillouin(WKB) transmission tunneling theory has been simulated.The dependence of the source-to-drain tunneling current on channel length and barrier height is examined.Inversion layer quantization,band-gap narrowing,and drain induced barrier lowering effects have been included in the model.It has been observed that the leakage current density increases severely below 4 nm channel lengths,thus putting a limit to the scaling down of the MOSFETs.The results match closely with the numerical results already reported in literatures. 相似文献
6.
The influence of temperature on the intensity of light emitted by as well as the carrier life time of a standard AlGaAs based light emitting diode has been investigated in the temperature range from 345 to 136 K. The open-circuit voltage decay(OCVD) technique has been used for measured the carrier lifetime. Our experimental results reveal a 16% average increase in intensity and a 163.482-19.765 ns variation in carrier lifetime in the above temperature range. Further, theoretical and experimental analysis show that for negligible carrier density the intensity is inversely proportional to carrier lifetime for this sample. 相似文献
7.
Grooved gate structure Metal-Oxide-Semiconductor (MOS) device is considered as the most promising candidate used in deep and super-deep sub-micron region, for it can suppress hot carrier effect and short channel effect deeply. Based on the hydrodynamic energy transport model, using two-dimensional device simulator Medici, the relation between structure parameters and hot carrier effect immunity for deep-sub-micron N-channel MOSFET's is studied and compared with that of counterpart conventional planar device in this paper. The examined structure parameters include negative junction depth, concave corner and effective channel length. Simulation results show that grooved gate device can suppress hot carrier effect deeply even in deep sub-micron region. The studies also indicate that hot carrier effect is strongly influenced by the concave corner and channel length for grooved gate device. With the increase of concave corner, the hot carrier effect in grooved gate MOSFET decreases sharply, and with the redu 相似文献
8.
A 5G network must be heterogeneous and support the co-existence of multilayer cells, multiple standards, and multiple application systems. This greatly improves link performance and increases link capacity. A network with co-existing macro and pico cells can alleviate traffic congestion caused by multicast or unicast subscribers, help satisfy huge traffic demands, and further extend converge. In order to practically implement advanced 5G technology, a number of technical problems have to be solved, one of which is inter-cell interference. A method called Almost Blank Subframe(ABS) has been proposed to mitigate interference; however, the reference signal in ABS still causes interference. This paper describes how interference can be cancelled by using the information in the ABS. First, the interference-signal model, which takes into account channel effect, time and frequency error, is presented. Then, an interference-cancellation scheme based on this model is studied. The timing and carrier frequency offset of the interference signal is compensated. Afterwards, the reference signal of the interfering cell is generated locally and the channel response is estimated using channel statistics. Then, the interference signal is reconstructed according to previous estimation of channel, timing, and carrier frequency offset. The interference is mitigated by subtracting the estimated interference signal. Computer simulation shows that this interference-cancellation algorithm significantly improves performance under different channel conditions. 相似文献
9.
This paper presents the analytical modeling of subthreshold current and subthreshold swing of short- channel fully-depleted (FD) strained-Si-on-insulator (SSOI) MOSFETs having vertical Gaussian-like doping pro- file in the channel. The subthreshold current and subthreshold swing have been derived using the parabolic approx- imation method. In addition to the effect of strain on silicon layer, various other device parameters such as channel length (L), gate-oxide thickness (tox), strained-Si channel thickness (ts_Si), peak doping concentration (Np), project range (Rp) and straggle (op) of the Gaussian profile have been considered while predicting the device characteris- tics. The present work may help to overcome the degradation in subthreshold characteristics with strain engineering. These subthreshold current and swing models provide valuable information for strained-Si MOSFET design. Ac- curacy of the proposed models is verified using the commercially available ATLASTM, a two-dimensional (2D) device simulator from SILVACO. 相似文献
10.
ZHANG Ye HE Chen JIANG Lingge 《电子学报:英文版》2008,(3):507-512
After considering the memory effect among series events occurring on the channel, we propose a novel event model to analyze the channel status more precisely. The memory effect is caused by the backoff freezing regulation of IEEE 802.11 Distributed coordination function (DCF), which has been ignored before and thus resulted in the inaccurate evaluation of the network performance. Based on our new event model, the network performance of IEEE 802.11 DCF, including throughput, packet delay distribution and energy efficiency is analyzed. Simulation results show that our model is highly accurate. 相似文献
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用电化学液结方法测量了在470℃于氢气氛下开管扩锌InP样品的载流子浓度分布、不同深度的光伏谱和少于扩散长度。结果表明:在扩散区形成浓度为1017~1018cm-3较平坦的空穴分布;少于扩散长度由衬底的8~10μm降至表面的0.29μm以下;若轻微腐蚀去严重损伤的样品表层,将较大地提高新表层的少子扩散长度。 相似文献
15.
