Gate Engineering in TiN/La/TiN and TiLaN Metal Layers on Atomic-Layer-Deposited $\hbox{HfO}_{2}/\hbox{Si}$

Electrical Properties of ZrO2/Al2O3/ZrO2‐Based Capacitors with TiN, Ru, and TiN/Ru Top Electrode Materials

“…This TiO x N y layer must have adversely interfered with the electrical properties of the ZAZ film by decreasing the overall capacitance density. The absence of this adverse layer in Figure b indicates that this layer can be removed by the oxygen scavenging effect of the adopted TiN top electrode layer . This will be discussed in greater detail later.…”

“…The TiN or La‐doped TiN metal gate layer, which was deposited on 4 nm‐thick HfO 2 /Si, efficiently reduced the thickness of the interfacial SiO x layer between HfO 2 and Si which was formed before the metal gate deposition. Moreover, after post‐deposition annealing, the interface SiO x layer disappeared almost completely . This improved the total capacitance density of the MIS structure without significant leakage degradation.…”

“…Nonetheless, the TiN top electrode has its own merit: it has good adhesion to the SiO 2 layer (interlayer dielectric), making the integration process efficient. In the case of the TiN/HfO 2 /Si metal‐insulator‐semiconductor (MIS) structure, the almost unavoidable interfacial SiO 2 (or SiO x ) layer at the HfO 2 /Si interface can be reduced by the scavenging effect of the TiN electrode on the oxygen atoms, which contributes to the increase in the total capacitance of the MIS structure . While the Si‐O bonding energy is usually higher than the Ti‐O bonding energy, TiN plays the role of a (remote) oxygen scavenger.…”

“…Second, the oxygen‐scavenging effect of the TiN layer should be considered. It has been extensively reported in the MIS field effect transistor field that several metal gate electrodes – including TiN, which has a higher oxidation potential – scavenge oxygen atoms from the interfacial oxide layer at the high‐k gate insulator/semiconductor interface even though the electrodes do not directly contact the interface . The authors’ group has studied this bottom interfacial layer elimination through the top electrode process in depth.…”

Structural and electrical properties of Nb/NbN gates on HfO2 gate dielectrics

“…Metal nitrides used for metal gate applications have been widely investigated because of their good thermal stability, good characteristics of their oxygen diffusion barrier, and tunable work functions [8][9][10][11][12][13][14][15].…”