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1.
A two-dimensional threshold voltage analytical model for metal-gate/high-k/SiO2/Si stacked MOSFETs 下载免费PDF全文
In this paper the influences of the metal-gate and high-k/SiO 2 /Si stacked structure on the metal-oxide-semiconductor field-effect transistor(MOSFET) are investigated.The flat-band voltage is revised by considering the influences of stacked structure and metal-semiconductor work function fluctuation.The two-dimensional Poisson's equation of potential distribution is presented.A threshold voltage analytical model for metal-gate/high-k/SiO 2 /Si stacked MOSFETs is developed by solving these Poisson's equations using the boundary conditions.The model is verified by a two-dimensional device simulator,which provides the basic design guidance for metal-gate/high-k/SiO 2 /Si stacked MOSFETs. 相似文献
2.
HfO2-based metal-oxide semiconductor (MOS) capacitors were irradiated with high-energy ion beam to study the irradiation effects in these films. HfO2 thin films deposited by radio frequency (rf)-sputtering were irradiated with 80 MeV O6+ ions. The samples were irradiated and characterized at room temperature. Devices were characterized via 1 MHz capacitance–voltage (C?V) measurements using the midgap method. The irradiation induced dispersion in accumulation and depletion regions with increasing fluence is observed. After irradiation, the midgap voltage shift (Δ V mg) of?0.61 to?1.92 V, flat band voltage shift (Δ V fb) of?0.48 to?2.88 V and threshold voltage shift (Δ V th) of?0.966 to?1.96 V were observed. The change in interface trap charge and oxide trap charge densities after 80 MeV O6+ ions irradiation with fluences were determined from the midgap to flat band stretch out of C?V curves. The results are reported and explained in terms of changes in microstructure and dielectric properties of the HfO2 thin films after irradiation. 相似文献
3.
随着金属氧化物半导体场效应管(MOSFETs)等比缩小到45 nm技术节点,具有高介电常数的栅介质材料(高k材料)取代传统的SiO2已经成为必然,然而Hf基高k材料在实际应用中仍然存在许多不足,而稀土元素掺杂在提高Hf基栅介质材料的k值、降低缺陷密度、调整MOSFETs器件的阈值电压等方面表现出明显的优势.本文综述了Hf基高k材料的发展历程,面临的挑战,稀土掺杂对Hf基高k材料性能的调节以及未来研究的趋势.
关键词:
k栅介质')" href="#">Hf基高k栅介质
稀土掺杂
氧空位缺陷
有效功函数 相似文献
4.
Investigation of 4H—SiC metal—insulation—semiconductor structure with Al2O3/SiO2 stacked dielectric 下载免费PDF全文
Atomic layer deposited (ALD) Al2O3/dry-oxidized ultrathin SiO2 films as high-k gate dielectric grown on the 8° off-axis 4H-SiC (0001) epitaxial wafers are investigated in this paper. The metal-insulation-semiconductor (MIS) capacitors, respectively with different gate dielectric stacks (Al2O3/SiO2, Al2O3, and SiO2) are fabricated and compared with each other. The I-V measurements show that the Al2O3/SiO2 stack has a high breakdown field ( ≥ 12 MV/cm) comparable to SiO2, and a relatively low gate leakage current of 1× 10-7 A/cm2 at electric field of 4 MV/cm comparable to Al2O3. The 1-MHz high frequency C-V measurements exhibit that the Al2O3/SiO2 stack has a smaller positive flat-band voltage shift and hysteresis voltage, indicating less effective charge and slow-trap density near the interface. 相似文献
5.
S. Abermann C. Henkel O. Bethge G. Pozzovivo P. Klang E. Bertagnolli 《Applied Surface Science》2010,256(16):5031-5034
The impact of the ZrO2/La2O3 film thickness ratio and the post deposition annealing in the temperature range between 400 °C and 600 °C on the electrical properties of ultrathin ZrO2/La2O3 high-k dielectrics grown by atomic layer deposition on (1 0 0) germanium is investigated. As-deposited stacks have a relative dielectric constant of 24 which is increased to a value of 35 after annealing at 500 °C due to the stabilization of tetragonal/cubic ZrO2 phases. This effect depends on the absolute thickness of ZrO2 within the dielectric stack and is limited due to possible interfacial reactions at the oxide/Ge interface. We show that adequate processing leads to very high-k dielectrics with EOT values below 1 nm, leakage current densities in the range of 0.01 A/cm2, and interface trap densities in the range of 2-5 × 1012 eV−1 cm−2. 相似文献
6.
In this article, the authors developed a high-k HoTiO3 gate dielectric deposited on Si (1 0 0) through reactive cosputtering. They found that the HoTiO3 dielectrics annealed at 800 °C exhibited excellent electrical properties such as high capacitance value, small density of interface state, almost no hysteresis voltage, and low leakage current. This phenomenon is attributed to the decrease in intrinsic defect (related to oxygen vacancy) due to a rather well-crystallized HoTiO3 structure and composition observed by X-ray diffraction, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy, respectively. 相似文献
7.
