Abstract
Tungsten thin film was deposited on p-(100) silicon substrate by using the LPCVD(low pressure chemical vapor deposition) technique. $WF_6$ was used as a source gas for tungsten and $SiH_4$ was used as a reducing gas for $WF_6$. Tungsten thin film was deposited by either SiH4 or Si substrate reduction of $WF_6$ under cold-wall condition and it was deposited by $SiH_4$ reduction of $WF_6$ under hot-wall condition. The crystal structure of deposited thin film under both conditions were identified to be bcc (body centered cubic). The physical and electrical properties of deposited thin films were investigated. The deposited film under hot-wall condition changed to $WSi_2$ film by the annealing under $800^{\circ}C.$ From the experimental results and theoretical considerations, the change of the crystal structure of the thin film by annealing was discussed. $WSi_2$ thin film, which was known to have good compatibility with Si substrate, could be produced under hot-wall condition although the film properties were superior under cold-wall condition.
저압 화학 기상 증착법을 사용하여 $WF_6$의 환원반응으로 텅스텐 박막을 p형 실리콘 (100)표면위에 증착하였다. Cold-wall조건에서는 실리콘 기판과 $SiH_4$를 각각 이용하여 $WF_6$를 환원시켜 텅스텐 박막을 증착하였으며 hot-wall 조건에서는 $WF_6$를 $SiH_4$로 환원시켜 증착하였다. 박막의 결정구조는 어느 조건에서나 체심입방구조를 이루었으며, 증착조건에 따른 박막의 물리적 및 전기적 특성을 조사하였다. 증착된 박막을 온도 $800^{\circ}C$에서 열처리한 결과 hot-wall 조건의 박막이 $WSi_2$로 변화하였다. Hot-wall과 cold-wall조건에서의 박막을 분석한 결과 박막의 특성은 cold-wall조건이 우수하나 hot-wall조건에서는 열처리 방법에 의하여 실리콘 기판과 적합성이 우수한 것으로 알려진 $WSi_2$ 박막의 제조가 가능함을 알 수 있었다.