Effective mobility and interface-state density of La2O3 nMISFETs after post deposition annealing

Abstract

Abstract:In this paper, we reported the effective mobility and the interface-state density of La 2 O 3 nMISFETs fabricated under different post deposition annealing (PDA) conditions; annealing temperature (300 • C -600 • C) and ambient (N 2 or O 2 ). High effective mobility of 312 cm 2 /Vs and low interface-state density of 6 × 10 10 cm −2 /eV were obtained from La 2 O 3 nMISFET with equivalent oxide thickness (EOT) of 1.7 nm after PDA at 300 • C in N 2 ambient for 10 minutes. Gate leakage current density was 6.8 × 10 −6 A/cm 2 . We found that peak effective mobility decreased with increasing anneal temperature, regardless of annealing ambient. We also observed a monotonous relationship between effective mobility and interface-state density. This behavior suggests that lowering the interface-state density is essential to obtain high mobility in the high-κ/Si structure. and Al 2 O 3 gate dielectrics with equivalent oxide thickness 5-10Å," Symp.

TiN Capping Effect on High Temperature Annealed RE-Oxide MOS Capacitors for Scaled EOT

“…Among high-k materials, RE-oxides are promising, since they can directly contact with Si substrate by forming silicate layer [3]. For instance, a satisfactory interfacial property with a peak effective mobility of over 300 cm 2 /Vs has been reported with La 2 O 3 dielectrics [4]. However, the excess oxygen supplied from the gate electrode to the La 2 O 3 dielectric increases the EOT especially with high-temperature processes ( Figure 1).…”

Impact of Alkali Earth Elements Incorporation on Electrical Characteristics of La2O3 Gated MOS Device

“…It has been reported that La 2 O 3 can achieve an EOT below 1 nm by forming a La-silicate layer with a k-value ranging from 8 to 14 at Si interface with fairly nice performance (2). However, it also suffers from the fixed charge-related mobility degradation at an EOT below 1.3 nm.…”

Carrier separation and Vth measurements of W-La2O3 gated MOSFET structures after electrical stress

“…Compared to other high-k materials, La 2 O 3 has been considered as a potential candidate for the long-term replacement of SiO 2 because of its relatively high dielectric constant and band offsets to silicon [1,2]. Moreover, since La 2 O 3 -gated transistors have presented good initial electrical characteristics [3], the research on this material should advance to the next stage where reliability data are collected and the understanding of the mechanisms for dielectric degradation and breakdown is identified in order to minimize the sources that lead to failure. In this report, we studied the impact of stress polarity on the breakdown and electrical degradation mechanisms of W-La 2 O 3 gated MOSFETs.…”