Soon-Yeol Park

Numerical simulation of on thermal nanoimprint lithography (NIL) process

Nanoimprint lithography (NIL) relies on a direct mechanical deformation of the resist material and can therefore achieve resolutions beyond the limitations which are set by a light diffraction or a beam scattering. In addition, NIL is expected to realize a low cost and high-throughput production. In this work, we modeled the NIL process and employed commercially available software, COMSOL Multi-physics, for the implementation of our model. In this paper, we report the stress distribution of the polymer deformation process on the imprinting pressure.

Kinetic Monte Carlo study on transient enhanced diffusion: posterior to amorphisation process

We report our theoretical investigations on the suppression of boron diffusion in the silicon substrate posterior to pre-amorphisation implant (PAI). We numerically investigated the defect-generating behaviour of silicon atoms and their subsequent effect on the transient enhanced diffusion (TED) of boron as a new species for PAI. Our kinetic Monte Carlo simulation revealed that Si–PAI produces more interstitials than the case of Ge–PAI, while Ge–PAI makes interstitial moves further up to the surface than the Si–PAI case during the annealing process, which results in the suppression of the boron TED.

Atomistic modeling on carbon co-implant with silicon pre-amorphization implant technique

In this paper, boron transient enhanced diffusion in silicon pre-amorphization implant (PAI) and carbon co-implant PAI is investigated via kinetic Monte Carlo approach. The damages induced by Si-PAI and carbon co-implant are calculated. Boron implantation and subsequent annealing are thereafter performed. The simulation implies that carbon co-implant PAI reduces the amount of interstitial near the surface when compared with Si-PAI and that carbon co-implant with silicon PAI reduced TED effectively.

Ab-initio Calculations of Stress Effects on Indium Diffusion in Uniaxally Strained Silicon

This paper investigates tensile uniaxial strain effects on indium atom migration for researching shallow junction devices by using ab-initio calculation. This study reveals which tensile strain on silicon substrate affect the total and migration energy of In-Si complexes.

Fabrication of Micron-scale Elliptical Structures for Vertical Optical Via Applications

Previously proposed shape of the optical via structures are simple 45 degree mirrors with or without metal coatings, and simple elliptical shapes. To improve alignment tolerance and coupling efficiency, various shape of the optical via structures are fabricated and optical characteristics of the shapes are measured.

Ab-Initio Calculations of Indium Migration in Uniaxial Strained Silicon

In this paper, we present our ab-initio study on energy configurations, minimum energy path (MEP), and migration energy for neutral indium diffusion in a uniaxial tensile strained {100} silicon layer. Our ab-initio calculation of the electronic structure allowed us to figure out transient atomistic configurations during the indium diffusion in strained silicon. We found that the lowest-energy structure (Ins - Sii Td) consists of indium sitting on a substitutional site while stabilizing a silicon self-interstitial in a nearby tetrahedral position. Our ab-initio calculation implied that the next lowest energy structure is Ini Td, the interstitial indium at the tetrahedral position. We employed the nudged elastic band (NEB) method for estimating the MEP between the two structures. The NEB method allowed us to find that that diffusion pathway of neutral indium is kept unchanged in strained silicon while the migration energy of indium fluctuates in strained silicon.