Electrostatically screened, voltage-controlled electrostatic chuck
US6169652A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 12, 1999 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Mar 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02N13/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Employing an electrostatically screened, voltage-controlled electrostatic chuck particularly suited for holding wafers and masks in sub-atmospheric operations will significantly reduce the likelihood of contaminant deposition on the substrates. The electrostatic chuck includes (1) an insulator block having a outer perimeter and a planar surface adapted to support the substrate and comprising at least one electrode (typically a pair of electrodes that are embedded in the insulator block), (2) a source of voltage that is connected to the at least one electrode, (3) a support base to which the insulator block is attached, and (4) a primary electrostatic shield ring member that is positioned around the outer perimeter of the insulator block. The electrostatic chuck permits control of the voltage of the lithographic substrate; in addition, it provides electrostatic shielding of the stray electric fields issuing from the sides of the electrostatic chuck. The shielding effectively prevents electric fields from wrapping around to the upper or front surface of the substrate, thereby eliminating electrostatic particle deposition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.