ZT thin films produced by metal organic-chemical vapour deposition to be used as high-k dielectrics

Low-Energy Ar+ Ion-Beam-Induced Amorphization and Chemical Modification of Potassium Titanyl Arsenate (001) Crystal Surfaces

“…First we consider the case of the pristine KTA surface to establish the chemical state of cations in the crystal. The Ti 2p 3/2 peak at about 458.9 eV with a ∆E Ti 2p of 5.8 eV are in excellent agreement with the literature reports [28][29][30][31][32][33][34][35][36][37] and characterize the chemical state of Ti ions as Ti 4+ in KTA crystal. In general, the KTP-type framework is constructed by linked TiO 6 octahedra and PO 4 (AsO 4 in KTA) tetrahedra with covalent oxide bonds and KO n polyhedra with ionic bonds.…”

“…Alteration of the structure and chemical composition of materials due to energetic ions or neutral particles is the most important concern in physical chemistry of surfaces/interfaces. The mechanism of ion-induced alteration of single and/or binary component oxides is well established. − ,− The Ti-bearing oxides have been particularly investigated in the past to investigate the effect of ions, such as helium, argon, and oxygen, and neutral particles since these materials exhibit various stoichiometric states and multiple valence states of Ti. − ,− Formation of reduced states, such as Ti 3+ , Ti 2+ , and even metallic Ti, on the surfaces of TiO 2 and other Ti-bearing simple oxides due to ion beam-induced alteration, depending on the conditions, of surface layers is well-known. − Chemical changes are usually attributed to the preferential sputtering. However, the mechanism of multicomponent oxide crystals in not well-developed and requires further attention.…”

“…The observation that there is no shift in BE of Ti 2p doublet and no shoulder formation in the Ti 2p 3/2 component on the lower BE side clearly indicates that there is no change in chemical state of Ti. It is quite interesting to see that the interaction of the (001) KTA surfaces with Ar + ions does not generate reduced Ti that is typically observed for KTP family crystals and other titanates, [29][30][31][51][52][53] and practically all Ti remain in Ti 4+ state. The detailed XPS scans of As 3p doublet and As 3d establishes the chemical state of arsenic as As 5+ for 3).…”

“…[29][30][31][51][52][53][54][55] The Ti-bearing oxides have been particularly investigated in the past to investigate the effect of ions, such as helium, argon, and oxygen, and neutral particles since these materials exhibit various stoichiometric states and multiple valence states of Ti. [29][30][31][50][51][52][53][54] Formation of reduced states, such as Ti 3+ , Ti 2+ , and even metallic Ti, on the surfaces of TiO 2 and other Ti-bearing simple oxides due to ion beam-induced alteration, depending on the conditions, of surface layers is wellknown. [51][52][53][54] Chemical changes are usually attributed to the preferential sputtering.…”

X-ray photoelectron spectroscopy study of ZrO2∕TiO2∕Si stack

“…3 However, further investigation shows that there are still many issues of HfO 2 and ZrO 2 as high-k dielectrics, 4-6 such as interfacial layer formation, low crystallization temperature ͑Ͻ500°C͒, and high permeability to oxygen and boron penetration during their deposition and postannealing processing, which cause their equivalent oxide thickness ͑EOT͒ scaling and reliability concerns. 16,17 In fact, it has already been reported that ZrTiO 4 has a high dielectric constant ͑Ͼ30͒. Further EOT scaling requires dielectrics with both high dielectric constant and high crystallization temperature.…”