The Cornerstone Project:

Transcription

1 The Cornerstone Project: UK Silicon Photonics Fabrication Capability based on DUV Photolithography Dr Stevan Stanković University of Southampton

2 Outline Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 2

3 Introduction Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 3

4 Market predictions for silicon photonics Data Centres and High Performance Computing are expected to be major market for silicon photonics! But other applications will be interesting as well! Source: Silicon Photonics Report - Yole Développement. 4

5 Research & development in silicon photonics Academia heavily relies on e-beam lithography (EBL) for patterning E-beam lithography pros: superb resolution maskless lithography E-beam lithography cons: long writing times (fabrication bottleneck) not a standard industrial tool Link between academia and industry is needed: fabricate devices in an industrially-compatible way (i.e. based on DUV lithography) Multi Project Wafer (MPW) services offered by foundries: Designs submitted by multiple customers are made in one fabrication run (sharing design space on wafers/chips and fabrication costs) 5

6 Limitations of current MPW services MPW services in silicon photonics are offered by research foundries: Imec (Belgium), CEA-Leti (France), IHP (Germany), IME (Singapore),... MPW service pros: high yield sophisticated quality assurance (QA) access to component libraries MPW service cons: limited design flexibility long turnaround times (> 8 months) relatively high prices Can researchers have a dedicated MPW service that will give them back some design flexibility? 6

7 What is CORNERSTONE? Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 7

8 CORNERSTONE - Overview CORNERSTONE: CAPABILITY FOR OPTOELECTRONICS, METAMATERIALS, NANOTECHNOLOGY AND SENSING EPSRC-funded project ( ) with a total budget of 3.2 million Goal: Vision: to establish silicon photonics fabrication capability that can support photonics research in the UK via MPW service to underpin photonics research in UK and support wide range of research activities, attracting both academic and commercial partners 8

9 CORNERSTONE - Partners Three UK universities involved: 1) University of Southampton (Prof. Graham Reed) Wafer-scale processing (DUV photolithography) 2) University of Glasgow (Prof. Marc Sorel) Chip-level processing (e-beam lithography) 3) University of Surrey (Prof. Jonathan England) Ion implantation 9

10 Equipment: DUV scanner Model: Nikon NSR-S204B Configured for 8 wafers Reduction ratio 1:4 Light source: KrF laser at 248nm Resolution: 180nm Depth of 180nm: 500nm Exposure field: 25mm x 33mm Lens NA: 0.68 Stepping precision (3s): < 25nm 10

11 DUV lithography: accompanying equipment TEL ACT-8 track Hitachi S8840 critical dimensions (CD) SEM KLA-Tencor 5200XP overlay metrology system Spin-coating, baking and postexposure development of wafers Post-development and postetching inspection tool Layer to layer alignment error inspection tool 11

12 Cleanroom facilities - Southampton E-beam lithography Contact lithography (i-line) Wet & dry etch systems Furnaces and RTA systems PECVD, LPCVD & ALD systems Thermal evaporation & RI sputtering systems CMP, wafer dicing,... Bonding: wafer, wire, flip-chip FIB, SEM, ellipsometry,... 12

13 Cleanroom facilities - Glasgow E-beam lithography (Vistec VB6 & Nanobeam nb5 systems ) Nanoimprint lithography Optical lithography (i-line) Thermal processing Wet & dry etch systems SEM, ellipsometry, profilometers,... 13

14 Facilities at Ion Beam Centre - Surrey External beam line Ion implantation: 2 MV high energy implanter 200 kv high current implanter 2 kev to 4 MeV implantation energy Ion beam analysis Processing & characterisation Focused ion beam facility 14

15 Fabrication capabilities passive devices Spectrometers Suspended waveguides M. Nedeljkovic et al., IEEE Photon. Technol. Lett., vol. 28, iss. 4, G. Z. Mashanovich et al., J. Sel. Top. Quantum Electron., vol. 21, iss. 4, Tuneable processor cores D. Pérez et al., Nat. Commun., vol.8, 636, Passives with heaters M. Nedeljkovic et al., IEEE Photon. Technol. Lett., vol. 26, pp ,

16 DUV lithography process development Grating couplers - FIB cross-section Grating couplers - SEM 16

17 DUV lithography process development Grating couplers - FIB cross-section Grating couplers - SEM Designed width: 315 nm Etched width: nm 17

18 E-beam lithography capabilities (Glasgow) Passives Passives with heaters M. Strain et al., IEEE Nat. Commun., vol. 5, 4856,

