Energy distribution of interface state charge density in Cu-nSi Schottky diode with thin interfacial oxide layer
TL;DR: In this paper, the experimental energy distribution of the interface state charge density in Cu-nSi diodes is obtained from the current-voltage characteristics using a modified technique which considers the effect of series resistance.
Abstract: The experimental energy distribution of the interface state charge density in Cu-nSi diodes is obtained from the current-voltage characteristics using a modified technique which considers the effect of series resistance. The energy distribution of the interface state charge density is found to be linear over a bias voltage range of 0.1 to 0.3 V.
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TL;DR: In this article, the authors attempt to interpret the experimentally observed nonideal Al-pSi Schottky diode I-V and C-V characteristics, and derive expressions for the capacitance-voltage relationship at low frequency and high frequency.
Abstract: In this study we attempt to interpret the experimentally observed nonideal Al–pSi Schottky diode I – V and C – V characteristics. The expressions for the capacitance–voltage relationship at low frequency and high frequency are derived considering two non idealities, namely interface states and series resistance. After extracting the diode parameters from the I – V and C – V characteristics, theoretical plots for the high frequency and low frequency capacitance are obtained using the expressions derived. A comparison of the latter with available experimental plots reveals that the expressions for the low frequency and high frequency capacitance derived here are simpler, more accurate and closer to experimental results than those used in the past. The variation of interface state density with the applied bias voltage is obtained from the low frequency and high frequency C – V plots by using the capacitance technique. To examine the validity of the present approach, the value of density of interface states is compared with that obtained by the multifrequency admittance method. It is observed that there is good agreement between the results obtained by both methods.
78 citations
TL;DR: In this paper, the effect of shunt resistance on Schottky barrier diodes was investigated and it was found that shunt resistances have a remarkable effect at low bias in contrast to the series resistance which influences the electrical characteristics at large bias.
Abstract: The electrical characteristics of Schottky barrier diodes were studied considering the effect of shunt resistance. Both the DC and the AC behaviour of the device were investigated. It was found that the shunt resistance has a remarkable effect at low bias in contrast to the series resistance which influences the electrical characteristics at large bias. The standard evaluation techniques based on the DC characteristics are found to be inaccurate in the presence of the shunt resistance. Also, the AC conductance and capacitance of the device are significantly influenced, making our previously developed model limited in the presence of a shunt resistance. The well-known conductance and capacitance techniques for the characterization of these devices seem to be inapplicable at low bias because of the above-mentioned parasitic effect.
48 citations
TL;DR: In this article, a capacitance technique to determine the interface state density of metal-semiconductor contact is developed which takes care of interfacial oxide layer and series resistance of the device.
Abstract: A capacitance technique to determine the interface state density of metal—semiconductor contact is developed which takes care of interfacial oxide layer and series resistance of the device. The technique is applied to Pt- and Co-nSi contacts, and the energy distributions of interface state density are determined. For both devices, the distribution is found to be initially flat, then increasing sharply with energy.
41 citations
TL;DR: In this paper, the thermal stability of MIS and intimate Ni/n-LEC GaAs Schottky diodes has been investigated using currentvoltage (I-V ) techniques after being annealed in the range of 100-600°C for 5 min in N 2 atmosphere.
Abstract: The thermal stability of Schottky diode parameters of the fabricated MIS and intimate Ni/n-LEC GaAs Schottky diodes have been investigated using current–voltage ( I – V ) techniques after being annealed in the range of 100–600°C for 5 min in N 2 atmosphere. It has been seen that the intimate device is thermally more stable than the MIS device. The I – V characteristics of the MIS device were deteriorated after 400°C, while those of the intimate device, after 600°C. This has been attributed to the fact that the MIS Ni/n-LEC GaAs SBDs heated from 100°C to 400°C suffers from problems arising from the native oxide layer formed on the GaAs surface. Thus, it has been concluded that a reacted contact is thermodynamically stable in the absence of the native oxide layer than an unannealed one or than MIS diodes up to a given annealing temperature. Furthermore, we have evaluated the equilibrium interface charge density and the interface state charge density distribution from the forward bias I – V characteristics of the diodes which show MIS diode behavior before and after annealing. The results have supported our interpretations related to the ideality factor and Schottky barrier height.
