High-Current Back-Illuminated Partially Depleted-Absorber p-i-n Photodiode With Depleted Nonabsorbing Region

• Published in: IEEE transactions on microwave theory and techniques 2010-11, Vol.58 (11), p.3154-3160
• Main Authors: Sakai, K, Ishimura, E, Nakaji, M, Itakura, S, Hirano, Y, Aoyagi, T
• Format: Article
• Language: English
• Subjects: Capacitance; Depletion; Electronics; Frequency response; Heat transfer; Microwaves; Noise levels; p-i-n photodiodes (PDs); Photoconductivity; Photodiodes; photodiodes (PDs); PIN photodiodes; Radio frequencies; Radio frequency; Solids; Space charge; Thermal energy; Thermal resistance
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2010.2075470

We demonstrate a high-current back-illuminated InGaAs/InP p-i-n photodiode (PD), whose depleted region comprises partially depleted-absorbing, depleted-absorbing, and depleted-nonabsorbing layers to increase RF power output. The back-illuminated PD has an advantage of small thermal resistance between a photoabsorber and a heat sink for avoiding catastrophic thermal failure. The thermal resistance decreases with an increase in the detecting area; however, it simultaneously increases the capacitance, imposing a limitation on the RF response. To reduce the capacitance, we have incorporated a depleted-nonabsorbing layer into a partially depleted absorber PD structure that photogenerated electrons can drift trough. We have fabricated two samples, one with a detecting area of 50 μm, and the other with a detecting area of 70 μm in diameter. Both PDs show high RF power outputs of 28.7 and 29.0 dBm at a frequency of 5 GHz, and 25.7 and 26.7 dBm at each -3-dB frequency of 10.5 and 7 GHz, respectively.