Depletion Mode MOSFET Using La-Doped BaSnO₃ as a Channel Material

Abstract

The high room-temperature mobility that can be achieved in BaSnO has created significant excitement for its use as channel material in all-perovskite-based transistor devices such as ferroelectric field effect transistor (FET). Here, we report on the first demonstration of n-type depletion-mode FET using hybrid molecular beam epitaxy grown La-doped BaSnO as a channel material. The devices utilize a heterostructure metal-oxide semiconductor FET (MOSFET) design that includes an epitaxial SrTiO barrier layer capped with a thin layer of HfO used as a gate dielectric. A field-effect mobility of ∼70 cm V s, a record high transconductance value of >2mS/mm at room temperature, and the on/off ratio exceeding 10 at 77 K were obtained. Using temperature- and frequency-dependent transport measurements, we quantify the impact of the conduction band offset at the BaSnO/SrTiO interface as well as bulk and interface traps on device characteristics.

Wide Bandgap Perovskite Oxides with High Room‐Temperature Electron Mobility

“…53,75,79,80 n-type BaSnO 3 on SrTiO 3 grown by hybrid molecular beam epitaxy (MBE) has a transmission of ~ 80%. 131 The optical transmission and room-temperature conductivity of BaSnO 3 are comparable to the value of transmission and room-temperature conductivity in ITO. 9,77 Theory predicts BaSnO 3 transmission in the visible range to be independent of doping.…”

“…Yue et al, however, reported that in devices based on SrTiO 3 (κ = 300) as the gate dielectric, the I on /I off ratio was poor (≈ 2) at room temperature and >10 7 at 77 K. The room-temperature field-effect mobility reported was 70 cm 2 V -1 s -1 compared to 90 cm 2 V -1 s -1 with LaInO 3 as the gate oxides. 126,131 These results also revealed that parameters such as the interface trap density and the band offset between the gate oxide and the channel material play a significant role. Use of a barrier layer of (Sr,Ba)SnO 3 between the gate oxide (parylene) and the BaSnO 3 channel was proposed by Fujiwara et al to suppress the interfacial scattering from traps, which resulted in a mobility of 52 cm 2 V -1 s -1 .…”

Ab-Initio Study of Electronic and Structural Properties for BaSnO3 Compound Using DFT Calculations and FP-LAPW Technique in Wein2k Software

“…The certain value of the volume which is minimum energy of the volume, after this value energy of the volume increases, this is called optimized equilibrium energy, because the system is in the equilibrium. pressure derivatives of the bulk modulus and Bulk modulus at 0 value [21,22,33]. Bulk…”

Perovskite oxides as transparent semiconductors: a review

“…According to the literature, BaSnO 3 (belonging to the perovskite family), shows a wide band gap (E g > 3.1 eV) [ 91 ], a high thermal stability [ 55 ], and a high carrier mobility up to 320 cm 2 ·V −1 ·s −1 in single crystals at room temperature [ 51 ] and 70 cm 2 ·V −1 ·s −1 in epitaxial films [52], respectively. Caused by the high mobility, BaSnO 3 -based materials have been used as a semiconductor layer in oxide thin film transistors (TFTs) [ 92 – 95 ] and other photoelectronic devices [ 96 – 98 ]. It should be mentioned that the mobility of BaSnO 3 is much higher than that of SrVO 3 .…”