Method and apparatus for ionizing gas with point of use ion flow delivery
US4827371A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1988 |
| Grant date | May 2, 1989 |
| Priority date | — |
| Expiry date | Apr 4, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05F3/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Potentially damaging electrostatic charges on semiconductor wafers or other objects are suppressed during the manufacturing process by generating ions in a flow of nitrogen or other non-reactive gas and by delivering the ionized flow to the product region through an enclosed flow path. The ions are produced by directing X-rays or other ionizing radiation into a shielded chamber portion of the flow path where flow is relatively slow and a large volume of gas is exposed to the X-rays. The ionized flow is then transmitted to the product region through a relatively narrow tubulation in which flow velocity is higher. Inter-relating of the flow rate and the length and diameter of the delivery tube minimizes ion loss from contact with the tube wall and from charge exchange with each other. The process and apparatus do not generate ozone or metallic particles, which can damage the products, as may occur with prior systems which use high voltage electrodes to ionize the air. The method and apparatus may also be used for other purposes such as air purification.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.