Is he ever going to quit? 1 High power, high speed and high - PowerPoint PPT Presentation

Is he ever going to quit? 1

High power, high speed and high linearity photodiode for NextGen-VLA antenna project Qinglong Li, Andreas Beling, Joe C. Campbell University of Virginia, Charlottesville, VA 22904

Outline • High power photodiode in analog link • Normal incidence high power photodiode • 3 bands: 10 ~ 40 GHz, 40 ~ 65 GHz, 75 ~ 110 GHz • Evanescently coupled waveguide photodiode • High linearity photodiode • Summary 1

Photodiode Laser or LED diode Photodetector Solar cell 2

Analog optic link Our Research interests • Signal transmission – Video distribution in CATV – Antennas – Radio-over-Fiber (RoF) for wireless communication • Signal processing – MMW/THz signal generation – Optical beam-forming network in phased array radar 3

Why high power? Link gain Photocurrent Link gain Spurious-free dynamic range Noise figure Noise figure Spurious-free dynamic range 6 4

Photodiode Saturation Behavior Space charge effect Carrier distribution Carrier velocities Electric field collapse Thermal effect • High carrier concentration in depletion region Heat sink • E-field collapses Layer parameters • Carrier transport disrupted Bias voltage • RF output power compressed 5

Photodiode Speed • High Speed h ν – Carrier transit time • Reduce carrier travel distance P N – RC time constant Transit time • Smaller device surface area • Thicker device depletion region • Introduce an inductor (high impedance transmission line) L Photodiode model Z L Z 0 >> Z L R s R p I photo C pd 6 8

Uni-Traveling Carrier (UTC) Photodiodes PIN • P + absorber + transparent collection I-layer • Quasi-field accelerates electron transport UTC • Holes relax fast within V drift,e dielectric relaxation time • Only electron traveling benefits bandwidth Ishibashi etal (IEICE Trans. Electron. 2000) 7

Charge-Compensated Modified UTC with “Cliff” Layer 1. Charge compensated collector CC-UTC UTC High E Absorber High Current E Current Field Field Dark Field Dark Field e 2. Partially depleted absorber i. high e-field at heterjunction ii. Increase responsivity without sacrificing BW 3. “Cliff” layer to maintain high field in depleted absorber at high current 4. Flip-chip bonding for surface normal PDs depleted InGaAs InP cliff layer absorber InP drift layer Transition layers undepleted InGaAs absorber Collector “Cliff” layer diamond 8

Normal Incidence Photodiodes: RF Output Power and Saturation Current versus Frequency R = 0.75 A/W Flip-chip bonded MUTC R = 0.45 A/W R = 0.17 A/W diamond 15. X. Wang, et al., IEEE Photon. Technol. Lett., vol. 19, no. 16, pp. 1272–1274, 9. X. Li, S. Demiguel, et al., Electron. Lett., vol. 39, no. 20, Oct. 2003. 2007. 10. Z. Li, et al., Proc. 37th Europ. Conf. Optical Commun. (ECOC 16. M. Chtioui, et al., IEEE Photon. Technol. Lett., vol. 20, no. 3, pp. 202–204, 2008. 2011) , Geneva, Switzerland, Sept. 2011. 11. N. Duan, et al., 19 th Annu. Meeting IEEE Lasers Electro-Optics 17. Z. Li, et al., IEEE J. Quantum Electronics, vol. 46, no. 5, 2010. 18. N. Li, et al., IEEE Photon. Technol. Lett., vol. 16, no. 3, pp. 864-866, 2004. Soc.(LEOS 2006), Oct. 2002, pp. 52-53, paper WD2.3. 19. M. Chtioui, et al., IEEE Photon. Technol. Lett. , vol.24, no.4, pp.318-320, 2012. 12. K. Sakai, et al., IEEE Trans. Microwave Theory Tech., vol. 58, no. 20. X. Xie et al., Optica, vol. 1, no. 6, pp. 429 – 436, 2014. 11, pp. 3154-3160, 2010. 21. Q. Zhou et al., IEEE Photonics Tech. Lett., vol. 25 ,No. 10 , pp. 907-909, 2013. 13. N. Shimizu, et al., Electron. Lett . , vol. 36, no. 8, pp. 750-751, April 22. Y.-S. Wu et al. 2008 2000. 9 14. D. A. Tulchinsky, et al., J. Lightwave Tech.., vol. 26, no. 4, pp. 408- 416, 2008.

