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1.
A typical 1/f noise is excited in GaAs filament with the Hooge noise parameter of about αH=2×10-3 . The noise level increases in proportion to the square of the terminal voltage, and decreases approximately in inverse proportion to the total number of carriers within the device. A transition from the typical 1/f noise characteristics to the diffusion noise characteristics of MESFETs was observed when the electric field was increased above 1 kV/cm. The noise parameters were also investigated as a function of the device width between 2 and 200 μm. Deep levels within the n-GaAs active layer and the high electric field are the main factors of the nonideal 1/f characteristics 相似文献
2.
Noise spectroscopy has been used as a sensitive technique to assess the quality of InxGa1-xAs linear graded buffer layers grown onto GaAs substrates. Samples having different dislocation structure and quality, determined by design and growth conditions, have been analyzed. Samples with a high dislocation density have been shown to be very efficient 1/f noise sources, with Hooge's parameters (αH) as high as 4×10-1. A Hooge model, based on mobility fluctuation in the depletion regions surrounding dislocations, has been used to explain the observed dependence of αH on mobility μ. While a power law αH∝μβ with β≈-1 is found for the noise generated in samples with a high dislocation density (HDD), β≈+2 seems to hold when sample quality improves, where much lower αH values (100 times) are obtained. These results allow to correlate the scattering centers that limit the mobility with the noise sources existing in the conducting layer of these structures 相似文献
3.
Casady J.B. Dillard W. Johnson R.W. Agarwal A.K. Siergiej R.R. Wagner W.E. III 《Electron Device Letters, IEEE》1995,16(6):274-276
The noise spectra for n-channel, depletion-mode MOSFETs fabricated in 6H-SiC material were measured from 1-105 Hz at room temperature. Devices were biased in the linear regime, where the noise spectra was found to be dependent upon the drain-to-source bias current density. At a drain-to-source current of 50 μA for MOSFETs with a W/L of 400 μm/4 μm, the measured drain-to-source noise power spectral density was found to be A/(fλ), with A being 2.6×10-12 V2, and λ being between 0.73 and 0.85, indicating a nonuniform spatial trap density skewed towards the oxide-semiconductor interface. The measured Hooge parameter (αH) was 2×10-5. This letter represents the first reported noise characterization of 6H-SiC MOSFET's 相似文献
4.
The carrier-induced index change was measured using a novel injection-reflection technique in combination with differential carrier lifetime data. The observed relation between index change and injected carrier density at bandgap wavelength is nonlinear and is approximately given by δn act=-6.1×10-14 ( N )0.66 for a 1.5-μm laser and δn act=-1.3×10-14 (N )0.68 for a 1.3-μm laser. The carrier-induced index change for a 1.3-μm laser at 1.53-μm wavelength is smaller and is given by δn act=-9.2×10-16 (N )0.72 相似文献
5.
The 1/f noise of an n-type silicon MOSFET has been studied under conditions ranging from accumulation to depletion at 300 K. The experimental results are interpreted in terms of a bulk phenomenon and are characterized by Hooge's empirical 1/f noise parameter α with values between 10-7 and 10-5. The α value for surface conduction at strong accumulation can be at least one order of magnitude larger than the value for bulk conduction 相似文献
6.
Luo M.-Y. Bosman G. Van Der Ziel A. Hench L.L. 《Electron Devices, IEEE Transactions on》1988,35(8):1351-1356
A 1/f noise model for diodes operating in the thermionic-emission mode under forward-bias conditions has been developed. The model is based on mobility and diffusivity fluctuations occurring in the space-charge region and accounts for the current-limiting role of the metal-semiconductor interface The bias dependence of the 1/f noise spectral density calculated from this model is in excellent agreement with the results of the authors' experiments but is at variance with the predictions of a model developed by T.G.M. Kleinpenning (1979). From the experimental data, a value of 4.2×10-9 for the Hooge parameter is derived. This value is in good agreement with theoretical calculation for electrons in silicon 相似文献
7.
