Self-ionized and inductively-coupled plasma for sputtering and resputtering

Abstract

A magnetron sputter reactor for sputtering deposition materials such as tantalum, tantalum nitride and copper, for example and its method of use, in which self-ionized plasma (SIP) sputtering and inductively coupled plasma (ICP) sputtering are promoted, either together or alternately, in the same or different chambers. Also, bottom coverage may be thinned or eliminated by ICP resputtering in one chamber and SIP in another. SIP is promoted by a small magnetron having poles of unequal magnetic strength and a high power applied to the target during sputtering. ICP is provided by one or more RF coils which inductively couple RF energy into a plasma. The combined SIP-ICP layers can act as a liner or barrier or seed or nucleation layer for hole. In addition, an RF coil may be sputtered to provide protective material during ICP resputtering. In another chamber an array of auxiliary magnets positioned along sidewalls of a magnetron sputter reactor on a side towards the wafer from the target. The magnetron preferably is a small, strong one having a stronger outer pole of a first magnetic polarity surrounding a weaker outer pole of a second magnetic polarity and rotates about the central axis of the chamber. The auxiliary magnets preferably have the first magnetic polarity to draw the unbalanced magnetic field component toward wafer. The auxiliary magnets may be either permanent magnets or electromagnets.

1 - 12 . (canceled) 
     
     
         13 . A tool for depositing metal into a hole having an aspect ratio of at least 4:1 and formed in a dielectric layer of a substrate, comprising: a transfer chamber; an IMP sputter chamber coupled to said transfer chamber and adapted to form an inductively coupled plasma in said IMP chamber and adapted to sputter deposit a deposition material comprising a metal in said hole in said inductively coupled plasma; and an SIP chamber coupled to said transfer chamber and adapted to form a self-ionized plasma in said SIP chamber and adapted to sputter deposit a deposition material comprising a metal in said hole in said self-ionized plasma. 
     
     
         14 . The tool of  claim 13  wherein said SIP chamber has sidewalls arranged around a central axis; a pedestal for supporting said substrate in said SIP chamber; a sputtering target positioned in opposition to said pedestal along said central axis, a processing space being defined in a region between said pedestal, said target, and said sidewalls; a magnetron positioned on a side of said target opposite said processing space; and auxiliary magnets disposed at least partially around said processing space having a first magnetic polarity along said central axis. 
     
     
         15 . The tool of  claim 14  wherein said target is spaced from said pedestal by a throw distance that is greater than 50% of a diameter of the substrate 
     
     
         16 . The tool of  claim 13  wherein said IMP chamber has a pedestal adapted to support and bias said substrate, and a said tool comprises a controller adapted to control said pedestal to bias said substrate to attract ions of said inductively coupled plasma to resputter deposition material. 
     
     
         17 . The tool of  claim 16  wherein said resputtering includes removing deposition material deposited on a bottom of said hole. 
     
     
         18 . The tool of  claim 13  wherein said SIP chamber has a sputter target comprising tantalum. 
     
     
         19 . The tool of  claim 13  wherein said SIP chamber has a sputter target comprising copper. 
     
     
         20 . The tool of  claim 13  wherein said IMP chamber has a sputter target comprising tantalum. 
     
     
         21 . The tool of  claim 13  wherein said IMP chamber has a sputter target comprising copper. 
     
     
         22 . The tool of  claim 13 , wherein said IMP chamber has an internal RF coil adapted to inductively couple RF energy to said inductively coupled plasma. 
     
     
         23 - 82 . (canceled)