Field-emission type electron source and charged particle beam device using the same
OwnerDazhi Chen, Zhongwei Cheninventors
Life of this patent
Estimating the term…
Abstract
A field-emission type electron source includes (i) a single-crystal tungsten rod having a sharpened terminus and (ii) a mass of ZrO formed only on a portion of the surface, or the entire surface, of the sharpened terminus. In preferred design, the single-crystal tungsten rod is placed in a gaseous medium that consists of oxygen and a non-oxygen gas. The molar ratio between oxygen and the non-oxygen gas is greater than 1:1.
Claims20
A field-emission type electron source comprising a crystal rod placed in a gaseous medium, wherein the crystal rod is a single-crystal tungsten rod, a LaB6 crystal rod, or a CeB6 crystal rod;
- wherein the gaseous medium consists of oxygen and a non-oxygen gas, and wherein a molar ratio between oxygen and the non-oxygen gas is greater than 1:1, 10:1, 50:1, or 100:1.
The field-emission type electron source according to claim), wherein the gaseous medium maintains a pressure of from about 10−11 torr to 10−8 torr within the electron source.
A charged particle beam device comprising a field-emission type electron source,
- wherein the field-emission type electron source comprises a crystal rod placed in a gaseous medium, wherein the crystal rod is a single-crystal tungsten rod, a LaB6 crystal rod, or a CeB6 crystal rod;
- wherein the gaseous medium consists of oxygen and a non-oxygen gas, and wherein a molar ratio between oxygen and the non-oxygen gas is greater than 1:1, 10:1, 50:1, or 100:1.
Dependencies are inferred from the claim text.