Minority-carrier electron lifetime, mobility and diffusion length in heavily doped p-type Si were measured at 296 and 77 K. It was found that a 296 K μn (pSi)≈μn (nSi) for N AA≲5×1018 cm-3, while μn (pSi)/μn (nSi)≈1 to 2.7 for higher dopings. The results also show that for N AA≲3×1019 cm-3, D (pSi) at 77 K is smaller than that at 296 K, while for higher dopings D n (pSi) is larger at 77 K than at 296 K. μn (pSi) at 77 K increases with the increasing doping above N AA>3×1018 cm-3, in contrast to the opposite dependence for μn (nSi) in n+ Si 相似文献
8.
Electrical characteristics of Al/yttrium oxide (~260 Å)/silicon dioxide (~40 Å)/Si and Al/yttrium oxide (~260 Å)/Si structures are described. The Al/Y2O3/SiO2/Si (MYOS) and Al/Y2 O3/Si (MYS) capacitors show very well-behaved I -V characteristics with leakage current density <10-10 A/cm2 at 5 V. High-frequency C - V and quasistatic C -V characteristics show very little hysteresis for bias ramp rate ranging from 10 to 100 mV/s. The average interface charge density (Q f+Q it) is ~6×1011/cm2 and interface state density D it is ~1011 cm-2-eV-1 near the middle of the bandgap of silicon. The accumulation capacitance of this dielectric does not show an appreciable frequency dependence for frequencies varying from 10 kHz to 10 MHz. These electrical characteristics and dielectric constant of ~17-20 for yttrium oxide on SiO2/Si make it a variable dielectric for DRAM storage capacitors and for decoupling capacitors for on-chip and off-chip applications 相似文献
9.
The equivalent base noise SIb of InP/InGaAs heterojunction bipolar transistors (HBT's) with a circular pattern emitter is investigated experimentally at a low frequency ranging from 10-105 Hz. The measured SIb exhibits the 1/f dependence in an overall frequency range without any accompanying burst noise. Furthermore, SIb varies as Ibγ for the base current Ib and as d-2 for the emitter diameter d, where the value of γ ranges from 1.62-1.72 depending on d of HBT's used. The 1/f noise model, which rigorously deals with the recombination current at the base surface Ibs as a function of Ib as well as of d is proposed. Applying our noise model to the dependence of SIb on Ib, as well as on d, reveals that even though γ is less than two, the origin of SIb is due to the recombination of electrons at the exposed base surface near the emitter edges. On the basis of theoretical considerations for the diffusion length of electrons and traps at the base surface, the Hooge parameter αH for the noise due to the base surface recombination is deduced to be in the order of 10 -2 for the first time 相似文献
10.
p+-n junction diodes for sub-0.25-μm CMOS circuits were fabricated using focused ion beam (FIB) Ga implantation into n-Si (100) substrates with background doping of Nb=(5-10)×10 15 and Nb+=(1-10)×1017 cm-3. Implant energy was varied from 2 to 50 keV at doses ranging from 1×1013 to 1×1015 cm-2 with different scan speeds. Rapid thermal annealing (RTA) was performed at either 600 °C or 700°C for 30 s. Diodes fabricated on Nb+ with 10-keV Ga+ exhibited a leakage current (IR) 100× smaller than those fabricated with 50-keV Ga+. Tunneling was determined to be the major current transport mechanism for the diodes fabricated on Nb+ substrates. An optimal condition for I R on Nb+ substrates was obtained at 15 keV/1×1015 cm-2. Diodes annealed at 600°C were found to have an I R 1000× smaller than those annealed at 700°C. I -V characteristics of diodes fabricated on Nb substrates with low-energy Ga+ showed no implant energy dependence. I -V characteristics were also measured as a function of temperature from 25 to 200°C. For diodes implanted with 15-keV Ga +, the cross-over temperatures between I diff and I g-r occurred at 106°C for Nb + and at 91°C for Nb substrates 相似文献
11.
