Reliability of ALD Hf_1-XZr_xO₂ Deposited by Intermediate Annealing or Intermediate Plasma Treatment

Abstract

The reliability of atomic layer deposited Hf1-xZrxO2 with x=0.8 on a SiON interfacial layer (IL) has been analyzed in detail for three different oxide deposition processes, (i) DADA: samples were subjected to dielectric deposition and thermal annealing in a cyclical process; (ii) DSDS: samples were subjected to similar cyclical process with dielectric deposition and exposure to Ar plasma; and (iii) As-Dep: the dielectric for the control samples was deposited without any intermediate step. Capacitance-voltage and current-voltage characteristics of the MOS capacitors (MOSCAP) with metal gate (TiN), subjected to a constant field stress of 2.75 × 107 V/cm in the gate injection mode, show that the flat-band voltage shift (∆VFB ) and stress induced leakage current (SILC) below 100 s stress is the lowest for DSDS samples whereas the worst degradation was observed for DADA samples. However, identical degradation was observed in all sample types when stress was increased to 1000 s. Intermediate plasma exposure (DSDS process) seems to supress the oxide trap formation as it provides EOT downscaling ability and good reliability performance. The reliability characteristics, when compared with pure HfO2, seem to improve with the addition of ZrO2.

Post Plasma Oxidation Processed ALD Al2O3/Hf1-xZrxO2Thin Films on Ge Substrates: Reliability

“…5a). 7,15 Furthermore, the C-V characteristics show a typical partial inversion at 100 KHz ( Fig. 2a) and a complete inversion at 100 Hz ( Fig.…”

“…[4][5][6] ALD Hf 1-x Zr x O 2 with different Hf to Zr compositions has been explored as an alternative of HfO 2 since the tetragonal phase which has higher dielectric constant can be stabilized. [7][8][9] In addition, in situ control of Hf/Zr precursor ratio during the ALD process, better film deposition and oxide growth rate, and better quality interfacial layer are critical for higher-k dielectrics with enhanced electrical performance and reliability. 10 Slot-plane-antenna (SPA) plasma treatment has been shown to enhance the CVD and ALD grown oxides quality and reliability along with better interfacial layer properties when the films were exposed to SPA plasma during or after the deposition.…”

(Invited) Reliability Considerations of High-K Gate Dielectrics Deposited by Various Intermediate Treatment

“…Therefore, it can be concluded that the combination of alloying with ZrO 2 and intermediate plasma exposure enhances the reliability characteristics while reducing EOT (19).…”

Enhancing chemisorption efficiency and thin-film characteristics via a discrete feeding method in high-k dielectric atomic layer deposition for preventing interfacial layer formation

“…The formation of an interfacial layer results in capacitance reduction because such a layer has a low relative permittivity. 1–3 Additionally, interfacial layers induce leakage current degradation by acting as trap sites. The reliability of a DRAM capacitor is also deteriorated by its interfacial characteristics.…”