Interaction of PbTiO₃ Films with Si Substrate

Abstract

An investigation was made of the reasons why ferroelectric PbTiO3 films are hard to grow on single-crystal Si substrates. PbTiO3 films were formed on Si(100) and MgO(100) single-crystal substrates, and X-ray photoelectron spectroscopy (XPS) was used to analyze the composition, chemical structure and oxidation state at the interface between the substrate and the film. It was found that lead, oxygen and silicon diffused markedly at the interface and that the PbTiO3 film experienced both a lead deficiency and Si diffusion. These phenomena are thought to be the reasons why it is difficult to form good PbTiO3 films on silicon substrates by chemical vapor deposition (CVD). It was observed that the addition of TiO2 and ZrO2 films at the interface with the silicon substrate reduced the diffusion of Si to the PbTiO3 film.

The Controlled Synthesis of Metastable Oxides Utilizing Epitaxy and Epitaxial Stabilization

“…Unfortunately, direct growth of functional oxides on silicon is frequently accompanied by extensive interdiffusion or chemical reactions that degrade the properties of the oxide, the underlying silicon, or both, and leads to electrically active defects at the semiconductor/oxide interface (D it ). [327][328][329][330][331][332][333] Such defects at the semiconductor/oxide interface preclude many potential applications, e.g., FeRAMs with a nondestructive readout based on the resistance of the semiconductor channel. [334][335][336][337][338][339][340][341][342][343] That PbTiO 3 , BaTiO 3 , and SrTiO 3 are all unstable in direct contact with silicon is evident from the chemical reactions below 344 …”

Fabrication and characterization of Au/SBT/LZO/Si MFIS structure

“…However, when the ferroelectric thin film is directly deposited on a silicon substrate, severe interfacial problems, such as interdiffusion, low-k oxide layer formation or crystalline quality degradation arise [3]. The metal-ferroelectricinsulator-semiconductor (MFIS) structure where the buffer insulator is inserted at the interface between the ferroelectric layer and Si substrate, has been proposed as a solution for interfacial problems [4].…”

Ferroelectric properties of SrBi2Ta2O9 thin films on Si (100) with a LaZrO x buffer layer

“…MFSFETs, where ferroelectric thin film is directly deposited on a silicon substrate, have some problems. These problems are, for example, interdiffusion of constituent elements, formation of an amorphous SiO 2 layer with a low-k dielectric constant at the interface of the ferroelectric film and Si substrate and crystalline quality degradation [3]. To solve these problems, we propose a metal-ferroelectric-insulator-semiconductor (MFIS) structure with a good insulator that works as buffer between the ferroelectric layer and Si substrate [4].…”