Nano-laminate vs. direct deposition of high permittivity gadolinium scandate on silicon by high pressure sputtering

High-kgadolinium scandate on Si obtained by high pressure sputtering from metal targets andin-situplasma oxidation

“…According to the C-V gate results of figure 7(a), this can be promoted by a low temperature treatment. The same effect was observed by our group in [17,22] were we used binary Gd 2 O 3 and Sc 2 O 3 to form the ternary material after the FGA. Focusing on the G-V gate curves of figure 7(b), before the FGA, the conductance is higher than after the FGA at moderate temperatures.…”

“…This top layer is the amorphous gadolinium scandate. As in previous works [17], there are not traces of the presence of a nanolaminate, confirming the intermixing promoted by our fabrication process. The thickness of the film is fairly uniform for all analyzed regions, and there are no indications of polycristallinity.…”

“…The targets can be fabricated with extremely high purity, and since the gas used is typically composed of high purity Ar, N 2 and O 2 , film contamination can be minimal. Non-elementary materials can be obtained with composite targets [17], by co-sputtering [18] or reactive sputtering [19]. Also a nanolaminate can be obtained by sequential sputtering.…”

“…In our group we deposited previously Gd 2−x Sc x O 3 by HPS but using oxide targets, either from a GdScO 3 target [17] or by annealing Gd 2 O 3 -Sc 2 O 3 nanolaminates [22]. In both approaches during the first stages of growth the bare Si surface was exposed to the oxygen present in the plasma that comes from the oxide target.…”

Limitations of high pressure sputtering for amorphous silicon deposition

“…More recently, HPS has been used to deposit high permittivity dielectrics such as HfO 2 and Gd 2 O 3 [10][11][12]. However, high pressure plasmas are known to be a propitious environment for the formation of dust particles [13] that could be related with the presence of undesirable species in the plasma.…”