Physical Structure and Inversion Charge at a Semiconductor Interface with a Crystalline Oxide

Abstract

We show that the physical and electrical structure and hence the inversion charge for crystalline oxides on semiconductors can be understood and systematically manipulated at the atomic level. Heterojunction band offset and alignment are adjusted by atomic-level structural and chemical changes, resulting in the demonstration of an electrical interface between a polar oxide and a semiconductor free of interface charge. In a broader sense, we take the metal oxide semiconductor device to a new and prominent position in the solid-state electronics timeline. It can now be extensively developed using an entirely new physical system: the crystalline oxides-on-semiconductors interface.

Ultrafast structural dynamics of perovskite superlattices

“…2(b)). The lattice parameters and, thus, the ferroelectric properties of thin PZT layers can be changed over a wide range, e.g., by tailoring the strain in the layer [2][3][4]. The two lattice coordinates essential for the ferroelectric properties are the tetragonality η = c/a and the socalled soft mode coordinate ξ (Fig.…”

“…Polar solids crystallizing in a perovskite structure have received much interest because of their particular structural and electronic properties [1][2][3][4][5]. Electronic and/or spin correlations in such materials give rise to charge ordering, ferroelectricity, superconductivity, ferromagnetism and other phenomena.…”

Monolithic integration of perovskites on Ge(001) by atomic layer deposition: a case study with SrHfxTi1-xO3

“…However, the absence of grain boundaries in amorphous films is a potential advantage as grain boundaries can serve as defect trap sites. [11] Crystalline oxides have been reported on silicon [12][13][14] and germanium. [13,15] These crystalline oxides on semiconductors (COS) can offer high dielectric constants, perfection of the crystal structure at the oxide/semiconductor interface, and the possibility to coherently bond across the interface and minimize dangling bonds.…”

Atomic layer deposition of crystalline SrHfO3 directly on Ge (001) for high-k dielectric applications

“…However, crystalline oxides have the potential to create a nearly perfect electrical interface by drastically reducing the interface trap density (D it < 10 10 cm À2 eV À1 ). 19,20 For a material to be suitable as a gate dielectric replacement, it needs to satisfy several requirements, including high permittivity, sufficiently large band gap and proper band alignment (with 1 eV offset to both bands) to the semiconductor, thermodynamic stability, good film morphology, and high interface quality. Materials related to TiO 2 , including STO and BTO, have high permittivities, but the conduction band offsets with Si and Ge are very small to negligible.…”