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The paper presents a method for fast calculating the electronic states in twodimensional quantum structures based on AIIIBV nitrides. The method is based on the representation of electronic states in the form of a linear combination of bulk wave functions of materials, from which quantum structures are made. The parameters and criteria for the selection of bulk wave functions that provides fast convergence of the numerical procedures for calculating the eigenvalues of the quantum Hamiltonian have been considered. The results of the calculations have been given both for one polar InGaN/GaN quantum well and for a system of several quantum wells. Being based on the full band structure of AIIIBV nitrides with a wurtzite-type crystal lattice, the proposed approach takes into account the states far from the center of the Brillouin zone, while preserving the computational efficiency of traditional methods of envelope function in approximating the effective mass. [ABSTRACT FROM AUTHOR]

Some technological features of p-type Hg1-xCdxTe (x ≈ 0.3) liquid phase epitaxy layers grown on Cd1-yZnyTe (y ≈ 0.04) substrates are briefly discussed. Energy dispersive analysis of mercury-cadmium-telluride (MCT) layers and metal contacts (Au(In)/Cr(Mo,Ti)) to MCT layers together with their current-voltage characteristics at T ≈ 80 and 300 K are considered. It is shown that Cr(Mo,Ti)/MCT contacts have ohmic characteristics or close to them at T ≈ 80 and 300 K for both n- and p-type MCT layers. This gives the opportunity to form ohmic contacts to n- and p-type pads in one technological cycle. The contact resistance Rc is much smaller as compared to the HgCdTe p-n junction resistance R0[ RcA (< 10–2 Ω cm2) ≪ R0A (> 103 Ω cm2), where R0 is the zero bias diode resistance at T = 80 K, and A is the MCT (x ≈ 0.3) junction area]. So, such contacts are appropriate for the fabrication of photovoltaic HgCdTe detectors. [ABSTRACT FROM AUTHOR]

In this paper, a review of microwave avalanche transit-time diode (IMPATT diode) structures has been presented. The structure of IMPATT diode with a sharp p-n junction on Si has been considered, and functions of the ohmic contacts have been shown. Physical and technical requirements for contacts have been formulated as based on their functional purpose and the existing technological base. A review of existing ohmic contacts and their ranking in terms of suitability and promising use in IMPATT diode have been made. The structure of metallization for IMPATT diode was chosen in the framework of the specificity of the IMPATT diode operation. [ABSTRACT FROM AUTHOR]

In this work, the method of electrophysical diagnostics of ohmic contacts to n+-n-n+ structures for powerful silicon impact ionization avalanche transit-time diodes has been proposed. The specific resistivity of the Au-Ti-Pd-n+-n-n+-Si contacts and the current-flow mechanism within the temperature range 100...360 K has been investigated. The generalized method for studying the temperature dependence of the specific contact resistance in the case of multilayer structures with non-uniform doping level has been proposed. The values of the specific contact resistance have been calculated from the temperature dependence of the total resistance of the vertical structure. The offered method can be used to control the electrophysical parameters of ohmic contacts between the etching cycles in technology of manufacturing powerful silicon impact ionization avalanche transittime diodes. [ABSTRACT FROM AUTHOR]

The method of electrophysical diagnostic of n+-n-n+ structures at the etching stage of manufacturing process of power IMPATT diodes has been proposed. A numerical method for specific contacts resistance calculation of vertical ohmic contacts with a non-uniform doping level has been developed. Vertical ohmic contacts Au-Ti- Pd-n+-n-n+-Si both before and after etching were used for experimental checking this model. It has been computed the value of contact resistance in the interface metal-n+ with correction of contribution of n+-n and n-n+ resistances to the total resistance. The values of total effective resistances of vertical ohmic contacts Au-Ti-Pd-n+-n-n+-Si may be calculated using the Cox-Strack method. We used solutions of Laplace's equation for computation of specific contact resistance metal-n+ without contribution of interfaces n+-n and n-n+. The values of specific contact resistance were ~10-6 Ohm·cm². This method allows to control the manufacture process by monitoring the changes in electrophysical properties of the structure between etching cycles. [ABSTRACT FROM AUTHOR]

Presented in this paper are experimental data on structural properties of contact metallization and temperature dependence of the specific contact resistance for ohmic contacts Au-Ti-Pd-n+-InP and Au-Ti-Ge-Pd-n+-InP prepared using the method of successive thermal evaporation of metals in oil-free vacuum in one process cycle onto the n+-n-n++-n+++-InP epitaxial structure heated to 300 °C. It has been theoretically and experimentally shown that within the temperature range 250...380 K the current transport mechanism in the ohmic contacts Au-Ti-Pd-n+-InP is thermal-field one, and in the ohmic contacts Au-Ti-Ge-Pd-n+-InP it is caused by conductivity along metal shunts linked with dislocations. According to the X-ray diffraction data, the density of these dislocations in the near-contact InP area is ~109 cm-2. [ABSTRACT FROM AUTHOR]

Experimental data on manufacturing the ohmic contacts Au-Ti-Pd-n+-InP, formed using vacuum deposition of metal onto a heated to 300 °C substrate representing an epitaxial n+-n-n++-n+++-InP structure. The specific contact resistance measured at room temperature was about 7·10-5 Ohm·cm². Voltage-current characteristics within the temperature range 110 to 380 K are linear. Gunn diodes with such contacts, which were made as a straight mesa-structure in a pulsed mode (pulse duration of 100 ns, pulse ratio of 1000, operating current of 2.2 A), generated the microwave power ~10 mW in the V-band. [ABSTRACT FROM AUTHOR]

We present the results of investigation of the barrier height and ideality factor in Schottky barrier diodes based on Au--TiB2--n-SiC 6H relying on measuring the current-voltage and capacitance-voltage characteristics. Improving the accuracy of the methods that take into account the effect of the series resistance in calculating the ideality factor and barrier height has been shown with the Cheung method and direct approximation one. It has been ascertained that an inconsistency between real current-voltage characteristics and its model -- the temperature dependence of the barrier height, the ideality factor dependence on the voltage -- introduces the basic error into the calculated parameters in the diode under study. [ABSTRACT FROM AUTHOR]

Proposed has been the method of formation a thermally stable ohmic contact to the diamond without high-temperature annealing with the resistivity ~50 to 80 Ohm∙cm² when Rs = 3∙107 Ohm/ eing based on the analysis of correlation dependence between the resistivity of contact and that of semiconductor for the unannealed sample and the sample after rapid thermal annealing it has been shown that variation of the contact resistance on the plate is related with that of semiconductor and may be caused by inhomogeneity of the dopant distribution. [ABSTRACT FROM AUTHOR]

A finline version of detector with flat Schottky barrier diodes is developed. It is intended for operation in the 400-600 GHz frequency range. The detector electrical parameters are studied. The detector conversion ratio at a frequency of 420 GHz is 97 V/W. [ABSTRACT FROM AUTHOR]