SmScO 3 thin films as an alternative gate dielectric

Abstract

Samarium scandate thin films deposited on (100) Si have been investigated structurally and electrically. Rutherford backscattering spectrometry and transmission electron microscopy results show that the films are stoichiometric, amorphous, and smooth. X-ray diffraction analysis indicates that SmScO3 starts to crystallize at 900 °C. Capacitance and leakage current measurements reveal C-V curves with negligible hysteresis, a dielectric constant around 29 for 6 nm thick films, low leakage current densities in the range of 10−7 A/cm2, an effective oxide charge density of ∼5×1011 cm−2, and an interface trap density of 4.5×1011 (eV cm2)−1.

Maximizing performance for higher K gate dielectrics

“…Various groups have studied the properties of many other crystalline lanthanides and scandates [23][24][25][26][27][28][29][30][31][32][33] as recently reviewed by Schlom et al 34 Their band offsets have been measured by internal photoemission. 23,31 The interesting point about these oxides is that they all have a band gap of ϳ5.3-5.7 eV, as they have the same conduction band minimum of La or Sc d states.…”

Si-compatible candidates for high-κdielectrics with thePbnmperovskite structure

“…These compounds are at the focus of the present work. Some of them have been studied in thin-film form, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] but the full dielectric tensor of these materials has not yet been established, making the selection of materials best suited for high-applications difficult.…”

Investigation of terbium scandate as an alternative gate dielectric in fully depleted transistors

“…3 and 4͒ to LaScO 3 with ϭ28, 5 and even SmScO 3 with even ϭ29. 6 Both, bandgap and bandoffsets of these materials to silicon are sufficiently large. 7 Smooth, amorphous films can be deposited by different deposition techniques and most of the scandates remain amorphous in contact with silicon even when heated up to 1000°C.…”