Fabrication of tunneling dielectric thin-film transistor with very thin SiN_x films onto source and drain

Abstract

Tunneling Dielectric Thin-Film Transistor (TDTFT), which was proposed to reduce the gate-off current by utilizing a tunneling effect, was fabricated in a bottom-gate structure. For the tunneling dielectric, a 1.7-nm-thick SiN_x film was deposited onto the source and drain by a low-pressure chemical vapor deposition (LPCVD) method. The gate-off current of the TDTFT was reduced less than 1/10 in comparison with a conventional TFT. Although the subthreshold characteristics and the g_m were degraded due to the tunnel resistance, it will be compensated by further thinning of SiN_x film or using the material with the barrier height lower than SiN_x.