Interfacial Dead-Layer Effects in Hf-Silicate Films with Pt or RuO₂ Gates

Abstract

The interfacial dead-layer (DL) effects at the interfaces between Hf-silicate films and Pt or RuO2 gate metals are examined. The Si content in the Hf-silicate film was controlled to vary the dielectric constant (k). The DL effect was strongly dependent on the k value of the Hf-silicate layer, and was suppressed when the Si content was increased to ∼80% (k ≈ 6). This Si content also coincides with the Fermi level pinning-free composition. Therefore, the optimum high-k gate dielectric structure could be a higher-k layer HfO2 capped with a lower-k layer (k ≈ 6) with minimum thickness (∼1 nm) for the best dielectric performance.

Atomic layer deposition of B2O3/SiO2 thin films and their application in an efficient diffusion doping process

“…Here, it should be noted that SiO 2 is assumed to be bulk glass (amorphous) and the density of B 2 O 3 was extracted from its crystallographic data since only a few percent s difference is expected even by assuming different structural phases. 28 Interestingly, we conrmed that the normalized areal oxygen density of B 2 O 3 is much higher than that of SiO 2 (Table 1). It implies that interface dipoles formed by the oxygen movement to the upper SiO 2 would trigger negative effective elds to the gate region, resulting in the reduction of V FB .…”

“…Herein, for both the SiO 2 and B 2 O 3 /up-SiO 2 cases, the Ru gate has an ideal EWF value of $4.8 eV, which is probably due to low interface trap densities between strongly covalent bonded SiO 2 and chemically inert Ru metal. 28 However, the notable thing is that the slope of the B 2 O 3 /up-SiO 2 lms is higher than that of SiO 2 lms, indicating the V FB shi to the (À) direction. This result agrees well with that in previous publications, which could be attributed to two possible reasons: (i) the presence of well-known positive xed charges in B 2 O 3 17,[29][30][31] and (ii) the formation of electric dipoles formed at the B 2 O 3 /SiO 2 interface.…”

Nano-composite MOx materials for NVMs

“…In this chapter, we concentrate on Si-and Ge-NCs floating gate memories with thin metal oxide high-κ dielectric stacks as HfO 2 (and its associated silicate) and Al 2 O 3 . There are many technological approaches used for the production of high-κ metal oxide dielectric films including or not NCs, such as ALD [34,35], different chemical vapor deposition (CVD) techniques [36][37][38], sol-gel process [39,40], and pulsed laser deposition [41,42]. Despite its flexibility, only few investigations have explored the potentialities of radio-frequency magnetron sputtering (RF-MS) [29,43,44].…”

Optical, structural and electrical characterizations of stacked Hf-based and silicon nitride dielectrics

“…There are many technological approaches used for the production of high-k dielectric films such as atomic layer deposition (ALD) [6,7], different chemical vapor deposition (CVD) techniques [8][9][10], sol-gel process [11,12], pulsed laser deposition [13,14] etc. However, despite its flexibility radio-frequency magnetron sputtering (RF-MS) was not often addressed [15,16].…”

“…The parameters of the stacked structures investigated. The EOT values for were estimated using the data for dielectric constants for Hf-based materials taken from Ref [6,10,27]…”