Myung-Jae Lee

Bio: Myung-Jae Lee is an academic researcher from Korea Institute of Science and Technology. The author has contributed to research in topics: CMOS & Avalanche photodiode. The author has an hindex of 17, co-authored 67 publications receiving 975 citations. Previous affiliations of Myung-Jae Lee include École Polytechnique Fédérale de Lausanne & Yonsei University.

High-Performance Back-Illuminated Three-Dimensional Stacked Single-Photon Avalanche Diode Implemented in 45-nm CMOS Technology

Abstract: We present a high-performance back-illuminated three-dimensional stacked single-photon avalanche diode (SPAD), which is implemented in 45-nm CMOS technology for the first time. The SPAD is based on a P+/Deep N-well junction with a circular shape, for which N-well is intentionally excluded to achieve a wide depletion region, thus enabling lower tunneling noise and better timing jitter as well as a higher photon detection efficiency and a wider spectrum. In order to prevent premature edge breakdown, a P-type guard ring is formed at the edge of the junction, and it is optimized to achieve a wider photon-sensitive area. In addition, metal-1 is used as a light reflector to improve the detection efficiency further in backside illumination. With the optimized 3-D stacked 45-nm CMOS technology for back-illuminated image sensors, the proposed SPAD achieves a dark count rate of 55.4 cps/μm2 and a photon detection probability of 31.8% at 600 nm and over 5% in the 420–920 nm wavelength range. The jitter is 107.7 ps full width at half-maximum with negligible exponential diffusion tail at 2.5 V excess bias voltage at room temperature. To the best of our knowledge, these are the best results ever reported for any back-illuminated 3-D stacked SPAD technologies.

Si avalanche photodetectors fabricated in standard complementary metal-oxide-semiconductor process

Abstract: The authors report silicon avalanche photodetectors (APDs) fabricated with 0.18μm standard complementary metal-oxide-semiconductor (CMOS) process without any process modification or a special substrate. When the bias is above the avalanche breakdown voltage, CMOS-compatible APD (CMOS-APD) exhibits negative photoconductance in photocurrent-voltage relationship and rf peaking in the photodetection frequency response. The reflection coefficient measurement of CMOS-APD indicates that rf peaking is due to resonance caused by appearance of inductive components in avalanche region. The rf-peaking frequency increases with the increasing reverse bias voltage.

10-Gb/s 850-nm CMOS OEIC Receiver With a Silicon Avalanche Photodetector

Abstract: We present a 10-Gb/s optoelectronic integrated circuit (OEIC) receiver fabricated with standard 0.13-μm complementary metal-oxide-semiconductor (CMOS) technology for 850-nm optical interconnect applications. The OEIC receiver consists of a CMOS-compatible avalanche photodetector (CMOS-APD), a transimpedance amplifier (TIA), an offset cancellation network, a variable equalizer (EQ), a limiting amplifier (LA), and an output buffer. The CMOS-APD provides high responsivity as well as large photodetection bandwidth. The TIA is composed of two-stage differential amplifiers with high feedback resistance of 4 kΩ. The EQ compensates high-frequency loss by controlling the boosting gain with a capacitor array. The LA consists of five-stage gain cells with active feedback and negative capacitance to achieve broadband performance. With the OEIC receiver, we successfully demonstrate transmission of 10-Gb/s optical data at 850 nm with a bit error rate of 10-12 at the incident optical power of -4 dBm. The OEIC receiver has the core chip area of about 0.26 mm2 and consumes about 66.8 mW.

Resistive switching transition induced by a voltage pulse in a Pt/NiO/Pt structure

Abstract: We have observed a switching transition between bistable memory switching and monostable threshold switching in Pt/NiO/Pt structure. Bistable memory switching could be changed to monostable threshold switching by applying a positive electrical pulse with height of 2 V and width between 10−2 and 10−4 s. The change is reversible by applying a negative electrical pulse with the same height and width. By considering polarity- and width-dependence of the switching transition and compositional difference on electrical properties in NiOx, we have proposed a model in which the migration of oxygen ions (O2−) is responsible for the switching transition in Pt/NiO/Pt structures.

