• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.82-88
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• 1996

A simpel formular is proposed for the analysis of gate delay of CMOS gate in the low V$_{GS}-V_{TH}$ scaling. The effects of magnitude of V$_{GS}-V_{TH}$ on gate delay can be readily found through the formula so that it can be used ot design the device parameters in the low V$_{DD}$ CMOS circuits. The measured sresutls confirm the usability of the proposed formula and quantifies the improtance of V$_{TH}$ effects on gate delay under low voltae operation. Applying the formula to the prototype NMOSFET devices representing the five generations of technology, the impacts of the V$_{GS}-V_{TH}$ on the various aspects of the circuit and device characteristics are investigated in a consistent manner.

• Journal of IKEEE
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• v.28 no.1
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• pp.110-115
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• 2024

This paper analyzed the V_th (Threshold Voltage) variations in 3D NAND Flash memory with tapered O/N/O (Oxide/Nitride/Oxide) structure and O/N/F (Oxide/Nitride/Ferroelectric) structure, where the blocking oxide is replaced by ferroelectric material. With a tapering angle of 0°, the O/N/F structure exhibits lower resistance compared to the O/N/O structure, resulting in reduced V_th variations in both the upper and lower regions of the WL (Word Line). Tapered 3D NAND Flash memory shows a decrease in channel area and an increase in channel resistance as it moves from the upper to the lower WL. Consequently, as the tapering angle increases, the V_th decreases in the upper WL and increases in the lower WL. The tapered O/N/F structure, influenced by V_fe proportional to the channel radius, leads to a greater reduction in V_th in the upper WL compared to the O/N/O structure. Additionally, the lower WL in the O/N/F structure experiences a greater increase in V_th compared to the O/N/O structure, resulting in larger V_th variations with increasing tapering angles.

• Journal of Life Science
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• v.7 no.1
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• pp.39-48
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• 1997

Cigarette is the risk factor of Lung cancer, chronic obstructive pulmonary disease and ischemic heart disease. So I have studied the effect of Macmoondongtang in rat exposed to cigarette smoke. Thirty-six healthy rat subjects were divided into 6 groups-the control group(sample I), the groups of administration of Platycodi Radix(sampleII), Adenophorae Radix(sampleIII), Liriopsis Tuber(sampleIV), Maximowicziae Fructus(sample V) and Macmoondongtang(sample VI), and expose to cigarette per day for 12 days. 1. On level of leckocyte are significant all the group of sampleII, sampleIII, sample IV, sample V, sample VI on 6th day and singificant the groups of sampleIV, sample V on 12th day. 2. On level of hemoglobin are singificant the groups of sample IV, sample V, sample VI, on 6th day, and significant sample II, sample III, sample IV, sample V, sample VI on 12th day. 3. On platelet level are significant all the group of sampleII, sample III, sample IV, sample V, sample VI on 12th day. 4. On SOD activity are significant all the groups of sample IV, sample VI, on 6th day, and significant sampleII, sample III, sample VI on 12th day. According to the results, Macmoondogtang is effective to risk of cigarette smoke.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.288-292
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• 2013

In this paper, a carbon implant is investigated in detail from the perspectives of performance advantages and side effects for the thick n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET). Threshold voltage ($V_{th}$) adjustment using a carbon implant significantly improves the $V_{th}$ mismatch performance in a thick (3.3-V) n-MOS transistor. It has been reported that a bad mismatch occurs particularly in the case of 0.11-${\mu}m$ $V_{th}$ node technology. This paper investigates a carbon implant process as a promising candidate for the optimal $V_{th}$ roll-off curve. The carbon implant makes the $V_{th}$ roll-off curve perfectly flat, which is explained in detail. Further, the mechanism of hot carrier injection lifetime degradation by the carbon implant is investigated, and new process integration involving the addition of a nitrogen implant in the lightly doped drain process is offered as its solution. This paper presents the critical side effects, such as Isub increases and device performance shifts caused by the carbon implant and suggests an efficient method to avoid these issues.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.262-263
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• 2011

