10 GHz bandwidth of Si avalanche photodiode fabricated by standard 0.18 μm CMOS process

Silicon avalanche photodiode was fabricated by O.lSjum CMOS process and was characterized. The bandwidth of 10GHz with the sensitivity of 0.1 AW was achieved with the electrode spacing of 0.84/μm and the detection area of 10x10/μm2. © 2014 Engineers Australia

Optimizing silicon avalanche photodiode fabricated by standard CMOS process for 8 GHz operation

Silicon avalanche photodiode (APD) was fabricated by standard 0.18 μm CMOS process. The current-voltage characteristic and frequency response was measured for the APD with and without guard ring. With the guard ring around the perimeter of the diode junction, it shows a better performance for the maximum bandwidth but in contrast lower in responsivity. To enhance the bandwidth, the detection area and the PAD size for RF probing are optimized to 10 × 10 μm2 and 30 × 30 μm2, respectively, to decrease the device capacitance, the spacing of interdigital electrode is narrowed to 0.84 μm to decrease carrier transit time, and by cancelling the carriers photo-generated in the deep layer and the substrate because the carriers are slow diffusion carriers. As a result, the maximum bandwidth of 8 GHz was achieved along with a gain-bandwidth product of 280 GHz. © 2015 IEEE

Characterizing Silicon Avalanche Photodiode Fabricated by Standard 0.18µm CMOS Process for High-Speed Operation

nMOS-type and pMOS-type silicon avalanche photodiodes (APDs) were fabricated by standard 0.18µm CMOS process, and the current-voltage characteristic and the frequency response of the APDs with and without guard ring structure were measured. The role of the guard ring is cancellation of photo-generated carriers in a deep layer and a substrate. The bandwidth of the APD is enhanced with the guard ring structure at a sacrifice of the responsivity. Based on comparison of nMOS-type and pMOS-type APDs, the nMOS-type APD is more suitable for high-speed operation. The bandwidth is enhanced with decreasing the spacing of interdigital electrodes due to decreased carrier transit time and with decreasing the detection area and the PAD size for RF probing due to decreased device capacitance. The maximum bandwidth was achieved with the avalanche gain of about 10. Finally, we fabricated a nMOS-type APD with the electrode spacing of 0.84µm, the detection area of 10×10µm2, the PAD size for RF probing of 30×30µm2, and with the guard ring structure. The maximum bandwidth of 8.4GHz was achieved along with the gain-bandwidth product of 280GHz

High speed and high responsivity avalanche photodiode fabricated by standard CMOS process in blue wavelength region

金沢大学理工研究域フロンティア工学系Quadrant silicon avalanche photodiodes (APDs) were fabricated by standard 0.18µm CMOS process, and were characterized at 405nm wavelength for Blu-ray applications. The size of each APD element is 50×50µm2. The dark current was 10pA at low bias voltage, and low crosstalk of about -80dB between adjacent APD elements was achieved. Although the responsivity is less than 0.1A/W at low bias voltage, the responsivity is enhanced to more than 1A/W at less than 10V bias voltage due to avalanche amplification. The wide bandwidth of 1.5GHz was achieved with the responsivity of more than 1A/W, which is limited by the capacitance of the APD. We believe that the fabricated quadrant APD is a promising photodiode for multi-layer Blu-ray system