10 GHz ~ 40 GHz Design RC time limited BW Contact layer InGaAs, p+, Zn, 2x10 19 , 50nm RC and transit time InP, p+, Zn, 2x10 18 , 100nm Grading InGaAsP,Q1.1, p+, Zn, 5x10 18 , 15nm Grading InGaAsP,Q1.4, p+, Zn, 5x10 18 , 15nm Un-depleted absorber InGaAs, p+, Zn, 2x10 18 , 100nm Un-depleted absorber InGaAs, p+, Zn, 1.2x10 18 , 150nm Un-depleted absorber InGaAs, p+, Zn, 8x10 17 , 200nm Un-depleted absorber InGaAs, p+, Zn, 5x10 17 , 250nm Depleted absorber InGaAs, n - , Si, 1x10 16 , 350nm Grading InGaAsP, Q1.4, n - , Si, 1x10 16 , 15nm Grading InGaAsP,Q1.1, n - , Si, 1x10 16 , 15nm • 24-µm diameter MUTC-K device exhibits 40 GHz Cliff layer InP, n - , Si, 1.4x10 17 , 50nm bandwidth with inductive peaking Drift layer InP, n - , Si, 1x10 16 , 700nm • CPW design: W:30 µm, G: 200 µm, L: 90 µm InP, n+, Si, 1.0x10 18 , 100nm • The estimated transit-time bandwidth is 47 GHz (9 ps InP, n+, Si, 1.0x10 19 , 900nm transit time). InP, semi-insulating substrate, • Estimated R: 0.97 A/W (with AR coating and top Double side polished metal mirror with backside illumination) 10

40 GHz ~ 65 GHz device design Contact layer InGaAs, p+, Zn, 2x10 19 , 50nm RC time InP, p+, Zn, 2x10 18 , 100nm limited BW Grading InGaAsP,Q1.1, p+, Zn, 5x10 18 , 15nm RC and transit time Grading InGaAsP,Q1.4, p+, Zn, 5x10 18 , 15nm Un-depleted absorber InGaAs, p+, Zn, 2x10 18 , 100nm Un-depleted absorber InGaAs, p+, Zn, 1.2x10 18 , 150nm Un-depleted absorber InGaAs, p+, Zn, 8x10 17 , 150nm Depleted absorber InGaAs, n - , Si, 1x10 16 , 250nm Grading InGaAsP, Q1.4, n - , Si, 1x10 16 , 15nm Grading InGaAsP,Q1.1, n - , Si, 1x10 16 , 15nm • 18-µm diameter MUTC-V device exhibits 65 GHz Cliff layer InP, n - , Si, 1.4x10 17 , 50nm bandwidth with inductive peaking Drift layer InP, n - , Si, 1x10 16 , 400nm • CPW design: W:25 µm, G: 220 µm, L: 140 µm InP, n+, Si, 1.0x10 18 , 100nm • The estimated transit-time bandwidth is 72 GHz (6 ps InP, n+, Si, 1.0x10 19 , 900nm transit time). InP, semi-insulating substrate, • Estimated R: 0.76 A/W (with AR coating and top metal Double side polished mirror with backside illumination) 11

75 GHz ~ 110 GHz Contact layer InGaAs, p+, Zn, 2x10 19 , 50nm RC time limited BW InP, p+, Zn, 2x10 18 , 100nm RC and transit time Grading InGaAsP,Q1.1, p+, Zn, 2x10 18 , 10nm Grading InGaAsP,Q1.4, p+, Zn, 2x10 18 , 10nm Un-depleted absorber InGaAs, p+, Zn, 2x10 18 , 50nm Un-depleted absorber InGaAs, p+, Zn, 1x10 18 , 50nm Un-depleted absorber InGaAs, p+, Zn, 5x10 17 , 50nm Depleted absorber InGaAs, n - , Si, 1x10 16 , 150nm Grading InGaAsP, Q1.4, n - , Si, 1x10 16 , 10nm Grading InGaAsP,Q1.1, n - , Si, 1x10 16 , 10nm Cliff layer InP, n - , Si, 3x10 17 , 30nm • 10-µm diameter MUTC-W device exhibits 110 GHz Drift layer InP, n - , Si, 1x10 16 , 280nm bandwidth with inductive peaking InP, n+, Si, 1.0x10 18 , 100nm • CPW design: W:30 µm, G: 200 µm, L: 100 µm • The estimated transit-time bandwidth is 117 GHz (3.8 InP, n+, Si, 1.0x10 19 , 1000nm ps transit time). InP, semi-insulating substrate, • Estimated R: 0.41 A/W (with AR coating and top Double side polished metal mirror with backside illumination) 12

