Gap fill materials and bottom anti-reflective coatings comprising hyperbranched polymers

New anti-reflective or fill compositions having improved flow properties are provided. The compositions comprise a dendritic polymer dispersed or dissolved in a solvent system, and preferably a light attenuating compound, a crosslinking agent, and a catalyst. The inventive compositions can be used to protect contact or via holes from degradation during subsequent etching in the dual damascene process. The inventive compositions can also be applied to substrates (e.g., silicon wafers) to form anti-reflective coating layers having high etch rates which minimize or prevent reflection during subsequent photoresist exposure and developing.