This paper proposes a new three-dimensional (3D) photolithography technology for a high-resolution micropatterning process on a fiber substrate. A brief review on the lithography technology of the non-planar surface is also presented. The proposed technology mainly comprises the microfabrication of the 3D exposure module and the spray deposition of thin resist films on the fiber. The 3D exposure m...
The development of SiC and GaN power semiconductor market The current state of SiC technology and market, and the development trend in the next few years. The SiC device market is promising. Sales of Schottky barrier diodes have matured and MOSFET shipments are expected to increase significantly over the next three years. According to Yole Développement analysts, SiC is very mature in terms of dio...
In this paper, using a fully-coupled, three-dimensional electro-thermal device simulator, we study the mechanism of efficiency degradation at high current operation in planar GaN-based light emitting diodes (LED). In particular, the improvement of the efficiency degradation using thicker conductive GaN substrates has been demonstrated. First, it is found that local Joule heating inside thin conduc...
For homogeneous materials, the ultrasonic immersion method, associated with a numerical optimization process mostly based on Newton's algorithm, allows the determination of elastic constants for various synthetic and natural composite materials. Nevertheless, a principal limitation of the existing optimization procedure occurs when the considered material is at the limit of the homogeneous hypothe...
The bonding-temperature-dependent lasing characteristics of 1.5 a µm GaInAsP laser diode (LD) grown on a directly bonded InP substrate or Si substrate were successfully obtained. We have fabricated the InP substrate or Si substrate using a direct hydrophilic wafer bonding technique at bonding temperatures of 350, 400, and 450 °C, and deposited GaInAsP or InP double heterostructure layers on this I...
We have improved the efficiency of photoconductive antennas (PCAs) using low-temperature-grown GaAs (LT-GaAs). We found that the physical properties of LT-GaAs photoconductive layers greatly affect the generation and detection characteristics of terahertz (THz) waves. In THz generation, high photoexcited carrier mobility and the presence of a few As clusters in the LT-GaAs are two important factor...