The depolarization in a metal- p -ferroelectric- n -semiconductor structure is calculated based on an analysis of the experimental parameters of a ferroelectric hysteresis loop in a metal-ferroelectric-metal structure. For a semiconductor, the Poisson equation is solved using a standard method, while, for a ferroelectric, a numerical integration is applied. Two variants of semiconductor parameters are considered: (i) a thick n -type region (there is a region of electrical neutrality beyond a space-charge region), and (ii) a thin n -type region (an electric field penetrates all the way through this region). It is shown that depolarization significantly reduces ferroelectric polarization, and this reduction is stronger in the case of a semiconductor with lower doping. If the electric field penetrates all the way through the n -type region, depolarization decreases as the n -type region becomes thinner.

The parameters of a ferroelectric material without initial polarization are simulated. The ferroelectric material is doped with a shallow-level impurity. One of the contacts is represented by the Schottky barrier, and the other contact is ohmic. The variations in the electric field, potential, polarization, and permittivity through the depth of the space charge layer are calculated. It is shown that the value of the permittivity in low fields, εeff0, can be determined from the parameters of the experimental hysteresis loop. In low fields (E < 105 V/cm), the permittivity depends on the field only slightly. Therefore, for (E < 105 V/cm), the value of εeff0 can be used as the average value of εeff in processing the experimental data. The calculation of the dependence of the reverse capacity squared on the potential-barrier height shows that, at low voltages, this dependence is nearly linear. This allows the concentration of shallow dopants to be determined from the dependence. The thickness of the space charge layer and the polarization near the contact are calculated as functions of the potential-barrier height. The results of the simulation can be used in processing the experimental data.

Structural defects at the interface between Pb0.95La0.05Ti0.8Zr0.2O3 and La1.85Sr0.15CuO4 were studied using the method of isothermal current relaxation. Two cases were considered: (a) the width of the defect-containing layer is much smaller than the width of the space-charge region and (b) the width of the defect-containing layer is greater than the width of the space-charge region. It is shown that, for the samples studied, the width of the defect-containing layer exceeds 50–100 Å, and the density of states for deep-level centers in the energy interval Ev+(0.55–0.65) eV is about 3×1020 cm−3 eV−1; this value corresponds to a surface state density of about 2×1014 cm−2 eV−1. It is shown that the density of states for deep-level centers increases from the interface into the depth of the semiconductor.

In metal-insulator-semiconductor (MIS) structures with a thin dielectric layer, account must be taken of the effect of current through the insulator on the charge of surface states. The capture of carriers to surface states suppresses the thermal emission from these states. This latter process decelerates the increase of the surface state charge when the surface potential increases (in absolute value). The high-frequency capacitance technique yields an underestimated (down to zero in the limiting case) density of surface states. An anomalous dependence of the surface state density on the surface potential may indicate uniform distribution of the current density over the insulator area.

Current-voltage ( I-V ) characteristics of an all-perovskite ferroelectric-semiconductor field-effect transistor (FET) were simulated. The modeling is based on an analysis of an experimental hysteresis loop of a metal-ferroelectric-metal structure. The charge in the semiconductor, electric fields in the semiconductor and ferroelectric (FE), and FE polarization at the FE-semiconductor interface are calculated at a given semiconductor surface potential. The Poisson equation is solved numerically across the FE thickness. The semiconductor surface potential, semiconductor charge, FE polarization, electric field and voltage drop in the FE are calculated as functions of the applied voltage. By using appropriate semiconductor thickness and built-in voltage between the FE and the gate, it is possible to provide a remanent polarization necessary for the opening and blocking of the FET channel in the ascending and descending portions of the hysteresis loop, respectively. The I-V characteristics and the voltage drop along the FET channel are calculated and analyzed for both polarities of the drain bias. The results make it possible to predict I-V characteristics of an all-perovskite ferroelectric FET.

The hysteresis in the dependence of the polarization P on the electric field E was simulated for a metal-ferroelectric-semiconductor structure with a perovskite semiconductor. The simulation is based on the analysis of an experimental P(E) hysteresis loop observed in a metal-ferroelectric-metal structure and approximated by hyperbolic tangent. Poisson’s equation is numerically integrated with consideration for the dependence of the ferroelectric permittivity on electric field. The depolarizing action of the semiconductor reduces the remanent polarization several times, with the depolarization effect more pronounced for a semiconductor with lower impurity concentration.

