Schottky Body Diode를 집적하여 향상된 Reverse Recovery 특성을 가지는 50V Power MOSFET

이병화,조두형,김광수,Lee, Byung-Hwa,Cho, Doo-Hyung,Kim, Kwang-Soo 한국전기전자학회 2015 전기전자학회논문지 Vol.19 No.1

본 논문에서는 U-MOSFET 내부의 기생 body 다이오드(PN diode)를 쇼트키 body 다이오드(Schottky body diode)로 대체한 50V급 전력 U-MOSFET을 제안하였다. 쇼트키 다이오드는 PN 다이오드와 비교 시, 역 회복 손실(reverse recovery loss)을 감소시킬 수 있는 장점을 가지고 있다. 따라서 전력 MOSFET의 기생 body 다이오드를 쇼트키 body 다이오드를 대신함으로써 역 회복 손실을 최소화 할 수 있다. 제안된 쇼트키 body 다이오드(Schottky body diode) U-MOSFET(SU-MOS)를 conventional U-MOSFET(CU-MOS)와 전기적 특성을 비교한 결과, 전달(transfer) 및 출력(output)특성, 항복(breakdown)전압 등 정적(static) 특성의 변화 없이 감소된 역 회복 손실을 얻을 수 있었다. 즉, 쇼트키 다이오드의 폭(width)이 $0.2{\mu}m$, 쇼트키 장벽 높이(Schottky barrier height)가 0.8eV일 때 첨두 역전류(peak reverse current)는 21.09%, 역 회복 시간(reverse recovery time)은 7.68% 감소하였고, 성능지수(figure of merit(FOM))는 35% 향상되었다. 제안된 소자의 특성은 Synopsys사의 Sentaurus TCAD를 사용하여 분석되었다. In this paper, 50V power U-MOSFET which replace the body(PN) diode with Schottky is proposed. As already known, Schottky diode has the advantage of reduced reverse recovery loss than PN diode. Thus, the power MOSFET with integrated Schottky integrated can minimize the reverse recovery loss. The proposed Schottky body diode U-MOSFET(SU-MOS) shows reduction of reverse recovery loss with the same transfer, output characteristic and breakdown voltage. As a result, 21.09% reduction in peak reverse current, 7.68% reduction in reverse recovery time and 35% improvement in figure of merit(FOM) are observed when the Schottky width is $0.2{\mu}m$ and the Schottky barrier height is 0.8eV compared to conventional U-MOSFET(CU-MOS). The device characteristics are analyzed through the Synopsys Sentaurus TCAD tool.

Rectifying and breakdown voltage enhancement of Au/n-GaN Schottky diode with Al-doped ZnO films and its structural characterization

Janardhanam, V.,Jyothi, I.,Lee, Sung-Nam,Reddy, V. Rajagopal,Choi, Chel-Jong Elsevier S.A. 2019 Thin Solid Films Vol.676 No.-

<P><B>Abstract</B></P> <P>Radio frequency magnetron sputtered Al-doped zinc oxide (AZO) thin films were formed on n-type gallium nitride (GaN). X-ray diffraction reflections and Raman modes confirmed the formation of the AZO films. The optical band gap of the deposited AZO film was found to be 3.31 eV and exhibited a fairly smooth surface and continuous growth across the surface with a grainy structure. The Au/AZO/n-GaN heterojunction Schottky diode was fabricated and investigated the influence of the presence of AZO layer in Au/n-GaN Schottky diode, characterizing its electrical and breakdown voltage properties. The AZO layer led to an excellent improvement in the rectifying behavior with an increase in barrier height of the Au/n-GaN Schottky diode from 0.69 to 0.90 eV. Reverse breakdown voltage of the Au/n-GaN Schottky diode and Au/AZO/n-GaN heterojunction diode were obtained to be 86 and 232 V, respectively, without any edge termination methods. The AZO layer effectively reduced the interface states in the Au/n-GaN Schottky diodes. Schottky and Poole-Frenkel emission mechanisms dominated the reverse current in Au/n-GaN Schottky diode and Au/AZO/n-GaN heterojunciton diode, respectively. The results signify the importance of the metal-insulator-semiconductor structure and in particular the AZO layer in reducing the leakage current and improving the device performance. A further improvement in breakdown voltage can be achieved by employing field plate and guard-ring structures for edge termination.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fabricated Au/Al-doped ZnO (AZO)/n-GaN heterojunction diode by sputtering AZO films. </LI> <LI> X-ray diffraction and Raman modes confirmed the formation of AZO films. </LI> <LI> AZO films deposited on GaN exhibited a fairly smooth surface with a grainy structure. </LI> <LI> Excellent improvement in rectification of Au/n-GaN Schottky diode by AZO insertion. </LI> <LI> Breakdown voltage of Au/n-GaN Schottky diode rises from 86 to 232 V by AZO insertion. </LI> </UL> </P>

