Measuring-analytical complex for investigation of local C-V- characteristics of semiconductor barrier structures on the basis of AFM

Разработан автоматизированный измерительный комплекс для локального исследования вольт-фарадных характеристик полупроводниковых структур на основе зондовой системы атомно-силового микроскопа.Automated measuring complex for local research of capacitor-voltage characteristics of semiconductor structures based on the probe system of an atomic force microscope has been developed.Работа выполнена при финансовой поддержке РФФИ (грант 16-32-00342) с использованием оборудования Регионального центра зондовой микроскопии коллективного пользования (РЦЗМкп) при ФГБОУ ВО «РГРТУ» (ckp.rsreu.ru) в НОЦ неупорядоченных и наноструктурированных материалов и устройств на их основе (ННМУ)

ФОРМИРОВАНИЕ ЗОЛЬ-ГЕЛЬ МЕТОДОМ И СВОЙСТВА ТОНКИХ ПЛЕНОК ТАНТАЛАТА СТРОНЦИЯ ВИСМУТА

The formation technology by sol-gel based on acetic acid sols and the electrophysical characteristics examination results of the strontium tantalate thin films of 240 nm thick are represented.Приведены технология формирования золь-гель методом из уксуснокислых золей и результаты исследования электрофизических характеристик пленок танталата стронция висмута толщиной 240 нм

Механизмы формирования гетерофазных сегнетоэлектрических пленок цирконата-титаната свинца

An experimental and theoretical study of the formation processes of "impurity" phase inclusions in ferroelectric oxides is carried out via example of polycrystalline lead zirconate-titanate (PZT) films. A feature of these compositions is relatively high volatility of lead oxides, which can lead to deficiency of these components in the composition of the ferroelectric film formed during high-temperature crystallization. To avoid lead losses, some excess is added to the solution in the process of synthesis. Experimental samples of PZT films are obtained using sol-gel method with different contents of lead oxide, the crystallization of the ferroelectric phase of the films is carried out in air at 600 °C. In the films, the inclusions of lead oxide impurity phase are found, and the size distribution of these inclusions are obtained. Model concepts are presented and a system of equations is proposed describing the dispersed inclusions formation kinetics of new phases of different stoichiometric composition at the interfaces in polycrystalline films of multicomponent ferroelectric oxides due to bulk diffusion and grain-boundary segregation. Comparison of the experimental data with the theoretical model gives qualitative agreement. The approach generality makes it possible to extend the model to other systems of multicomponent ferroelectric polycrystalline materials.Проведено экспериментальное и теоретическое изучение процессов образования включений "примесных" фаз в сегнетоэлектрических оксидах на примере поликристаллических пленок цирконата-титаната свинца (ЦТС). Особенностью данных составов является сравнительно высокая летучесть оксидов свинца, что может приводить к дефициту этих компонентов в составе формируемой сегнетоэлектрической пленки в ходе высокотемпературной кристаллизации. Чтобы избежать потери свинца, в процессе синтеза в раствор добавляют его некоторый избыток. Экспериментальные образцы пленок ЦТС были получены золь-гель-методом с различным содержанием оксида свинца, кристаллизация сегнетоэлектрической фазы пленок осуществлялась на воздухе при температуре 600 °C. В пленках обнаружены включения примесной фазы оксида свинца, получено распределение включений по размерам. Изложены модельные представления и предложена система уравнений, описывающие кинетику образования дисперсных включений новых фаз различного стехиометрического состава на границах раздела в поликристаллических пленках многокомпонентных сегнетоэлектрических оксидов за счет процессов объемной диффузии и зернограничной сегрегации. Сопоставление экспериментальных данных с теоретической моделью дало согласие на качественном уровне. Общность подхода позволяет распространить модель на другие системы многокомпонентных сегнетоэлектрических поликристаллических материалов

Formation Mechanisms for Hetero-Phase Ferroelectric Films of Lead Zirconate Titanate

An experimental and theoretical study of the formation processes of "impurity" phase inclusions in ferroelectric oxides is carried out via example of polycrystalline lead zirconate-titanate (PZT) films. A feature of these compositions is relatively high volatility of lead oxides, which can lead to deficiency of these components in the composition of the ferroelectric film formed during high-temperature crystallization. To avoid lead losses, some excess is added to the solution in the process of synthesis. Experimental samples of PZT films are obtained using sol-gel method with different contents of lead oxide, the crystallization of the ferroelectric phase of the films is carried out in air at 600 °C. In the films, the inclusions of lead oxide impurity phase are found, and the size distribution of these inclusions are obtained. Model concepts are presented and a system of equations is proposed describing the dispersed inclusions formation kinetics of new phases of different stoichiometric composition at the interfaces in polycrystalline films of multicomponent ferroelectric oxides due to bulk diffusion and grain-boundary segregation. Comparison of the experimental data with the theoretical model gives qualitative agreement. The approach generality makes it possible to extend the model to other systems of multicomponent ferroelectric polycrystalline materials

Sol-gel Formation and properties of strontium bismuth tantalate thin films

The formation technology by sol-gel based on acetic acid sols and the electrophysical characteristics examination results of the strontium tantalate thin films of 240 nm thick are represented

Low-resistance and high-resistance states in strontium titanate films formed by the sol–gel method

A change in the resistance of strontium titanate structures formed by the sol–gel method has been demonstrated. The transition of a strontium titanate film with a thickness of about 300 nm from the highresistance to low-resistance state occurs when the bias voltage on the silicon/titanium dioxide/platinum/strontium titanate/nickel capacitor structure reaches the values of about 10 V. The resistance changes from several ohms to several tens of kiloohms. For a thicker film (~400 nm), the switching voltage increases while the resistance of the structure in the high-resistance state reaches several hundreds of kiloohms. Supposedly, the main role in changing the resistance is played by deep levels whose population changes by the applied voltage. The prospects for the application of strontium titanate films in memory memristor elements have been discussed

Structural Dependent Eu3+ Luminescence, Photoelectric and Hysteresis Effects in Porous Strontium Titanate

Eu3+ doped porous nanostructured SrTiO3 films and powder fabricated by sol-gel route without using any precursor template are characterized by different morphology and phase composition. The films and the power show red and yellow luminescence with the most intensive photoluminescence (PL) bands at 612 nm and 588 nm, respectively. Raman, secondary ion mass spectrometry(SIMS), andX-ray diffraction(XRD) analysisof undopednanostructuredporousSrTiO3 films showed the presence of TiO2, SrO, and SrTiO3 phases and their components. The undoped porous SrTiO3 films are photosensitive and demonstrate resistive switching. The capacitance-voltage hysteresis loops with the width of about 6 V in the frequency range of 2 kHz—2 MHz were observed