共查询到20条相似文献,搜索用时 15 毫秒
1.
The properties of different rectifying metallizations (Al, Ti/Pt, WNx) on GaAs have been investigated for various surface preparation procedures. In particular, in situ hydrogen plasma treatments were used to remove residual surface contamination (mainly O and C) and a nitrogen plasma to grow a thin mixed nitride layer. Al and Ti/Pt Schottky diodes with an ideality factor very close to 1, but with reduced barrier height, were found after the H2 plasma as a consequence of H diffusion into GaAs. The Schottky barrier height was further reduced if a H2 + N2 plasma was performed. The N content in the sputtering environment during the WNx deposition affects the diode properties of plasma-treated WNx contacts. By increasing the N2 partial pressure, the diode barrier height is reduced, probably due to nitridization of the GaAs surface. Such differences disappear after annealing the diodes in arsine overpressure at 800°C. WNx contacts deposited under different conditions on H2 plasma treated substrates also show a similar Schottky barrier height after such annealing. 相似文献
2.
We present an analysis of Schottky barriers in n-InP made by incorporating a thin native oxide. An oxidation technique using nitric acid under illumination produces an oxide layer with uniform composition distribution within the layer. The growth rate is interpreted as being partially limited by diffusion presumably of oxygen through oxide. The Au Schottky barrier formed on a 40–80 Å thick oxide layer exhibits little degradation of the ideality factor n (1.04 < n < 1.10) and an increase of the barrier height by greater than 0.3 eV, resulting in at least a 10?4 times smaller reverse leakage current density, compared with conventional Au-InP barriers. The barrier height increase is analysed by a generalised model, and is found to be produced by the existence of fixed negative charges in the oxide layer. From the present analysis, a surface state density of 6.0 × 1012 cm?2 eV?1 and an equivalent surface density of negative charges of 2.8 × 1012 cm?2 are determined independently. The origins of these, particularly of the surface states, are considered in relation to the P vacancies at the oxide-InP interface. 相似文献
3.
A. P. Bibilashvili A. B. Gerasimov Z. D. Samadashvili L. G. Chopozov 《Russian Microelectronics》2000,29(2):113-116
The effect of germanium content in a titanium film, as well as treatment methods and conditions, on the Schottky barrier height (φb) and the ideality factor (n) for Ti-Ge / GaAs contacts were investigated. It is shown that photon treatment provides better contacts than thermal treatment. 相似文献
4.
In this work, we prepared metal/interlayer/semiconductor (MIS) diodes by coating of an organic film on p-Si substrate. Metal(Al)/interlayer(Orange GOG)/semiconductor(p-Si) MIS structure had a good rectifying behavior. By using the forward-bias I-V characteristics, the values of ideality factor (n) and barrier height (BH) for the Al/OG/p-Si MIS diode were obtained as 1.73 and 0.77 eV, respectively. It was seen that the BH value of 0.77 eV calculated for the Al/OG/p-Si MIS diode was significantly larger than the value of 0.50 eV of conventional Al/p-Si Schottky diodes. Modification of the potential barrier of Al/p-Si diode was achieved by using thin interlayer of the OG organic material. This was attributed to the fact that the OG organic interlayer increased the effective barrier height by influencing the space charge region of Si. The interface-state density of the MIS diode was found to vary from 2.79 × 1013 to 5.80 × 1012 eV−1 cm−2. 相似文献
5.
In this study, the displacement current of Au/p-diamond Schottky contacts was studied by comparing them with low-Mg-doped p-GaN Schottky contacts. In the current–voltage (I–V) characteristics, the current was proportional to the voltage sweep speed at V >−1.5 V. The differential output waveform was obtained through AC operation. Therefore, the displacement current was dominant in the low voltage region where in the true current was extremely small due to the large Schottky barrier height of 1.57 eV. The memory effect, due to the charge and discharge of localized acceptor-type deep-level defects, was negligible in the I–V curve. A clear AC differential signal was confirmed. This suggested that the interface defect density of the p-diamond contacts was very small compared to the p-GaN contacts. Hence, p-diamond Schottky contacts were expected to be a good candidate for a key device such as a phase modulator in a wireless transmitter. 相似文献
6.
