The effect of post-deposition annealing on the chemical, structural and electrical properties of Al/ZrO2/La2O3/ZrO2/Al high-k nanolaminated MIM capacitors

Nanoscale dielectric properties of TiO2 in SiO2 nanocomposite deposited by hybrid PECVD method

“…The best compromise was obtained for a 3.8 nm-thick sublayer (ε r around 30 and dielectric loss around of 0.5 at 100 Hz) [9]. This apparent ε r enhancement, observed in various nanolaminates, is not only related to the permittivity of the involved materials but also to physical phenomena occurring at the interfaces such as charges accumulation by Maxwell-Wagner-type dielectric relaxation [9,15,16] or chemical modifications [9][10][11][12][13][14][15]. Moreover, for many nanolaminates, dielectric properties improvement need high-temperature post-deposition annealing (i.e.…”

“…In a second approach, high-k multilayers stacking or nanolaminates were investigated since they lead to a reduction in leakage current and an increase in ε r which depends on the number of layers [1]. Studies on various dielectric stacks are reported in the literature, mainly developed by Atomic Layer Deposition (ALD), as TiO 2 -Al 2 O 3 [9], HfO 2 -Al 2 O 3 [10], VO 2 -SiO 2 [11], Ta 2 O 5 -HfO 2 [12], ZrO 2 -HfO 2 [12], Ta 2 O 5 -ZrO 2 [12], HfO 2 -SiO 2 [13] or ZrO 2 -La 2 O 3 [14]. These stacks associate layers of high-k materials with highly insulating ones as SiO 2 or Al 2 O 3 [15].…”

“…Moreover, for many nanolaminates, dielectric properties improvement need high-temperature post-deposition annealing (i.e. up to 700 °C-800 °C) [12][13][14][15] that could be a limitation for the integration in microelectronic devices. A third approach based on Nanocomposites (NC) appears promising, since results on nanolaminates demonstrate that interfaces have a strong influence on relative dielectric permittivity increasing [15].…”

Dielectric Constant Enhancement and Leakage Current Suppression of Metal–Insulator–Metal Capacitors by Atomic Layer Annealing and the Capping Layer Effect Prepared with a Low Thermal Budget

“…13−15 However, it is difficult for a single ZrO 2 layer to achieve a low leakage current density due to the presence of vacancy-type defects (such as oxygen vacancies) while keeping a low EOT. 16 Hence various oxide stack structures, such as ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ), 17,18 ZrO 2 /SiO 2 / ZrO 2 (ZSZ), 19,20 ZrO 2 /Y 2 O 3 /ZrO 2 (ZYZ), 21 and ZrO 2 / La 2 O 3 /ZrO 2 (ZLZ), 22 have been proposed and investigated, in which the ZAZ structure is the most widely used oxide stack in MIM capacitors in recent years. 17,18 The introduction of an Al 2 O 3 interlayer into the oxide stack can suppress the leakage current.…”

“…In recent decades, high- K dielectrics have been intensively studied to meet the specification of high-performance MIM capacitors. − Among the high- K dielectrics, ZrO 2 is attractive because of its high dielectric constant, large energy bandgap, and excellent compatibility with semiconductor fabrication processes. − However, it is difficult for a single ZrO 2 layer to achieve a low leakage current density due to the presence of vacancy-type defects (such as oxygen vacancies) while keeping a low EOT . Hence various oxide stack structures, such as ZrO 2 /Al 2 O 3 /ZrO 2 (ZAZ), , ZrO 2 /SiO 2 /ZrO 2 (ZSZ), , ZrO 2 /Y 2 O 3 /ZrO 2 (ZYZ), and ZrO 2 /La 2 O 3 /ZrO 2 (ZLZ), have been proposed and investigated, in which the ZAZ structure is the most widely used oxide stack in MIM capacitors in recent years. , The introduction of an Al 2 O 3 interlayer into the oxide stack can suppress the leakage current. , However, it results in a decrease in the capacitance . The crystallinity of ZrO 2 on the upper layer of Al 2 O 3 is deteriorated by the Al 2 O 3 interlayer, resulting in a decrease in the dielectric constant. , In order to get a good crystallinity of ZrO 2 overlying the Al 2 O 3 interlayer, the postannealing treatment at a temperature of ∼600 °C is usually needed. ,− Nevertheless, the high-temperature annealing leads to an increase in leakage current as a result of the generation of grain boundaries, which hinders the reduction of the oxide thickness in the MIM structure for further EOT scaling .…”