Deep-level centers in GaAs-based p-n junctions, which were fabricated by a liquid phase epitaxy in hydrogen or argon ambients, were investigated. The minority charge carrier lifetime for p-layers grown in hydrogen is an order of magnitude larger than that for p-layers grown in argon. It is demonstrated that disimilar deep-level centers are formed in different gas media. Two types of deep-level centers, which act as hole traps, are found in the samples grown in hydrogen. The Arrhenius dependences for these centers are close to known dependences for HL2 and HL5 centers, suggesting that the centers observed can be identified as HL2 and HL5 centers. One type of deep-level center, which is a hole trap, is found in the samples grown in argon. This center is identified as arsenic in the gallium sublattice.

A method for determining the energy spectrum of charges and surface-state densities at the interfaces of semiconductor-insulator-semiconductor structures was developed; the method is based on the analysis of capacitance-voltage characteristics. The method was experimentally tested with Si-SiO2-Si structures prepared by direct bonding of both mirror-polished smooth wafers and wafers with a regular mesoscopic relief pattern at the inner surface of the wafers to be bonded. The density of surface states is lower at the surfaces with a regular relief pattern than that at the surfaces without the surface relief.

An investigation was made to determine how a regular relief on the silicon surface influences gettering in silicon-silicon-dioxide structures. The regular relief was created by a photolithographic technique before oxidation and comprised an orthogonal network of overlapping bands. The gettering was determined from the isothermal relaxation of the capacitance of a silicon-silicon-dioxide structure after switching from strong inversion to even stronger inversion. It is shown that a regular relief at the silicon-silicon-dioxide interface is an effective getter at a depth of several hundred micron.

A new method has been developed for separating a signal consisting of several exponentials into its separate components. Modeling has been carried out for two exponentials with close-lying time constants and with amplitudes of the same order of magnitude. The method possesses high resolution.

The available techniques of the estimation of the time instability of insulator - III-V semiconductor compound interface characteristics (TIG) have been analyzed. The method of the TIC determination based on either long-term isothermal capacitance transient or voltage transient was proposed for MIS structures. It has been demonstrated with comparative investigations of TIC for InP-SiO2(CVD) and Si-SiO2(CVD) structures, which were obtained in one process, as well as for Si-SiO2(thermal) structure, that the relative changes in either capacitance or voltage are a criterion for TIG, as well as allowing to determine the energy and spatial distribution of deep level centers in the insulator in the vicinity of the interface.

The constant capacitance method with measurement of the voltage-time dependence over a long period of time is used to determine the profile of the density of deep-level centers in an insulator at an interface with a semiconductor. The distribution of deep-level centers in silicon dioxide near an interface with indium phosphide is measured. It is shown that the density of deep-level centers does not depend on the coordinate at distances in the interval 22–27 Å from the interface.

Existing diagnostic techniques used to evaluate the temporal instability of the parameters of a semiconductor-insulator interface with deep-level centers are analyzed. A method is proposed for evaluating temporal instability according to the long-term isothermal transient behavior of the capacitance of a metal-insulator-semiconductor structure. The energy spectrum of the effective density of surface states is determined for n-type InP-SiO2-Al structures prepared by chemical vapor deposition. The variation of the capacitance during long-term isothermal relaxation provides a criterion of temporal instability of a semiconductor-insulator interface.

We have proposed a novel modification of silicon direct bonding (SDB) technique dealing with silicon wafers joined in such a way that a smooth surface of one wafer is attached to the grooved surface of the other. This paper presents some experimental data related to devices based on the developed SDB-technique. By the method employing a regularly grooved interface, continuously bonded void-free P-N, P-P and N-N-structures with the initially misoriented wafers were fabricated and examined. Mapping the series resistance of I-V-curves on 60 mm diameter bonded structures demonstrated the absence of pronounced interfacial defects all over the operating area. By using the capacitance spectroscopy (DLTS) method it was shown that the deep level center concentration in the vicinity of bonded interface in the grooved-smooth structures is one order of value lower than in the conventional smooth-smooth SDB-structures.

A comparative study of InP and Si surfaces passivated by has been carried out in order to single out the effects associated with the structural peculiarities of the insulator. has been deposited on InP and Si simultaneously at low temperature. Moreover, different regimes for deposition of the insulator have been used. Values obtained for the time instability (TIS) of interface characteristics of Si - and InP - were in close agreement. Experimentally, the presence of distorted and ruptured Si - O bonds was found in the bulk of deposited by low-temperature techniques on both InP and Si, even though the refractive index (n) and permittivity of were virtually coincident with those for thermal . Small departures of from stoichiometry, which manifested themselves as small deviations (<0.016) of n from the value for thermal , were accompanied by the appearance of a frequency dependence of as well as by an increase of several fold in TIS for both structures.