Maruyama A. Shen D.S. Chu V. Liu J.Z. Campbell I. Fauchet P.M. Wagner S. 《Electron Devices, IEEE Transactions on》1989,36(12):2853-2858
A detailed study of the growth of amorphous hydrogenated fluorinated silicon (a-Si:H, F) from a DC glow discharge in SiF4 and H2 is discussed. The electrical properties of the films can be varied over a very wide range. The bulk properties of the best films that were measured included an Urbach energy E u =43 meV, a deep-level defect density N s=1.5×1015 cm-3, and a hole drift mobility of 8×10-3 cm2 V-1 s-1, which reflects a characteristic valence band energy of 36 meV. It was found that E u, N s, and the density of surface states N ss are related to each other. Under the deposition condition of the films with the best bulk properties, N ss reaches its highest value of 1×1014 cm-2. It is suggested that in growth from SiF4/H2, the density of dangling bonds at the growing surface is very sensitive to the deposition conditions 相似文献
12.
Canali C. Paccagnella A. Zanoni E. Lanzieri C. Cetronio A. 《Electron Device Letters, IEEE》1991,12(2):80-81
In the above-named work (see ibid., vol.11, p.113-15, March 1990), Hui et al. proposed a method to measure impact ionization current in GaAs MESFETs and evaluated the impact ionization coefficient αn in GaAs. For electric fields greater than approximately 1.5×105 V-cm-1, αn can be fitted to the equation αn=4.0×10 6×exp (-2.3×106/E). In the present work, the commenters performed careful measurements of gate current I g in GaAs MESFET devices similar to those used by Hui et al., and they show that the ionization coefficient still fits the above equation down to αn=10-4 cm-1 . These results extend the previous data by three orders of magnitude. In a reply, the original authors affirm that the commenters have significantly improved the accuracy of the data previously presented 相似文献
13.
The authors have recently shown that specific and stable n or p doping may be obtained on poly(paraphenylene), providing moderate implantation conditions with appropriate ions are used. Here they describe a pn +-junction made in intrinsic insulating poly(paraphenylene) (α<10-12 Ω-1 cm-1) by implantation (E ≃50 keV) of alkali metal ions (essentially caesium for n doping) and halogen (iodine for p doping) 相似文献
14.
de Murcia M. Gasquet D. Elamri A. Nougier J.-P. Vanbremeersch J. 《Electron Devices, IEEE Transactions on》1991,38(11):2531-2539
The variation of the diffusion coefficient D (E ) versus the electric field strength E is determined at 300 K in n-type GaAs (N D=3×10-17 cm-3 ), using pulsed high-frequency noise measurements. D (E ) is found to increase slightly at low field, then to decrease down to one tenth of its ohmic value near the threshold field. Long (⩾4 μm) real n+-n-n+ Gunn diodes, with an arbitrary doping profile, can be modeled. Comparisons are made, and excellent agreement is found, between experimental and theoretical characteristics of two real diodes, with notch and with gradual doping profiles. The doping profile N D(x ) is shown to have a considerable influence on the diode behavior, in regard to the electric field profile as well as the noise characteristics. Using the impedance field method, the noise current is modeled and found to by very sensitive in the D (E ) variation law, in particular in the range of 2.5-4 kV/cm. The agreement between the experimental noise and the computed noise of real diodes is quite satisfactory when using the D (E ) determined 相似文献
15.
Shen H.Y. Zhou Y.P. Lin W.X. Zeng Z.D. Zeng R.R. Yu G.F. Huang C.H. Jiang A.D. Jia S.Q. Shen D.Z. 《Quantum Electronics, IEEE Journal of》1992,28(1):48-51
On the basis of accurately measured refractive indexes, the authors have obtained the Sellmeier's equations for flux grown KTiOPO 4 (KTP) crystal and used them to calculate the phase matched angles (&thetas;m, φm) and effective nonlinear coefficients (d eff) for type I and III second harmonic generation (SHG) and sum frequency mixing (SFM) of radiations at 1.0795 and 1.3414 μm. The optimum phase matching conditions for 1.0795 and 1.3414 μm SHG are that &thetas;m=86.88 and 58.88°, respectively, in an XZ plane (φ=0) and for SMF of 1.0795 and 1.3414 μm in the same plane 76.02°. The corresponding d eff values calculated from &thetas; ms are 18.07×10-9 and 17.42×10-9 esu 相似文献
16.
