Distributed inductively-coupled plasma source
US6273022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Mar 14, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/321
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for inductively coupling electrical power to a plasma in a semiconductor process chamber. In a first aspect, an array of induction coils is distributed over a geometric surface having a circular transverse section. Each coil has a transverse section which is wedge-shaped so that the adjacent sides of any two adjacent coils in the array are approximately parallel to a radius of the circular transverse section of the geometric surface. The sides of adjacent coils being parallel enhances the radial uniformity of the magnetic field produced by the coil array. In a second aspect, electrostatic coupling between the induction coils and the plasma is minimized by connecting each induction coil to the power supply so that the turn of wire of the coil which is nearest to the plasma is near electrical ground potential. In one embodiment, the near end of each coil connects directly to electrical ground. In second and third embodiments, two coils are connected in series at the near end of each coil. In the second embodiment, the opposite ("RF hot") end of each coil is connected to a respective balanced output of an RF power supply. In the third embodiment, the hot end of on…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.