GB998239A - A method of manufacturing thin metal films - Google Patents

Abstract

<PICT:0998239/C6-C7/1> A metal film of, e.g., Sb, In, Pb, Zn or Cd, is vapour deposited on to a substrate which is cooled during the deposition, after which the film is heated and reacted with a gas, e.g. oxygen, water vapour or hydrogen. A substrate 6, on to which lands 16 have been deposited, is supported in a housing 2 and cooled by a source 14 of liquid oxygen. With a low pressure in the housing maintained by a pump 11, a metal 10 in a crucible 80 is heated and evaporated on to the substrate through a mask (not shown) to form a film 12 in contact with the lands 16 from which probes 18, 20 extend to a suitable meter 22 to monitor the electrical resistance of the film. When evaporation is completed, cooling is stopped and the substrate heats to room temperature causing agglomeration of the film which increases its resistance. At a given resistance, oxygen from a reservoir 24 is introduced into the housing to react with the film and stop further agglomeration. The oxygen supply is stopped when a constant resistance reading indicates that agglomeration has ceased. If oxygen is introduced sooner, agglomeration is prevented and a film free of voids is obtained. The film resistance may be monitored optically by a photocell sensing light passing through the film. The metal film may then be covered with an insulating material, e.g. silicon monoxide.