Plasma enhanced pulsed layer deposition

Abstract

A process system and a deposition method for depositing a highly controlled layered film on a workpiece is disclosed. The basic component of the apparatus is a pulsing plasma source that is capable of either exciting or not-exciting a first precursor. The pulsing plasma source includes an energy source to generate a plasma, and a plasma adjusting system to cause the plasma to either excite or not-excite a precursor. The precursor could flow continuously (an aspect totally new to ALD), or intermittently (or pulsing, standard ALD operation process). The deposition method includes the steps of pulsing the plasma to excite/not-excite the precursors and the ambient to deposit and modify the deposited layers. This procedure then can be repeated until the film reaches the desired thickness.

1 . A process system for depositing a highly controlled layered film on a workpiece, the process system comprising: 
 a process chamber;    at least one first precursor source that is coupled to the process chamber for providing a continuous flow of the at least one first precursor into the process chamber;    an energy source that is coupled to the process chamber for generating a plasma therein; and    a plasma adjusting system configured to repeat the following sequence: 
 (i) to turn on the plasma for a sufficient length of time to excite the at least one first precursor to promote a plasma-enhanced reaction of the at least one first precursor at the workpiece surface, and  
 (ii) to turn off the plasma for a sufficient length of time to prevent plasma excitation of the at least one first precursor thereby preventing a plasma-enhanced reaction of the at least one first precursor at the workpiece surface.  
   
   
   
       2 . The process system of  claim 1  wherein the energy source is selected from the group consisting of an inductive coupled plasma (ICP) source, capacitance plasma source, microwave guide plasma source, electron cyclotron resonance (ECR) plasma source, magnetron plasma source, and DC power plasma source.  
   
   
       3 . The process system of  claim 1  further including a heater for heating the workpiece to a process temperature.  
   
   
       4 . The process system of  claim 1  further including a second precursor source for providing at least one second precursor into the process chamber, wherein the at least one second precursor is provided only when the plasma is turned off.  
   
   
       5 . The process system of  claim 4  further including a third precursor source for providing at least one third precursor into the process chamber, wherein the at least one third precursor is provided only when the plasma is turned on.  
   
   
       6 . The process system of  claim 5  further including a fourth precursor source for providing at least one fourth precursor into the process chamber, wherein the at least one fourth precursor is provided only when the plasma is turned on.  
   
   
       7 . The process system of  claim 1  further including a third precursor source for providing at least one third precursor into the process chamber, wherein the at least one third precursor is provided only when the plasma is turned on.  
   
   
       8 . The process system of  claim 1  further including a fourth precursor source for providing at least one fourth precursor into the process chamber, wherein the at least one fourth precursor is provided only when the plasma is turned on.  
   
   
       9 . The process system of  claim 1  comprising a plurality of first precursor sources that are coupled to the process chamber for providing first precursors into the process chamber.  
   
   
       10 . The process system of  claim 1  wherein the plasma power level is in the range of 15 to 6000 watts when the plasma is turned on.  
   
   
       11 . The process system of  claim 1  further including means for evacuating the at least one first precursor.  
   
   
       12 . A process system for depositing a highly controlled layered film on a workpiece, the process system comprising: 
 a process chamber;    at least one first precursor source that is coupled to the process chamber for providing a pulsed flow of at least one precursor into the process chamber;    an energy source that is coupled to the process chamber for generating a plasma therein; and    a plasma adjusting system configured to repeat the following sequence: 
 (i) to turn on the plasma for a sufficient length of time to excite the at least one first precursor to promote a plasma-enhanced reaction of the at least one first precursor at the workpiece surface, and  
 (ii) to turn off the plasma for a sufficient length of time to prevent plasma excitation of the at least one first precursor thereby preventing a plasma-enhanced reaction of the at least one first precursor at the workpiece surface;  
   whereby the pulsed flow of the at least one first precursor is substantially synchronized with the plasma adjusting system so that there is no first precursor flow when the plasma is turned off and there is first precursor flow when the plasma is turned on.    
   
   
       13 . The process system of  claim 12  wherein the energy source is selected from the group consisting of an inductive coupled plasma (ICP) source, capacitance plasma source, microwave guide plasma source, electron cyclotron resonance (ECR) plasma source, magnetron plasma source, and DC power plasma source.  
   
   
       14 . The process system of  claim 12  further including a heater for heating the workpiece to a process temperature.  
   
   
       15 . The process system of  claim 12  further including a second precursor source for providing a continuous flow of at least one second precursor into the process chamber.  
   
   
       16 . The process system of  claim 15  further including a third precursor source for providing at least one third precursor into the process chamber, wherein the at least one third precursor is provided only when the plasma is turned off.  
   
   
       17 . The process system of  claim 16  further including a fourth precursor source for providing at least one fourth precursor into the process chamber, wherein the at least one fourth precursor is not excited by the plasma when the plasma is turned on.  
   
   
       18 . The process system of  claim 12  further including a third precursor source for providing at least one third precursor into the process chamber, wherein the at least one third precursor is provided only when the plasma is turned off.  
   
   
       19 . The process system of  claim 12  further including a fourth precursor source for providing at least one fourth precursor into the process chamber, wherein the at least one fourth precursor is not excited by the plasma when the plasma is turned on.  
   
   
       20 . The process system of  claim 12  comprising a plurality of first precursor sources that are coupled to the process chamber for providing first precursors into the process chamber.  
   
   
       21 . The process system of  claim 12  further including means for evacuating the at least one first precursor.