arXiv subjects

Supratic Chakraborty

Publications and source records attributed to Supratic Chakraborty.

3 recordsLinked to original sources

arXiv2024

Laser induced transition in Cerium Oxide thin film

The complex interaction between the intrinsic and extrinsic state variables of strongly correlated insulator thin films is drawing interest as it shows memristive behavior that may be used in neuromorphic computing. In this study, we have observed that laser irradiation in cerium oxide thin film helps to make transition from metastable state. We study the transport properties of cerium oxide thin film which shows the metal-insulator transition. As for ceria the reduction of oxidation states depends upon oxygen vacancy defects which can be controlled by external ways due to which the transport property can vary. In this study, a decrease in the value of transition temperature under dark conditions was observed as laser-induced and we have explained this result by the generation of energy states observed from temperature-dependent photoluminescence (PL) study, oxygen vacancy defects, and polaron hopping within ceria.

cond-mat.mtrl-sci↗

arXiv2016

Size and density controlled metal nanocluster embedded metal-oxide-semiconductor structure for memory applications

Metal-nanoclusters (NC), deposited by magnetron-based nanocluster source coupled with quadrupole mass filter (QMF) assembly having independent control over its size and density, are used in fabricating NC-based non-volatile memory (NVM) devices. The effect of diameter and density on the NVM charge storage characteristics are presented where Ag is used as the metal NC. The Ag-NC, sandwiched between HfO$_2$ tunnel and control oxides, is deposited by using the combination of the above two instruments. No annealing is performed at any stage of the device fabrication. The largest hysteresis loop area in the capacitance-voltage ($C-V$) characteristics of metal-oxide-semiconductor (MOS) characteristics is observed for a cluster density of 1 $\times$ 10$^{11}$ cm$^{-2}$. Further, an NC size dependent hysteresis loop area is observed with the MOS devices where the NC diameter is varied from 3 to 1.5 nm keeping the NC density at 1 $\times$ 10$^{11}$ cm$^{-2}$. The device performance is found to be improved with a reduction of the NC size and shows its best with the NC diameter of 1.5 nm. The storage time of the NVM devices also increases with the decrease in the NC diameter and exhibits their best performances for the NCs with a diameter of 1.5 nm.

cond-mat.mtrl-sci↗

arXiv2015

Identification of annealing temperature for high-$κ$-based gate oxides using differential scanning calorimetry

This article identifies the process of crystallization of thin high-$κ$ dielectric films and an optimal range of annealing temperature in the field of high-$κ$ dielectric-based metal-oxide-semiconductor (MOS) technology for its improved electrical performances. Differential Scanning Calorimetry (DSC) technique is employed to understand the thermal behaviour of thin high-$κ$ dielectric films of HfO$_2$, deposited by rf sputtering, on Si. The exothermic trends of the DSC signal and Grazing Incidence X-ray diffraction (GIXRD) data indicate an amorphous to crystalline transition in the high-$κ$ film at higher temperature. The enthalpy-temperature variation shows a glass temperature (T$_g$) at $\sim$ 590 $^o$C beyond which an amorphous to m-HfO$_2$ crystalline transition takes place. Further, the Hf-Silicate formation, observed in DSC measurement and corroborated by Fourier transformed Infrared Spectroscopy (FT-IR) studies, indicates that the process of formation of Hf-Silicate begins at $\sim$ 717 $^oC$. High-frequency (HF) capacitance-voltage $(C-V)$ and current density - voltage $(J-V)$ characteristics establish that the crystallization of the film is not the root cause of degradation of the electrical properties of the high-$κ$-based MOS devices, rather the device degrades due to formation of interfacial Hf-Silicate.

cond-mat.mtrl-sci↗