Toru Ifuku, Masanori Otobe, Akira Itoh and Shunri Oda,

Tokyo Institute of Technology,
Department of Physical Electronics and Research Center for Quantum Effect Electronics,
Meguro-ku, Tokyo 152, Japan.
 

Recently, single electron charging effect has been demonstrated by using nanocrystalline Si (nc-Si) structures. We have fabricated nc-Si by SiH$_4 plasma cell with very-high-frequency (VHF) excitation [1,2]. However, it has been difficult to fabricate a uniform grain-sizestructure, which means the characteristics of single electron charging phenomena were not stable and were fluctuated. In this study, a new method using pulsed gas plasma technique to fabricate nc-Si is proposed in order to make a uniform grain-size structure. The grain size was controlled using pulsed gas supply of H$_2$ into SiH$_4$. The nucleation rate in the gas phase of SiH$_4$ plasma increasesduring supplying H$_2$, and the growth of nuclei can be suppressed. The next H$_2$ pulse effectively extract nc-Si out of plasma cell through the orifice to the substrates in the ultra-high-vacuum (UHV) chamber. With this method, fabrication of nc-Si with a diameter around 8nm and a narrow spread of grain size were realized successfully. Materials Research Society Symposium Proceedings; in Press; 学術誌; (1997)