중성자 조사된 SiC Schottky Diode의 온도 의존 특성

김성수,구상모,Kim, Sung-Su,Koo, Sang-Mo 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.10

The temperature dependent characteristics on the properties of SiC Schottky Diode has been investigated. In this study, the temperature dependent current-voltage characteristics of the SiC Schottky diode were measured in the range of 300 ~ 500 K. Divided into pre- and post- irradiated device was measured. The barrier height after irradiation device at 500 K increased 0.15 eV compared to 300 K, the barrier height of pre- neutron irradiated Schottky diode increased 0.07 eV. The effective barrier height after irradiation increased from 0.89 eV to 1.05 eV. And ideality factor of neutron irradiated Schottky diode at 500 K decreased 0.428 compared to 300 K, the ideality factor of pre- neutron irradiated Schottky diode decreased 0.354. Also, a slight positive shift in threshold voltage from 0.53 to 0.68 V. we analyzed the effective barrier height and ideality factor of SiC Schottky diode as function of temperature.

Development of Planar Schottky Diode on GaAs Substrate for Terahertz Applications

Won-Young Uhm,Seok-Gyu Choi,Min Han,Keun-Kwan Ryu,Sung-Chan Kim 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.5

In this paper, we demonstrate the planar Schottky diode on GaAs substrate for terahertz applications. A nanoscale dot and T-shaped disk has been developed as the anode for terahertz Schottky diode. The low parasitic elements of the nanoscale anode with T-shaped disk yield high cutoff frequency characteristic. The fabricated Schottky diode with anode diameter of 500 nm has series resistance of 21 Ω, ideality factor of 1.32, junction capacitance of 8.03 fF, and cutoff frequency of 944 GHz.

초광대역 전이 구조를 이용한 다이오드 검파기 설계

김인복(In Bok Kim),김영곤(Young Gon Kim),김태규(Tae Gyu Kim),김강욱(Kang Wook Kim) 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.8

본 논문에서는 두 개의 초광대역 전이 구조를 이용한 다이오드 검파기의 설계 과정을 처음으로 소개하고, 이를 제작하여 측정한 결과를 소개한다. 제안된 검파기에서는 두 개의 초광대역 전이 구조를 입ㆍ출력단의 정합 회로로 사용하였다. 검파기 회로 구현시 일반 쇼트키 다이오드 및 무 바이어스 쇼트키 다이오드를 사용하여 각각 검파기를 구현하고, 그 성능을 비교하였다. 일반 쇼트키 다이오드를 사용하여 제작된 검파기는 11 ㎓에서 20 ㎓까지의 주파수 대역에서 10 ㏈ 이상의 반사 손실을 가지며, 제작된 검파기의 감도는 30 ㎷/㎽이었다. 또한, 무 바이어스 쇼트키 다이오드를 사용한 검파기의 경우, 측정된 검파기의 감도는 300 ㎷/㎽로서 훨씬 증가하였다. In this paper, a design of broadband detectors utilizing two ultra-wideband transitions is described for the first time, and the implementation method and measurement results of the detectors are provided. Two ultra-wideband transitions are used for input/output matching circuits for the diode detectors. Two detectors have been implemented using general Schottky diodes and zero-bias Schottky diodes. With general Schottky diodes, the fabricated detector provides less than 10 ㏈ return loss from 11 ㎓ to 20 ㎓, and the detector sensitivity is 30 ㎷/㎽. The detector with zero-bias Schottky diodes shows significantly higher detection sensitivity(300 ㎷/㎽).

