Methods of filling gaps with tungsten are described. The methods include a tungsten dep-etch-dep sequence to enhance gapfilling yet avoid difficulty in restarting deposition after the intervening etch. The first tungsten deposition may have a nucleation layer or seeding layer to assist growth of the first tungsten deposition. Restarting deposition with a less-than-conductive nucleation layer would impact function of an integrated circuit, and therefore avoiding tungsten “poisoning” during the etch is desirable. The etching step may be performed using a plasma to excite a halogen-containing precursor while the substrate at relatively low temperature (near room temperature or less). The plasma may be local or remote. Another method may be used in combination or separately and involves the introduction of a source of oxygen into the plasma in combination with the halogen-containing precursor.