한국정보통신학회논문지 (Journal of the Korea Institute of Information and Communication Engineering)

  • 제18권3호
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  • Pages.663-669
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  • 2014
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  • 2234-4772(pISSN)
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  • 2288-4165(eISSN)
한국정보통신학회 (The Korea Institute of Information and Commucation Engineering)
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HfO2 열처리 온도 및 두께에 따른 RRAM의 전기적 특성

Electrical Characteristics of RRAM with HfO2 Annealing Temperatures and Thickness

  • Choi, Jin-Hyung (Department of Electronics Engineering, Incheon National University) ;
  • Yu, Chong Gun (Department of Electronics Engineering, Incheon National University) ;
  • Park, Jong-Tae (Department of Electronics Engineering, Incheon National University)
  • 투고 : 2013.12.27
  • 심사 : 2014.03.05
  • 발행 : 2014.03.31
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초록

본 연구에서는 RRAM (Resistive Random Access Memory) 소자의 $HfO_2$ 열처리 온도와 두께에 따라 소자의 전기적 특성을 측정하였다. 제작한 소자는 상부전극이 Pt/Ti(150nm), 하부전극은 Pt(150nm), 산화층 $HfO_2$의 두께는 45nm와 70nm이고, 열처리를 하지 않은 소자와 $500^{\circ}C$, $850^{\circ}C$ 로 열처리를 한 3 종류이다. 온도에 따라 소자의 전기적 성능으로 셋/리셋 전압, 저항변화를 측정하였다. 온도에 따른 기본특성 분석 실험 결과 온도가 증가함에 따라 셋 전압은 감소하고 리셋 전압은 증가하여 감지 여유 폭이 감소하였다. 열처리 온도가 $850^{\circ}C$ 소자가 고온 특성이 가장 우수한 것을 보였다. $HfO_2$ 산화층의 두께 45nm 소자가 70nm 소자보다 감지 여유 폭이 크지만 결함으로 LRS(Low Resistive State)에서 저항이 큰 것으로 측정되었다. $HfO_2$ 산화층 증착 시 결함을 줄일 수 있는 공정조건을 설정하면 초박막의 RRAM 소자를 제작할 수 있을 것으로 기대된다.

The electrical characteristics of RRAM with different annealing temperature and thickness have been measured and discussed. The devices with Pt/Ti top electrode of 150nm, Pt bottom electrode of 150nm, $HfO_2$ oxide thickness of 45nm and 70nm have been fabricated. The fabricated device were classified by 3 different kinds according to the annealing temperature, such as non-annealed, annealed at $500^{\circ}C$ and annealed at $850^{\circ}C$. The set and reset voltages and the variation of resistance with temperatures have been measured as electrical properties. From the measurement, it was found that the set voltages were decreased and the reset voltage were increased slightly, and thus the sensing window was decreased with increasing of measurement temperatures. It was remarkable that the device annealed at $850^{\circ}C$ showed the best performances. Although the device with thickness of 45nm showed better performances in the point of the sensing window, the resistance of 45nm devices was large relatively in the low resistive state. It can be expected to enhance the device performances with ultra thin RRAM if the defect generation could be reduced at the $HfO_2$ deposition process.

키워드

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