Demonstration of a silicon field-effect transistor using AlN as the gate dielectric

Abstract

As a precursor to cointegration of blue and ultraviolet light emitting nitrides with silicon microelectronics, an AlN on Si(111) metal‐insulator‐semiconductor field effect transistor has been fabricated and characterized. Current–voltage data show the threshold voltage and transconductance to be −0.8 V and 6 ms/mm, respectively, for a 50 nm insulator thickness. The ideal threshold voltage is 0.09 V. From the transconductance, a channel mobility of 45 cm²/V s is inferred. Capacitance versus voltage (C–V) measurements on a 210 nm film showed a flatband voltage of −4.2 V, corresponding to 8×10¹¹ cm⁻² trapped charges at the interface. Comparison of the experimental high‐frequency (1 MHz) C–V plot to the theoretical plot indicates the presence of fast interface states. High‐resolution transmission electron microscopy studies showed the AlN/Si(111) interface to be surprisingly well ordered in places, with the large lattice mismatch accommodated via a quasiperiodic array of misfit dislocations.