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.

Technology can facilitate the provision of healthcare to older adults. Wearable devices are thus increasingly prevalent amidst perpetual component miniaturization and cost reduction. This study aimed to determine whether existing application (app) interfaces are suitable for older adults by comparing the perceived usability and emotional reactions of younger users and older users to the health information display formats of wearable interfaces. Based on the outcomes of a literature review and expert recommendations, four health display interfaces—text, diagram, image, and animation—were developed and revised. Thirty respondents in Miaoli, Taiwan, were invited to participate in a questionnaire and interviews. The collected data were analyzed and discussed to develop design recommendations. The findings of this study were as follows: (1) the diagram interface had the lowest performance; (2) the respondents preferred the animation interface, which produced strong affective valence, thereby suggesting that animation generated positive emotions, yielding a result consistent with expert views and existing design principles; and (3) older users were more accepting of the text interface than the younger users, who exhibited negative emotions toward the text interface, highlighting a significant generation gap.

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In this letter, a high-k composite oxide composed of La 2 O 3 and HfO 2 is investigated for n-In 0.53 Ga 0.47 As metal-oxide-semiconductor (MOS) capacitor application. The composite oxide was formed by depositing five layers of La 2 O 3 (0.8 nm)/HfO 2 (0.8 nm) on InGaAs with post deposition annealing at 500°C. The MOS capacitors fabricated show good inversion behavior, high capacitance, low leakage current, with excellent interface trap density (D it ) of 7.0 × 10 11 cm −2 eV −1 , small hysteresis of 200 mV and low capacitance equivalent thickness of 2.2 nm at 1 kHz were also achieved. Index Terms-HfO 2 , InGaAs, La 2 O 3 , metal-oxide-semiconductor (MOS), molecular beam deposition (MBD), post deposition annealing (PDA).