화학공학소재연구정보센터
Korean Journal of Materials Research, Vol.19, No.1, 28-32, January, 2009
Ni/4H-SiC Field Plate Schottky 다이오드 제작 시 과도 식각에 의해 형성된 Nickel_Titanium 이중 금속 Schottky 접합 특성과 공정 개선 연구
Characteristics of Nickel_Titanium Dual-Metal Schottky Contacts Formed by Over-Etching of Field Oxide on Ni/4H-SiC Field Plate Schottky Diode and Improvement of Process
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Silicon carbide (SiC) is a promising material for power device applications due to its wide band gap (3.26 eV for 4H-SiC), high critical electric field and excellent thermal conductivity. The Schottky barrier diode is the representative high-power device that is currently available commercially. A field plate edge-terminated 4H-SiC was fabricated using a lift-off process for opening the Schottky contacts. In this case, Ni/Ti dual-metal contacts were unintentionally formed at the edge of the Schottky contacts and resulted in the degradation of the electrical properties of the diodes. The breakdown voltage and Schottky barrier height (SBH, ΦB) was 107 V and 0.67 eV, respectively. To form homogeneous single-metal Ni/4H-SiC Schottky contacts, a deposition and etching method was employed, and the electrical properties of the diodes were improved. The modified SBDs showed enhanced electrical properties, as witnessed by a breakdown voltage of 635 V, a Schottky barrier height of ΦB=1.48 eV, an ideality factor of n=1.04 (close to one), a forward voltage drop of VF=1.6 V, a specific on resistance of Ron=2.1 mΩ-cm2 and a power loss of PL=79.6Wcm-2.
  1. Hu S, Sheng K, Solid-State Electron., 48(10), 1861 (2004)
  2. Itoh A, Kimoto T, Matsunami H, in Proceedings of Intemational Symposium on Power Semiconductor Devices & ICs, (Yokohama, Japan, May 1995), IEEE p. 101. (1995)
  3. Neudeck PG, Larkin DJ, Powel1 JA, Matus LG, Salupo CS, Appl. Phys. Lett., 64(11), 1386 (1994)
  4. Alok D, Baliga BJ, McLarty PK, IEEE Electron Device Lett., 15(10), 394 (1994)
  5. Weitze1 CE, Palmour JW, Carter CH, Jr, Nordquist KJ, IEEE Electron Device Lett., 15(10), 406 (1994)
  6. Pensl G, Choyke WJ, Physica B, 185(1-4), 264 (1993)
  7. Bluet JM, Ziane D, Guillot G, Tournier D, Brosselard P, Montserrat J, Godignon P, Superlattices Microstruct., 40(4-6), 399 (2006)
  8. Rhoderick EH, Williams RH, Metal-Semiconductor Contacts, 2nd ed., p.15 , Hammond P, Grimsdale RL, Oxford University Press, New York, USA (1988). (1988)
  9. Sullivan JP, Tung RT, Pinto MR, J. Appl. Phys., 70(12), 7403 (1991)
  10. Perez R, Mestres N, Montserrat J, Tournier D, Godignon P, Phys. Status Solidi A, 202(4), 692 (2005)
  11. Marc C, Vipin T, Madangarli P, Zhang Q, Sudarshan TS, IEEE Trans. Electron Devices, 48(12), 2659 (2001)
  12. Khemka V, Patel R, Chow TP, Gutmann RJ, Solid-State Electron., 43(10), 1945 (1999)
  13. Kim DW, Mast. Thesis (in Korean), p. 21-28, Seoul National University, Seoul (2004). (2004)
  14. Saxena V, Nong SJ, Steckl, IEEE Trans. Electron Devices, 46(3), 456 (1999)
  15. Skromme BJ, Luckowski E, Mater. Sci. Forum, 338(342), 1029 (2000)
  16. Zhao JH, Sheng K, International Journal of High Speed Electronics and Systems, 15(4), 821 (2005)