19 Modulator capabilities Cross-section MZI carrier-depletion modulators Eye diagram Top view microscope image 56 Gbit/s Advanced modulation techniques Input signal Output signal 112 Gbit/s PAM4 19

20 Integration capabilities CMOS driver chips Year Power Speed mw 30 Gb/s Power efficiency pj/bit Wire bonding Flip-chip bonding mw 40 Gb/s 6.63 pj/bit 33 mw at 22 Gb/s with ER of 3.03 db. 7mm D. Pérez et al., Nat. Commun., vol.8, 636,

21 What is offered? Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 21

22 CORNERSTONE What is offered? Three SOI photonic platforms: 1) 220nm Si on 2mm BOX 2) 340nm Si on 2mm BOX 3) 500nm Si on 3mm BOX Passive devices fabrication runs: Waveguides, MUX, DEMUX, filters, heaters,... Active device fabrication runs: Modulators,... 22

23 CORNERSTONE What is offered? Three Si etch depths for each SOI platform: 1) Shallow etch step for grating couplers 2) Intermediate etch step for rib waveguides 3) Full etch (down to BOX) for strip waveguides Four implantation steps for active runs: Low and high doping levels for both n-type (phosphorous) and p-type (boron) implantation steps Metallisation layers and heaters: - Two metal layers for heater filament and contact pads - Metallisation for ohmic Si contacts 23

24 How can you benefit? Use CORNERSTONE MPW service for proof-ofprinciple designs and prototypes High-risk design chip-scale processing Low(er)-risk design wafer-scale processing (small-volume production possible) Perfect your design through iterations until it is ready for large-volume fabrication Chip-scale (Glasgow) Wafer-scale (Southampton) Bespoke Foundry Run 24

25 How it works? Download design rules and GDS template files from the CORNERSTONE website: Submit you design (GDSII file) on the same website (click on Mask submission link) before the deadline Technical support via Cost: Design area Active Devices Passive devices mm x 4.9 mm 35,000 TBC 5.6 mm x 2.9 mm 20,000 TBC - free of charge for the UK academia (until September 2019) 25

26 MPW service calls Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 26

27 Previous MPW service calls - summary Three MPW fabrication runs have been announced and completed: 1) MPW #1 passive devices on 220nm SOI (deadline: 01/02/2017, delivered on 08/05/2017) 2) MPW #2 passive devices + heaters on 220 nm SOI (deadline: 30/06/2017, delivery this month) 3) MPW #3 passive devices on 500nm SOI (deadline: 28/07/2017, delivered on 27/09/2017) Breakdown of designs and customers: 1) MPW #1: 7 designs submitted, 4 external users from academia (University of Manchester, University of Bristol, UCL, University of St Andrews ) 2) MPW #2: 13 designs submitted, 5 external users (Oxford, Bristol, UCL, St Andrews, Cambridge) 3) MPW #3: 6 designs submitted, 2 external users (University of Bristol, University of Cambridge) 27

28 Current MPW call active devices Currently, the first call for active devices is active (MPW #4): 3 Si etch depths (70nm, 120nm and 220nm), 4 implantation steps, on a 220nm SOI platform Mask submission deadline: Friday 1 st December 2017 Expected delivery: by 27 th July 2018 Cost: free access to UK academia; for other customers: 20k for 5.6 x 4.9 mm 2 design space 35k for x 4.9 mm 2 design space Design rules available on the website: For all queries, cornerstone@soton.ac.uk 28

29 Active devices calls: Future MPW service calls tentative dates Call #9 220 nm SOI platform July 2018 Call # nm SOI platform January 2019 Passive devices calls: Call #5 340 nm SOI platform November 2017 Call #6 220 nm SOI platform January 2018 Call #7 500 nm SOI platform March 2018 Call #8 220 nm SOI platform May 2018 Call # nm SOI platform July 2018 Call # nm SOI platform September 2018 Call # nm SOI platform November

30 Summary Introduction What is CORNERSTONE? What is offered? MPW service calls Summary 30

31 CORNERSTONE - Summary CORNERSTONE MPW service is offered to customers both academic and commercial (free of charge for UK academia) DUV photolithography equipment is installed and process development is underway fabrication based on this capability will be offered in 2018 Long-term vision: Silicon photonics fabrication capability, developed within the CORNERSTONE project will underpin photonics research in UK (both in academia and industry) 31

32 CORNERSTONE Contacts & Websites Primary contact: (Professor Graham T. Reed) Technical contact: (Dr Callum Littlejohns and Dr Stevan Stanković) Technical contact at Glasgow: (Dr Graham Sharp) Administrative contact: CORNERSTONE website: University of Southampton: University of Glasgow: University of Surrey: 32