The Transactions of the Korean Institute of Electrical Engineers C (대한전기학회논문지:전기물성ㆍ응용부문C)

The Korean Institute of Electrical Engineers (대한전기학회)
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The Effects of Etch Process Parameters on the Ohmic Contact Formation in the Plasma Etching of GaN using Planar Inductively Coupled $CH_4/H_2/Ar$ Plasma

평판 유도 결합형 $CH_4/H_2/Ar$ 플라즈마를 이용한 GaN 건식 식각에서 공정변수가 저항성 접촉 형성에 미치는 영향

  • Kim, Mun-Yeong ;
  • Tae, Heung-Sik (Dept.of Electronics Electrical Engineering, Kyungpook National University) ;
  • Lee, Ho-Jun (Uiduk University) ;
  • Lee, Yong-Hyeon ( Dept.of Electronics Electrical Engineering, Engineering College, Kyungpook National University) ;
  • Lee, Jeong-Hui ( Dept.of Electronics Electrical Engineering, Engineering College, Kyungpook National University) ;
  • Baek, Yeong-Sik ( Dept.of Electronics Electrical Engineering, Engineering College, Kyungpook National University)
  • 김문영 (慶北大 電子電氣工學部 大學院) ;
  • 태흥식 (慶北大 電子電氣工學部) ;
  • 이호준 (威德大 電子電氣工學部) ;
  • 이용현 (慶北大 電子電氣工學部) ;
  • 이정희 (慶北大 電子電氣工學部) ;
  • 백영식 (경북대 전자전기공학부)
  • Published : 2000.08.01
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Abstract

We report the effects of etch process parameters on the ohmic contact formation in the plasma etching of GaN. Planar inductively coupled plasma system with $CH_4/H_2/Ar$gas chemistry has been used as etch reactor. The contact resistance and the specific contact resistance have been investigated using transfer length method as a function of RF bias power and %Ar gas concentration in total flow rate. AES(Auger electron spectroscopy) analysis revealed that the etched GaN has nonstoichiometric Ga rich surface and was contaminated by carbon and oxygen. Especially large amount of carbon was detected at the sample etched for high bias power (or voltage) condition, where severe degradation of contact resistance was occurred. We achieved the low ohmic contact of $2.4{\times}10^{-3} {\Omega}cm^2$ specific contact resistance at the input power 400 W, RF bias power 150 W, and working pressure 10mTorr with 10 sccm $CH_4$, 15 sccm H2, 5 sccm Ar gas composition.

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References

  1. Seikoh Yoshida, 'Reliability of metal semiconductor field- effect transistor using GaN at high temperature,' Journal of Applied Physics, vol. 84, no. 5, pp. 2940, 1998 https://doi.org/10.1063/1.368448
  2. C.J. Sun, 'Quantum shift of band-edge stimulated emission in InGaN-GaN multiple quantum well light-emitting diodes,' Applied Physics Letters, vol. 70, pp. 2978, 1997 https://doi.org/10.1063/1.118762
  3. S. Nakamura, 'Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes,' Applied Physics Letters, vol. 69, pp. 4056, 1996 https://doi.org/10.1063/1.117816
  4. R.J. Shul, 'Comparison of dry etch techniques for GaN,' Electronics Letters, vol. 32, no. 15, pp. 1408, 1996 https://doi.org/10.1049/el:19960943
  5. C.B. Vartuli, '$Cl_2/Ar\;and\;CH_4/H_2/Ar$ dry etching of III-V nitrides,' Journal of Applied Physics, vol. 80, pp. 3705, 1996 https://doi.org/10.1063/1.363320
  6. S.J. Pearton, 'Inductively Coupled Plasma Etching of III - V Nitrides in $CH_4/H_2/Ar\;and\;CH_4/H_2/N_2$ Chemistries,' Journal of Electrochemical Society, vol. 144, no. 8, 1997 https://doi.org/10.1149/1.1837905
  7. A.T. Ping, 'Dry Etching of GaN Using Chemically Assisted Ion Beam Etching with HCI and $H_2/Cl_2$,' Journal of Electronic Materials, vol. 25, no. 5, pp. 825, 1996 https://doi.org/10.1007/BF02666643
  8. J.S. Foresi, 'Metal contacts to gallium nitride,' Applied Physics Letters, vol. 62, no. 22, pp. 2859, 1993 https://doi.org/10.1063/1.109207
  9. Dieter K. Schroder, Semiconductor Material and Device Characterization, John Wiley & Sons, Inc. pp. 99-120, 1990
  10. A.T. Ping, 'The Effects of Reactive Ion Etching-Induced Damage on the Characteristics of Ohmic Contacts to n-Type GaN,' Journal of Electronic Materials, vol. 27, no. 4, pp. 261, 1998 https://doi.org/10.1007/s11664-998-0397-4