Silicon Photonics Photo-Detector Announcement. Mario Paniccia Intel Fellow Director, Photonics Technology Lab

Transcription

1 Silicon Photonics Photo-Detector Announcement Mario Paniccia Intel Fellow Director, Photonics Technology Lab

2 Agenda Intel s Silicon Photonics Research 40G Modulator Recap 40G Photodetector Announcement Vision of Future Terascale Platforms Summary 2

3 Photonics: The technology of emission, transmission, control and detection of light (photons) aka fiberoptics & opto-electronics Today: Most photonic devices made with exotic materials, expensive processing, complex packaging Silicon Photonics Vision: Research effort to develop photonic devices using silicon as base material and do this using standard, high volume silicon manufacturing techniques in existing fabs Benefit: Bring volume economics to optical communications 3

4 Intel s Silicon Photonics Research Continuous Wave Silicon Raman Laser (Feb 05) Electrically Pumped Hybrid Silicon laser (September 2006) 40 Gb/s TODAY 1GHz ( Feb 04) 1GHz 10 Gb/s (Apr (Apr 05) 40 Gb/s (Jul 07) Achieved 40 Gb/s for most devices Next: Focus on integration 4

5 40Gb/s Silicon Laser Modulator Encodes data on a light beam at 40Gbps Fastest Si modulator on par with fastest modulators available commercially 5

6 Guiding Light Communications Intel Litho transistor Silicon Silicon oxide oxide Ex: Rib waveguide Silicon Bandgap is Transparent to infra Red light (λ>1.1um) Can guide light in Silicon But does not absorb/detect 6

7 How do we absorb light: Use Germanium Bandgap engineering i.e. add another material Ge is the most promising candidate: High absorption for wavelengths of interest CMOS compatible Silicon Silicon Germanium oxide oxide Ex: Rib waveguide bigger is better 7

8 Challenge: Strain Crystal structure of germanium is 4% larger than silicon. This introduces strain when Ge is grown on Si. Result crystal lattice dislocations excess noise Bulk Films of Si and Ge Strained Si 1-x Ge x on Si Relaxed Si 1-x Ge x on Si a Ge ~.565 nm a Si ~.543 nm misfit dislocation Misfit dislocations typically create threading dislocations which h degrade device performance - dark current (I( dk ) goes up. By optimizing the thermal growth process parameters we can minimize defects impact. 8

9 Photodetector Design SEM Cross-Section N-Ge i-ge P-contact P-contact Si Si SiO SiO 2 2 (BOX) Si Si (Substrate) Passivation N-contact Ge Ge Rib Rib waveguide P-contact P-contact 9

10 World s best Waveguide Photodetector Performance Performance combines Speed = bits per second Efficiency = % of photons detected Noise = dark current ) Results: 40 Gb/s operation 95% efficient (up to λ ~1.56um) < 200nA of dark current 10

11 Experimental Results: Normalized response (db) ~ 31 GHz roll-off 1G 1 10G Frequency (GHz) 31 GHz Optical Bandwidth 40 Gb/s Data transmission World s Best Performing Ge Waveguide Photodetector 11

12 Tera-leap to Parallelism: ENERGY-EFFICIENT PERFORMANCE Hyper-Threading Instruction level parallelism Dual Core 10 s to 100 s of cores Quad-Core The days of single-core chips Era of Tera-Scale Computing More performance Using less energy TIME All this compute capability may require high speed optical links 12

13 Future Physical I/O for a Tera-scale Servers Core-Core: Core: On Die Interconnect fabric Memory: Package 3D Stacking Chip-Chip: Chip: Fast Copper FR4 or Flex cables Memory Memory Tb/s of I/O Tera-scale CPU Memory CPU 2 Memory Integrated Tb/s Optical Chip 13

14 Silicon Photonics for Computing Future: A Terabit Optical Chip Optical Fiber Multiplexor 25 modulators at 40Gb/s 25 hybrid lasers A future integrated terabit per second optical link on a single chip 14

15 Silicon Photonics for Computing Integrating into a Tera-scale System This transmitter would be combined with a receiver Rx Tx Which could then be built into an integrated, silicon photonic chip 15

16 Silicon Photonics for Computing Integrating into a Tera-scale System This integrated silicon photonic chip could then be integrated And this board could be into computer boards integrated into a Tera- scale system Integration of photonic devices will be critical in future applications. 16

17 Summary Worlds Best performing Silicon Germanium Photo-detector - Capable of operating at 40 Gbps - Low dark current and great responsivity - Details to be presented at Group IV conference Tokyo Japan Sept 20 th Background - Silicon is transparent to Infrared light and good for routing light - Germanium must be added to allow Silicon to absorb light - Intel used a unique process to grow Germanium on Silicon and produce an efficient Silicon Germanium photo-detector Vision - Build highly integrated Si Photonics chips for optical communication - Build using high-volume, low cost manufacturing processes - Enables terabit optical links 17

18 Links Silicon Photonics at Intel site - Scale/1419.htm Blog about recent modulator advance - ulator.html 18

19 What We are Announcing Worlds Best performing Silicon Germanium Photodetector - Capable of operating at 40 Gbps - Low dark current and great responsivity - Details to be presented at Group IV conference Tokyo Japan Sept 20 th Background - Silicon is transparent to Infrared light and good for routing light - Germanium must be added to allow Silicon to absorb light - Intel used a unique process to grow Germanium on Silicon and produce an efficient Silicon Germanium photo-detector Vision - Build highly integrated Si Photonics chips for optical communication - Build using high-volume, low cost manufacturing processes - Enables terabit optical links for tera scale platforms 19

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21 DC Photodetector Performance 10-2 Current (A) Dark current Photocurrent Voltage (V) Quantum efficiency (%) μm long PD 100 μm long PD Wavelength (nm) Dark current of photodetector is still below noise floor of amplification circuitry. Quantum efficiency is excellent at ~95%. 21