Evgeny V. Kuimov

A solution to the problem of resonant tunneling current saturation is proposed. This problem does not allow, within the traditional compact models, a correct qualitative and quantitative analysis to be carried out of the volt-ampere characteristics of double-barrier heterostructures. The reason for this problem is the asymptotic behavior of the function describing the structure transparency, so a non-saturating compact model was proposed to solve the problem of current transfer analysis in the region of negative differential conductivity. Validation of the proposed model confirmed its adequacy without losing the ability to analyze current transfer processes. This makes the developed compact model effective for simulating the operation of a wide range of devices with a resonant tunneling diode as a nonlinear element, regardless of the position of the operating point.

When designing devices operating in the terahertz range based on resonant tunneling structures with an operating point in the region of negative differenti

Methodologically, the problem of analyzing the parameters of the purpose of microwave radiometric receivers on heterostructure elements has been successfully solved and the effectiveness of approaches to assessing the probability of yield has been proven. However, the problem of synthesizing such receivers within the framework of complex design and technological optimization in the concept of four principles is still poorly formalized due to its complexity and the new heterostructure implementation of the element base of such microwave radiometric receivers. To ensure the required level of reliability of such devices, it is necessary to develop a practice-oriented technique for synthesizing their parameters, which will ensure the maximum level of reliability of the product at a minimum or limited cost. The purpose of the study is to develop a methodological formalization of the solution to the problem of synthesizing microwave radiometric receivers on heterostructure elements according to the reliability criterion, taking into account the specifics of the monolithic integrated implementation of the circuits of such devices. The result of the work done is a technique for synthesizing microwave radiometric receivers on heterostructure elements according to the reliability criterion based on four basic principles of complex design and technological optimization. The results of the study can be used in the development, production and operational support of microwave radiometric receivers on heterostructure elements by the manufacturer, which will increase production efficiency, reduce costs and improve product quality.

The introduction of RTDs into modern industry is complicated by a number of reasons, the most important of which is ensuring a given shape of the I-V characteristic. To date, there are no mathematical models of current transfer in RTDs intended for engineering applications, i.e., having an acceptable degree of correspondence between the simulation results and experimental data in all sections of the I-V characteristic with adequate requirements for computing resources. Objective – development of a model of electrical characteristics of resonant tunnel diodes for the design of electronic equipment based on heterostructure devices with transverse current transfer. It is shown that the most promising approach for the design of electronic devices is the compact modeling approach. An original function is proposed for estimating the tunnel transparency coefficient in order to solve the problem of the occurrence of non-physical current saturation in the section of negative differential conductivity. A self-consistent procedure for calculating the interelectronic interaction potential within a compact model has been developed, taking into account the initial conditions of a special type to improve the adequacy of calculating the hysteresis loop on the current-voltage characteristics of resonant tunneling diodes. It has been shown that the developed compact model allows predicting the current-voltage characteristics of resonant tunneling diodes with high accuracy in various areas, including the area contrast (average deviation <0.5%), as well as the curvature and hysteresis parameters (average deviation <1% and 1.5%, respectively). In combination with low requirements for computing resources, a conclusion has been made about the prospects of integrating the proposed compact model into modern CAD systems.

This paper presents an effective compact model of current transfer for the estimation of hysteresis parameters on the volt-ampere characteristics of resonant-tunneling diodes. In the framework of the compact model, the appearance of hysteresis is explained as a manifestation of internal bistability due to interelectronic interaction in the channel of the resonant-tunneling structure. Unlike the models based on the method of equivalent circuits, the interelectronic interaction in the compact model is taken into account using the concentration parameter. Model validation allowed us to confirm the high accuracy of the model not only at the initial section of the volt-ampere characteristics, but also at the hysteresis parameters traditionally predicted with low accuracy, namely the loop width (∆ < 0.5%) and contrast (∆ < 7%). Thus, it is concluded that the models are promising for integration into systems for synthesizing the electrical characteristics of resonant-tunneling diodes.

A model of current transfer in resonant tunnel structures has been developed to develop applications for nonlinear elements of RFID tags. Unlike the previous models of this class, the developed model exhibits manifestations of interelectronic interaction. The expected work in the model is distinguished by high accuracy in the initial section (average relative deviation within 1%), low requirements for computing resources (reduced time complexity of the calculation by more than 400 times compared to traditional approaches), and the absence of coefficients without theoretical estimates, which makes it promising for high accuracy in TCAD systems for designing a new generation microwave device.

A compact analytical model of current transfer was developed to estimate the characteristics of heterostructured devices. The absence of empirical correction factors and the explicit accounting of the interelectronic interaction differentiates it from previous similar models. The model obtains an estimates of the electron density in the quantum well of the heterostructural channel and applies a self-consistent correction for resonance levels. It also provides accuracy in the positive differential resistance region of the I–V characteristics in the AlGaAs structures, with an average relative error not exceeding 2%. The time complexity of the calculations of the I–V characteristics using this model is several orders of magnitude less than that of calculations using ab initio models. Its high accuracy and low temporal complexity of calculations of I–V characteristics allow this model to be integrated in systems for the design and calculation of reliability indicators for devices, including terahertz devices.

A portion of negative differential conductivity in the I‒V characteristics of resonant-tunneling structures is interesting as the working portion of high-frequency signal generators. However, at present, estimation of the current density in this portion for practical calculations faces certain difficulties. The phenomenological nature of the common models does not allow one to analyze and correct the calculation techniques according to physical considerations. The high requirements for computational resources prevent solution of the problems of the synthesis of design parameters to ensure the desired level of performances of resonant-tunneling devices during the design process. In this study, a compact current transport model is presented, which makes it possible not only to predict the initial portion of the I‒V characteristics of resonant-tunneling structures with high accuracy, but, owing to its simplicity and physical transparency, to obtain the I‒V characteristic of a resonant-tunneling structure with a relative error of ~1% within a time acceptable for engineering applications.