特征在于低于约10的介电常数(k)且具有至少约2.5 g/cm3的密度的介电质AlO、AlOC、 AlON、及AlOCN薄膜，被沉积在部分已制成半导体设备上作为蚀刻终止层及/或扩散阻障层。在一实施例中，在iALD制程腔室中将包含暴露介电质层(例如ULK介电质)与暴露金属层的基板与含铝化合物(例如三甲基铝)接触，并允许含铝化合物吸附在基板的表面上。此步骤系在无等离子的情况下运行。接下来，将未吸附的含铝化合物从制程腔室中移除，并在等离子中使用包含CO2或N2O及惰性气体的制程气体来处理基板，以形成AlO、AlOC、AlON、或AlOCN层。然后重复运行这些步骤。

Dielectric AlO, AlOC, AlON and AlOCN films characterized by a dielectric constant (k) of less than about 10 and having a density of at least about 2.5 g/cm3are deposited on partially fabricated semiconductor devices to serve as etch stop layers and/or diffusion barriers. In one implementation, a substrate containing an exposed dielectric layer (e.g., a ULK dielectric) and an exposed metal layer is contacted with an aluminum-containing compound (such as trimethylaluminum) in an iALD process chamber and the aluminum-containing compound is allowed to adsorb onto the surface of the substrate. This step is performed in an absence of plasma. Next, the unadsorbed aluminum-containing compound is removed from the process chamber, and the substrate is treated with a process gas containing CO2or N2O, and an inert gas in a plasma to form an AlO, AlOC, or AlON layer. These steps are then repeated.