Design Summary PD size Band Responsivity Projected I sat Projected P RF ( Φ : µ m ) (GHz) (A/W) (mA) (dBm) 24 10 ~ 40 0.97 126 23 @ 40 GHz 18 40 ~ 65 0.76 82 19 @ 65 GHz 10 75 ~ 110 0.41 53 14 @ 110 GHz æ ö w æ - wt ö I ( ) 1 1 exp( j ) Bandwidth ç ÷ = ´ ç ÷ ç ÷ ç ÷ - w + w + wt 2 I ( 0 ) 1 L C j C ( R R ) j estimation: è ø è ø total PD PD L S Transit time RC I Responsivity ph - a = = - - 2 d R R ( 1 R )( 1 e ) thickness estimation: ideal surface P in 13

Normal Incidence Photodiodes: RF Output Power and Saturation Current versus Frequency R = 0.75 A/W Flip-chip bonded MUTC 0.97 A/W R = 0.45 A/W 0.76 A/W R = 0.17 A/W diamond 0.41 A/W 15. X. Wang, et al., IEEE Photon. Technol. Lett., vol. 19, no. 16, pp. 1272–1274, 9. X. Li, S. Demiguel, et al., Electron. Lett., vol. 39, no. 20, Oct. 2003. 2007. 10. Z. Li, et al., Proc. 37th Europ. Conf. Optical Commun. (ECOC 16. M. Chtioui, et al., IEEE Photon. Technol. Lett., vol. 20, no. 3, pp. 202–204, 2008. 2011) , Geneva, Switzerland, Sept. 2011. 11. N. Duan, et al., 19 th Annu. Meeting IEEE Lasers Electro-Optics 17. Z. Li, et al., IEEE J. Quantum Electronics, vol. 46, no. 5, 2010. 18. N. Li, et al., IEEE Photon. Technol. Lett., vol. 16, no. 3, pp. 864-866, 2004. Soc.(LEOS 2006), Oct. 2002, pp. 52-53, paper WD2.3. 19. M. Chtioui, et al., IEEE Photon. Technol. Lett. , vol.24, no.4, pp.318-320, 2012. 12. K. Sakai, et al., IEEE Trans. Microwave Theory Tech., vol. 58, no. 20. X. Xie et al., Optica, vol. 1, no. 6, pp. 429 – 436, 2014. 11, pp. 3154-3160, 2010. 21. Q. Zhou et al., IEEE Photonics Tech. Lett., vol. 25 ,No. 10 , pp. 907-909, 2013. 13. N. Shimizu, et al., Electron. Lett . , vol. 36, no. 8, pp. 750-751, April 22. Y.-S. Wu et al. 2008 2000. 14 14. D. A. Tulchinsky, et al., J. Lightwave Tech.., vol. 26, no. 4, pp. 408- 416, 2008.

Normal incidence Bandwidth-Efficiency Trade Off 1 1000 Transit time Bandwidth(GHz) 0.9 - a h = - d ( 1 e ) 0.8 thickness i Quantum Efficiency 0.7 0.6 3 . 5 v 0.5 100 = f tr p 0.4 2 d 0.3 0.2 0.1 0 10 0 1 2 3 Absorption thickness (µm) 17 15

MUTC Waveguide Photodiodes Evanescently coupled MUTC PD P Optical Intensity distribution Absorber Absorber I ph Drift layer Optical WG N input WG 16

Frequency Response Simulation 63% efficiency improvement compared with surface normal Size (µm 2 ) Responsivity (A/W) Bandwidth (GHz) 24 0.40 129 35 0.48 120 17 19 50 0.67 110