A Study of Reactively Sputtered Ti-Si-N Diffusion Barrier for Cu Metallization

혼합기체 sputtering 법으로 증착된 Cu 확산방지막으로의 Ti-Si-N 박막의 특성 연구

  • Park, Sang-Gi (School of Metallurgical and Materials Engineering, Kookmin University) ;
  • Lee, Jae-Gap (School of Metallurgical and Materials Engineering, Kookmin University)
  • 박상기 (국민대학교 금속재료공학부) ;
  • 이재갑 (국민대학교 금속재료공학부)
  • Published : 1999.05.01

Abstract

We have investigated the physical and diffusion barrier property of Ti-Si-N film for Cu metallization. The ternary compound was deposited by using reactive rf magnetron sputtering of a TiSi$_2$target in an Ar/$N_2$gas mixture. Resistivities of the films were in range of 358$\mu$$\Omega$-cm, to 307941$\mu$$\Omega$-cm, and tended to increase with increasing the $N_2$/Ar flow rate ratio. The crystallization of the Ti-Si-N compound started to occur at 100$0^{\circ}C$ with the phases of TiN and Si$_3$N$_4$identified by using XRD(X-ray Diffractometer). The degree of the crystallization was influenced by the $N_2$/Ar flow ratio. The diffusion barrier property of Ti-Si-N film for Cu metallization was determined by AES, XRD and etch pit by secco etching, revealing the failure temperature of 90$0^{\circ}C$ in 43~45at% of nitrogen content. In addition, the very thin compound (10nm) with 43~45at% nitrogen content remained stable up to $700^{\circ}C$. Furthermore, thermal treatment in vacuum at $600^{\circ}C$ improved the barrier property of the Ti-Si-N film deposited at the $N_2$(Ar+$N_2$) ratio of 0.05. The addition of Ti interlayer between Ti-Si-N films caused the drastic decrease of the resistivity with slight degradation of diffusion barrier properties of the compound.

Keywords

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