From EBIC images to qualitative minority carrier diffusion length maps

Area of Science:

• Materials Science
• Semiconductor Physics
• Device Engineering

Background:

• Accurate characterization of semiconductor devices is crucial for performance optimization.
• Minority carrier diffusion length is a key parameter influencing device efficiency.
• Existing methods for diffusion length mapping can be complex or limited in scope.

Purpose of the Study:

• To introduce a novel and efficient method for mapping minority carrier diffusion length.
• To apply this method to cross-sectional samples of semiconductor devices.
• To validate the accuracy and utility of the proposed technique.

Main Methods:

• Utilizes a single Electron-Beam Induced Current (EBIC) acquisition.
• Analyzes the variation in the EBIC signal slope at each scanned point.
• Applies the method to a pinned photodiode array on low-doped silicon epitaxy.

Main Results:

• Successfully extracted an electron diffusion length map for the pinned photodiode array.
• The obtained diffusion length map aligns well with the device's doping profile.
• Quantitative confirmation of the measured diffusion length map was achieved through TCAD simulations.

Conclusions:

• The presented EBIC-based method provides an effective approach for minority carrier diffusion length mapping.
• The technique demonstrates accuracy and reliability, validated by experimental data and simulations.
• The study discusses the advantages and limitations of this novel characterization method.