MOCVD mass production for cost efficient solar cell

Transcription

1 MOCVD mass production for cost efficient solar cell Dr. Frank Schulte AIXTRON AG

2 Outline AIXTRON: Company, Business and Products The Solar Cell Market Cost Reduction in MOCVD production Conclusion confidential

3 AIXTRON: Company, Business and Products The Solar Cell Market Cost Reduction in MOCVD production Conclusion confidential

4 Global Presence Global Customers Global Growth Markets AIXTRON Inc. Sunnyvale, CA, USA AIXTRON Ltd. Cambridge, UK AIXTRON AG Aachen, Germany Headquarters AIXTRON Europe Epigress AB Lund, Sweden AIXTRON Korea Co. Ltd. Seoul, South Korea AIXTRON AG Shanghai, P.R.China AIXTRON KK Tokyo, Japan AIXTRON Taiwan Co. Ltd.; Hsinchu Representation confidential

5 One Technology Multiple Solutions Business Technology Applications confidential Gas Phase Deposition Nano Scale Material Engineering Compound Semiconductors MOCVD, OVPD LEDs/OLEDs for displays LEDs/OLEDs for lighting III-V Compound and Organic solar cells Optoelectronics for telecom/datacom Organic Electronics for flexible displays and RFID CD-, DVD-lasers High frequency for wireless High power SiC Carbon Nanotube Structures Silicon Semiconductors AVD, ALD, CVD Metal and oxide films for CMOS transistors Traditional NAND-Flash Memory Traditional, next generation DRAM Memory TFH Thin Film Heads for data storage hard disk drives

6 Global MOCVD Market Shares 2005 Total: $156m 6% 13% 17% 64% AIXTRON Veeco Nippon Sanso Others 2006 Total: $202m 20% 14% 4% 62% 18% 2007 Total: $289m 10% 2% 70% Source: VLSI RESEARCH Inc confidential

7 AIXTRON: Company, Business and Products The Solar Cell Market Design, Growth and Cost Reduction in MOCVD production Conclusion confidential

8 AIXTRON s Mission to Mars Space Application confidential

9 Roadmap for Development of Solar Cells for Space Applications Source: Man Tech for Multi-Junction Solar Cells ( Fraunhofer ISE/ RWE Solar (27.1%) Spectrolab (29%) confidential

10 Terra Watt free Solar Energy per Day arriving the earth catch something from this confidential

11 Future Energy Supply - Photovoltaic Electricity Possible Scenario for Europe in 2050 Primary energy use EJ/a solar cells on every roof Key-Technology: III-V Concentrator Multi Junction Photovoltaic Devices solar power plants confidential

12 Solar cell development 1-junction 6-junction GaAs GaAs η ~ 24.2 % AM1.5g GaInP GaInAs GaAs η ~ 31.1 % 300xAM1.5d GaInP GaInAs active Ge η ~ 27.1 % AM0 RWE/ISE AlGaInP GaInP AlGaInAs GaInAs active Ge AlGaInP GaInP AlGaInAs GaInAs GaInNAs active Ge half current double voltage confidential

13 Requirements for MOCVD of PV Devices High Efficiency & Long Lifetime; FF Determined by Device design & material quality: Minimized Energy Losses Suppress Thermal Losses : band gap design Suppress Recombination Losses: Layer Quality, Device Design Minimized mechanical stress for device on thin Ge (plastic phase): No strong mechanical forces Curvature control for metamorphic growth Multi Junction Cells need good junction between cells: Tunnel Diodes Tunneling requires sharp interfaces for doping, composition, thickness, low series resistance FF= blue/yellow area optimum = 1; realistic = confidential

14 Requirements for MOCVD of PV Devices Multi-Junction Solar Cell Structure MOCVD requirements: Crystalline quality Material purity interface quality Uniformity Film thickness Film composition Doping confidential

