Si-based On-chip Optical Interconnects

Shang WangECE423

12/16/06

Disadvantages of Electrical Interconnects

Scaling Problem —— ”Aspect Ratio” Limit

2

2

2 2 2 2

Total RC time constant:

Now scaling with factor:

, ,

Now Total RC time constant:

( ) ( )

l l

l l l l

l l l l l l

R C l

s

R R s l sl C C

R C l R s C sl R C l

The same!!!

2, 1R l A C l B RC A l

However, optical interconnects do not have such problem!

Other Advantages of Optical Interconnects

Timing Accuracy Design Simplification

• voltage isolation • Absence of wave reflection and impedance

matching • avoid inductive crosstalk• frequency independence

On-chip Optical Interconnect Data Path

Silicon Laser

Silicon Optical

Modulator

Silicon Waveguide

Si-based Photo Det

ector

Driver Amplifier

Electrical Logic Cell

Electrical Logic Cell

On-chip

Si-based Light Source——Raman Silicon Laser

Simulated Raman Scattering (SRS)

A reversely biased p-i-n diode to eliminate the TPA-induced FCA

Silicon Optical Modulator0 [ ]r

e h D FBox

N N V Vet t

e en N 0.8( )h hn N

2 effn L

metal-oxide-semiconductor (MOS) capacitor

Mach-Zehnder Interferometer (MZI)

Si-based Photo detector

SiGe multiple quantum wells (MQW)

Conclusion

The concept of optical interconnect brings a brilliant future for the dense interconnects to the silicon chips.

The recent achievement in Intel of the silicon laser, silicon optical modulator and silicon-based photodetector shows the potential of monolithic integration of silicon-based optoelectronics.

Thank you!