Journal of the Korean Vacuum Society (한국진공학회지)

The Korean Vacuum Society (한국진공학회)
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Improved light extraction efficiency of vertical AlGaInP-based LEDs by n-AlGaInP surface roughening

n-표면 거칠기가 형성된 AlGaInP 수직형 적색 발광다이오드의 광추출효율 증가

  • 서재원 (국립순천대학교 재료금속공학과) ;
  • 오화섭 (국립순천대학교 재료금속공학과) ;
  • 송현돈 (에피플러스(주) 소자공정팀) ;
  • 박경욱 (에피플러스(주) 소자공정팀) ;
  • 유성욱 (에피플러스(주) 소자공정팀) ;
  • 박영호 (에피플러스(주) 소자공정팀) ;
  • 박해성 (에피플러스(주) 소자공정팀) ;
  • 곽준섭 (국립순천대학교 재료금속공학과)
  • Published : 2008.07.30
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Abstract

In order to increase extraction efficiency of AlGaInP-based vertical RED LEDs, chemical wet etching technique was produced by using a roughened surface with triangle-like morphology. A commonly used $H_3PO_4$-based solution was applied for chemical wet etching. The light extraction of AlGaInP LED was related to the n-side roughed surface morphology. The morphology of roughed surface is analyzed by the atomic force microscope (AFM). As a result, the roughed surface AlGaInP LED has a root-mean-square (RMS) roughness of 44 nm. The brightness shows 41% increase after roughening n-side surface, as compared to the ordinary flat surface LED.

AlGaInP 기반 수직형 적색 LED (Light Emitting Diode)의 광추출효율을 증가시키기 위하여 화학적 etching 기술을 이용하여 n-AlGaInP 표면에 삼각꼴 모양의 거칠기를 형성하였다. Etching은 $H_3PO_4$계의 용액을 이용하여 화학적 etching을 진행 하였다. AlGaInP etching은 광추출효율의 증가와 밀접한 관련을 갖고 있으며 AFM (Atomic Force Microscope)을 이용하여 AlGaInP 표면을 분석하여 약 44 nm의 RMS (root-mean-square) 거칠기가 형성됨을 알 수 있었다. 광추출효율은 기존 수직형 적색 LED보다 거칠기가 형성된 수직형 적색 LED에서 41%의 높은 발광 효율을 보임으로써 고효율 수직형 적색 LED의 가능성을 보였다.

Keywords

References

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