Abstract: Spin-on HSQ is employed to gap fill patterned metal layers in manufacturing ultra high density, multi-metal layer semiconductor devices. The degradation of deposited HSQ layers during formation of borderless vias, as from photoresist stripping using an O.sub.2 -containing plasma, is significantly reduced or prevented by including hydrogen in the stripping plasma. Embodiments include stripping in a plasma containing a sufficient amount of a forming gas (H.sub.2 /N.sub.2) to prevent reduction of the number of Si--H bonds of the deposited HSQ gap fill layer below about 70%, before and after solvent cleaning.

Abstract: Spin-on HSQ is employed to gap fill metal layers in manufacturing a high density, multi-metal layer semiconductor device. The degradation of deposited HSQ layers during formation of borderless vias, as from photoresist stripping using an O.sub.2 -containing plasma, is overcome by treating the degraded HSQ layer with an H.sub.2 -containing plasma to restore the dangling Si--H bonds, thereby passivating the surface and preventing moisture absorption, before filling the via opening with conductive material, such as a barrier layer.