Method of processing a surface of a workpiece
A plasma generator generates positive ions and negative ions in a plasma. An ion extracting portion ( 4, 5 ) selectively extracts the generated positive ions and negative ions from the plasma, and accelerates the extracted ions in a predetermined direction. The positive ions and the negative ions are selectively applied to the workpiece (X). The plasma generator applies a high-frequency voltage to a process gas in a vacuum chamber for generating a plasma which is composed of positive ions and electrons from the process gas, and interrupts the high-frequency voltage for attaching the electrons to the residual process gas to generate negative ions. The application of the high-frequency voltage and the interruption of the high-frequency voltage are alternately repeated.
1. A method of processing a surface of a workpiece, comprising:
generating positive ions and negative ions in a plasma;
selectively extracting the generated positive ions and negative ions from said plasma, and accelerating the extracted ions in a predetermined direction; and
selectively applying said positive ions and said negative ions to said workpiece.
2. A method of processing a surface of a workpiece according to claim 1 , wherein said generating comprises:
applying a high-frequency voltage to a process gas in a vacuum chamber for generating a plasma which is composed of positive ions and electrons from said process gas;
interrupting said high-frequency voltage for attaching said electrons to the residual process gas to generate negative ions; and
repeating the application of said high-frequency voltage and the interruption of said high-frequency voltage.
3. A method of processing a surface of a workpiece according to claim 1 , wherein said generating comprises:
generating a plasma which is composed of positive ions and electrons from a process gas in a vacuum chamber; and
attaching said electrons to the residual process gas to generate negative ions at a downstream part of a plasma generated space.
4. A method of processing a surface of a workpiece according to claim 1 , wherein said positive ions and said negative ions are alternately extracted from said plasma and alternately applied to said workpiece.
5. A method of processing a surface of a workpiece according to claim 1 , wherein said ions are applied to said workpiece while said workpiece is being shielded from a radiation produced by said plasma.
6. A method of processing a surface of a workpiece according to claim 1 , wherein said workpiece comprises a semiconductor device, and said ions are applied to said semiconductor device for forming a gate dielectric film thereon.
7. A method of processing a surface of a workpiece according to claim 1 , wherein said workpiece comprises an organic material, and said ions are applied to said organic material for etching said organic material.
8. A method of processing a surface of a workpiece, comprising:
generating positive ions and negative ions in a plasma;
selectively extracting the generated negative ions from said plasma, and accelerating the extracted negative ions in a predetermined direction; and
applying said negative ions to said workpiece.
9. A method of processing a surface of a workpiece according to claim 8 , wherein said negative ions are applied to said workpiece while said workpiece is being shielded from a radiation produced by said plasma.
10. A method of processing a surface of a workpiece according to claim 8 , wherein said workpiece comprises a semiconductor device, and said negative ions are applied to said semiconductor device for forming a gate dielectric film thereon.
11. A method of processing a surface of a workpiece according to claim 8 , wherein said workpiece comprises an organic material, and said negative ions are applied to said organic material for etching said organic material.
12. A method of processing a surface of a workpiece, comprising:
generating positive ions and negative ions in a plasma;
alternately extracting the generated positive ions and negative ions from said plasma, and accelerating the extracted ions in a predetermined direction;
neutralizing the accelerated ions to convert them into neutral particles with use of a neutralization device; and
applying said neutral particles to said workpiece while shielding said workpiece from a radiation produced by said plasma with use of said neutralization device.
13. A method of processing a surface of a workpiece according to claim 12 , wherein said workpiece comprises a semiconductor device, and said neutral particles are applied to said semiconductor device for forming a gate dielectric film thereon.
14. A method of processing a surface of a workpiece according to claim 12 , wherein said workpiece comprises an organic material, and said neutral particles are applied to said organic material for etching said organic material.
15. A method of processing a surface of a workpiece, comprising:
generating positive ions and negative ions in a plasma;
selectively extracting the generated negative ions from said plasma, and accelerating the extracted negative ions in a predetermined direction;
neutralizing the accelerated negative ions to convert them into neutral particles with use of a neutralization device; and
applying said neutral particles to said workpiece while shielding said workpiece from a radiation produced by said plasma with use of said neutralization device.
16. A method of processing a surface of a workpiece according to claim 15 , wherein said workpiece comprises a semiconductor device, and said neutral particles are applied to said semiconductor device for forming a gate dielectric film thereon.
17. A method of processing a surface of a workpiece according to claim 15 , wherein said workpiece comprises an organic material, and said neutral particles are applied to said organic material for etching said organic material.