Filterless optical oxygen sensor based on a CMOS buried double junction photodiode.

Area of Science:

• Integrated circuit design
• Optoelectronics
• Semiconductor device physics

Background:

• Optical signal detection often requires bulky and expensive off-chip filters.
• Extracting desired signals from optical noise is a significant challenge in many applications.
• Existing solutions can be power-hungry and costly to manufacture.

Purpose of the Study:

• To present a novel custom CMOS integrated circuit (IC) for optical signal detection and processing.
• To eliminate the need for external optical filters through on-chip integration.
• To achieve low-cost fabrication and low power consumption.

Main Methods:

• Design and fabrication of a custom CMOS IC incorporating a buried double junction (BDJ) photodiode.
• Integration of on-chip signal processing circuitry for enhanced signal extraction.
• Utilizing standard commercial fabrication processes without post-processing.

Main Results:

• Successful integration of a BDJ photodiode and signal processing on a single CMOS IC.
• Demonstrated elimination of the requirement for off-chip optical filters.
• Achieved improved signal extraction from optical background noise.
• Verified low-cost fabrication potential due to standard CMOS processes.
• Confirmed low operating and standby power consumption.

Conclusions:

• The custom CMOS IC with BDJ photodiode offers a compact, efficient, and cost-effective solution for optical signal detection.
• On-chip signal processing significantly enhances signal quality by mitigating background noise.
• The integration enables reduced system complexity, power consumption, and manufacturing costs.