Schottky Diode의 특성과 CSTL

오상식,김재형 인제대학교 1983 仁濟醫學 Vol.4 No.4

This paper described the characteristics of Schottky diode and Complementary Schottky Transistor Logic (CSTL) with Schottky diode. The Schottky barrier heights of Al and Al-2%Si layers to n-type Si were measured using I-V measurement and their values were 0.67eV and 0.85eV, respectively. To measure ac characteristics of CSTL, 29-stage ring oscillator and T-flip flop had been designed and fabricated according to Standard bipolar Process. For Al and Al-2%Si Schottky contact, the minimum propagation delay time and the maximum toggle frequency were measured to be 5ns, 10ns, 22MHz and 16MHz, respectively.

Effect of annealing of graphene layer on electrical transport and degradation of Au/graphene/n-type silicon Schottky diodes

Kim, D.J.,Kim, G.S.,Park, N.W.,Lee, W.Y.,Sim, Y.,Kim, K.S.,Seong, M.J.,Koh, J.H.,Hong, C.H.,Lee, S.K. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.612 No.-

We have investigated the effect of annealing of graphene sheets on the electrical properties of Au/graphene/n-type silicon Schottky diode. Large scale graphene sheets were grown by chemical vapor deposition and then annealed at 300, 400, and 500<SUP>o</SUP>C; one sheet was left un-annealed as the control. The diodes were fabricated by transferring the graphene sheets directly onto n-type Si substrates and the current-voltage (I-V) and capacitance-voltage (C-V) characteristics were evaluated. The average values of the Schottky barrier height (SBH) and ideality factor (η) for the as-fabricated Au/graphene/n-type silicon Schottky diode from I-V measurements were determined to be ~0.8+/-0.01eV and ~1.79+/-0.05, respectively, whereas the SBH from C-V measurements was ~0.89+/-0.01eV. The electrical transport characteristics measured at room temperature indicated that annealing of graphene sheet prior to the transfer of the graphene onto the n-Si substrates significantly reduces the electric degradation of the Schottky diodes, even though no distinct differences in other electric properties, including ideality factors and SBHs, before or after annealing of the graphene sheets were observed. Thus, by simply annealing the graphene sheets at 500<SUP>o</SUP>C, we found that the Au/graphene/n-type silicon Schottky diode showed an approximately 3.3-fold lower series resistance as compared with the un-annealed Schottky diode under air exposure of up to 7days. These annealed diodes showed significantly reduced electrical degradation by removing the potentially trapped H<SUB>2</SUB>O and/or O<SUB>2</SUB> at the interface between the graphene layer and the n-Si substrate.

Electrical Transport Measurements and Degradation of Graphene/n-Si Schottky Junction Diodes

박노원,이원영,이상권,김동주,김길성,형정환,홍창희,고중혁,김근수 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.1

We report on the electrical properties, such as the ideality factors and Schottky barrier heights,that were obtained by using current density - voltage (J − V ) and capacitance - voltage (C − V )characteristics. To fabricate circularly- and locally-contacted Au/Gr/n-Si Schottky diode, we depositedgraphene through the chemical vapor deposition (CVD) growth technique, and we employedreactive ion etching to reduce the leakage current of the Schottky diodes. The average values of thebarrier heights and the ideality factors from the J −V characteristics were determined to be 0.79± 0.01 eV and 1.80 ± 0.01, respectively. The Schottky barrier height and the doping concentrationfrom the C − V measurements were 0.85 eV and 1.76 × 1015 cm−3, respectively. Fromthe J − V characteristics, we obtained a relatively low reverse leakage current of 2.56 × 10−6mA/cm−2 at −2 V, which implies a well-defined rectifying behavior. Finally, we found that theGr/n-Si Schottky diodes that were exposed to ambient conditions for 7 days exhibited a 3.2-foldhigher sheet resistance compared with the as-fabricated Gr/n-Si diodes, implying a considerableelectrical degradation of the Gr/n-Si Schottky diodes.

