Design Issues Caused by Unwanted Channel Edge Effects in SOI-CMOS Devices for Analog RF Applications

HyeokjaeLee,Jong-HoLee,YoungJunePark 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.41 No.6

We study extensively the channel edge effects of silicon-on-insulator (SOI) metal-oxide semiconductor eld-effect transistors (MOSFETs) technology. The increases of degraded-harmonic distortion in narrow-width devices are investigated for sub-0.2 m partially depleted (PD) SOI MOSFETs. From these results, we suggest device design guidelines for analog RF applications in SOI MOSFETs and bulk-silicon MOSFETs.

Low-Frequency Noise Characteristics for Mini-Field Dual-Body SOI Structure

HyeokjaeLee,이종호,YoungJunePark,HongShickMin 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.40 No.1

The low-frequency noise characteristics of the devices formed for mixed mode circuit applications (mini-field dual-body structure) is investigated. A noise overshoot is not observed in MOSFETs in fully depleted silicon-on-insulator (SOI) devices but high resistance still exists in body-tied partially depleted SOI devices. We found that there is a correlation between the low-frequency noise overshoot and the body resistance. The low-frequency noise characteristics of the devices formed for mixed mode circuit applications (mini-field dual-body structure) is investigated. A noise overshoot is not observed in MOSFETs in fully depleted silicon-on-insulator (SOI) devices but high resistance still exists in body-tied partially depleted SOI devices. We found that there is a correlation between the low-frequency noise overshoot and the body resistance.

Effects of Shallow Trench Isolation on Silicon-on-Insulator Devices for Mixed Signal Processing

HyeokjaeLee,YoungJunePark,HongShickMin,이종호,HyungsoonShin,WookyungSun,Dae-GwanKang 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.40 No.4

The transconductance and the low-frequency noise of SOI MOSFETs with shallow trench isolation (STI) structures are investigated qualitatively for various device sizes and three dierent gate shapes. Devices with the channel region butted to the STI region show a reduction in the mobility and the increase in the low-frequency noise as the channel width is reduced. In comparison, the devices without STI butted channel region show a much lower reduction in the mobility and increase in the noise characteristics with the channel width. From the charge pumping and noise measurement results, the interface-state generated by the STI process is identied for the first time, as the cause of these anomalous phenomena.

Reduction of Reverse Short-Channel E ect in High-Energy Implanted Retrograde Well

HyeokjaeLee,YoungJunePark,HongShickMin,HyungsoonShin,Dae-GwanKang 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.40 No.4

In this research, the reverse short channel eect (RSCE) is signicantly dierent in electrical behavior for diffused well and high-energy (>150 keV - boron) implanted retrograde well (HRW) due to dopant diffusion kinetics. The magnitude of the VTH is signicantly smaller in the HRW than in diused well. We investigate the in uence of various implantation energies and doses on the RSCE, and we use process and device simulation to analyze the RSCE.

Matching Characteristics by Forward VB Effects of SOI MOSFETs for RF-Analog Applications

HyeokjaeLee,이종호,YoungJunePark 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.III

In this paper, we show that with a positive body bias, the electrical characteristics of metal oxide semiconductor eld eective transistors (MOSFET's) can be improved for those applications which are primarily concerned with threshold-matching eect. A positive body bias is also applied to improve the short channel eect and to reduce the active power. Making the body available improves the devices and enables new applications. We present the matching characteristics of the partially depleted silicon-on-insulator (SOI) NMOSFET's.

Design Consideration of Gate Shape in SOI MOSFETs for RF Applications

HyeokjaeLee,HyunchulNah,YoungJunePark,HongShickMin,이종호 한국물리학회 2002 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.40 No.4

The scale down of CMOS-SOI technologies has challenged toward the deep-submicron minimum feature size. This leads to great expectations for CMOS RF applications. Especially, the scale of the gate length along with the relatively wide gate width in RF-SOI circuits leads to reconsideration of gate design parameters, such as parasitic capacitance and AC/DC body potential instability. In this paper, we present the fT and the fmax properties associated with layout (nger width) and gate shapes (T-shape and H-shape structures) of multi-nger structures in sub-0.2-m partially depleted (PD) SOI devices. From analysis of unwanted parasitic eects, such as the gm variation (gm), and the extra parasitic capacitance variation (Cgs), and the body instability, we find the resulting speed characteristics (fT and fmax) to be strong functions of the number of ngers and the types of gate shapes.

