Ionized pvd with sequential deposition and etching

Abstract

An iPVD apparatus ( ) is programmed to deposit material ( ) into high aspect ratio submicron features ( ) on semiconductor substrates ( ) by cycling between deposition and etch modes within a vacuum chamber ( ). The modes operate at different power and pressure parameters. Pressure of more than 50 mTorr, for example, is used for sputtering material from a target while pressure of less than a few mTorr, for example, is used to etch. Bias power on the substrate is an order of magnitude higher for etching, producing several hundred volt bias for etching, but only a few tens of volts for deposition. The alternating etching modes remove deposited material that overhangs edges of features on the substrate, removes some of the deposited material from the bottoms ( ) of the features, and resputters the removed deposited material onto sidewalls ( ) of the features. The substrate ( ) is cooled during deposition and etching, and particularly during etching to substantially below 0° C. RF energy is coupled into the chamber ( ) to form a high density plasma, with substantially higher RF power coupled during deposition than during etching. The substrate ( ) is moved closer to the plasma source during etching than during deposition.