Recent progress in MOCVD Technology for Electronic and Optoelectronic Devices

Transcription

1 AIXTRON SE Recent progress in MOCVD Technology for Electronic and Optoelectronic Devices Prof Dr.-Ing. Michael Heuken 1,2 Vice President Corporate Research&Development 1) AIXTRON SE, Dornkaulstr. 2, Herzogenrath, Germany 2) RWTH-Aachen University, Templergraben 55, Aachen, Germany

2 Contents Introduction State of the art MOCVD Energy saving by using GaN/AlGaN HEMT Micro LED for Displays Conclusion and Takeaway

3 The revolution in mobile telephony 3

4 Compound semiconductor for power control 4

5 5 Market opportunities for compound semiconductor

6 Principle of MOVPE Ga(CH 3 ) 3 + AsH 3 GaAs +3CH 4

7 Basic understanding of the Planetary Reactor carrier + group V elements carrier + group III elements + dopants wafer injector rotating infrared/inductive heated wafer carrier quartz glass ceiling radial and horizontal flow of gases above rotating substrates

8 Gas transport mechanisms in the Planetary Reactor 8 Group V Group III Group V forced convection flux (by main flow) diffusion flux Triple injector Resulting growth profile Dominant species fluxes: J convect U Y MO on rotated wafer J diff D Y MO J = MO species mass flux = gas density U = local flow velocity Distance from center Y MO = mass fraction of MO D = diffusion coefficient Depletion of group-iii species results in flat growth rate profile by disc rotation Uniformity controlled by balance of convective and diffusive fluxes M.Heuken et al. JCG 303 (2007) 318

9 G5+: Single Wafer performance w Batch reactor cost benefits 9 G5+ 5x200 mm NO COMPROMISE IN TUNING: Individual wafer rotation and GFR flow control = good on-wafer uniformity by design Injector enabling full tuning flexibility ADVANCED YIELD MANAGEMENT: Single wafer rotation, combined with radial horizontal gas flow Reset of reactor each run with Cl 2 in-situ cleaning No Part Exchange Excellent Run-to-Run Stability Temperature matching between each individual wafers, within a run and run to run

10 AIX G5+ C: CS High-Volume Manufacturing Award Requirements for MOCVD in HVM: Cassette-to-Cassette 150/200 mm Si wafer automation for fab integration and throughput In-situ Reactor Cleaning for process robustness and yield G5+ C Cassette-to-Cassette dual module cluster On-wafer temperature process control for highest reproducibility and yield High throughput for lowest Cost-ofownership (COO) Qualified device level layer processes for fast time to market Cassette-to-Cassette Module Vacuum Robot

11 AIXTRON G5+ C PLANETARY REACTOR 11 Power Transistor: 100x SL + Active Layers 100x SL buffer to target 650 V Increased carbon level in SL by means of autodoping Reference D-Mode device stack with active layers Reflectivity Curvature Total thickness: ~5.0 µm Bow X (µm) Bow Y (µm) Sample C No strain relaxation even with 100x SL RT bow comparable to 50x SL

12 AIXTRON G5+ C PLANETARY REACTOR 12 Thickness and AlGaN Barrier Al Composition Mapping White Light Interference: Photoluminescence: Mean thickness: 4.5 µm* STD: 0.4% (3mm EE) *Note: WLI underestimates actual thickness by ~10% due to refractive index averaging Mean Al concentration: 27.4% STD: 0.50% abs. (3mm EE) Hall data: R sheet (W/sq) Carrier density (10 12 cm -2 ) Carrier mobility (cm 2 /Vs) G5+ C features excellent uniformities for both thickness and AlGaN barrier Al composition

13 AIXTRON G5+ C PLANETARY REACTOR 13 I-V Breakdown Characteristics Current (A/mm 2 ) T = 25 C 1 µa/mm 2 Forward Reverse Current (A/mm 2 ) T = 150 C Forward Reverse Voltage (V) Voltage (V) 800 V / 900 V 600 V / 770 V 650 V specification met at room temperature / very close at 150 C

14 AIXTRON G5+ C PLANETARY REACTOR 14 E-Mode HEMT: Output Characteristics and R on Mapping Power transistor (W g = 36 mm): 400 V gs = On-resistance (R on ) mapping (Wmm): I d (ma/mm) V ds (V) Max current of 13 A in the device Uniform on-resistance across entire wafer diameter

15 Intra & Inter wafer layer thickness uniformity & reproducibility 15 Inter-Run Intra & Inter-Wafer Mean Thickness in µm Intra-wafer uniformity: σ/mean=0.44% Inter-run uniformity: σ/mean=0.24% Inherent process reproducibility delivers highest onwafer performance at high throughput!

16 Selected products market penetration 16 Sources: Texas Instruments, Electronic Products

17 Micro LED and it s potential as emerging display technology Micro LED opens a new field of opportunities Large Size Displays Brightness -> Small pixels -> High contrast ratio Head Up Display -> High Dynamic Range -> High Definition TV Display -> Color Gamut -> Interactive Smart Watches Brightness Efficiency -> battery lifetime Augmented Reality Brightness -> compete with ambient light Smartphone time Brightness -> battery lifetime -> pixels much smaller than pitch allow integration of sensor matrix

18 Larger Wafer Sizes Required for Micro LED Processing Assume: 10mm x 10mm Stamps with Pixels for Transfer 4 wafer 6 wafer 52 stamps 10mm x 10mm 3mm E.E. 137 stamps 10mm x 10mm 3mm E.E. Fill Factor = 75% Fill Factor = 84% Courtesy: CALY Technologies Larger wafer sizes improve wafer utilization 6 or 8 Requirement driven by Back End Technology Shift

19 MFC MFC MFC MFC MFC Pyro Individual Wafer Temperature Control Topside Temperature Measurement Flying Height Temperature Satelite Wafer Temperature measured by a UV Pyrometer Gas foil rotation is individually controlled for each satellite (wafer). Flying height of satellite over the main disc determines the temperature adjusted by individual flow rate. Individual Flow for each Satellite (Wafer)

20 PL Wavelength Uniformity Results for Blue LED InGaN /GaN MQW on sapphire in 8x6 configuration 2nm W/W ~ 0.40nm R/R ~ 0.30nm DOM = 450.9nm = 0.50nm (3mm e.e.) on-w 0.55nm BLUE mled

21 PL Wavelength Uniformity Results for Green LED InGaN /GaN MQW on sapphire in 8x6 configuration 1.7nm W/W ~ 0.30nm R/R ~ 0.20nm DOM = 525.9nm = 0.60nm (3mm e.e.) on-w ~ 0.75nm GREEN mled

22 PL Wavelength Uniformity Results for Red LED GaInP /AlGaInP MQW on GaAs in 8x6 configuration 1.5nm W/W ~ 0.30nm R/R ~ 0.25nm DOM = 627.0nm = 0.32nm (3mm e.e.) on-w 0.40nm RED mled

23 Summary & Key Take Aways 23 AIXTRON is developing a complete CVD manufacturing solution for compound semiconductor based on existing production technology GaN based Transistors for Power and Microwave Applications R/G/B Micro LED production technology for future Displays Business target: Next Generation MOCVD for HVM

24 Thank you very much for your attention. If you have any further questions or require more information, please contact us at: Professor Dr. M. Heuken AIXTRON SE Dornkaulstr Herzogenrath Germany Phone +49 (2407) Fax +49 (2407) E-Mai info@aixtron.com