Ge is considered to have several advantages over Si due to its high mobility
and direct bandgap, which makes it ideal for optoelectronic applications.
The manipulation of bulk Ge into small structures has drawn a lot of interest
due to the numerous distinctive properties caused by the impact of size
quantization. Porous materials are ideally suited for sensing application due
to theirlarge effective surface area beside the fabrication of porous is simple.
In this work, porous Ge is investigated for potential visible to near-infrared
metal semiconductor metal (MSM) photodetector. The study investigated the
performance and characterization of porous Ge (P-Ge) on Si substrate at
different depths of porous (1 µm, 0.25 µm and 0.01 µm) by using SILVACO
Athena and Atlas device simulator. Athena process simulator was used to
construct the device structure while ATLAS device simulator was used to
characterize the electrical and optical characteristics’ effect on the different
sizes of the P-Ge fabricated on the Si substrate. The comparison of the porous
devices were then made with bulk Ge devices (bulk Ge-on-Si, bulk Ge-onGe) to identify the exploitation of porosity resulted in a significant
performance of current gains, spectral response, Schottky barrier height,
and also photo and dark current. It was found that the P-Ge at 0.01 µm depth
showed an improved current gain compared to other porous structures while
bulk Ge-on-Si obtain greater current gain than bulk Ge-on-Ge. This evidence
indicates that P-Ge produces a better performance of MSM photodetector
than the bulk device. The spectral response of P-Ge shows a peak response
at 800nm, which is the near-infrared (IR) region supporting the feasibility of
the P-Ge to be utilized for visible to near IR photodetection.