15 High Efficiency SC - Lowest Oxygen &Carbon Al.85Ga.15As SIMS Results AlAs/Al 0.12 Ga 0.88 As DBR grown at IQE with EpiPure TM TMA Oxygen concentration as low as detection limit Suppression of nonradiative recombination for highest Device Efficiency confidential

16 Planetary Reactor sharpest interfaces confidential X-ray measurement (straight line) and fit (dotted line) of two InGaAs QWs followed by a GaAsP strain compensating layer. Planetary Reactor enables sharpest interfaces Source: Feedback controlled growth of strain-balanced InGaAs multiple quantum wells in metal-organic vapour phase epitaxy using an in situ curvature sensor MZorn1, F Bugge1, T Schenk2, U Zeimer1, M Weyers1 and J-T Zettler2 1 Ferdinand-Braun-Institut f ur H ochstfrequenztechnik (FBH), Gustav- Kirchhoff-Str. 4, D Berlin, Germany 2 LayTec GmbH, Helmholtzstr , D Berlin, Germany

17 p++ - Al Ga As Carbon-Auto doping Res. Uniformity (Lehighton) < 3 % 2,10E+20 p++ AlGaAs (intrinsic) n [cm-³] 1,90E+20 1,70E+20 1,50E+20 1,30E+20 1,10E+20 9,00E+19 7,00E+19 5,00E+19 y = 2E+20x -1,1575 Very sensitive to T-Uniformity 1 1,2 1,4 1,6 1,8 2 2,2 2,4 2,6 V/III - ratio p++ doping calibration for Tunnnel Diode ( measured by XRD) confidential Planetary Reactor enables precise control of doping

18 P: 18 confidential jh1 AlGaInP: PL Wavelength Distribution - no edge exclusion - Std Dev: 0.06% (0.37 nm) Unmatched uniformity Date: Planetary Reactor

19 Folie 18 jh1 jhofeldt Ergebnis aus Labordemo 248G: Run G1384_7 jhofeldt;

20 Requirements for PV Mass Production Highest process performance confidential Wide process window, excellent process stability Unmatched uniformities (Yield) and material quality Metamorphic growth on Ge Lowest Cost of Ownership (CoO) Highest throughput Highest material efficiency Low maintenance

21 AIXTRON: Company, Business and Products The Solar Cell Market Cost Reduction in MOCVD production Conclusion confidential

22 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime Yield Uniformity Defects Reliability Running costs per wafer area Consumables Precursor, gases Parts Design!! confidential

23 For design optimization modelling and simulation Guidance for reactor and process development Reduced risk in prototyping and design Speed-up of time to market Need for modelling in the industry is clearly driven by Reduction of Cost of Ownership (CoO) (e. g. by larger wafer load capacity, lower gas consumption, increased through-put, expanded usable wafer area) Enhancement of process performance (e. g. enable challenging process regimes) Improvement of process robustness (e. g. run-to-run uniformity, sensitivity to process variations) confidential

24 Scope of modelling and simulation Analysis of transport and reaction phenomena: Flow dynamics laminar and mixed convective flow Heat transfer & thermal management conduction / convection thermal radiation inductive, resistive, and lamp heating Used also in the Apollon Grant Agreement no Growth chemistry multicomponent diffusion (e. g. H 2, N 2, NH 3, group-iii alkyls) reaction kinetics nucleation dynamics thin film deposition Computed flow field at inlet zone of the Planetary Reactor confidential

25 AIXTRON s New GaAs Mass Production Reactor Planetary Reactor confidential AIX2800G4-R providing Highest throughput Best Production Stability & Performance Best Cost of Ownership Dedicated to Highest Commercial Benefit

26 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime confidential

27 Planetary Reactor principle AsH 3 TMGa = Ga(CH 3 ) 3 carrier + group V elements wafer injector rotating infrared/inductive heated wafer carrier carrier + group III elements + dopants quartz glass ceiling Radial flow Rotating substrates Separate inlets confidential