Flexible electronics, a future technology of electronics, require a low cost integrated circuit that can be built on various types of the flexible substrates. As a potential candidate for this application, a single walled carbon nanotube network is studied as an active device with a scheme of thin film transistor. Transistors are formed on a plastic foil by the Roll-to-Roll (R2R) and the Roll-to-Device (R2D) printing method. For both printing methods, electrical transports for the transistors are presented with the temperature dependence of threshold voltage (V_Th) and mobility from the measured transfer curves at temperatures ranging from 10 K to 300 K. It is observed that ${\mu}=0.044cm^2/V{\cdot}sec$ and V_Th=7.28V for R2R and ${\mu}=0.025cm^2/V{\cdot}sec$ and V_Th=3.10V for R2D, both for the temperature at 300K. Temperature dependence of mobility and V_Th is observed. However for R2R, the temperature dependence of V_Th is constant. It is the difference between, R2R and R2D.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.92-97
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• 2013

In this paper the author proposes a method of implementing a numerical model for threshold voltage ($V_{th}$) shift in organic thin-film transistors (OTFTs) into SPICE tools. $V_{th}$ shift is first numerically modeled by dividing the shift into sequentially ordered groups. The model is then used to derive a simulations model which takes into simulation parameters and calculation complexity. Finally, the numerical and simulation models are implemented in AIM-SPICE. The SPICE simulation results agree well with the $V_{th}$ shift obtained from an OTFT fabricated without any optimization. The proposed method is also used to implement the stretched-exponential time dependent $V_{th}$ shift in AIM-SPICE and the results show the proposed method is applicable to various types of $V_{th}$ shifts.

• Current Applied Physics
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• v.18 no.11
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• pp.1447-1450
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• 2018

The electron spin resonance (ESR) detects point defect of the In-Ga-Zn oxide (IGZO) like singly ionized oxygen vacancies and excess oxygen, and get spin density as a parameter of defect state. So, we demonstrated the spin density measurement of the IGZO film with various deposition conditions and it has linear relationship. Moreover, we matched the spin density with the total BTS and the threshold voltage ($V_{th}$) distribution of the IGZO thin film transistors. The total BTS ${\Delta}V_{th}$ and the $V_{th}$ distribution were degraded due to the spin density increases. The spin density is the useful indicator to predict $V_{th}$ instability of IGZO TFTs.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1263-1264
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• 2007

자계 유도 고상결정화(FESPC)를 이용하여 제작한 다결정실리콘(poly-Si) 박막 트랜지스터(TFT)는 비정질 실리콘 박막 트랜지스터(a-Si:H TFT)보다 뛰어난 전기적 특성과 우수한 안정성을 지닌다. $V_{DS}$ = -0.1 V에서 채널 폭과 길이가 각각 $5\;{\mu}m$, $7\;{\mu}m$인 P형 TFT의 이동도(${\mu}$)와 문턱 전압($V_{TH}$)은 각각 $31.98\;cm^2$/Vs, -6.14 V 이다. FESPC TFT는 일반 poly-Si TFT에 비해 채널 내 결정 경계 숫자가 많아서 상대적으로 열악한 특성을 가진다. 채널 길이 $5\;{\mu}m$인 TFT의 $V_{TH}$는 채널 길이 $18\;{\mu}m$ 소자의 $V_{TH}$보다 1.36V 작지만, 일반적으로 큰 값이다. 이 현상은 채널에 다수의 결정 경계가 존재하고, 수평 전계가 크기 때문이다. 수평 전계가 증가하면, 결정 경계의 전위 장벽 높이가 감소하게 되는데, 이는 DIGBL 효과이다. ${\mu}$의 증가에 따라서, 드레인 전류가 증가하고 $V_{TH}$은 감소한다. 활성화 에너지($E_a$)는 드레인 전압과 결정 경계의 수에 따라 변하는데, 드레인 전압이 크거나 결정 경계의 수가 감소하면 $E_a$는 감소한다. $E_a$가 감소하면 $V_{TH}$가 감소한다. 유리기판 위의 FESPC를 이용한 P형 poly-Si TFT의 $V_{TH}$는 채널의 길이와 $V_{DS}$에 영향을 받는다. 증가한 수평 전계가 결정 경계에서 에너지 장벽을 낮추는 효과를 일으키기 때문이다.

