Epistar Corporation

National Science Council

Yi-Chih Lin

Shang-Ju Tu

Shyh-Lin Tsao

Hao-Chih Yu

Ming-Chin Chen

This application provides a high power semiconductor device, which is characterized by forming two diodes connected in parallel and a schottky contact on a channel layer to lower the turn-on voltage and turn-on resistance of the high power semiconductor device at the same time and to enhance the breakdown voltage.

High power semiconductor device

A semiconductor power device includes a substrate, an active region having a recess and disposed on the substrate, a first conductivity type semiconductor layer disposed on the recess and devoid of overlapping with the recess, a gate electrode disposed on the active region wherein a portion of the gate electrode is disposed in the recess, a dielectric layer between the active region and the gate electrode, and a two dimension electron gas formed in the active region.

Semiconductor power device

A coherent optical communication receiver of a satellite optical communication system, having a telescope, an automatic frequency control circuit and a frequency shift keying demodulator. The automatic frequency control circuit has a local oscillating laser, a light polarization controller, a optical coupler, a photo-detector, a microwave matching network, a microwave mixer, a frequency discriminator and a low pass frequency filter. The coherent optical communication receiver can receive a frequency control signal of a distant laser signal to perform a heterodyne receiving between the emitter and the receiver distant away from each other. With the consideration of the decay of vibration and atmosphere, the quality of the satellite optical communication can still be maintained. The structure and fabrication of the receiver are simple with a low fabrication cost, and the receiver is suitable for being applied to high speed satellite communication system.

Growing community of inventors

Hsinchu, Taiwan

Yi-Chih Lin