High speed Si-OEIC(OPIC) for optical pickup

An optical pickup OPIC(TM) with a built-in highspeed split photodiode and new device structure, has been developed. We have successfully fabricated the OPIC with a cutoff frequency of 56MHz for 780nm wavelength radiation. We developed hologram laser[1][2][3] in which a semi-conductor 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 61MHz for 780nm wavelength radiation. This photodiode has a double-layer anti-reflection film consisted of a silicon oxide film as the first layer and a silicon nitride film as the second layer. In this paper, we show the structure of this new device, its fabrication process and the performance of the photodiode and OPIC.