Methods for achieving metal fill in small features

Abstract

A method of electroplating on a workpiece having a sub-30 nm feature generally includes applying a chemistry to the workpiece, the chemistry including a halide ion concentration in the range of about 55 ppm to about 250 ppm and a metal cation solute species, and applying an electric waveform for less than about 5 seconds, wherein the electric waveform includes a period of ramping of current and a period of pulse plating.

The embodiments of the disclosure in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A method of electroplating on a workpiece having a sub-30 nm feature, the method comprising:
 (a) applying a chemistry to the workpiece, the chemistry including a halide ion concentration in the range of about 55 ppm to about 250 ppm and a metal cation solute species; and   (b) applying an electric waveform for less than about 5 seconds, wherein the electric waveform includes a period of ramping of current and a period of pulse plating.   
     
     
         2 . The method of  claim 1 , wherein the metal cation is copper. 
     
     
         3 . The method of  claim 1 , wherein the halide ion concentration is in the range of about 120 ppm to about 150 ppm. 
     
     
         4 . The method of  claim 1 , wherein the halide ion is selected from the group consisting of chloride, bromide, and iodide ions, and combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the ramping of current is selected from the group consisting of linear continuous ramping, non-linear continuous ramping, or pulsed ramping. 
     
     
         6 . The method of  claim 1 , wherein the ramping period is for a period of less than about 0.1 seconds (100 msecs). 
     
     
         7 . The method of  claim 1 , wherein the ramping period begins after a delay period. 
     
     
         8 . The method of  claim 1 , wherein the ramping achieves a current level selected from the group consisting of in the range of about 1 amps to about 15 amps, and in the range of about 7 amps to about 15 amps. 
     
     
         9 . The method of  claim 1 , wherein the pulsing period is for a period of less than about 2 seconds (2000 msecs). 
     
     
         10 . The method of  claim 1 , wherein the pulsing period has a duty cycle in the range of about 20% to about 75%. 
     
     
         11 . The method of  claim 1 , wherein the pulsing period has a duty cycle of about 50%. 
     
     
         12 . The method of  claim 1 , wherein the individual pulses extend for a pulse length selected from the group consisting of about 1 msec to about 100 msec, about 5 msec to about 100 msec, and about 5 msec to about 50 msec. 
     
     
         13 . The method of  claim 1 , wherein the on current pulses are at a current level selected from the group consisting of in a range of about 1 to about 30 amps and in a range of about 4.5 to about 30 amps. 
     
     
         14 . The method of  claim 1 , wherein the off current pulses are at a current level in a range selected from the group consisting of about 0 amps to about 20 amps, about 0 amps to about 10 amps, and about 0 amps to about 5 amps. 
     
     
         15 . The method of  claim 1 , wherein the waveform further includes a triggered hot entry. 
     
     
         16 . A method of electroplating on a workpiece having a sub-30 nm feature, the method comprising:
 (a) applying a chemistry to the workpiece, the chemistry including a halide ion concentration in the range of about 55 ppm to about 250 ppm and a metal cation solute species; and   (b) applying an electric waveform, wherein the electric waveform includes a period of ramping of current for a period of less than about 100 msecs and a period of pulse plating for less than about 2 secs.   
     
     
         17 . A method of electroplating on a workpiece having a sub-30 nm feature, the method comprising:
 (a) applying a chemistry to the workpiece, the chemistry including a halide ion concentration in the range of about 120 ppm to about 150 ppm and a metal cation solute species; and   (b) applying an electric waveform, wherein the electric waveform includes a period of ramping of current for a period of less than about 100 msecs and a period of pulse plating for less than about 2 secs.