The behaviour of carrier mobility in the inversion channel of gateless p-MOSFETs with thin (7-50 nm) Ta2O5 layers, having a dielectric constant of (23-27) and prepared by rf sputtering of Ta in an Ar-O2 mixture, has been investigated. It is shown that independently of the high dielectric constant of the layers, the transport properties in the channel are strongly affected by defects in Ta2O5/Si system in the form of oxide charge and interface states. These defects act as scattering centers and are responsible for the observed minority carrier mobility degradation. Both, the oxide and the interface state charges are virtually independent on the oxygen content (in the range 10-30%) during the sputtering process. A reduction of the oxide charge and the density of interface states with increasing Ta2O5 film thickness was found, which results in the observed increase of the inversion channel mobility with thickness. It is assumed that the bond defects (broken or strained Ta-bonds as well as weak Si-O bonds in the transition region between Ta2O5 and Si) are much more probable sources of defect centers rather than Ta and O vacancies or impurities. 相似文献
16.
Role of Dislocation Scattering on the Electron Mobility of n-Type Long Wave Length Infrared HgCdTe on Silicon 总被引:1,自引:0,他引:1
M. Carmody D. Edwall J. Ellsworth J. Arias M. Groenert R. Jacobs L.A. Almeida J.H. Dinan Y. Chen G. Brill N.K. Dhar 《Journal of Electronic Materials》2007,36(8):1098-1105
It has been reported that the basic electrical properties of n-type long wave length infrared (LWIR) HgCdTe grown on silicon, including the majority carrier mobility (μ
e) and minority carrier lifetime (τ), are qualitatively comparable to those reported for LWIR HgCdTe grown on bulk CdZnTe by
molecular beam epitaxy (MBE). Detailed measurements of the majority carrier mobility have revealed important differences between
the values measured for HgCdTe grown on bulk CdZnTe and those measured for HgCdTe grown on buffered silicon substrates. The
mobility of LWIR HgCdTe grown on buffered silicon by MBE is reported over a large temperature range and is analyzed in terms
of standard electron scattering mechanisms. The role of dislocation scattering is addressed for high dislocation density HgCdTe
grown on lattice-mismatched silicon. Differences between the low temperature mobility data of HgCdTe grown on bulk CdZnTe
and HgCdTe grown on silicon are partially explained in terms of the dislocation scattering contribution to the total mobility. 相似文献
17.
Tuong Khanh Vu Yoshio Ohshita Yasutaka Yagi Nobuaki Kojima Masafumi Yamaguchi 《Materials Science in Semiconductor Processing》2003,6(5-6):551-553
The conversion efficiency of boron (B)-doped Czochralski silicon (Cz-Si) solar cells decreased by light illumination or minority carrier injection. Defects are induced by illumination and they act as trap centers, shorten the minority carrier (electron) lifetime. The energy level of this minority carrier trap center was determined by analyzing the open-circuit voltage (VOC) changes as a function of substrate temperature. When substrate temperature is low, all electrons which are captured by the trap centers recombine with holes and they do not contribute to the generation of electric power. However, as the substrate temperature is increasing, some of the captured electrons are thermally excited to the conduction band before recombination. Hence, the lifetime of minority carriers are improved and VOC is recovered. Based on this result, the energy level of trap center induced by light illumination is estimated to be 0.26 eV, which corresponds to the boron–oxygen-related defect (EC-0.26 eV). 相似文献
18.
Mintairov S. A. Andreev V. M. Emelyanov V. M. Kalyuzhnyy N. A. Timoshina N. K. Shvarts M. Z. Lantratov V. M. 《Semiconductors》2010,44(8):1084-1089
A technique for determining a minority carrier’s diffusion length in photoactive III–V layers of solar cells by approximating
their spectral characteristics is presented. Single-junction GaAs, Ge and multi-junction GaAs/Ge, GaInP/GaAs, and GaInP/GaInAs/Ge
solar cells fabricated by hydride metal-organic vapor-phase epitaxy (H-MOVPE) have been studied. The dependences of the minority
carrier diffusion length on the doping level of p-Ge and n-GaAs are determined. It is shown that the parameters of solid-state diffusion of phosphorus atoms to the p-Ge substrate from the n-GaInP nucleation layer are independent of the thickness of the latter within 35–300 nm. It is found that the diffusion length
of subcells of multijunction structures in Ga(In)As layers is smaller in comparison with that of single-junction structures. 相似文献
19.
Masato Yoshiya Takahiro Okabayashi Masahiro Tada Craig A. J. Fisher 《Journal of Electronic Materials》2010,39(9):1681-1686
First principles calculations using the generalized gradient approximation to density functional theory have been carried
out to evaluate formation energies of defects and the resultant changes in electronic structure of NaCoO2 and Na0.5CoO2. The calculated formation energies confirm that Na vacancies form readily in this material, particularly through volatilization
at elevated temperatures, consistent with experimentally observed behavior. Numerical analysis of the change in charge distribution
upon Na vacancy formation shows that the vacancy plays a crucial role in modifying the electronic properties of the material.
In these p-type thermoelectric materials, Na vacancies act as a reservoir for the minority carrier (electrons), removing them from the
CoO2 layer while simultaneously increasing the concentration of majority carriers (holes) available for conduction in the CoO2 layer. 相似文献