Patent ID: 9738966
Date: 2017-08-22
CPC Classifications: C23C

Claim:
1. A method of forming an iron film on a deposition substrate, the method comprising: directing an electron beam onto the surface of an iron source comprising 99.98 atomic percent, or less, of iron; the remainder of the iron source comprising impurity elements having boiling points lower than that of the iron at the deposition conditions; wherein the electron beam heats the surface of the iron source to a temperature above its melting point, such that at least a portion of the surface of the iron source melts and iron and impurities from the melted iron source evaporate into the gas phase and then deposit as a solid film on a surface of the deposition substrate; and further wherein the temperature to which the iron source is heated by the electron beam is high enough that the concentration of the impurities in the gas phase is the same as, or lower than, the concentration of the impurities in the iron source, so that the solid film deposited on the deposition substrate has an impurity concentration that is the same as, or lower than, that of the iron source.