Avalanche Amplification in Silicon Lateral Photodiode Fabricated by Standard 0.18 m CMOS Process

A silicon lateral photodiode is fabricated by standard 0.18µm CMOS process, and the optical detection property is characterized. The photodiode has interdigital electrode structure with the electrode width of 0.22µm and the electrode spacing of 0.6µm. At 830nm wavelength, the responsivity is 0.12A/W at low bias voltage, and is increased to 0.6A/W due to avalanche amplification. The bandwidth is also enhanced from 12MHz at low bias voltage to 100MHz at the bias voltage close to the breakdown voltage.