Water-free Inherent selective pulsed chemical vapor deposition (CVD) of HfO₂/TiO₂ nanolaminates on Si and SiO₂ in preference to SiCOH has been studied. SiCOH is highly porous alkylated SiO₂, which is used as a nonreactive low-k dielectric. Ti(OⁱPr)₄ [titanium(IV) isopropoxide] and Hf(O^tBu)₄ [Hafnium tert butoxide] were used in the CVD study. Previous studies showed that metal alkoxide precursors could form oxide films through thermal decomposition. However, single oxide films greater than 2 nm can be rough due to crystallization. To solve this issue, HfO₂/TiO₂ nanolaminate structures were studied. With sequential dosing of each precursor in a supercycle at 300 °C sample temperature, HfO₂/TiO₂ nanolaminate films with thin (less than 3 nm) sublayers were selectively deposited. The films were smooth with root mean square (RMS) roughness lower than 0.5 nm and almost amorphous from XRD analysis; this is unexpected since both oxides readily crystalize. Amorphous nanolaminate oxide film deposition with high selectivity was achieved by controlling each sublayer thickness and the Hf:Ti ratio. TEM studies proved that ∼ 20 nm of the nanolaminate film could also be selectively deposited on nanoscale patterned surfaces. This selective amorphous nanolaminate oxide CVD process has a potential to be applicable in the nanoscale patterning in MOSFET fabrication.

已经研究了 HfO ₂ /TiO ₂纳米层压材料在 Si 和 SiO ₂上的固有选择性脉冲化学气相沉积 (CVD)，而不是 SiCOH。SiCOH 是高度多孔的烷基化 SiO ₂，​​用作非反应性低 k 电介质。Ti(O ⁱ Pr) ₄ [异丙醇钛(IV)]和Hf(O ^t Bu) ₄ [叔丁醇铪]用于CVD研究。以前的研究表明，金属醇盐前体可以通过热分解形成氧化膜。然而，大于 2 nm 的单层氧化膜会因结晶而变得粗糙。为了解决这个问题，HfO ₂ /TiO ₂纳米层压结构进行了研究。在 300 °C 样品温度下，在超级循环中按顺序添加每种前体，HfO ₂ /TiO ₂选择性沉积具有薄（小于 3 nm）子层的纳米层压薄膜。薄膜光滑，均方根 (RMS) 粗糙度低于 0.5 nm，XRD 分析几乎是无定形的；这是出乎意料的，因为两种氧化物都容易结晶。通过控制每个子层的厚度和 Hf:Ti 比率，实现了具有高选择性的非晶纳米层压氧化物薄膜沉积。TEM 研究证明，约 20 nm 的纳米层压薄膜也可以选择性地沉积在纳米级图案化表面上。这种选择性非晶纳米层压氧化物 CVD 工艺有可能适用于 MOSFET 制造中的纳米级图案化。