提供了使用等离子体增强化学气相沉积（PECVD）形成高蚀刻选择性，低应力可灰化硬掩模（AHM）的方法。 在某些实施例中，所述方法包括以下步骤：在使用双射频等离子体源沉积AHM的同时，保持高频射频功率恒定，来脉冲低频射频功率。 根据各种实施例，低频射频功率可以在非零电平之间进行脉冲，或通过切换电源接通和断开。 因此，沉积的高选择性AHM可能由于一个或多个因素而具有降低的应力，包括降低AHM下的离子和原子撞击以及在AHM中捕获的氢的较低水平。

High etching selection using a PECVD (plasma enhanced chemical vapor deposition) also, it is provided with a method of forming the low stress AHM (ashable hard mask) of. In certain embodiments, the method may involve the step of maintaining a constant high frequency RF power and the low-frequency pulse radio-frequency power during deposition of the AHM uses dual-radio frequency plasma source. In accordance with various embodiments, the low frequency RF power is a non-pulse can be switched by turning on the power or between the zero level and the switching off. As a result of the high select AHM-deposited may also have a reduced stress due to one or more factors, including low levels of the trapped ions in the reduced and hydrogen atoms and AHM impinging on the AHM.