Piezoresistive Sensitivity, Linearity and Resistance Time Drift of Polysilicon Nanofilms with Different Deposition Temperatures

Our previous research work indicated that highly boron doped polysilicon nanofilms (≤100 nm in thickness) have higher gauge factor (the maximum is ∼34 for 80 nm-thick films) and better temperature stability than common polysilicon films (≥ 200nm in thickness) at the same doping levels. Therefore, in order to further analyze the influence of deposition temperature on the film structure and piezoresistance performance, the piezoresistive sensitivity, piezoresistive linearity (PRL) and resistance time drift (RTD) of 80 nm-thick highly boron doped polysilicon nanofilms (PSNFs) with different deposition temperatures were studied here. The tunneling piezoresistive model was established to explain the relationship between the measured gauge factors (GFs) and deposition temperature. It was seen that the piezoresistance coefficient (PRC) of composite grain boundaries is higher than that of grains and the magnitude of GF is dependent on the resistivity of grain boundary (GB) barriers and the weight of the resistivity of composite GBs in the film resistivity. In the investigations on PRL and RTD, the interstitial-vacancy (IV) model was established to model GBs as the accumulation of IV pairs. And the recrystallization of metastable IV pairs caused by material deformation or current excitation is considered as the prime reason for piezoresistive nonlinearity (PRNL) and RTD. Finally, the optimal deposition temperature for the improvement of film performance and reliability is about 620 °C and the high temperature annealing is not very effective in improving the piezoresistive performance of PSNFs deposited at lower temperatures

Surface- and tip-enhanced resonant Raman scattering from CdSe nanocrystals

Surface- and tip-enhanced resonant Raman scattering (resonant SERS and TERS) by optical phonons in a monolayer of CdSe quantum dots (QDs) is demonstrated. The SERS enhancement was achieved by employing plasmonically active substrates consisting of gold arrays with varying nanocluster diameters prepared by electron-beam lithography. The magnitude of the SERS enhancement depends on the localized surface plasmon resonance (LSPR) energy, which is determined by the structural parameters. The LSPR positions as a function of nanocluster diameter were experimentally determined from spectroscopic micro-ellipsometry, and compared to numerical simulations showing good qualitative agreement. The monolayer of CdSe QDs was deposited by the Langmuir–Blodgett-based technique on the SERS substrates. By tuning the excitation energy close to the band gap of the CdSe QDs and to the LSPR energy, resonant SERS by longitudinal optical (LO) phonons of CdSe QDs was realized. A SERS enhancement factor of 2 × 10 3 was achieved. This allowed the detection of higher order LO modes of CdSe QDs, evidencing the high crystalline quality of QDs. The dependence of LO phonon mode intensity on the size of Au nanoclusters reveals a resonant character, suggesting that the electromagnetic mechanism of the SERS enhancement is dominant. Finally, the resonant TERS spectrum from CdSe QDs was obtained using electrochemically etched gold tips providing an enhancement on the order of 10 4 . This is an important step towards the detection of the phonon spectrum from a single QD.Deutsche ForschungsgemeinschaftRussian Science FoundationCluster of Excellence for Advanced Electronics DresdenEuropean Cooperation in Science and Technolog

ОСОБЛИВОСТІ ДЕФОРМАЦІЇ МЕЗАТЕНЗОРЕЗИСТОРІВ МІКРОННИХ РОЗМІРІВ

The effect of dihedral angles in the junction region of tensoresistive layer to contact pads on strain distribution in mesa-piezoresistor body was studied using the finite element method. Influence of mesa-piezoresistor geometry on its sensitivity was demonstrated. Используя технику конечно-элементного моделирования, исследовано влияние двугранных углов в области перехода тензорезистивного слоя к контактным площадкам на распределение деформаций в теле мезатензорезистора. Показано влияние геометрических размеров мезатензорезисторов на их чувствительность.Використовуючи техніку кінцево-елементного моделювання, досліджено вплив двогранних кутів в області переходу тензорезистивного шару до контактних площадок на розподіл деформацій у тілі мезатензорезистора. Показано вплив геометричних розмірів мезатензорезисторів на їхню чутливість

КІНЦЕВО-ЕЛЕМЕНТНЕ МОДЕЛЮВАННЯ ТЕНЗОРЕЗИСТИВНОГО МОДУЛЯ ТИСКУ

The impact of singularity points on stress distribution in piezoresistive module is investigated by means of FEM simulation. The strong influence of singularities on stress distribution in silicon-glass interface is presented in this paper. Используя технику конечно-элементного моделирования, исследовано влияние сингулярных точек на распределение напряжений в пьезорезистивном модуле. Показано сильное влияние сингулярностей на распределение напряжений на интерфейсе кремний-стекло.Використовуючи техніку кінцево-елементного моделювання, досліджено вплив сингулярних точок на розподіл напруг у п’єзорезистивному модулі. Показано сильний вплив сінгулярностей на розподіл напруг на інтерфейсі кремній-скло

ANALYSIS OF CREATING STEREOTYPE WITHIN COLLECTIVE CONSCIOUSNESS IN THE USSR IN THE PERIOD OF SOCIALIST TRANSFORMATIONS (BASED ON MEDIA MATERIAL 1920-1930)

Background: The article proposes the stereotypes used in the USSR in the process of forming a socialist type of collective consciousness (1920-1930). It reveals the concepts of stereotype, social stereotyping, manipulation, and the use of these tools in forming public opinion. Objective: The goal is to identify the stereotypes used in the USSR in the formation of the socialist type of social consciousness (1920-1930). Methods: The prevalent research method is content analysis. The material for the research is the newspapers “Pravda”, “Trud”, and “Izvestiya”, published during the mentioned period. These exact newspapers were the tool for shaping public opinion in the Soviet Union. Results: The work discloses the stereotype “Us and Them” on the examples for forming the concepts “New Man” and “Enemy of the People”. Moreover, the concept of "enemy of the people" has expanded over time and began to include more and more new social classes of Soviet society. The article also examines in detail the relationship between the "new man" and the church (religion), the "new man" and science (invention), the "new man" and education. Conclusion: The main conclusion that was made based on the results of this study is that the processes of stereotyping perform the specified functions of modeling the social system through the rational use of the potential and mechanisms of the media space