A unified simulation of Schottky and ohmic contacts 总被引:3,自引:0,他引:3
The Schottky contact is an important consideration in the development of semiconductor devices. This paper shows that a practical Schottky contact model is available for a unified device simulation of Schottky and ohmic contacts. The present model includes the thermionic emission at the metal/semiconductor interface and the spatially distributed tunneling calculated at each semiconductor around the interface. Simulation results of rectifying characteristics of Schottky barrier diodes (SBD's) and resistances under high impurity concentration conditions are reasonable, compared with measurements. As examples of application to actual devices, the influence of the contact resistance on salicided MOSFETs with source/drain extension and the immunity of Schottky barrier tunnel transistors (SBTTs) from the short-channel effect (SCE) are demonstrated 相似文献
8.
The effect of hydrogenation (incorporation of atomic hydrogen) on the properties of n-GaAs and the characteristics of Au-GaAs Schottky barrier contacts (the ideality factor of the current-voltage characteristic
n, the barrier height ϕ
b, and the reverse voltage V
r at a current of 10 μA) has been investigated. The n-GaAs surface was bare (A-type samples) or was protected by an ultrathin (∼50 ?) layer of SiO2 (B-type samples) during hydrogenation. It was shown that there was an optimal hydrogenation regime for the A-type samples (temperature range 150–250 °C and duration 5 min), for which n and V
r reached their minimum and maximum values, respectively. For the B-type samples, n and V
r improve starting from minimal durations and temperatures of hydrogenation and remain constant or even improve over the entire
investigated range of temperatures (100–400 °C) and durations (1–50 min). The donor impurity passivation processes are roughly
the same for the A-and B-type samples.
Fiz. Tekh. Poluprovodn. 32, 1343–1348 (November 1998) 相似文献
9.
The thermal stability of a 100-nm thick sputter-deposited Re film as contact to 6H-SiC was studied by backscattering spectrometry and by measurements of the forward current-voltage (I-V) characteristic. The initial Schottky barrier height of 0.71 eV and ideality factor of 1.6 change after 2 h of annealing in vacuum at 700/spl deg/C to 1.04 eV and 1.1, respectively. They remain stable after annealing for additional 2 h at that same temperature. The initial change is attributed to a recovery of sputter damage in the SiC. The observed stability of the Schottky barrier is attributed to the thermodynamic stability of Re with SiC, as confirmed by the unchanging backscattering depth profiles. After annealing at 900/spl deg/C, the Schottky barrier becomes unstable although no interaction between the Re film and the SiC substrate is detectable in the depth profiles. 相似文献
10.
Bhatnagar M. Baliga B.J. Kirk H.R. Rozgonyi G.A. 《Electron Devices, IEEE Transactions on》1996,43(1):150-156
This paper reports analysis of the role of defects on the electrical characteristics of high-voltage 6H-SiC Schottky rectifiers. The measured reverse leakage current of high-voltage Ti and Pt rectifiers was found to be much higher than that predicted by thermionic emission theory and using a barrier height extracted from the C-V measurements. In this paper, a model based upon the presence of defects at the 6H-SiC/metal interface is used to explains this behavior. It is proposed that these defects result in lowering of the barrier height in the localized regions and thus, significantly affect the reverse I-V characteristics of the Schottky contacts. The presence of electrically active defects in the Schottky barrier area has been verified by EBIC studies 相似文献
11.
The Schottky barrier height of sputtered TiN on both p- and n-type silicon was determined by I-V and C-V measurements. The barrier height is found to increase on n-Si and to decrease on p-Si, upon thermal annealing. The experimental results are explained in terms of sputtering damage. This damage is modeled by donor-like traps whose concentration decays exponentially from the silicon surface. A characteristic length equal to 45 Å accounts for the observed characteristics. The trap-free values of the barrier height were obtained by I-V measurements after sequential thermal annealing up to 600°C. These values are φBn = 0.55 V on n-type and φBp = 0.57 V on p-type silicon. 相似文献
12.
13.
This paper deals with the modeling of the electronic characteristics of semiconductor devices based on Schottky contacts in low-dimensional systems. For the capacitance-voltage characteristics, a quasi-two-dimensional quantum mechanical model is developed and validated. For the current-voltage characteristics, a unified model is presented, considering both the tunneling as well as the thermionic emission mechanisms. Our theoretical predictions suggest that for photodetection applications the use of these contacts, replacing conventional metal-semiconductor junctions, can reduce the dark current by at least one order of magnitude. 相似文献
14.
