대한전자공학회논문지SD (Journal of the Institute of Electronics Engineers of Korea SD)

대한전자공학회 (The Institute of Electronics and Information Engineers)
권호 표지

고전압 GaN 쇼트키 장벽 다이오드의 완충층 누설전류 분석

Analysis for Buffer Leakage Current of High-Voltage GaN Schottky Barrier Diode

  • 황대원 (고려대학교 전기전자전파공학부) ;
  • 하민우 (전자부품연구원 화합물소자연구센터) ;
  • 노정현 (전자부품연구원 화합물소자연구센터) ;
  • 박정호 (고려대학교 전기전자전파공학부) ;
  • 한철구 (전자부품연구원 화합물소자연구센터)
  • Hwang, Dae-Won (School of Electrical Engineering, Korea University) ;
  • Ha, Min-Woo (Compound Semiconductor Devices Research Center, Korea Electronics Technology Institute) ;
  • Roh, Cheong-Hyun (Compound Semiconductor Devices Research Center, Korea Electronics Technology Institute) ;
  • Park, Jung-Ho (School of Electrical Engineering, Korea University) ;
  • Hahn, Cheol-Koo (Compound Semiconductor Devices Research Center, Korea Electronics Technology Institute)
  • 투고 : 2010.09.06
  • 발행 : 2011.02.25
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초록

본 논문에서 실리콘 기판 위에 성장된 GaN 에피탁시를 활용하여 고전압 쇼트키 장벽 다이오드를 제작하였으며, 금속-반도체 접합의 열처리 조건에 따른 GaN 완충층 (buffer layer) 누설전류와 제작된 다이오드의 전기적 특성 변화를 연구하였다. Ti/Al/Mo/Au 오믹 접합과 Ni/Au 쇼트키 접합이 제작된 소자에 설계 및 제작되었다. 메사를 관통하는 GaN 완충층의 누설전류를 측정하기 위하여 테스트 구조가 제안되었으며 제작하였다. $700^{\circ}C$에서 열처리한 경우 100 V 전압에서 측정된 완충층의 누설전류는 87 nA이며, 이는 $800^{\circ}C$에서 열처리한 경우의 완충층의 누설전류인 780 nA보다 적었다. GaN 쇼트키 장벽 다이오드의 누설전류 메커니즘을 분석하기 위해서 Auger 전자 분광학 (Auger electron spectroscopy) 측정을 통해 GaN 내부로 확산되는 Au, Ti, Mo, O 성분들이 완충층 누설전류 증가에 기여함을 확인했다. 금속-반도체 접합의 열처리를 통해 GaN 쇼트키장벽 다이오드의 누설전류를 성공적으로 감소시켰으며 높은 항복전압을 구현하였다.

We have fabricated GaN Schottky barrier diode (SBD) for high-voltage applications on Si substrate. The leakage current and the electrical characteristics of GaN SBD are investigated by annealing metal-semiconductor junctions. Ohmic junctions of Ti/Al/Mo/Au and Schottky junctions of Ni/Au are used in the fabrication. A test structure is proposed to measured buffer leakage current through a mesa structure. When annealing temperature is increased from $700^{\circ}C$ to $800^{\circ}C$, measured buffer leakage current is also increased from 87 nA to 780 nA at the width of 100 ${\mu}m$. The diffusion of Au, Ti, Mo, O into GaN buffer layer increases the leakage current and that is verified by Auger electron spectroscopy. Experimental results show that the low leakage current and the high breakdown voltage of GaN SBD are achieved by annealing metal-semiconductor junctions.

키워드

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