Noise characteristics of lattice-matched InGaAs/InAlAs heterostructure p-i-n photodiodes

Summary form only given. The authors report the experimental characterization of a set of three InGaAs/InAlAs heterostructure p-i-n photodiodes. Current-voltage, capacitance-voltage, S-parameter, and noise data were collected at room temperature over a wide range of bias current and voltage and a function of incident light intensity. The first device consisted of 360 alternating, undoped, lattice-matched In_0.53Ga_0.47As and In_0.52Al_0.48As layers 30 AA wide, sandwiched between an n⁺ and a p⁺ absorption layer of In_0.53Ga_0.47As. In the second and third device the number of layers and the layer width were respectively 200 and 90 AA and 50 and 500 AA. The capacitance-voltage data indicate that, in the dark, the heterostructure photodiodes are depleted gradually when the reverse bias is increased, i.e. one quantum well at a time. As a result, two high-field depleted regions at the contacts and a low-field undepleted region in the center are formed. Upon illumination by a light-emitting diode (1350 nm), the p-i-n photodiodes show large excess noise levels up to 500 MHz. Beyond this frequency the 30-AA devices show full short noise at field strengths E where impact ionization and Zener tunneling are absent, 0\n\n\t\t