28 18x3 11x2 12x4 5x6 35x2 24x2 8x4 7x6 49x2 8x confidential

29 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime confidential

30 High Growth Rate GaInAs (In=1%) Growth Growth Rate Rate [µm/h] [µm/h] Comparison 15x4 to 12x4inch: with same molar flow similar growth rates confidential Molar Flow [µmol/min]

31 AIX 2800G4-R including Automated Satellite Handler: Gate Mechanism confidential

32 AIX 2800G4-R including Automated Satellite Handler: Satellite Exchange confidential

33 Planetary Reactor AIXTRON s New GaAs System Dedicated to Highest Commercial Benefit Higher Throughput shorter cycle time: Automated Satellite Loader Increased wafer capacity: 60x2/15x4inch Less Maintenance Downtime Increase hardware uptime: Graphite Ceiling no calibration/conditioning runs: Graphite Cover Star Enhanced Uniformity / Efficiency Improved process performance and stability: Triple Gas Injector confidential AIX2800G4 R dedicated to Highest Commercial Benefit

34 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime Yield Uniformity Defects Reliability Running costs per wafer area Consumables Precursor, gases Parts Design confidential

35 Al 0.14 GaInP Bulk material PL Uniformity Scan 2inch 0mm edge exclusion 60x2inch confidential Av. Wavelength 605.6nm stdev nm Av. Wavelength 605.6nm stdev nm Av. Wavelength 605.4nm stdev nm Av. Wavelength 605.4nm stdev nm Wafer to wafer uniformity: no detectable difference 2.4µm/h growth rate

36 Low Particle Density after Device growth Total number of particle: Ø(17-200µm) = confidential Enhanced by Wafer Handler Wafer ID

37 Solar Cell In-Situ Monitoring: EpiCurve TT LASER X D ( z ) substrate wafer (bent due to strain) confidential parallel laser beam susceptor T Method: distance variation of parallel laser beams Control of Strain during growth on Ge 2D CCD camera z

38 Strain Design by EpiCurve TT confidential Courtesy: M. Zorn, FBH Berlin, AIX 200/4 Strain Design layer by layer MQW 5.0nm InGaAs / 50nm GaAs

39 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime Yield Uniformity Defects Reliability Running costs per wafer area Consumables Precursor, gases Parts Design confidential

40 Stability after Reactor-Maintenance: AlGaInP-DH + exchange graphite star and ceiling AGIP-DH: PL wavelength NO edge exclusion PL lambda avg. [nm] , , , , , confidential Ref. DH MQW Cover star exchange Ceiling exchange run no. Pl avg. Lid open in GB PL max-min < 1nm Change of Wavelength after Maintenance NO CALIBRATION RUNS REQUIRED 7 6,5 6 5,5 5 4,5 4 3,5 3 2,5 2

41 Cost reduction in MOCVD production Cost of Ownership Throughput Substrate area per Run Cycle time Uptime Yield Uniformity Defects Reliability Running costs per wafer area Consumables Precursor, gases Parts Design confidential

42 Efficiency Data Efficiency Comparison precusor *all values calculated acc. to O. Kayser, Chemtronics 1988, Vol. 3, June, pp 90ff confidential 15x4inch 8x6inch 12x4inch AlAs/GaAs DBR GaInP AIX2800G4-R AlAs/GaAs DBR GaInP AlAs/GaAs DBR High Material Utilization in AIX2800G4-R AIX2600G3 GaInP TMGa 42.7% 39.9% 65.7% 60.9% 36.0% 38.0% TMAl 37.8% 52.8% 36.0% n.a. TMIn 34.2% 42.2% n.a. 33.0%

43 Conclusion Reliable mass production system fulfilling the CoO request is developed and in qualification for LED production Further qualification and optimization of design will be done adapted to the solar cell demand Like in the Appollon project with - Modelling - Hardware and insitu optimization - Solar Cell design confidential