KOSEN 한인과학기술자네트워크

Research interests

My specific research interests have been focused on solving challenges on electronics including transistors with nanofabrication processes and materials for 7nm technology node and beyond. While my on-going research activities continue to evolve, my historical research programs can be divided into three focus areas, namely:

1. Electronic materials research on the latest challenges logic devices and memory devices including process and materials
2. Novel electronic device applications with nano-scale 2-D materials, nanowires, and QDs
3. GaN electronics

A summary of this researches follows.

Materials integration and nanofabrication for advanced device applications 

I obtained a significant amount of my microfabrication and nanofabrication experience while at Applied Materials and Sun Microsystems. Since I gained that experience, I have been able to leverage both the new skills and my materials & device background to contribute to several advanced device applications. The figure shows the challenges of the future nanowire-based devices that I am interested in investigating, which describes the challenges of the gate all around the structure with nanowires transistor array with a nanoscale device. This effort utilized deposition equipment (CVD, PVD, and ALD systems) that are capable of depositing thin films of metals, semiconductors, and insulating materials. These tools allow these thin-film materials (metals, semiconductors, and insulators) to be deposited in a combinatorial or layered fashion. 

Novel electronic device applications with nano-scale 2-D materials, nanowires, and QDs 

Two-dimensional electronic materials (MoS2, etc): Two-dimensional materials are attractive for use in next-generation nanoelectronic devices as they are relatively easy to fabricate complex structures from compared to one-dimensional materials. Because monolayer MoS2 has a direct bandgap, it can be used to construct interband tunnel FETs. It will offer lower power consumption than classical transistors. Monolayer MoS2 could be used in applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting, and energy-related materials and devices. Novel electronic applications with 2D materials and nanowires for biosensors: For example, Graphene is a covalent 2D electron system comprised of a single layer of carbon atoms arranged in a hexagonal honeycomb lattice. It has a unique electronic structure with linear dispersion, vanishing effective mass, extremely high carrier velocities, strong optical absorption over a wide wavelength range, and excellent thermal and mechanical properties. Because of these characteristics, there has been a strong interest in using it in electronics and optoelectronics. The limited gate-field induced tunability of the current through it and the excellent transport properties recommend it for fast analog and sensor applications. This will be a good platform for developing low-cost diagnostic devices for global health problems (HIV, or e.coli infection, etc). Moreover, I aim to develop technologies to capture various cell types from blood using nanoparticles and microscale technologies. 

GaN electronics

Integral to consumer electronics and many clean energy technologies, power electronics can be found in everything from electric vehicles and industrial motors to laptop power adaptors and inverters that connect solar panels and wind turbines to the electric grid. For nearly 50 years, silicon chips have been the basis of power electronics. However, as clean energy technologies and the electronics industry has advanced, silicon chips are reaching their limits in power conversion — resulting in wasted heat and higher energy consumption. GaN is a revolutionary technology that will impact two major and distinct applications: high frequency and high power electronics. Through NRC’s GaN Electronics initiative in Canada, this will ensure that GaN technology will create wealth and a greener future for Canadians by establishing a strong industrial GaN manufacturing capability. NRC is the only Canadian foundry for GaN electronics and a global leader in the field. By collaborating with NRC at Ottawa, GaN-based technology will be gained a distinct competitive advantage by having access to the leading national research and technology development facilities, including the Ottawa-based Canadian Photonics Fabrication Centre (CPFC). 

Deep learning and wearables for Parkinson’s disease

IoT sensor networks We will also introduce the use of technology to generate quantitative unbiased outcomes related to PD motor symptoms, such as tremor, gait, and falls, or to determine the level of engagement in physical activity in the context of an exercise program for PD. In order to do this, we have assembled a multidisciplinary group of academic researchers which include engineers with expertise in sensors, nanotechnology, mobile devices, computer science specialists, and specialists in understanding PD symptomology (kinesiologists and PD specialists). These individuals will be supported by industry who will provide additional resources including hardware and software development, and opportunities for commercialization. 

Signal process and electrode design for Deep Brain Stimulation 

The Deep Brain Stimulation (DBS) for Parkinson’s Disease Project has been researching a way to improve DBS through the development of a novel electrode that can both stimulate and record brain activity within the same device. Currently, recording and stimulation have to be done separately which lengthens the time of the procedure and can lead to discrepancies in the position of the electrode. Both issues increase the risk of complications. 

Advancing ultrasound performance through data acquisition: Creating a comprehensive guideline for physicians-in-training

Inexperienced physicians today do not automatically know how to manipulate an ultrasound probe to their advantage. They need instructions and help from other physicians for a period of time before they learn how to properly use an ultrasound device. Therefore the goal would be to find a way to create a guideline/manual (written instructions) to assist physicians in performing an ultrasound. 

Sensor development for sensitive detection and identification of airborne chemicals and biological agents 

Portable explosive detectors, chemical identifiers, and personal radiation detectors (PRD) are now commercially available and can routinely be used in the field for environmental, forensic, and material sampling. These devices are based on well-known technologies such as mass spectrometry, patch-chemical reactions, electrochemical sensing, ion-mobility spectrometry, laser-induced fluorescence, acoustic-wave-chemical sensing, and fiber-based optical detection. Although constant progress is being made to improve these techniques, a disruptive sensing technology can improve safety and help counter-terrorism by drastically enhancing detection performances in terms of sensitivity, selectivity, response time, and repeatability. The main objective of this proposal is to develop and demonstrate a new sensing technology.