N-channel single crystal Si nanoparticle schottky barrier transistor

In this work, we report n-channel Si nanoparticle Schottky barrier transistors with a vertical current flow structure. A YbSi_x Schottky barrier junction was used as a source/drain junction to make electrons majority carriers in nanoparticle transistor since the nanoparticles were intrinsic. Si nanoparticles were generated by a plasma aerosol method and directly deposited on source patterns. A layer of SiO₂ was initially used as the gate insulator. This was deposited by PECVD and annealed at 500°C in O ₂ producing a final thickness of approximately 2.5nm. In subsequent lots, this layer was replaced by HfO₂ to suppress short channel effects. The physical thickness of the HfO₂ was 4.5nm. The channel length of all devices was 15nm using a Cr metal gate. The Schottky barrier height of the YbSi_x junction was 0.68 eV to p-type Si. The effective electrical thickness of the HfO₂ gate oxide is 1.45nm with leakage current of 0.2A/cm² at 2.0V. I_D-V_D characteristic of the initial lot show that majority carriers are electrons and that the channel carrier concentration is modulated by gate bias but it dose not saturated due to short channel effects and contact resistance.