This paper reports the fabrication details of ion-implanted Si:P blocked-impurity band photodetectors with lateral structure. A set of performance data has been measured under the operating temperature of 5.5 K. The device exhibits good blocking characteristics with low dark current density under 10<sup>−4</sup> A/cm<sup>2</sup>. Linear black-body response has been observed at small bias voltage (1 V) and low temperature (5.5 K) with the peak responsivity of 0.8 A/W. The photocurrent (PC) spectra show response peak at 27.3 μm and extend to 40 μm (~7.5 THz), which indirectly proves the feasibility of the preparation of Si:P BIB detectors using ion implantation. In addition, other small features in the PC spectra are designated to associate with the photothermal ionization and the silicon phonon absorption processes. Our work provides an alternative convenient approach to fabricate Si:P BIB detector for far-infrared and terahertz radiation detection.
Avalanche photodiodes(APDs) have attracted more and more attention due to their single photon detection ability.
However, low dark current is a prerequisite for APDs which are used as single photon avalanche photodiodes (SPADs).In this work,Planar-type Separate Absorption Grading Charge Multiplication(SAGCM) InP/InGaAs APD are fabricated and
simulated with ISE-TCAD. We present a detailed analysis of dark current and gain experimentally and theoretically. The
effect of the generation-recombination process,the tunneling process,the surface leakage process and the multiplication
process on the total dark current are discussed.The dark current gain ratio (Id/M) is used to demonstrate the tunneling
current. Simulation results indicate that the thickness of multiplication and trap-assisted tunneling effect have a great
influence on the tunneling current:thin multiplication layer and traps will lead to a substantial increase in the tunneling current component, therefore appropriate multiplication layer thickness and low traps are necessary to obtain good APDs with low dark current. Compared with the simulation results,it shows that our APDs have low tunneling current even at
breakdown point.In addition, the distinctions between different process of dark current provide a good guidance for the
optimization of the APD.