A silicon avalanche photodetector fabricated with standard CMOS technology with over 1 THz gain-bandwidth product.

Abstract: We present a silicon avalanche photodetector (APD) fabricated with standard complementary metal-oxide-semiconductor (CMOS) technology without any process modification or special substrates. The CMOS-APD is based on N+/P-well junction, and its current-voltage characteristics, responsivity, avalanche gain, and photodetection frequency response are measured. Gain-bandwidth product over 1 THz is achieved with the CMOS-APD having avalanche gain of 569 and 3-dB photodetection bandwidth of 3.2 GHz.

Light-emitting diodes

Abstract: Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

Nanofilamentary resistive switching in binary oxide system; a review on the present status and outlook

Abstract: This review article summarized the recent understanding of resistance switching (RS) behavior in several binary oxide thin film systems. Among the various RS materials and mechanisms, TiO2 and NiO thin films in unipolar thermo-chemical switching mode are primarily dealt with. To facilitate the discussions, the RS was divided into three parts; electroforming, set and reset steps. After short discussions on the electrochemistry of 'electrolytic' oxide materials, the general and peculiar aspects of these RS systems and mechanism are elaborated. Although the RS behaviors and characteristics of these materials are primarily dependent on the repeated formation and rupture of the conducting filaments (CFs) at the nanoscale at a localized position, this mechanism appears to offer a basis for the understanding of other RS mechanisms which were originally considered to be irrelevant to the localized events. The electroforming and set switching phenomena were understood as the process of CF formation and rejuvenation, respectively, which are mainly driven by the thermally assisted electromigration and percolation (or even local phase transition) of defects, while the reset process was understood as the process of CF rupture where the thermal energy plays a more crucial role. This review also contains several remarks on the outlook of these resistance change devices as a semiconductor memory.

Ratiometric optical nanoprobes enable accurate molecular detection and imaging

Abstract: Exploring and understanding biological and pathological changes are of great significance for early diagnosis and therapy of diseases. Optical sensing and imaging approaches have experienced major progress in this field. Particularly, an emergence of various functional optical nanoprobes has provided enhanced sensitivity, specificity, targeting ability, as well as multiplexing and multimodal capabilities due to improvements in their intrinsic physicochemical and optical properties. However, one of the biggest challenges of conventional optical nanoprobes is their absolute intensity-dependent signal readout, which causes inaccurate sensing and imaging results due to the presence of various analyte-independent factors that can cause fluctuations in their absolute signal intensity. Ratiometric measurements provide built-in self-calibration for signal correction, enabling more sensitive and reliable detection. Optimizing nanoprobe designs with ratiometric strategies can surmount many of the limitations encountered by traditional optical nanoprobes. This review first elaborates upon existing optical nanoprobes that exploit ratiometric measurements for improved sensing and imaging, including fluorescence, surface enhanced Raman scattering (SERS), and photoacoustic nanoprobes. Next, a thorough discussion is provided on design strategies for these nanoprobes, and their potential biomedical applications for targeting specific biomolecule populations (e.g. cancer biomarkers and small molecules with physiological relevance), for imaging the tumor microenvironment (e.g. pH, reactive oxygen species, hypoxia, enzyme and metal ions), as well as for intraoperative image guidance of tumor-resection procedures.

Status and Potential of Lithium Niobate on Insulator (LNOI) for Photonic Integrated Circuits

Abstract: Lithium niobate on insulator (LNOI) technology is revolutionizing the lithium niobate industry, enabling higher performance, lower cost and entirely new devices and applications. The availability of LNOI wafers has sparked significant interest in the platform for integrated optical applications, as LNOI offers the attractive material properties of lithium niobate, while also offering the stronger optical confinement and a high optical element integration density that has driven the success of more mature silicon and silicon nitride (SiN) photonics platforms. Due to some similarities between LNOI and SiN, established techniques and standards can readily be adapted to the LNOI platform including a significant array of interface approaches, device designs and also heterogeneous integration techniques for laser sources and photodetectors. In this contribution, we review the latest developments in this platform, examine where further development is necessary to achieve more functionalities in LNOI integrated optical circuits and make a few suggestions of interesting applications that could be realized in this platform. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim