NONE

ABSTRACT
In this dissertation we investigated the performances of metal- semiconductor contacts in different materials and their applications for optoelectronic devices.
For the study of thin Pt film deposited on p-Si substrate, which usually formed PtSi film as a kind of silicide, it can be used to fabricate the Schottky Barrier Diode (SBD) and performed as infrared focal plane array sensors used widely in the detection wavelength range of 3~5 mm. The electrical Schottky barrier height of 0.186 eV was obtained. It was observed that the grain size and the film thickness have negligible effect on the electrical barrier height. However, the quantum efficiency of the SBDs is strongly dependent on the film thickness. The quantum efficiency of the designed Schottky barrier detectors with PtSi film thickness of about 80Å at its peak value exceeded 1%. We concluded the positive quantum efficiency dependence on the film thickness is referred to the enhancement of elastic phonon scattering and the decrease of the quantum efficiency is deduced from the inelastic scattering, like hole/hole scattering, imperfection scattering and impurity scattering during the hot hole transporting to the PtSi/Si interface.
For the study of the InGaP Schottky contact with Ti/Pt/Au metals, thermal reliability and characterization of contacts were investigated. The best Schottky properties with a barrier height of 1.01 eV and ideality factor of 1.24 are obtained from the InGaP Schottky diodes treated with the diluted HCl solution. However, we found that the diluted NH4OH is more suitable chemical solution for the treatment of the InGaP surface in fabrication process. No significant change was found for samples annealed up to 450 ℃ but a drastic degradation was observed in samples annealed at 500℃ in the thermal reliability experiment. We deduce that the degradation was caused by the interdiffusion and penetration of metals into the semiconductor from Auger electron spectroscopy analysis.
Further, the ohmic contact properties of metals contacts with low and high band-gap semiconductor were examined. In the comparison of ohmic performance of Ti/Ni/Au and Ti/Pt/Au on InAs/graded/InGaAs/GaAs layers, good nonalloyed specific contact resistance was 1.0 x 10-6 and 3.0 x 10-6 W cm2 for Ti/Pt/Au and Ti/Ni/Au metallization systems, respectively. However, the thermal stability can be achieved at least up to 350℃ for Ti/Pt/Au metallization system, while the Ti/Ni/Au metallization can only thermally stabilize at 250℃. The degradation of the specific contact resistance at high annealing temperature is attributed to the induced decomposition of InAs and graded InGaAs layers from Rutherford backscattering spectroscopy spectra and the Auger electron spectroscopy depth profile.
For the ohmic contacts study of metal contacts on GaN, ultra-low specific contact resistivity of 9.8 x 10-6 W cm2 and 8 x 10-6 W cm2 were obtained using Nd/Al metallization with CTA of 250℃ for 5 min and RTA of 600℃ for 30 s. Surface morphology was smooth in the temperature range from 550 to 650℃ for rapid thermal annealing observed using atomic force microscopy. From Auger electron spectroscopy depth profiling analysis, the degradation of contact characteristics was due to the oxidation of Nd metal.
Finally we investigate the chemical solution treatment and post-annealing to eliminate the reactive-ion etching damage on GaN surface. By using KOH and H3PO4: H2O chemical solution treatments, the ohmic resistance of GaN LEDs can be improved by the removal of native oxide. Using thermal annealing above 700℃, the reverse breakdown performance of the GaN LEDs can be improved by restoration of the ion-induced damage. Nevertheless, at a temperature higher than 1000℃, both the forward and reverse current-voltage characteristics of the GaN LEDs are degraded because of the decomposition of GaN and the loss of nitrogen.

References of Chapter 1
[1] F. Braun, “On the Conduction Through Sulfurmetals,” Annual. Phys. Chem., vol. 153, pp. 556-563, 1874.
[2] W. schottky, “Semiconductor Theory of the Blocking Layer” (in German), Naturwissenschaften vol. 26, 843, 1938; “On the Semiconductor Theory of Blocking and Point Contact Rectifiers” (in German), Z. Phys., vol. 113, pp.367-414, 1939; “Simplified and Expanded Theory of Boundary Layer Rectifiers” (in German), Z. Phys., vol. 118, pp.539-592,1942.
[3] M.S. Shur and T.A. Fjeldly, “Compound-Semiconductor Field-Effect Transistors,” in Modern Semiconductor Device Physics, edited by S.M. Sze, pp. 81-135, John Wiley & Sons, New York, 1981
[4] T.C. Shen, G.B. Gao, and H. Morkoc, “Recent Developments in Ohmic Contacts for III-V Compound Semiconductor,” J. Vac. Sci. Technol., vol. B 10, pp. 2113-2132, 1992.
[5] J.W. Wu, C.Y. Chang, K.C. Lin, E.Y. Chang, J.S. Chen, and C.T. Lee, “The Thermal Stability of Ohmic Contact to N-Type InGaAs Layer,” J. Electron. Mater., vol. 24, pp. 79-82, 1995.
References of Chapter 2
[1] M. S. Tyagi, “Physics of Schottky Barrier Junctions” in Metal-Semiconductor Schottky Barrier Junctions and Their Applications, edited by B.L. Sharma, Plenum Press, New York, 1984.
[2] D. K. Schroder, Semiconductor Material and Device Characterization, John Wiley & Sons, Inc., 1998.
[3] A. G. Milnes and D. L. Feucht, Heterojunction and Metal-Semiconductor Junctions, Academic Press, 1972.
[4] S. M. Sze, Physics of Semiconductor Devices, John Wiley & Sons, New York, 1981.
[5] E. H. Rhoderick, Metal-Semiconductor Contacts, Oxford University Press, 1978.
[6] J. Bardeen, “Surface States and Rectification at a Metal-Semiconductor Contact,” Phys. Rev., vol. 71, pp. 717-727, 1947.
[7] C. A. Mead, “Metal-Semiconductor Surface Barriers,” Solid-St. Electron., vol. 9, pp. 1023-1032, 1966.
[8] P. L. Hower, W. W. Hooper, B. R. Cairns, R. D. Fairman and D. A. Tremer, In Semiconductors and Semimetals vol. 7A, Academic Press, 1971.
[9] H. H. Berger,”Models for Contacts to Planar Devices,” Solid-St. Electron., vol. 15, pp. 145-158, 1972.
[10] H. H. Berger, “Contact Resistance and Contact Resistivity,” J. Electrochem. Soc., vol. 119, pp. 507-514, 1972.
[11] H. Murrmann and D. Widmann, “Current Crowding on Metal Contacts to Planar Devices,” IEEE Trans. Electron Devices, vol. ED- 16, pp. 1022-1024, 1969.
[12] S. Dhar and B. R. Nag, “A Pulse Method for the Measurement of Contact Resistance and Bulk Resistance of Semiconductors Samples,” J. Electrochem. Soc., vol. 125, pp. 508-510, 1978.
[13] R. H. Cox and H. Strack, “Ohmic Contacts for GaAs Devices,” Solid-St. Electron., vol. 10, pp. 1213-1218, 1967.
[14] A. Martinez, Thesis, Universite Paul Sabatier, Toulouse , 1976.
[15] Y. K. Fang, C. Y. Chang and Y. K. Su, “Contact Resistance in Metal-Semiconductor Systems, “ Solid-St. Electron., vol. 22, pp. 933-938, 1979.
[16] L. E. Terry and R. W. Wilson, “Metallization Systems for Silicon Integrated Circuits,” Proc. IEEE, vol. 57, 1580-1586, 1969.
[17] E. Kuphal, “Low Resistance Ohmic Contancts to n- and p-InP,” Solid-St. Electron., vol. 24, pp. 69-78, 1981.
[18] W. Shockly, Rep. No. AL-TDR-64-207, Air Force Atomic Laboratory, Wright-Patterson AFB, OH, 1964.
[19] H. Murrmann and D. Widmann, “Messung Des Ubergangswiderstandes zwi-
schen metall und diffusionsschicht in Si-planar elementen,” Solid-St. Electron., vol. 12, pp. 879-886, 1969.
[20] G. K. Reeves and H. B. Harrison, “Obtaining the Specific Contact Resistance Transmission Line Model Measurements,” IEEE Electron Device Lett., vol. EDL-3, pp. 111-113, 1982.
[21] A. M. Goodman, “Metal-semiconductor barrier height measurement
by differential capacitance method-One carrier system,” J. Appl. Phys., vol. 34,
pp. 329-338, 1963.
[22] R. H. Fowler, “The analysis of photoelectric sensitivity curves for clean metals
at various temperatures,” Phys. Rev., vol. 38, 45-56, 1931.
References of Chapter 3
[1] W. F. Kosonoky, “Review of Schottky-barrier imager technology(Invited Paper),” SPIE proceedings, Infrared Detectors and Focal Plane Arrays, Orlando, 1308, pp. 2-26, SPIE Press, Washington, 1990.
[2] D. L. Clark and J.R. Berry, G. L. Compagna, “Design and performance of a 486 x 640 pixel platinum silicide IR imaging system,” SPIE Proceedings, Infrared Technology XVII, San Diego, 1540, pp. 303-311, SPIE Press, Washington, DC, 1991.
[3] N. Yutani, H. Yagi, M. Kimata, J. Nakanishi, S. Nagayoshi, and N. Tsubouchi, in: Proceeding of the International Electron Devices Meeting, Detectors, Sensors, and Displays-Charge Coupled Devices and MSM Photodetector, Washington DC, pp. 175-178, 1991.
[4] H. B Ghozlene, P. Beaufrére, and A. Authier, “Crystallography of PtSi Films on (001) silicon,” J. Appl. Phys., vol. 49, pp. 3998-4004, 1978.
[5] K. Fuji, H. Kanaya, Y.Kumagai, F. Hasegawa, and E. Yamaka, “Low-Temperature Formation of the PtSi Layer by Codeposition of Pt and Si in a Molecular Beam Epitaxy System,” Jpn.. J. Appl. Phys., vol. 30, pp. L455-L457, 1991.
[6] K. Konuma and H. Utsumi, “Epitaxial orientation of PtSi grown by Pt deposition on heated Si(100) substrate,” J. Appl. Phys., vol. 76, pp. 2181-2184, 1994.
[7] Y. Kumagai, K. Ishimoto, S. Hashimoto, K. Park, and F. Hasegawa, “Comparison of Planar to Columnar Transformation of PtSi Layers on Si(001) and Si(111) Substrates in the Si Capping Layer Growth Process,” Jpn.. J. Appl. Phys., vol. 34, pp. 4621-4626, 1995.
[8] G. J. Horng, C. Y. Chang, T. Chang, C. Ho, and C.S. Wu, “Microstructure Effect on Quantum Efficiency in PtSi/p-Si(100) Schottky Barrier Detector,” J. Materials Chem. and Phys., vol. 68, pp. 17-21, 2001.
[9] H. Elabd and W.F. Kosonocky, “Theory and Measurements of Photoresponse for Thin Film Pd2Si and PtSi Infrared Schottky-Barrier Detectors with Optical Cavity,” RCA review, vol. 43, pp. 569-589, 1982.
[10] P. G. McCafferty, A. Sellai, P. Dawson, and H. Elabd, “Barrier Characteristics of PtSi/p-Si Schottky Diodes as Determined from I-V-T Measurements,” Solid-St. Electron., vol. 39, pp. 583-592, 1996.
[11] W. A. Cabanski and M.J. Schulz, “Electronic and IR-Optical Properties of Silicide/Silicon Interface,” Infrared Phys., vol. 32, pp. 29-44, 1991.
[12] B. R. Capone, R.W. Taylor, and W.F. Kosonocky, ”Design and characterization of a Schottky infrared charge coupled device (IRCCD) focal plane array,” Opt. Eng., vol. 21, pp. 945-950, 1982.
[13] V. L. Dalel, “Simple Model for Internal Photoemission,” J. Appl. Phys., vol. 46, pp. 2274-2279, 1971.
[14] J. Silverman, P. Pellegrint, J.Comer, A. Golvbovic, M. Weeks, J. Mooney, and J. Fitzgerald, Mater. Res. Soc. Symp. Proc., vol. 54, pp. 515-520, 1986.
[15] J. M. Moony and J. Silverman, “The Theory of Hot-Electron Photoemission in Schottky-Barrier IR Detectors,” IEEE Trans. Electron Devices, vol. ED-32, pp. 33-39, 1985.
References of Chapter 4
[1] G. H. Olsen, M. Ettenberg and R. V. D. Aiello, “Vapor-grown InGaP/GaAs solar cells,” Appl. Phys. Lett., vol. 33, pp. 606-608, 1978.
[2] S. H. Groves, Z. L. Liau, S. C. Palmateer and J. N. Walpole, “GaInP mass transport and GaInP/GaAs buried-heterostructure lasers,” Appl. Phys. Lett., vol.
56, pp. 312-314, 1990.
[3] D. Jung, K. Hyuga and S. M. Bedair, “GaInP/GaAs Schottky diodes grown by atomic layer epitaxy and their application to MESFETs,” Semicond. Sci. & Technol., vol. 9, pp. 2107-2117, 1994.
[4] M. Takikawa and K. Joshin, “Pseudomorphic n-InGaP/InGaAs/GaAs high electron mobility transistors for low-noise amplifiers,” IEEE Electron Device Lett., vol. EDL-14, pp. 406-408, 1993.
[5] H. P. Shiao, C. D. Tsai, Y.K. Tu, W. Lin ande C. T. Lee, The Pacific Rim conference on Lasers and Electro-Optics (CLEO), p.96, 1995.
[6] H. P. Shiao, C. Y. Wang, Y. K. Tu, W. Lin and C. T. Lee, “InGaP/GaAs Multiquantum Barrier Structures Prepared by Low-Pressure Organometallic Vapor Phase Epitaxy,” Solid-St. Electron., vol. 38, pp. 2001-2004, 1995.
[7] K. Shiojima, K. Nishimura, T. Aoki and F. Hyuga, “Large Schottky barrier formed on epitaxial InGaP grown on GaAs,” J. Appl. Phys., vol. 77, 390-392, 1995.
[8] M. Ozeki, K. Kodama and A. Shibatoni, Gallium Arsenide and Related Compounds (Inst. Phys. Conf. Ser. 63), p.323, 1981.
References of Chapter 5
[1] Y. Shiraishi, N. Furuhata, A. Okamoto, “Influence of metal/n-InAs/interlayer/n-GaAs structure on nonalloyed ohmic contact resistance,” J. Appl. Phys., 76, pp. 5099-5110, 1994.
[2] C. K. Peng, T. Won, J. Chen, C. Litton, H. Morkoc, “High-gain n-p-n and p-n-p InGaAs/InAlAs double-heterojunction bipolar transistors with InAs cap layers by molecular-beam epitaxy,” IEEE Trans. Electron Devices, 35, pp. 2445-2446, 1988.
[3] S. S. Chen, C. C. Lin, W. H. Lan, S. L. Tu, C. K. Peng, ”Characteristics of Nonalloyed Pseudomorphic High Electron Mobility Transistors Using InAs/InxGa1-xAs(x = 12> 0)/AlyGa1-yAs(y = 02> 0.3) Contact Structures,” Jpn. J. Appl. Phys., vol. 36, pp. 3443-3447, 1997.
[4] J. M. Woodall, J. L. Freeouf, G. D. Pittit, T. J. Jackson, P. Kirchner, “Ohmic Contacts to n-GaAs Using Graded Band Gap Layers of Ga1-xInxAs Grown by Molecular Beam Epitaxy,” J. Vac. Sci. Technol., vol. 19, pp. 626-627, 1981.
[5] C. T. Lee, H.P. Shiao, N. T. Yeh, C. D. Tsai, Y. T. Lyu, Y. K. Tu,”Thermal Reliability and Characterization of InGaP Schottky Contact with Ti/Pt/Au Metals,” Solid-St. Electron., vol. 41, pp.1-5, 1997.
[6] C. K. Peng, G. Ji, N. S. Kumar, H. Morkoc, “Extremely low resistance nonalloyed ohmic contacts on GaAs using InAs/InGaAs and InAs/GaAs strained-layer superlattices,” Appl. Phys. Lett., 53, pp. 900-901, 1988.
[7] I. Mehdi, U. K. Reddy, J. Oh, J. R. East, G. I. Hadded, “Nonalloyed and alloyed low-resistance ohmic contacts with good morphology for GaAs using a graded InGaAs cap layer,” J. Appl. Phys., vol. 65, pp. 867-869, 1989.
[8] G. Stareev, H. Kunzel, “Tunneling behavior of extremely low resistancenonalloyed Ti/Pt/Au contacts to n(p)-InGaAs and n-InAs/InGaAs,” J. Appl. Phys., vol. 74, pp. 7592-7595, 1993.
[9] T. C. Shen, G. B. Gao, H. Morkoc, “Recent Developments in Ohmic Contacts for III-V Compound Semiconductors,” J. Vac. Sci. Technol., vol. B 10, pp. 2113-2132, 1992.
[10] J. W. Wu, C.Y. Chang, K. C. Lin, E. Y. Chang, J. S. Chen, C. T. Lee, “The Thermal Stability of Ohmic Contact to n-type InGaAs Layer,” J. Electron. Mater., vol. 24, pp. 79-82, 1995.
[11] Y. C. Chou, C. T. Lee, C. D. Chen, K. C. Chou, “Growth Temperature Dependence of Low-Noise MESFET in Molecular-Beam Epitaxy,” Electron. Lett., vol. 23, pp. 7-8, 1987.
[12] A. K. Sinha, T. E. Smith, M. H. Read, J. M. Poate, “N-GaAs Schottky diodes metallized with Ti and Pt/Ti,” Solid-St. Electron., vol. 19, pp. 489-492, 1994.
References of Chapter 6
[1] S. Strite and H. Morkoc, “GaN,AlN, and InN:A review,” J. Vac. Sci. Technol., vol. B 10, pp. 1237-1266, 1992.
[2] M. A. Khan, J. N. Kuznia, A. R. Bhattarai and D. T. Olson, “Metal Semiconductor Field Effect Transistor based on Single Crystal GaN,” Appl. Phys. Lett., vol. 62, pp. 1786-1787, 1993.
[3] M. A. Khan, A. R. Bhattarai, J. N. Kuznia and D. T. Olson, “High Electron Mobility Transistor based on a GaN-AlxGa1-xN heterojunction,” Appl. Phys. Lett., vol. 63, pp. 1214-1215, 1993.
[4] M. A. Khan, J. N. Kuznia, D. T. Olson, M. Blasingame and A. R. Bhattarai, “Schottky barrier photodetector based on Mg-doped p-type GaN films,” Appl. Phys. Lett., vol.. 63, pp.2455-2456, 1993.
[5] S. Nakamura, T. Mukai, and M. Senoh, “Candela-class high-brightness InGaN/AlGaN double-heterostructure blue-light-emitting diodes,” Appl. Phys. Lett. 64, pp. 1687-1689, 1994.
[6] X. H. Yang, T. J. Schmidt, W. Shan and J. J. Song, “Above room temperature near ultraviolet lasing from an optically pumped GaN film grown on sapphire,” Appl. Phys. Lett., vol. 66, pp. 1-3, 1995.
[7] M. E. Lin, Z. Ma, F. Y. Huang, Z. F. Fan, L. H. Allen and H. Morkoc, “Low Resistance Ohmic Contacts on wide band-gap GaN,” Appl. Phys. Lett., vol. 64, pp. 1003-1005, 1994.
[8] J. S. Foresi and T. D. Moustakes, “Metal contacts to gallium nitride,” Appl. Phys. Lett., vol. 62, pp. 2859-2861, 1993.
[9] J. D. Guo, C. I. Lin, M. S. Feng, F. M. Pan, G. C. Chi and C. T. Lee, “A bilayer Ti/Ag Ohmic Contact for highly doped n-type GaN films,” Appl. Phys. Lett., vol. 68, pp. 235-237, 1996.
[10] V. F. Masterov and L. F. Zakharenkov, “Rare-earth elements in III-V semiconductors (review),” Sov. Phys. Semicond., vol. 24, pp. 383-396, 1990.
[11] W. J. Ho, M. C. Wu, Y. K. Tu and H. H. Shih, “High responsivity GaInAs PIN photodiode by using erbium gettering,” IEEE Trans. Electron Dev. vol. ED-42, pp. 639-645, 1995.
[12] C. T. Lee, J. H. Yeh and Y. T. Lyu, “Characterization of Nd Doped AlGaAs Grown by Liquid Phase Epitaxy,” J. Crystal Growth, vol. 163, pp. 343-347, 1996.
[13] J. Burm, W. J. Schaff, L. F. Eastman, H. Amano and I. Akasaki, “75 Å GaN channel modulation doped field effect transistor,” Appl. Phys. Lett., vol. 68, pp. 2849-2851, 1996.
[14] S. Yoshida and J. Suzuki, “High-temperature reliability of GaN metal semiconductor field-effect transistor and bipolar junction transistor,” J. Appl. Phys., vol. 85, pp. 7931-7934, 1999.
[15] S. Nakamura, M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto and H. Kiyoku, “Room-temperature continuous-wave operation of InGaN multi-quantum-well-structure laser diodes with a long lifetime,” Appl. Phys. Lett., vol. 70, pp. 868-870, 1997.
[16] X. A. Cao, H. Cho, S. J. Pearton, G. T. Dang, A. P. Zhang, F. Ren, R. J. Shul, L. Zhang, R. Hickman and J. M. Van Hove, “Depth and thermal stability of dry etch damage in GaN Schottky diodes,” Appl. Phys. Lett., vol. 75, pp. 232-234, 1999.
[17] V. A. Dmitriev, K. G. Irvine, C. H. Carter,Jr., N. I. Kuznetsov and E. V. Kalinina, “Electric breakdown in GaN p-n junctions,” Appl. Phys. Lett., vol. 68, pp. 229-231, 1996.
[18] Z. Z. Bandic, P. M. Bridger, E. C. Piquette, T. C. McGill, R. P. Vaudo, V. M. Phanse and J. M. Redwing, “High voltage (450 V) GaN Schottky rectifiers,” Appl. Phys. Lett., vol. 74, pp. 1266-1268, 1999.
[19] B. Corbett and W. M. Kelly, “Surface recombination in dry etched AlGaAs/GaAs double heterostructure p-i-n mesa diodes,” Appl. Phys. Lett., vol. 62, pp. 87-89, 1993.
[20] J. L. Lee, J. K. Kim, J. W. Lee, Y. J. Park and T. Kim, “Effect of surface treatment by KOH solution on ohmic contact formation of p-type GaN,” Solid-St Electron., vol. 43, pp.435-438, 1999.