16 citations
TL;DR: In this paper, the Ti/n-GaAs(Te) Schottky barrier diodes have been annealed in the temperature range 200-400°C with steps of 100°C for 5 min.
Abstract: The Ti/n-GaAs(Te) Schottky barrier diodes have been annealed in the temperature range 200–400°C with steps of 100°C for 5 min. The barrier height value has increased with increasing annealing temperature. This increase has been attributed to that the annealing removes the passivation effect of the native oxide layer and reactivates the surface defects which are responsible for the Fermi level pinning. The value of equilibrium interface charge density Qss(0) has increased with increasing annealing temperature. It has been found that the experimental density distribution curves of the interface states and the values of equilibrium interface charge density Qss(0) has confirmed this interpretation. The results indicate that the negative equilibrium interface charge is responsible for the actual equilibrium barrier height value.
8 citations
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14,205 citations
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01 Jan 1978TL;DR: In this article, a review of the present knowledge of metal-semiconductor contacts is given, including the factors that determine the height of the Schottky barrier, its current/voltage characteristics, and its capacitance.
Abstract: A review is given of our present knowledge of metal-semiconductor contacts. Topics covered include the factors that determine the height of the Schottky barrier, its current/voltage characteristics, and its capacitance. A short discussion is also given of practical contacts and their application in semiconductor technology, and a comparison is made with p-n junctions.
4,279 citations
TL;DR: In this article, a realistic characterization of the Si-SiO 2 interface is developed, where a continuum of states is found across the band gap of the silicon, and the dominant contribution in the samples measured arises from a random distribution of surface charge.
Abstract: Measurements of the equivalent parallel conductance of metal-insulator-semiconductor (MIS) capacitors are shown to give more detailed and accurate information about interface states than capacitance measurements. Experimental techniques and methods of analysis are described. From the results of the conductance technique, a realistic characterization of the Si–SiO 2 interface is developed. Salient features are: A continuum of states is found across the band gap of the silicon. Capture cross sections for holes and electrons are independent of energy over large portions of the band gap. The surface potential is subject to statistical fluctuations arising from various sources. The dominant contribution in the samples measured arises from a random distribution of surface charge. The fluctuating surface potential causes a dispersion of interface state time constants in the depletion region. In the weak inversion region the dispersion is eliminated by interaction between interface states and the minority carrier band. A single time constant results. From the experimentally established facts, equivalent circuits accurately describing the measurements are constructed.
1,658 citations
TL;DR: In this paper, a theoretical and experimental study has been made of silicon Schottky diodes in which the metal and semiconductor are separated by a thin interfacial film.
Abstract: A theoretical and experimental study has been made of silicon Schottky diodes in which the metal and semiconductor are separated by a thin interfacial film. A generalized approach is taken towards the interface states which considers their communication with both the metal and the semiconductor. Diodes were fabricated with interfacial films ranging from 8 to 26 A in thickness, and their characteristics are related to this model. The effects of reduced transmission coefficients together with fixed charge in the film are investigated. The interpretation of the current-voltage characteristics and the validity of the C−2-V method in the determination of diffusion potentials are discussed.
1,519 citations
TL;DR: In this paper, the dependence of the barrier height of metal-semiconductor systems upon the metal work function is derived based on the following assumptions: (1) the contact between the metal and the semiconductor has an interfacial layer of the order of atomic dimensions; it is further assumed that this layer is transparent to electrons with energy greater than the potential barrier but can withstand potential across it.
Abstract: The dependence of the barrier height of metal-semiconductor systems upon the metal work function is derived based on the following assumptions: (1) the contact between the metal and the semiconductor has an interfacial layer of the order of atomic dimensions; it is further assumed that this layer is transparent to electrons with energy greater than the potential barrier but can withstand potential across it. (2) The surface state density (per unit area per electron volt) at the interface is a property only of the semiconductor surface and is independent of the metal. The barrier height φВn is defined here as the energy needed by an electron at the Fermi level in the metal to enter the conduction band of the semiconductor.
1,198 citations