Systems and methods for ion source control in ion implanters
US4754200A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1985 |
| Grant date | Jun 28, 1988 |
| Priority date | — |
| Expiry date | Sep 9, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/3171
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for operating an ion source having a filament-cathode and an anode. The method includes supplying direct current electrical power between the anode and the filament-cathode characterized by substantially constant arc current there between and varying arc voltage on the filament-cathode. Direct current electrical power is also supplied across the filament-cathode. The value of the arc voltage is monitored and the magnitude of electrical power supplied to the filament-cathode is altered in response to detected changes in the arc voltage to return the arc voltage to substantially a preset reference value. The monitoring step and the altering step are carried out at regular preset intervals. The altering step includes deriving an filament power error signal as a prearranged function which includes the difference in values between the monitored arc voltage and the preset reference value multiplied by a predefined integral gain value. The altering step also includes altering the magnitude of electrical power supplied to the filament-cathode by the value of the filament power error signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.