Engineering 1/f noise in porous silicon thin films for thermal sensing applications

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

The sensitivity of present-day thermal sensors operating in the long-wave infrared region, a critical range for night vision and other reconnaissance applications, is limited by the 1/f noise in the thermistor material, while their widespread applicability is restricted due to microfabrication incompatibilities with the standard processing for silicon-based microelectronics. Porous silicon films have a high temperature coefficient of resistance (TCR~2–10%K−1) and are compatible with microfabrication processes, making them suitable candidates for use in thermal sensors. In this work, the 1/f noise in porous silicon films in conjunction with TCR, both key parameters for high sensitivity thermal sensors are characterized. The inherent 1/f noise in these as-fabricated films is very high and increases significantly after exposure to atmosphere (oxidation). However, surface passivation at 600 °C, stabilises the film against atmospheric oxidation and reduces the 1/f noise level by orders of magnitude. Further, decreasing the porosity of passivated films from 90 to 40% decreased the 1/f noise by an order of magnitude. High TCR~6–7%K−1 along with low 1/f noise constant, K~10- 12 are obtainable with an optimised porosity~60–75% for films surface passivated at 600 °C. These results confirm great promise of porous silicon for low manufacturing cost, and higher sensitivity of the thermal sensors.

Original languageEnglish
Article number111302
JournalMicroporous and Mesoporous Materials
Volume324
DOIs
Publication statusPublished - Sept 2021

Fingerprint

Dive into the research topics of 'Engineering 1/f noise in porous silicon thin films for thermal sensing applications'. Together they form a unique fingerprint.

Cite this