In this study, we investigated the freezing point depression of liquids in nanostructures using a new thermomechanical method. First, we experimentally determined the freezing points of water, cyclohexane, and a certain organic material (Chem.A) in nanoscale structures using DSC measurements. Thereafter, we formulated a new equation by improving the Gibbs–Thomson equation, which is the conventional formula for representing the freezing point depression of a liquid in nanostructures. We introduced a new term in this new equation to represent the increase in the kinetic energy of the liquid molecule as a result of collision between the liquid molecules and nanostructure walls. Subsequently, we evaluated the solid–liquid interface free energy of sublimation materials by fitting the theoretical freezing point derived from the new equation to experimental data. In this study, we succeeded in reproducing the experimental data of freezing point depression using the proposed equation. In particular, the freezing points of cyclohexane and Chem.A in the nanostructure were better fitted by this new equation at 10 nm or more compared with the conventional equation. Our results show that the interaction between the wall of the nanostructure and liquid molecules affects freezing point depression.

This paper presents crystalline structures, surface morphology, and improved ferroelectric response in ultrathin film of 70 mol % vinylidene fluoride and 30 mol % trifluoroethylene copolymer with 22 nm thickness. Remanent polarization (Pr) of 45 mC∕m2 was obtained at maximum applied voltage of 11 V (500 MV/m) for the ultrathin film annealed at 142 °C. This Pr value is twice as high than that previously reported. We ascribed higher Pr to both smoothness of sample surface and no significant reduction of crystallinity and crystallite size when film thickness is down to 22 nm. Thermal annealing at the temperature above 135 °C induced the growth of flat-on lamella crystals with smoothed uniform surface morphology, and further thermal annealing at temperature of 142 °C led the realignment of crystal c axis in flat-on lamella parallel to the substrate.

Wet etching in nanometer-sized three-dimensional spaces creates new challengesbecause of the scaling of semiconductor devices with complex 3D architecture. Wet etching withinspaces is affected by the mass transport of the etchant ions that are impacted by the hydrophobicityand surface potential of surface. However, the kinetics of chemical reactions within the spaces is stillunclear.In this paper, we studied the effect of hydrophobicity and surface potential of silicon surface on SiO2etching in nanometer-sized narrow spaces by adding various additive components to etching solutions.We found that the transport of etchant ions into narrow spaces is governed by controlling thehydrophobicity and surface potential of the confined system walls.

Damage-free drying becomes increasingly difficult with the scaling of semiconductor devices. In this work, we studied a new sublimation drying technology for 3nm node and beyond. In order to investigate the collapse factor by conventional sublimation drying, we observed the pattern with cryo-SEM and revealed that the collapse occurred when the liquid film on the substrate solidified. Based on this result, we considered that it was important to deposit a solidified film uniformly from the substrate side to suppress collapse. Two key process parameters were evaluated to achieve the uniform formation of the solidified film. One is interfacial free energy and the other is film thickness of solution just before solidification. By optimizing two key parameters, it was successfully demonstrated to suppress pattern collapse of challenging devices. In this paper, we report on a new drying method: sublimation drying by LPD (Liquid-phase deposition).

Since Tetramethylammonium Hydroxide (TMAH) became widely used as a silicon etchant, e.g. the dummy gate removal for gate-last approach (RMG) [1, or Si fin formation on FinFET [, some careful preparations and optimizations have required implementation. These adaptations have involved not only chemical-related issues, but also hardware-related in order to satisfy the necessary process performance.