Virological Characteristics in Chronic Hepatitis B Patients with Concurrent HBsAg and anti-HBs Positivity

Hyeok-Jae Lee,Min-Hyeok Lee 대한의생명과학회 2012 Biomedical Science Letters Vol.18 No.3

In this study, we investigated the virological characteristics, HBV DNA levels and presence of mutations of "a" determinant in the HBsAg S gene in chronic hepatitis B patients with coexisting HBsAg and anti-HBs. The 18 patients who were diagnosed with chronic hepatitis B were both positive for HBsAg and anti-HBs. HBV Among them, 15 patients were DNA positive. The median of HBV DNA levels in serum was 2.18×107 copies/mL with the HBsAg+/anti-HBsAb+ patients. Also, 4 of 8 HBeAg negative patients had HBV DNA levels higher than 104 copies/mL and the median of HBV DNA levels was 2.03×106 copies/mL, which were significantly high. These results showed that viral replication still existed in most of the patients of the concomitant HBsAg and anti-HBs, and even in the some HBeAg negative patients. Furthermore, mutation within the "a" determinant of HBV were found in 7 of 15 patients. The most frequent changes were located at positions aa126. In addition, one mutation observed for HBsAg only positive.

A Case Report of HBsAg Seroclearance in Chronic Hepatitis B Patient

( Hyeok Jae Lee ),( Min-hyeok Lee ) 대한임상검사과학회 2012 대한임상검사과학회지(KJCLS) Vol.44 No.3

Hepatitis B surface antigen (HBsAg) seroclearance is a rare event in chronic hepatitis B virus (HBV) infection which acquires the disease early in life. A case study have examined with asymptomatic chronic hepatitis B carrier who exhibits HBsAg seroclearance in anti-HBe positive. We comprehensively studied the biochemical, virological and clinical aspects of a patient with HBsAg seroclearance. Liver biochemistry, serological markers, serum HBV DNA levels, and development of clinical complications were monitored. Mutation of hepatitis B virus is suspected serum HBsAg detected by the HBsAg assay systems of VITROS (OrthoClinical Diagnostics, USA), AxSYM (Abbott Laboratories, USA), Elecsys (Roche Diagnostics, Germany) and ADVIA Centaur (Bayer Diagnostics, USA). These four immunoassays showed negative results. Also, the patient had undetectable serum HBV DNA. Therefore, no mutation within the “a” determinant of HBsAg, which might escape detection from HBsAg immunoassay were found. Natural seroclearance was confirmed.

요침사 현미경검사를 위한 표본제작의 표준화 연구

Hyeok Jae LEE,Dae Heon KIM,Min-Hyeok LEE 대한임상검사과학회 2024 대한임상검사과학회지(KJCLS) Vol.56 No.2

요검사는 검사실에서 일상적으로 수행되는 기본적인 검사이다. 연구에서 새로운 프로토콜을 포함한 두 가지 수동 현미경검사 방법을 표준화된 chamber 방법과 비교하였다. 시험지검사와 자동 침사물 분석기에서 적혈구 양성 201개와 백혈구 양성인 201개 검체로 구성된 총 402개 검체를 분석 대상으로 선정했다. 적혈구 및 백혈구에 대한 표준화된 chamber 방법과 새로운 프로토콜 방법 간의 상관계수는 모두 r=0.98로, 높은 수준의 상관관계를 나타냈다. 이 두 방법 간의 동일 등급에 대한 쌍별 일치율은 적혈구의 경우 86.1%, 백혈구의 경우 88.6%였으며, 한 등급 차이 내 일치율은 모두 99.5%였다. 반면, 표준화된 chamber 방법과 중·소규모 검사실 방법 간의 일치율은 적혈구의 경우 11.9%, 백혈구의 경우 13.4%로, 동일 등급 일치율이 현저히 낮았고, 한 등급 차이 내 일치율은 각각 67.2%와 74.1%로 나타났다. 급내상관계수 및 Bland-Altman plot을 사용한 분석에서는 새로운 프로토콜이 다른 세 가지 수동 현미경검사 방법에 비해 우수한 일치도를 보인 것으로 확인되었다. 표준화된 chamber 방법과의 높은 상관관계와 일치도를 고려해 볼 때, 새로운 프로토콜 방법을 소변 침사물 표본제작의 표준화된 절차로 권장한다. Urinalysis is a fundamental diagnostic test routinely performed in clinical laboratories. We evaluated two manual microscopy methods, including a novel protocol, against the standardized chamber method. A total of 402 specimens, comprising 201 positive each for red blood cells (RBCs) and white blood cells (WBCs) by the strip test and automated urine sediment analyzer, were selected for the analysis. The correlation coefficients between the standardized chamber method and the novel protocol RBC and WBC test were both r=0.98, indicating a high degree of correlation. The pair-wise agreement rates for the same grade between these two methods were 86.1% for RBCs and 88.6% for WBCs, with rates within one grade difference of both at 99.5%. In contrast, the agreement rates between the standardized chamber method and smaller or medium-sized laboratory methods were notably lower, with the same-grade rates at 11.9% for RBCs and 13.4% for WBCs, and within one grade difference at 67.2% and 74.1%, respectively. Additional analyses using the intraclass correlation coefficient and Bland-Altman plots confirmed that the novel protocol exhibited superior agreement compared to the other three manual microscopy methods tested. Therefore, we recommend the novel protocol as a standardized procedure for urine sediment preparation, given its high correlation and agreement with the standardized chamber method.