La-doped HfO2 gate dielectric thin films have been deposited on Si substrates using La(acac)3 and Hf(acac)4 (acac = 2,4-pentanedionate) mixing sources by low-pressure metal-organic chemical vapor deposition (MOCVD). The structure, thermal stability, and electrical properties of La-doped HfO2 films have been investigated. Inductive coupled plasma analyses confirm that the La content ranging from 1 to 5 mol% is involved in the films. The films show smaller roughness of ∼0.5 nm and improved thermal stability up to 750 °C. The La-doped HfO2 films on Pt-coated Si and fused quartz substrates have an intrinsic dielectric constant of ∼28 at 1 MHz and a band gap of 5.6 eV, respectively. X-ray photoelectron spectroscopy analyses reveal that the interfacial layer is Hf-based silicate. The reliable value of equivalent oxide thickness (EOT) around 1.2 nm has been obtained, but with a large leakage current density of 3 A/cm2 at Vg = 1V + Vfb. MOCVD-derived La-doped HfO2 is demonstrated to be a potential high-k gate dielectric film for next generation metal oxide semiconductor field effect transistor applications. 相似文献
8.
High-k ytterbium oxide (Yb2O3) gate dielectrics were deposited on Si substrate by reactive sputtering. The structural features of these films after postdeposition annealing treatment were studied by X-ray diffraction and X-ray photoelectron spectroscopy. It is found that the Yb2O3 gate dielectrics annealed at 700 °C exhibit a larger capacitance value, a lower frequency dispersion and a smaller hysteresis voltage in C-V curves compared with other annealing temperatures. They also show negligible charge trapping under high constant voltage stress. This phenomenon is mainly attributed to the decrease in the amorphous silica thickness. 相似文献
9.
This paper describes the effect of ionizing radiation on the interface properties of Al/Ta2O5/Si metal oxide semiconductor (MOS) capacitors using capacitance–voltage (C–V) and current–voltage (I–V) characteristics. The devices were irradiated with X-rays at different doses ranging from 100?rad to 1?Mrad. The leakage behavior, which is an important parameter for memory applications of Al/Ta2O5/Si MOS capacitors, along with interface properties such as effective oxide charges and interface trap density with and without irradiation has been investigated. Lower accumulation capacitance and shift in flat band voltage toward negative value were observed in annealed devices after exposure to radiation. The increase in interfacial oxide layer thickness after irradiation was confirmed by Rutherford Back Scattering measurement. The effect of post-deposition annealing on the electrical behavior of Ta2O5 MOS capacitors was also investigated. Improved electrical and interface properties were obtained for samples deposited in N2 ambient. The density of interface trap states (Dit) at Ta2O5/Si interface sputtered in pure argon ambient was higher compared to samples reactively sputtered in nitrogen-containing plasma. Our results show that reactive sputtering in nitrogen-containing plasma is a promising approach to improve the radiation hardness of Ta2O5/Si MOS devices. 相似文献
10.
A metal–insulator–semiconductor structure device with Ge nanocrystals in SiO2 was synthesized and the electrical characteristics were investigated. Capacitance–voltage (C–V) curves show hysteresis and the measurements indicate that the device has charge storage effects and stores more holes than electrons. For decreasing measurement frequencies from 1 MHz to 500 Hz, both branches of the C–V hysteresis shift in the positive voltage direction. The slope of the left flank of the C–V hysteresis curve becomes stretched out with decreasing frequency. The slope of the right one appears frequency independent, while there is a small hump/step on the right flank of the C–V hysteresis curve for the lower frequency cases (500 Hz and 1 kHz). The role of Si/SiO2 interface states is discussed. 相似文献
11.
G.T. Ma J.S. Wang Q.X. Lin M.X. Liu Z.G. Deng X.C. Li H.F. Liu J. Zheng S.Y. Wang 《Physica C: Superconductivity and its Applications》2009,469(21):1954-1957
The lateral restorable characteristics of a translational symmetry high-Tc superconducting maglev system are investigated by measuring its resonant frequency (fRF) after a lateral displacement. The difference between whether this lateral displacement is restorable, meaning elastic or inelastic, is determined by whether or not the maglev body returns to its original position after a lateral displacement. The maximum restorable lateral displacement (δMRLD) is determined by the sudden change of the fRF vs. the maximum lateral displacement (δMLD) curve. The fRF of the high-Tc superconducting maglev system with different field-cooling height (FCH) and working height (WH) was obtained from the frequency domain vibration curve which was measured by a vibration measurement system. The results showed that, the δMRLD was reduced when the WH was decreased. The maximum restorable guidance force (FMRGF) was found to not always increase with the lowering of the WH for the same FCH. The lateral restorable stiffness (kLRS) was always enhanced with the decrease of the WH. The decrease of the δMRLD with the WH is interpreted by the fact that, the tangential field component (ΔH) across the surface of the high-Tc superconductor (HTSC) is easier to exceed the Jcλ value (Jc is the critical current density and λ is the London penetration depth) when the WH is lowered, and this makes the trapped flux lines become more susceptible in escaping its pinning sites. 相似文献
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13.
