Development of an integrated high speed silicon PIN photodiode sensor

A silicon integrated PIN photodiode sensor, combined with a bipolar IC on same substrate (that is, a PIN photo integrated circuit sensor: PIN-PICS), was developed by employing a high resistive P^-- epitaxial layer on a P⁺ substrate for creating a high speed and high optical responsivity PIN photodiode. We fabricated this device based on two special techniques: (1) the PIN photodiode is formed on a P^--/P⁺ substrate structure and isolated from bipolar components by the combination of a P^--well and a trench isolation, and (2) bipolar components are formed by the doubly diffused buried layer of the P^--well and the N⁺ collector wall. All of these components, such as npn and pnp transistors, were arranged within the lightly doped P^--well regions. From several kinds of trial samples, the following results were obtained. The PIN photodiode with 0.145 mm² active area indicated 680 MHz for cutoff frequency at 10 V bias with 830 mn radiation. In the case of 20 V bias, this value exceeded 1.5 GHz. This PIN-PICS was applied to a 10 Mbit/s burst mode compatible optical monolithic receiver and a transimpedance amplifier, and it has shown the expected results