Multi-Gain-Stage InGaAs Avalanche Photodiode With Enhanced Gain and Reduced Excess Noise

Abstract

We report the design, fabrication, and test of an InGaAs avalanche photodiode (APD) for 950-1650 nm wavelength sensing applications. The APD is grown by molecular beam epitaxy on InP substrates from lattice-matched InGaAs and InAlAs alloys. Avalanche multiplication inside the APD occurs in a series of asymmetric gain stages whose layer ordering acts to enhance the rate of electron-initiated impact ionization and to suppress the rate of hole-initiated ionization when operated at low gain. The multiplication stages are cascaded in series, interposed with carrier relaxation layers in which the electric field is low, preventing avalanche feedback between stages. These measures result in much lower excess multiplication noise and stable linear-mode operation at much higher avalanche gain than is characteristic of APDs fabricated from the same semiconductor alloys in bulk. The noise suppression mechanism is analyzed by simulations of impact ionization spatial distribution and gain statistics, and measurements on APDs implementing the design are presented. The devices employing this design are demonstrated to operate at linear-mode gain in excess of 6 000 without avalanche breakdown. Excess noise characterized by an effective impact ionization rate ratio below 0.04 were measured at gains over 1 000.

Modeling and Optimization of Avalanche Photodiode Electrical Parameters Using Multiobjective Genetic Algorithm

“…Therefore, in order to get a global view of avalanche photodiode performance, new models, designs and optimization approaches are necessary. In this context, several CMOS APDs have been proposed and their characteristics have been modelled to gain a better understanding of their behavior [3][4][5].…”

Comparison of flash lidar detector options

“…E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 2 ; 6 3 ; 5 1 8 Δλ ¼ λ 0 Figure 4 indicates the required filter BW for typical material effective index n eff ¼ 2. The widest sensor FoV occurs when a single array images the entire area; the angular distance to the corner of the array is E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 3 ; 6 3 ; 4 2 2 θ c ¼ DAS sqrt½ðN 2 x þ N 2 y Þ∕4;…”

“…1 Interframe timing jitter of the 1064-nm-sensitive 128 × 32-format GMAPD array was reported to be about 500 ps, which may have been dominated by clock signal distribution issues in its readout integrated circuit (ROIC) rather than the fundamental timing performance of the GMAPD pixels themselves; timing jitter for 32 × 32-format arrays of 1550-nm-sensitive pixels was reported to be in the 150-to 200-ps range. 1 The 30-μm 2 InGaAs LMAPD pixels analyzed typically operate at linear gain M ¼ 20 with 0.2-nA dark current at 273 K, quantum efficiency (QE) of 80%, and an excess noise factor (F) parameterized by ionization coefficient ratio k ¼ 0.2, resulting in F ¼ 5.56 at M ¼ 20. Multistage InGaAs LMAPDs that operate at gains approaching M ¼ 1000 with excess noise parameterized by k ¼ 0.04 have been reported, but they are not a mature technology.…”

“…Multistage InGaAs LMAPDs that operate at gains approaching M ¼ 1000 with excess noise parameterized by k ¼ 0.04 have been reported, but they are not a mature technology. 2 Low excess noise LMAPDs made from AlInAsSb 3 and InAs 4 have also been reported, but, among the high-gain LMAPDs, electron-avalanche HgCdTe LMAPDs are the most mature. HgCdTe LMAPDs can be manufactured to respond efficiently from the ultraviolet (UV) to the mid-wavelength infrared (MWIR) and can have high linear gains up to 1000 or more, maintaining an excess noise factor F near 1.…”

Experimental investigation of the charge-layer doping level in InGaAs/InAlAs avalanche photodiodes

“…So optimal operating temperature in an imaging system is suggested to be around 240 K. Fig. 4 shows the I-V characteristic of a 1:65 Â 10 À3 cm 2 APD with a charge-layer doping level of 3:5 Â 10 17 cm À3 for operating temperatures of 294 K and 140 K. Around 9 V reverse bias the photo-current level reaches a plateau from which we can identify the so-called ''punch-through'' voltage [16]. At that point, the depletion region has penetrated the charge layer and the collection of photo-generated carriers from the adjacent low-bandgap absorber and their injection into the multiplication region is at a maximum value.…”