Sputtering method and apparatus with small diameter RF coil

An apparatus for processing a workpiece, the apparatus comprising:

• a chamber enclosing a plasma generation area;
• a target having a sputtering surface facing said workplace and constituting a source of material to be sputtered and adapted to be biased to attract ions;
• a workplace support adapted to support said workpiece;
• an RF coil for inductively coupling RF energy into a plasma, said RF coil being positioned between said target and said workplace support so that an amount of sputtered material from said target is ionized;
• and
• a shield having an inner diameter surrounding at least a portion of said RF coil;
• wherein said RF coil has an outer diameter that is 30 to 75 percent of the inner diameter of said shield and smaller than said target and said workpiece, so that at least a portion of said ionized material is directed back towards said target.

A method for sputter depositing a layer on a workplace in a chamber, comprising:

• providing a target said chamber so that at least a portion of said target and said workpiece directly face one another;
• positioning an RF coil in said chamber at a location between said target and workplace, said RF coil having a smaller outer diameter than that of said target;
• positioning in said chamber a shield having an inner diameter surrounding at least a portion of said RF coil so that said RF coil outer diameter is 75% or less of said shield inner diameter;
• supplying energy to said RF coil to form a plasma having a plasma density gradient therein;
• sputtering said target to form sputtered material;
• wherein said plasma density gradient directs a first amount of said sputtered material from a central region of said target back towards said target and said plasma density gradient directs a second amount of said sputtered material from an outer region of said target back towards said target, wherein said first amount is greater than said second amount.