Ho-Jung Hwang

Ion implantation damage model for B, BF2, As, P, and Si in silicon

In this article we describe a newly proposed and consistent damage model in Monte Carlo simulation for the accurate prediction of a three-dimensional as-implanted impurity profile and point defect profile induced by ion implantation in (100) crystal silicon. An empirical electronic energy loss model for B, BF2, As, P, and Si self-implants over a wide energy range has been proposed for silicon-based semiconductor device technology and development. Our model shows very good agreement with secondary ion mass spectrometry data over a wide energy range. For damage accumulation, we have considered the self-annealing effects by introducing our proposed nonlinear recombination probability function of each point defect for computational efficiency. For the damage profiles, we compared the published Rutherford backscattering spectrometry (RBS)/channeling data with our results of phosphorus implants. Our damage model shows very reasonable agreements with the RBS/channeling experiments for phosphorus implants.

Nondestructive dopant profile measurement and its quantitative analysis using the nanocapacitance–voltage method

We propose a new method that can quantitatively extract the dopant profile in a nondestructive manner using scanning capacitance microscopy (SCM) or a nanocapacitance–voltage (nano-C–V) system. The method is based on a nanotip capacitor model, and not the common parallel-plate capacitor model. For the first time, we have physically analyzed a nanotip capacitor by considering the interaction between the air and a semiconductor and have calculated the full C–V curves and the rate of capacitance change with bias (dC/dV). We calculated the local dC/dV curve that was matched to the experimental dC/dV data. This quasi-three-dimensional modeling illustrates that the C–V characteristics derived from the nanotip model are different from those of a conventional parallel-plate method. We found that the increase in capacitance in the inversion region (characterized by a double peak in the dC/dV curve) is due to the quasispherical characteristics of the depleted layer generated by the nanotip located in the air. These...

Improvement of luminance and luminous efficiency for optimal Penning gas mixtures in alternating current plasma display panels

We propose the optimal mixing ratio of Ar or Kr in Ne (96%)–Xe (4%) and He (70%)–Ne (27%)–Xe (3%) to improve the luminance and luminous efficiency for alternating current plasma display panels. To verify the improvements, we measured the voltage, current, and luminance experimentally. We analyzed the luminous efficiency and the wall charge using the Q–V method and compared the results with the calculated values from a two-dimensional simulation. When a small amount of Ar (0.01%–0.1%) or Kr (0.01%–0.1%) was added to Ne–Xe or He–Ne–Xe at 200 Torr, we found that the luminance increased by more than 20%, the luminous efficiency increased by more than 25% and the wall charge increased by more than 25%. When a small amount of Ar (0.005%–0.1%) was added to He–Ne–Xe–Kr (0.005%) at 400 Torr, the luminance increased by more than 8%, the luminous efficiency increased by more than 18%, and the wall charge increased by more than 12%. In conclusion, these results showed that the additional Penning effect between He and...

Three-Dimensional Monte Carlo Simulation of Boron Implantation into Single-Crystal Silicon Considering Mask Structure

A new and computationally efficient three-dimensional Monte Carlo ion implantation simulator, TRICSI, has been developed to investigate three-dimensional mask effects for low-energy boron implantation into single-crystal silicon. The simulator accurately and efficiently simulates three-dimensional implanted doping profiles under the mask structure and window. All of the typical implant parameters such as dose, tilt angle, rotation angle, in addition to energy are considered. The orientation of silicon substrate, ion beam divergence, presence of native oxide layer, wafer temperature, orientation of masking edge, masking layer thickness, and structure and size of window are also taken into account.

A Special Issue on Nanoscale Modeling and Simulation

This special issue of Journal of Computational and Theoretical Nanoscience consists of 2 review and 12 research original papers. The increasing power of today’s computers forms the basis for an increasing significance of computer simulations in all fields, from quantum mechanics to biology, processes, devices, and applications in nanoscience. This special issue was intended to share very important results in advanced simulations techniques, multiscale modeling, as well as properties and applications to various materials and device problems from the leading research groups in Republic of Korea. A large number of manuscripts were received. After going through a very strict reviewing process, 2 review and 12 research papers were selected for publication in this special issue. One review paper on nanotube oscillators presents important progresses for their properties and applications in outstanding works by means of molecular dynamics simulations. Another review paper on traveling wave photodetectors presents recent advanced model using finite-difference time-domain (FDTD) method. The contributed papers

Trade-off Characteristic between Gate Length Margin and Hot Carrier Lifetime by Considering ESD on NMOSFETs of Submicron Technology

Hot carrier degradation and roll off characteristics of threshold voltage () on NMOSFETs as I/O transistor are studied as a function of Lightly Doped Drain (LDD) structures. Pocket dose and the combination of Phosphorus (P) and Arsenic (As) dose are applied to control roll off down to the gate length margin. It was seen that the relationship between roll off characteristic and substrate current depends on P dopant dose. For the first time, we found that the n-p-n transistor triggering voltage () depends on drain current, and both and snapback holding voltage () depend on the substrate current by characterization with a transmission line pulse generator. Also it was found that the improved lifetime for hot carrier stress could be obtained by controlling the P dose as loosing the roll off margin. This study suggests that the trade-off characteristic between gate length margin and channel hot carrier (CHC) lifetime in NMOSFETs should be determined by considering Electrostatic Discharge (ESD) characteristic.

Optimization of three-component gas Ne-Xe-Kr for high efficiency plasma display panel

Summary form only given, as follows. A plasma display panel (PDP) has been spotlighted as one of the promising candidates for a flat panel display. The improvement of luminous efficiency is one of the most important issues in making a plasma display into a large flat panel device. The most fundamental element determining the discharge property is the discharging gas injected into the cell of the AC PDP. Therefore, we aimed to find the optimum gas composition for maximum electric discharge. A new composition of a three-component gas, Ne-Xe-Kr, is proposed in order to achieve a high luminous efficiency (maximum electric discharge) in color PDP.