Fabrication parameters dependent morphology variation of silicon thin film

Abstract

Achieving two dimensional quantum structure of silicon with welldefined tuneable morphology is an outstanding issue. We present the preliminary results on fabrication parameters dependent silicon thin film production using VHF-PECVD method. Five samples are prepared on Si(100) substrate with gold (Au) catalyst by adjusting different parameters such as deposition time, temperature and the flow of precursor gas. The samples morphology are analysed using FESEM. The results reveal that the silicon thin film appear to be smooth and crystal-like after an enormous amount of hydrogen is inserted together with the precursor gas (silane) during the deposition process. More interestingly, the films exhibit silicon nanowires as the deposition time is increased up to 1 hour. This morphological transformation is attributed to the vapour-liquid-solid (VLS) mechanism related to the deposition process. Our results may contribute towards the development of nanosilicon based optoelectronics.