Mapping and simulation of processing-induced mechanical strain in GaAs laser diodes

Area of Science:

• Semiconductor device fabrication
• Optoelectronics
• Materials science

Background:

• Gallium arsenide (GaAs)-based laser diodes are crucial optoelectronic devices.
• Mechanical strain during fabrication can impact laser diode performance.
• Understanding strain distribution is essential for optimizing device design.

Purpose of the Study:

• To investigate the mechanical strain build-up during the fabrication of GaAs-based laser diodes.
• To quantify strain introduced by P contact metal thin films.
• To identify critical parameters influencing strain in laser diodes.

Main Methods:

• Characterization of test samples using photoluminescence (PL) polarization mapping from the facet.
• Comparison of experimental strain maps with finite element simulations.
• Fabrication of ridge waveguide structures with representative metal thin films.

Main Results:

• Experimental strain maps were generated, revealing strain distribution.
• Finite element simulations were used to validate experimental findings.
• The amount of strain introduced by the metal thin film was quantified.
• Key parameters influencing strain were identified.

Conclusions:

• The study quantifies strain in GaAs laser diode fabrication.
• Identified critical parameters enable a design strategy for improved laser diodes.
• This research paves the way for high-performance laser diode development.