Silicon photonics
What is the main reason silicon photonics is said to be well suited to mass production in semiconductor fabs?
- AIt can use the same silicon materials as CMOS, along with large-diameter wafers and equipment and processes such as lithography and etching
- BWaveguide dimensions are a few nm, the same as leading-edge logic, so the latest EUV lithography can be used directly
- CCompound semiconductors such as InP can also be handled freely in CMOS fabs exactly like silicon
Show answer and explanation
Answer: A. It can use the same silicon materials as CMOS, along with large-diameter wafers and equipment and processes such as lithography and etching
In silicon photonics, waveguides are formed on SOI wafers by lithography and dry etching, modulator pn junctions by ion implantation, and Ge photodetectors by selective epitaxial growth, with electrodes connected by metal interconnects. All of these use materials and processes established in CMOS fabs, enabling mass production with high precision and reproducibility on 200 mm and 300 mm wafers. Waveguide widths are a few hundred nm, so leading-edge logic scaling is unnecessary and DUV lithography is sufficient. On the other hand, compound semiconductors such as InP raise contamination concerns and are generally handled separately from CMOS fabs.