Laser Thermal Processing of Group IV Semiconductors for Integrated Photonic Systems

Abstract

In the quest to expand the functionality and capacity of group IV semiconductor photonic systems, new materials and production methods are constantly being explored. In particular, flexible fabrication and postprocessing approaches that are compatible with different materials and allow for tuning of the components and systems are of great interest. Within this research area, laser thermal processing has emerged as an indispensable tool that can be applied to enhance and/or modify the material, structural, electrical and optical properties of group IV elemental and compound semiconductors at various stages of the production process. Herein, the recent progress made in the application of laser processing techniques to develop integrated semiconductor systems in both fiber‐ and planar‐based platforms is evaluated. Laser processing has allowed for the production of semiconductor waveguides with high crystallinity in the core and low optical losses, as well as postfabrication trimming of device characteristics and direct writing of tunable strain and composition profiles for bandgap engineering and optical waveguiding. For each platform, the current challenges and opportunities for the future development of laser‐processed integrated semiconductor photonic systems are presented.

Semiconductor Multimaterial Optical Fibers for Biomedical Applications

“…As the functional materials inside fibers can be chemically deposited in independent stages, enabling fibers to possess design flexibility, fibers fabricated by the HPCVD technique can be further utilized to design fiber-integrated devices, including photoconducting detectors [ 96 ], fibers for infrared laser transmission [ 97 , 98 , 99 ], fibers for thermal sensation [ 100 ], radial fiber lasers, and wearable 2D and 3D array light detectors [ 101 ]. Although the length of fiber fabricated by HPCVD does not seem to be as scalable as that manufactured by drawing, semiconductor layers of 10 m in length have been accomplished, and larger lengths are conceivable [ 102 ].…”

Comparison of 20- to 1000-Hz pulsed laser and continuous laser ablation of single-crystal germanium wafers

“… – 3 Most traditional semiconductor material processing processes are inefficient and have a low-yield rate owing to variances in various materials and their inherent brittleness. Because of its high accuracy, noncontact nature, and ease of control, laser processing has key applications in wafer cutting, scribing, ablation, and slotting 4 , 5 . Laser processing is primarily a process of laser–material interaction, and the laser–material interaction mechanism must be thoroughly explored to increase the efficiency and quality of the process.…”

“…Because of its high accuracy, noncontact nature, and ease of control, laser processing has key applications in wafer cutting, scribing, ablation, and slotting. 4,5 Laser processing is primarily a process of laser-material interaction, and the laser-material interaction mechanism must be thoroughly explored to increase the efficiency and quality of the process.…”

Localised structuring of metal-semiconductor cores in silica clad fibres using laser-driven thermal gradients

“…The lower temperature systems are able, for example, to incorporate previously fabricated diodes into the preform, connected by wire that is spooled into the fibre as it draws 17 , while purely inorganic systems such as silicon-in-silica fibres perform a variety of optical functions, can be used at higher temperatures, and are chemically robust. Post-processing of as-drawn fibre has been employed to improve the properties of core materials, in particular for Group IV semiconductors 18 , which are typically inhomogeneous and/or polycrystalline as drawn, with impurities at the grain boundaries 19 . Dramatic improvement in the optical transparency 20 , 21 of silicon core fibres has been made, and non-linear optical behaviour is now well established 22 .…”

“…The lateral segregation method can also be used for fibres drawn with a mixture of semiconductors having a pseudo-eutectic phase diagram, such as Si-GaSb 18 . In Fig.…”