In-chip microstructures and photonic devices fabricated by nonlinear laser lithography deep inside silicon

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Silicon is crucial for microelectronics and integrated photonics.
• Current lithography limits 3D structure fabrication within silicon chips.
• There's a need for embedded optical elements and improved electronic-photonic integration.

Purpose of the Study:

• To demonstrate laser-based fabrication of complex 3D structures inside silicon.
• To enable the creation of novel photonic devices and functional microelements within silicon chips.
• To overcome limitations of current lithography for 3D silicon microfabrication.

Main Methods:

• Utilizing laser modification to create 1 µm-sized dots and rod-like structures within silicon.
• Leveraging the altered optical index of laser-modified silicon for photonic applications.
• Employing optional chemical etching to achieve desired 3D shapes.

Main Results:

• Successful fabrication of complex subsurface 3D structures in silicon.
• Demonstration of laser-modified silicon's potential for photonic devices due to altered optical index.
• Creation of microstructures for microfluidic cooling, vias, MEMS, photovoltaics, and photonics.

Conclusions:

• Laser-based fabrication offers a novel route to complex 3D structures within silicon.
• This technique enhances possibilities for integrated photonics, microfluidics, and microelectronic devices.
• The developed method provides a versatile platform for advanced silicon-based device engineering.