Patent · US Expired

X-Ray source and method of making same

US4439870A · kind A · utility

9Cited by
1References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 28, 1981
Grant dateMar 27, 1984
Priority date
Expiry dateDec 28, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J2235/088
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

It has been discovered that the diffusion of hydrogen species into the outside or water-cooled surface of a pure palladium anode included in an X-ray source causes various deleterious effects. To avoid these effects, a limited-depth hydrogen-barrier layer made, for example, of Pd.sub.3 Sn is formed within the anode extending from the outside surface thereof. The inside or target surface and a major extent of the palladium anode remain virtually unaffected during the forming step. The desired palladium emission characteristic of the anode is thereby preserved. In practice, the modified anode remains free of hydrogen and, as a result, exhibits a particularly advantageous long-life property. Such an anode constitutes an important part of a high-power X-ray lithographic system adapted for making VLSI devices.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.