Fabrication and characterization of novel high-speed InGaAs/InP uni-traveling-carrier photodetector for high responsivity

Abstract

A top-illuminated circular mesa uni-traveling-carrier photodetector (UTC-PD) is proposed in this paper. By employing Gaussian graded doping in InGaAs absorption layer and InP depleted layer, the responsivity and high speed response characteristics of the device are optimized simultaneously. The responsivity up to 1.071 A/W (the external quantum efficiency of 86%) is obtained at 1550 nm with a 40-µm diameter device under 10-V reverse bias condition. Meanwhile, the dark current of 7.874 nA and the 3-dB bandwidth of 11 GHz are obtained with the same device at a reverse bias voltage of 3 V.

Advances in High–Speed, High–Power Photodiodes: From Fundamentals to Applications

“…Therefore, a thinner absorber can be used in UTC-PD for a larger transit-time-limited bandwidth without sacrificing the RC-limited bandwidth by welldesigning a relatively thick collector. Additionally, some references show the detailed theoretical and experimental analysis of the characteristics for PIN-PD and UTC-PD, including energy band, electrical field, doping mechanism, optimization of absorber and collector, bandwidth, responsivity, saturation, and output power [56][57][58][59][60][61][62] as well as transient response [63], dark current [64,65], and P-contact shapes [66]. According to the abovementioned bandwidth equations and the values from Table 1, the 3-dB bandwidths for PIN-PD and UTC-PD can be calculated as shown in Figure 5a, including the assumed values during the calculation.…”

Modeling capacitance–voltage characteristic of TiW/p-InP Schottky barrier diode

“…The InP is the III-V compound semiconductor, and has been extensively used in many areas recently. [1,2] Compared with Si and GaAs, [3][4][5] metal film deposited on InP material has attracted a great deal of attention because of its high electron mobility, high-saturation drift velocity, direct energy band gap, and radiation hardness. The interface of the MS contact is very important for the device performances.…”