Edge Termination을 위해 Tilt-Implantation을 이용한 SiC Trench Schottky Diode에 대한 연구

송길용,김광수,Song, Gil-Yong,Kim, Kwang-Soo 한국전기전자학회 2014 전기전자학회논문지 Vol.18 No.2

본 논문에서는 실리콘 카바이드(silicon carbide)를 기반으로 한 tilt-implanted trench Schottky diode(TITSD)를 제안한다. 4H-SiC 트랜치 쇼트키 다이오드(trench Schottky diode)에 형성되는 트랜치 측면에 경사 이온주입(tilt-implantation)을 하여 소자가 역저지 상태(reverse blocking mode)로 동작 시 trench insulator가 모든 퍼텐셜(potential)을 포함하는 구조를 제안하고, 그 특성을 시뮬레이션을 통해 확인하였다. TITSD는 트랜치의 측면(sidewall)에 nitrogen을 $1{\times}10^{19}cm^{-3}$ 으로 도밍(doping) 하여 항복전압(breakdown voltage) 특성도 경사 이온주입을 하지 않았을 때와 같게 유지하면서 trench oxide insulator가 모든 퍼텐셜을 포함하도록 함으로써 termination area를 감소시켰다. 트랜치 깊이(trench depth)를 $11{\mu}m$로 깊게 하고 최적화된 폭(width)을 선택함으로써 2750V의 항복전압을 얻었고, 동급의 항복전압을 가진 가드링(guard ring) 구조보다 termination area를 38.7% 줄일 수 있다. 이에 대한 전기적 특성은 synopsys사의 TCAD simulation을 사용하여 분석하였으며, 그 결과를 기존의 구조와 비교하였다. In this paper, the usage of tilt-implanted trench Schottky diode(TITSD) based on silicon carbide is proposed. A tilt-implanted trench termination technique modified for SiC is proposed as a method to keep all the potentials confined in the trench insulator when reverse blocking mode is operated. With the side wall doping concentration of $1{\times}10^{19}cm^{-3}$ nitrogen, the termination area of the TITSD is reduced without any sacrifice in breakdown voltage while potential is confined within insulator. When the trench depth is set to 11um and the width is optimized, a breakdown voltage of 2750V is obtained and termination area is 38.7% smaller than that of other devices which use guard rings for the same breakdown voltage. A Sentaurus device simulator is used to analyze the characteristics of the TITSD. The performance of the TITSD is compared to the conventional trench Schottky diode.

Manipulating the structure of polyaniline by exploiting redox chemistry: Novel p-NiO/n-polyaniline/n-Si Schottky diode based chemosensor for the electrochemical detection of hydrazinobenzene

Ameen, S.,Akhtar, M.S.,Shin, H.S. Pergamon Press 2016 ELECTROCHIMICA ACTA Vol.215 No.-

New and effective chemosensor was fabricated using p-nickel oxide (NiO)/n-conducting polyaniline (PANI) based Schottky barrier diode for the detection of hydrazinobenzene chemical. The n-PANI was synthesized through in-situ chemical doping of PANI EB by using calcium hydride as dopant and subjected to elemental analysis, optical, structural and morphological properties. The appearance of a non-linear I-V behavior at the interface of Pt and p-NiO/n-PANI layer confirmed the formation of Schottky junction of the fabricated Pt/p-NiO/n-PANI/n-Si Schottky barrier diode. The electrochemical properties of Pt/p-NiO/n-PANI/n-Si Schottky barrier diode towards the detection of hydrazinobenzene were elucidated by cyclovoltametry (CV) measurements. The sensing results revealed that the Pt/p-NiO/n-PANI/n-Si Schottky barrier diode exhibited a stable, reliable high sensitivity ~90.5μAmM<SUP>-1</SUP>cm<SUP>-2</SUP>, good detection limit of ~5.11μM with correlation coefficient ® of ~0.99417 and short response time (10s). Herein, n-type chemical doping of PANI and the formation of Schottky barrier elicited the sensing parameters such as sensitivity, detection limit and correlation coefficient.