In this paper, 256 elements front-illuminated InGaAs mesa detector arrays were fabricated based on doped-InGaAs
absorbing layer in MOCVD-grown p-InP/n-InGaAs/n-InP
double-heterostructure epitaxial materials. The processing
includes mesa-making, SiNx passivation, growth of electrodes and so on. The current-voltage, capacitance-voltage
characteristics and response spectrum of the detector were measured. The results indicate that the InGaAs detector has
typical dark current about 0.9 nA at 0.5 V reverse-bias voltage, a capacitance as low as 49 pF at 1 reverse-bias voltage,
and the peak wavelength and cutoff wavelength at 1.57μm and 1.68μm respectively. The InGaAs detector arrays were
connected with two CTIA-structured L128 read-out integrated circuits, and the response signal and noise were obtained.
At room temperature, the mean peak detectivity of the InGaAs focal plane arrays (FPAs) is 1.9×1012
cmHz1/2W-1, and the
non-uniformity of response is superior to 6%. The laser beam induced current (LBIC) technique was used to investigate
the crosstalk and photoactive area of the InGaAs detectors. Its results indicate that there is little crosstalk between two
neighbor InGaAs detectors, about 7%. The photoactive area of InGaAs detector extends about 4.5 μm, and the reason is analyed in the paper.