Catherine Langpoklakpam

Ms. Catherine Langpoklakpam


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
11 February 2022 in Crystals
Verified
Journal Article
Open access
PDF file
CLCatherine Langpoklakpam
Catherine Langpoklakpam
ALAn-Chen Liu
An-Chen Liu
KCKuo-Hsiung Chu
Kuo-Hsiung Chu
LHLung-Hsing Hsu
Lung-Hsing Hsu
WLWen-Chung Lee
Wen-Chung Lee
Hao-Chung KuoHao-Chung Kuo
Hao-Chung Kuo
Owing to the superior properties of silicon carbide (SiC), such as higher breakdown voltage, higher thermal conductivity, higher operating frequency, higher operating temperature, and higher saturation drift velocity, SiC has attracted much attention from researchers and the industry for decades. With the advances in material science and processing technology, many power applications such as new smart energy vehicles, power converters, inverters, and power supplies are being realized using SiC power devices. In particular, SiC MOSFETs are generally chosen to be used as a power device due to their ability to achieve lower on-resistance, reduced switching losses, and high switching speeds than the silicon counterpart and have been commercialized extensively in recent years. A general review of the critical processing steps for manufacturing SiC MOSFETs, types of SiC MOSFETs, and power applications based on SiC power devices are covered in this paper. Additionally, the reliability issues of SiC power MOSFET are also briefly summarized.

27 September 2021 in Micromachines
Verified
Journal Article
Open access
PDF file
LHLung-Hsing Hsu
Lung-Hsing Hsu
YLYung-Yu Lai
Yung-Yu Lai
PTP. Tu
P. Tu
CLCatherine Langpoklakpam
Catherine Langpoklakpam
YCYa-Ting Chang
Ya-Ting Chang
Edward Yi ChangEdward Yi Chang
Edward Yi Chang
GaN HEMT has attracted a lot of attention in recent years owing to its wide applications from the high-frequency power amplifier to the high voltage devices used in power electronic systems. Development of GaN HEMT on Si-based substrate is currently the main focus of the industry to reduce the cost as well as to integrate GaN with Si-based components. However, the direct growth of GaN on Si has the challenge of high defect density that compromises the performance, reliability, and yield. Defects are typically nucleated at the GaN/Si heterointerface due to both lattice and thermal mismatches between GaN and Si. In this article, we will review the current status of GaN on Si in terms of epitaxy and device performances in high frequency and high-power applications. Recently, different substrate structures including silicon-on-insulator (SOI) and engineered poly-AlN (QST®) are introduced to enhance the epitaxy quality by reducing the mismatches. We will discuss the development and potential benefit of these novel substrates. Moreover, SOI may provide a path to enable the integration of GaN with Si CMOS. Finally, the recent development of 3D hetero-integration technology to combine GaN technology and CMOS is also illustrated.

23 June 2021 in Micromachines
Verified
Journal Article
Open access
PDF file
ALAn-Chen Liu
An-Chen Liu
PTP. Tu
P. Tu
CLCatherine Langpoklakpam
Catherine Langpoklakpam
YHYu-Wen Huang
Yu-Wen Huang
YCYa-Ting Chang
Ya-Ting Chang
Edward Yi ChangEdward Yi Chang
Edward Yi Chang
GaN has been widely used to develop devices for high-power and high-frequency applications owing to its higher breakdown voltage and high electron saturation velocity. The GaN HEMT radio frequency (RF) power amplifier is the first commercialized product which is fabricated using the conventional Au-based III–V device manufacturing process. In recent years, owing to the increased applications in power electronics, and expanded applications in RF and millimeter-wave (mmW) power amplifiers for 5G mobile communications, the development of high-volume production techniques derived from CMOS technology for GaN electronic devices has become highly demanded. In this article, we will review the history and principles of each unit process for conventional HEMT technology with Au-based metallization schemes, including epitaxy, ohmic contact, and Schottky metal gate technology. The evolution and status of CMOS-compatible Au-less process technology will then be described and discussed. In particular, novel process techniques such as regrown ohmic layers and metal–insulator–semiconductor (MIS) gates are illustrated. New enhancement-mode device technology based on the p-GaN gate is also reviewed. The vertical GaN device is a new direction of development for devices used in high-power applications, and we will also highlight the key features of such kind of device technology.

16 October 2023 in Micromachines
Verified
Journal Article
Open access
PDF file
CLCatherine Langpoklakpam
Catherine Langpoklakpam
ALAn-Chen Liu
An-Chen Liu
YHYi-Kai Hsiao
Yi-Kai Hsiao
Chun-Hsiung LinChun-Hsiung Lin
Chun-Hsiung Lin
Hao-Chung KuoHao-Chung Kuo
Hao-Chung Kuo
Gallium nitride (GaN) possesses remarkable characteristics such as a wide bandgap, high critical electric field, robust antiradiation properties, and a high saturation velocity for high-power devices. These attributes position GaN as a pivotal material for the development of power devices. Among the various GaN-based devices, vertical GaN MOSFETs stand out for their numerous advantages over their silicon MOSFET counterparts. These advantages encompass high-power device applications. This review provides a concise overview of their significance and explores their distinctive architectures. Additionally, it delves into the advantages of vertical GaN MOSFETs and highlights their recent advancements. In conclusion, the review addresses methods to enhance the breakdown voltage of vertical GaN devices. This comprehensive perspective underscores the pivotal role of vertical GaN MOSFETs in the realm of power electronics and their continual progress.

13 November 2025 in Electronics
Verified
Journal Article
Open access
PDF file
SMSusmita Mistri
Susmita Mistri
CLCatherine Langpoklakpam
Catherine Langpoklakpam
SESurya Elangovan
Surya Elangovan
Hao-Chung KuoHao-Chung Kuo
Hao-Chung Kuo
This review examines recent advances in Gallium Nitride (GaN) power semiconductor devices and their growing impact on the development of high-efficiency power conversion systems. It explores innovations in device design, packaging methods, and gate-driving strategies that have improved both performance and reliability. Key metrics such as switching speed, conduction losses, thermal management, and device robustness are analyzed, supported by reliability assessment techniques including Double-Pulse Testing (DPT). The discussion extends to current market dynamics and strategic industry initiatives that have catalyzed widespread GaN adoption. These combined insights highlight GaN’s role as a transformative material offering compact, efficient, and durable power solutions while identifying challenges that remain for broader implementation across diverse industries.

28 February 2023 in Micromachines
Verified
Journal Article
Open access
PDF file
CLCatherine Langpoklakpam
Catherine Langpoklakpam
ALAn-Chen Liu
An-Chen Liu
NYNeng-Jie You
Neng-Jie You
MKMing-Hsuan Kao
Ming-Hsuan Kao
WHWen-Hsien Huang
Wen-Hsien Huang
Jia-Min ShiehJia-Min Shieh
Jia-Min Shieh
In this study, we report a low ohmic contact resistance process on a 650 V E-mode p-GaN gate HEMT structure. An amorphous silicon (a-Si) assisted layer was inserted in between the ohmic contact and GaN. The fabricated device exhibits a lower contact resistance of about 0.6 Ω-mm after annealing at 550 °C. In addition, the threshold voltage shifting of the device was reduced from −0.85 V to −0.74 V after applying a high gate bias stress at 150 °C for 10−2 s. The measured time to failure (TTF) of the device shows that a low thermal budget process can improve the device’s reliability. A 100-fold improvement in HTGB TTF was clearly demonstrated. The study shows a viable method for CMOS-compatible GaN power device fabrication.