• Korean Journal of Acupuncture
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• v.20 no.4
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• pp.65-75
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• 2003

This study was carried to identify the component of Spleen Meridian Muscle in human, dividing into outer, middle, and inner part. Lower extremity and trunk were opened widely to demonstrate muscles, nerve, blood vessels and the others, displaying the inner structure of Spleen Meridian Muscle. We obtained the results as follows; 1. Spleen Meridian Muscle is composed of the muscle, nerve and blood vessels. 2. In human anatomy, it is present the difference between a term of nerve or blood vessels which control the muscle of Meridian Muscle and those which pass near by Meridian Muscle. 3. The inner composition of meridian muscle in human arm is as follows ; 1) Muscle; ext. hallucis longus tend., flex. hallucis longus tend.(Sp-1), abd. hallucis tend., flex. hallucis brevis tend., flex. hallucis longus tend.(Sp-2, 3), ant. tibial m. tend., abd. hallucis, flex. hallucis longus tend.(Sp-4), flex. retinaculum, ant. tibiotalar lig.(Sp-5), flex. digitorum longus m., tibialis post. m.(Sp-6), soleus m., flex. digitorum longus m., tibialis post. m.(Sp-7, 8), gastrocnemius m., soleus m.(Sp-9), vastus medialis m.(Sp-10), sartorius m., vastus medialis m., add. longus m.(Sp-11), inguinal lig., iliopsoas m.(Sp-12), ext. abdominal oblique m. aponeurosis, int. abd. ob. m., transversus abd. m.(Sp-13, 14, 15, 16), ant. serratus m., intercostalis m.(Sp-17), pectoralis major m., pectoralis minor m., intercostalis m.(Sp-18, 19, 20), ant. serratus m., intercostalis m.(Sp-21) 2) Nerve; deep peroneal n. br.(Sp-1), med. plantar br. of post. tibial n.(Sp-2, 3, 4), saphenous n., deep peroneal n. br.(Sp-5), sural cutan. n., tibial. n.(Sp-6, 7, 8), tibial. n.(Sp-9), saphenous br. of femoral n.(Sp-10, 11), femoral n.(Sp-12), subcostal n. cut. br., iliohypogastric n., genitofemoral. n.(Sp-13), 11th. intercostal n. and its cut. br.(Sp-14), 10th. intercostal n. and its cut. br.(Sp-15), long thoracic n. br., 8th. intercostal n. and its cut. br.(Sp-16), long thoracic n. br., 5th. intercostal n. and its cut. br.(Sp-17), long thoracic n. br., 4th. intercostal n. and its cut. br.(Sp-18), long thoracic n. br., 3th. intercostal n. and its cut. br.(Sp-19), long thoracic n. br., 2th. intercostal n. and its cut. br.(Sp-20), long thoracic n. br., 6th. intercostal n. and its cut. br.(Sp-21) 3) Blood vessels; digital a. br. of dorsalis pedis a., post. tibial a. br.(Sp-1), med. plantar br. of post. tibial a.(Sp-2, 3, 4), saphenous vein, Ant. Med. malleolar a.(Sp-5), small saphenous v. br., post. tibial a.(Sp-6, 7), small saphenous v. br., post. tibial a., peroneal a.(Sp-8), post. tibial a.(Sp-9), long saphenose v. br., saphenous br. of femoral a.(Sp-10), deep femoral a. br.(Sp-11), femoral a.(Sp-12), supf. thoracoepigastric v., musculophrenic a.(Sp-16), thoracoepigastric v., lat. thoracic a. and v., 5th epigastric v., deep circumflex iliac a.(Sp-13, 14), supf. epigastric v., subcostal a., lumbar a.(Sp-15), intercostal a. v.(Sp-17), lat. thoracic a. and v., 4th intercostal a. v.(Sp-18), lat. thoracic a. and v., 3th intercostal a. v., axillary v. br.(Sp-19), lat. thoracic a. and v., 2th intercostal a. v., axillary v. br.(Sp-20), thoracoepigastric v., subscapular a. br., 6th intercostal a. v.(Sp-21)

• Journal of IKEEE
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• v.24 no.1
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• pp.284-292
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• 2020

SiC-based devices perform well in high-voltage environments of more than 1200V compared to silicon devices, and are particularly stable at very high temperatures. Therefore, 1700V UMOSFET has been actively researched and developed for the use of electric power systems such as electric vehicles and aircrafts. In this paper, we analysed thermal variations of critical variables (breakdown voltage (BV), on-resistance (R_on), threshold voltage (v_th), and transconductance (g_m)) for the three type 1700V UMOSFETs-Conventional UMOSFET (C-UMOSFET), Source Trench UMOSFET (ST-UMOSFET), and Local Floating Superjunction UMOSFET (LFS-UMOSFET). All three devices showed BV increase, R_on increase, v_th decrease, and g_m decrease with increasing temperature. However, there are differences in BV, R_on, v_th, g_m according to the structural differences of the three devices, and the degree and cause of the analysis were compared. All results were simulated using sentaurus TCAD.