Photonics

Silicon photonics

Silicon photonics has applications in optical communication, sensing, Biomedical, AR/VR applications, automotive (LIDAR), Artificial intelligence (AI) & Machine learning (ML), High-performance computing

Photonic integrated circuits (PICs) can be fabricated by conventional Si fabrication techniques.

Key fabrication techniques:

• Substrates: SOI wafers

• Deposition: Sputtering, Chemical Vapor Deposition (CVD), specially PECVD, Molecular Beam Epitaxy (MBE),

  thermal oxidation for under cladding layer (Cladding oxide deposition)

• Photolithography: E-beam, DUV, Nanoimprint lithography (NIL)

• Etching: Inductively Coupled Plasma (ICP) dry etching, Focused Ion Beam (FIB) etching (Oxide etch back)

• Lift off

• Under Bump metallization (UBM)

• TSV 

• 2.5D/ 3D integration

• CMP Chemical Mechanical polishing & wafer bonding

• Annealing

Using the above techniques, Si Waveguides, ring resonators, couplers, modulators, etc., can be fabricated.

AR (Augmented reality)/ VR (Virtual reality)/ Head up displays

Gratings for light modulation

• Reflective gratings

• Diffractive grating

• Blazed grating

• Slanted gratings

• Binary grating

  Techniques used

• Nanoimprinting Directly on polymer

• Photolithography and etching on glass

Other Microoptoelectromechanical systems (MOEMS) or optical MEMS based sensors.