MIS-Like Structures with Silicon-Rich Oxide Films Obtained by HFCVD: Their Response as Photodetectors
Gabriel Omar Mendoza Conde1, José Alberto Luna López1, Zaira Jocelyn Hernández Simón1
1Centro de Investigaciones en Dispositivos Semiconductores (CIDS-ICUAP), Benemérita Universidad Autónoma de Puebla (BUAP), Col. San Manuel, Cd. Universitaria, Av. San Claudio y 14 Sur, Edificios IC5 y IC6, Puebla 72570, Mexico.
Sensors (Basel, Switzerland)
|May 28, 2022
Summary
Silicon-rich oxide (SRO) based MIS structures function as effective photodetectors. These devices show significant current increases under illumination, demonstrating potential for optical sensing applications.
Area of Science:
- Materials Science
- Semiconductor Physics
- Device Engineering
Background:
- Metal-insulator-semiconductor (MIS) structures are fundamental components in electronic devices.
- Silicon-rich oxide (SRO) thin films offer unique electrical and optical properties.
- Photodetectors are crucial for various sensing and imaging applications.
Purpose of the Study:
- To investigate the photodetector characteristics of MIS-type structures utilizing SRO thin films.
- To analyze the electrical transport mechanisms and photoresponse of these SRO-based MIS devices.
- To evaluate the performance metrics of SRO MIS structures as potential photodetectors.
Main Methods:
- Deposition of SRO thin films using hot filament chemical vapor deposition (HFCVD).
- Fabrication of MIS-type structures.
- Electrical characterization including current-voltage (I-V), current-time (I-t), and current-wavelength (I-λ) measurements.
- Analysis of conduction mechanisms (hopping and ohmic).
Main Results:
- SRO MIS structures exhibited a significant increase in illumination current (up to three orders of magnitude) compared to dark current.
- Photogenerated current reached 25 μA at -4 V reverse bias.
- Hopping and ohmic conduction mechanisms were identified.
- Key photodetector parameters included responsivity (254 mA/W), specific detectivity (2.21 × 10^11 cm Hz^1/2 W^-1), and NEP (49 pW) at 535 nm.
- Good switching behavior with rise and fall times between 120-150 ms was observed.
Conclusions:
- SRO-based MIS structures demonstrate promising performance as photodetectors.
- The observed characteristics suggest suitability for optical sensing in the visible spectrum (420-590 nm).
- The study highlights the potential of HFCVD-deposited SRO films for optoelectronic device applications.