The electrical analysis of Ni/n-GaP structure has been investigated by means of current–voltage (I–V), capacitance–voltage (C–V) and capacitance–frequency (C–f) measurements in the temperature range of 120–320 K in dark conditions. The forward bias I–V characteristics have been analyzed on the basis of standard thermionic emission (TE) theory and the characteristic parameters of the Schottky contacts (SCs) such as Schottky barrier height (SBH), ideality factor (n) and series resistance (Rs) have been determined from the I–V measurements. The experimental values of SBH and n for the device ranged from 1.01 eV and 1.27 (at 320 K) to 0.38 eV and 5.93 (at 120 K) for Ni/n-GaP diode, respectively. The interface states in the semiconductor bandgap and their relaxation time have been determined from the C–f characteristics. The interface state density Nss has ranged from 2.08 × 1015 (eV?1 m?2) at 120 K to 2.7 × 1015 (eV?1 m?2) at 320 K. Css has increased with increasing temperature. The relaxation time has ranged from 4.7 × 10?7 s at 120 K to 5.15 × 10?7 s at 320 K. 相似文献
15.
L. Lajaunie M.L. David F. Pailloux C. Tromas E. Simoen C. Claeys J.F. Barbot 《Materials Science in Semiconductor Processing》2008,11(5-6):300
A thin cobalt layer is deposited by electron beam evaporation onto a germanium substrate after an in situ cleaning annealing at 400 or 700 °C. The effect of these pre-treatments on the Co/Ge Schottky barrier properties and on the germanide formation is investigated by using different techniques. A strong influence of the pre-treatment is observed. The pre-treatment at 700 °C removes the native oxide but enhances the diffusion of contaminants. After post-metal deposition annealing, the sample pre-treated at 700 °C shows a double layer structure due to interdiffusion, whereas some large isolated islands are present in the sample pre-treated at 400 °C. 相似文献
16.
Sezai Asubay 《Microelectronic Engineering》2011,88(1):109-112
In this study, it has been investigated the electrical characteristics of identically prepared Al/p-InP Schottky diodes. The barrier heights (BHs) and ideality factors of all devices have been calculated from the electrical characteristics. Although the diodes were all identically prepared, there was a diode-to-diode variation: the effective barrier heights ranged from 0.83 ± 0.01 to 0.87 ± 0.01 eV, and the ideality factors ranged from 1.13 ± 0.02 to 1.21 ± 0.02. The barrier height vs. ideality factor plot has been plotted for the devices. Lateral homogeneous BH was calculated as a value of 0.86 eV from the observed linear correlation between BH and ideality factor, which can be explained by laterally inhomogeneities of BHs. The values of barrier height and free carrier concentration yielded from the reverse bias capacitance-voltage (C-V) measurements ranged from 0.86 ± 0.04 to 1.00 ± 0.04 eV and from (3.47 ± 0.39) × 1017 to (4.90 ± 0.39) × 1017 cm−3, respectively. The mean barrier height and mean acceptor doping concentration from C-V characteristics have been calculated as 0.91 eV and 3.99 × 1017 cm−3, respectively. 相似文献
17.
Sato S. Komiya K. Bresson N. Omura Y. Cristoloveanu S. 《Electron Devices, IEEE Transactions on》2005,52(8):1807-1814
The paper describes the impact of pseudo-MOS technique on threshold and flatband voltages, and why the threshold and flatband voltages depend on silicon-on-insulator (SOI) layer thickness. Our measurements and simulations suggest that the band-offset-induced depletion beneath the source contact obstructs the local formation of the inversion layer at the SOI/buried oxide interface; this effect becomes significant when the SOI layer thickness is reduced. The SOI layer thickness dependence of flatband voltage is analyzed in a similar manner. The temperature dependence of threshold and flatband voltages is also addressed. 相似文献
18.
The paper presents numerical computations of the Schottky barrier width, made by taking the free carrier space charge into account, and points to substantial discrepancies between the actual and conventionally assumed volume as a function of current. 相似文献
19.
Two-dimensional simulation of the sidegating effect in GaAs MESFETs has been performed. The result confirms that Schottky contacts on semi-insulating substrate cause serious high substrate leakage current and drain current reduction in GaAs MESFETs. The competition between the currents or biases of the contacts is found to be the cause of the S-type negative differential conductivity (S-NDC) or hysteresis observed when measuring the sidegating threshold 相似文献
20.
The Schottky-barrier energy φB of Pd contacts on InP, GaAs and Si were measured and the metallurgical behavior of the contact structures were studied using Auger electron spectroscopy. A carefully processed set of samples were used to show conclusively that φB is greater on p-InP that on n-InP, unlike the behavior of GaAs and Si Schottky diodes fabricated at the same time with similar processing steps. 相似文献