The capacitance characteristics of platinum nanoparticle (NP)-embedded metal–oxide–semiconductor (MOS) capacitors with gate Al2O3 layers are studied in this work. The capacitance versus voltage (C–V) curves obtained for a representative MOS capacitor exhibit flat-band voltage shifts, demonstrating the presence of charge storages in the platinum NPs. The counterclockwise hysteresis and flat-band voltage shift, observed from the C–V curves imply that electrons are stored in a floating gate layer consisting of the platinum NPs present between the tunneling and control oxide layers in the MOS capacitor and that these stored electrons originate from the Si substrate. Moreover, the charge remains versus time curve for the platinum NP-embedded MOS capacitor is investigated in this work. 相似文献
14.
AlGaN/GaN MIS-HEMT using NbAlO dielectric layer grown by atomic layer deposition 总被引:1,自引:0,他引:1 下载免费PDF全文
We present an AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT) with an NbAlO high-k dielectric deposited by atomic layer deposition (ALD).Surface morphology of samples are observed by atomic force microscopy (AFM),indicating that the ALD NbAlO has an excellent-property surface.Moreover,the sharp transition from depletion to accumulation in capacitance-voltage (C-V)curse of MIS-HEMT demonstrates the high quality bulk and interface properties of NbAlO on AlGaN.The fabricated MIS-HEMT with a gate length of 0.5 μm exhibits a maximum drain current of 960 mA/mm,and the reverse gate leakage current is almost 3 orders of magnitude lower than that of reference HEMT.Based on the improved direct-current operation,the NbAlO can be considered to be a potential gate oxide comparable to other dielectric insulators. 相似文献
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16.
Ji-Suo Wang Jian Feng Tang-Kun Liu Ming-Sheng Zhan 《International Journal of Theoretical Physics》2002,41(12):2427-2437
In this paper, the completeness of the k orthonormalized eigenstates of the operator (a
q
f(N
q
))
k
(k 3) is proved. We introduce a new kind of higher order squeezing and an antibunching. The properties of the Mth-order squeezing and the antibunching effect of the k states are investigated. The result shows that these states may form a complete Hilbert space, and the Mth order [M = (m + 1/2)k;m = 0,1,2,. . .] squeezing effects exist in all of the k states when k is even. There is the antibunching effect in all of the states. 相似文献
17.
High-k gate dielectric HfO2 thin films have been deposited on Si(1 0 0) by using plasma oxidation of sputtered metallic Hf thin films. The optical and electrical properties in relation to postdeposition annealing temperatures are investigated by spectroscopic ellipsometry (SE) and capacitance-voltage (C-V) characteristics in detail. X-ray diffraction (XRD) measurement shows that the as-deposited HfO2 films are basically amorphous. Based on a parameterized Tauc-Lorentz dispersion mode, excellent agreement has been found between the experimental and the simulated spectra, and the optical constants of the as-deposited and annealed films related to the annealing temperature are systematically extracted. Increases in the refractive index n and extinction coefficient k, with increasing annealing temperature are observed due to the formation of more closely packed thin films and the enhancement of scattering effect in the targeted HfO2 film. Change of the complex dielectric function and reduction of optical band gap with an increase in annealing temperature are discussed. The extracted direct band gap related to the structure varies from 5.77, 5.65, and 5.56 eV for the as-deposited and annealed thin films at 700 and 800 °C, respectively. It has been found from the C-V measurement the decrease of accumulation capacitance values upon annealing, which can be contributed to the growth of the interfacial layer with lower dielectric constant upon postannealing. The flat-band voltage shifts negatively due to positive charge generated during postannealing. 相似文献
18.
One-dimension InAlO 3 (ZnO) m superlattice nanowires were successfully synthesized via chemical vapor deposition.Transmission electron microscopy measurements reveal that the nanowires have a periodic layered structure along the 0001 direction.The photoluminescence properties of InAlO 3 (ZnO) m superlattice nanowires are studied for the first time.The near-band-edge emissions exhibit an obvious red shift due to the formation of the localized tail states.The two peaks centered at 3.348 eV and 3.299 eV indicate a lever phenomenon at the low-temperature region.A new luminescence mechanism is proposed,combined with the special energy band structure of InAlO 3 (ZnO) m. 相似文献
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20.
T. Watanabe H. Yokoyama M. Ogata 《Physica C: Superconductivity and its Applications》2009,469(15-20):1009-1012
To consider the origin of a pseudogap and a superconducting (SC) gap found in the high-Tc cuprates, we evaluated the momentum dependence of the singlet gap corresponding to the pseudogap and the SC gap in the t–J model, using an optimization variational Monte Carlo (VMC) method. In the underdoped regime, the singlet gap is significantly modified from the simple dx2-y2(d)-wave gap (∝ cos kx − cos ky) by the contribution of long-range pairings. Its angular dependence at the quasi Fermi surface is qualitatively consistent with those experimentally observed in both hole and electron-doped cuprates. On the other hand, a SC gap is almost unchanged, preserving the original simple d-wave form. Thus, it seems that the incoherent part of the singlet gap mainly influences the forms of observed gaps. 相似文献