Shnidman D.A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1989,35(2):389-400
A highly reliable, accurate, and efficient method of calculating the probability of detection, P N(X ,Y ), for N incoherently integrated samples, where X is the constant received signal-to-noise ratio of a single pulse and Y is the normalized threshold level, is presented. The useful range of parameters easily exceeds most needs. On a VAX/11 computer with double precision calculations, better than 13-place absolute accuracy is normally achieved. There is a gradual loss of accuracy with increasing parameter values. For example, for N =109, and with both NX and Y near 107, the accuracy can drop to ten places. The function P N(X ,Y ) can be equated to the generalized Marcum Q -function, Q m(α,β). The corresponding limits on α and β are roughly 4500 for the 13-place accuracy and 60000 for ultimate (INTEGER×4) limit 相似文献
17.
Davis L. Lam Y. Nichols D. Singh J. Bhattacharya P.K. 《Photonics Technology Letters, IEEE》1993,5(2):120-122
The authors have experimentally determined Auger recombination rates in compressively strained InxGa1-xAs/InGaAsP/InP MQW lasers for the first time. The Auger recombination rates were derived from the measured turn-on delay times during large-signal modulation of single-mode lasers. The Auger coefficient increases from 5±1×10-30 to 13±1×10-30 cm6 s-1 as the indium composition in the quantum well active region, x , increases from 0.53 to 0.73 相似文献
18.
The authors present measurement results of the temperature coefficient (TC) of magnetic field resolution B min for dual-collector lateral bipolar magnetotransistors (MTs)-over a temperature range 273 K⩽T ⩽373 K. For a bandwidth of 500 Hz centered around 750 Hz, the resolution turns out to be 600 nT at room temperature with a TC of +2.3×10-3/K. With the MT operating in medium injection, there is very little dependence of B min on bias conditions. In this regime, the correlation (Γ) between collector noise currents is the highest (near unity), where the forward current gain β of the MT is at its maximum. At higher injection levels, a degradation in Γ is observed, possibly due to emitter crowding effects, behaving in a manner similar to β. The degree of coherence appears to be dependent on frequency; Γ is higher at low frequencies where the base 1/f noise predominates and Γ degrades at higher frequencies when white noise levels from the collector epi region become significant 相似文献
19.
The amplitude of the electric field due to a straight line segment of uniform electric charges is shown to be given by E =2q (4πD ε0)-1 sen (α/2) where q is the linear charge density, α is the viewing angle (from the observation point to the filament extremities), and D is the distance to the filament; furthermore, the direction of the vector E lies on the bisector of the viewing angle. This result can greatly reduce the computation time in the analysis of EMC (electromagnetic compatibility) problems involving static or quasi-static charge distributions 相似文献
20.
Chromatic dispersion measurements on short lengths of monomode optical fiber by the technique of `white light' interferometry are presented. Improved optoelectronic signal processing and rigorous data reduction techniques have resulted in a temporal resolution of ⩾7×10-5 ps·nm-1 in a 1-m length of fiber, equivalent to 0.06% resolution in the measurement technique. This is equivalent to a first-order chromatic dispersion coefficient ( D (λ)) resolution of 0.07 ps·nm-1·-1. The second-order chromatic dispersion coefficient (S (λ)) resolution was 0.02 ps·nm-2·nm-1. Experimental results of D (λ) and S (λ) for three different fibers are compared to theoretical calculation of material and waveguide dispersion 相似文献