Modulation transfer function and quantum efficiency correlation at long wavelengths (greater than 800 nm) in linear...

Area of Science:

• Optoelectronics
• Solid-state physics
• Image sensor technology

Background:

• Commercial linear silicon charge coupled imagers (CCIs) are widely used in imaging applications.
• Understanding their performance characteristics, such as spectral modulation transfer function (MTF), is crucial for optimizing image quality.
• Existing MTF theories often need refinement to accurately model real-world device behavior.

Purpose of the Study:

• To measure and compare the spectral MTF of multiple identical commercial CCIs.
• To develop and validate an MTF theory incorporating detector aperture and lateral carrier diffusion.
• To investigate the correlation between spectral MTF, quantum efficiency (QE), and minority carrier lifetime.

Main Methods:

• Experimental measurement of spectral MTF for several commercial CCIs.
• Theoretical modeling of MTF, including detector aperture effects and one-dimensional lateral carrier diffusion.
• Correlation analysis of spectral MTF, QE, and minority carrier lifetime across different CCIs.
• Model parameterization using carrier lifetime as a variable.

Main Results:

• A strong agreement was achieved between experimental MTF data and theoretical predictions with appropriate model parameters.
• A significant correlation was observed between long-wave (> 800-nm) MTF and spectral quantum efficiency (QE) across the tested CCIs.
• Minority carrier lifetime was identified as a critical parameter influencing both MTF and QE.

Conclusions:

• The developed MTF theory accurately describes the performance of commercial CCIs.
• Minority carrier lifetime is a key determinant of both spectral MTF and QE in silicon CCIs.
• This understanding facilitates improved design and performance prediction for imaging devices.