High speed Si-OEIC (OPIC) for optical pickup

Abstract

An optical pickup OPIC/sup TM/ with a built-in high-speed split photodiode and new device structure, has been developed. We have successfully fabricated the OPIC with a cutoff frequency of 56 MHz for 780 nm wavelength radiation. We developed hologram laser in which a semiconductor laser, the OPIC and hologram glass are set as a unit, too. The development of these OPIC were made possible by the high-speed split photodiode, which have very high resistive Si substrate for reduction of the junction capacitance. The cutoff frequency of the high speed split photodiode thus realized is 61 MHz for 780 nm wavelength radiation. This photodiode has a double-layer anti-reflection film consisting of a silicon oxide film as the first layer and a silicon nitride film as the second layer. We show the structure of this new device, its fabrication process and the performance of the photodiode and OPIC.