Smooth electro-insulating layer formation on substrate - by high frequency cathodic sputtering in two stages

摘要

During formation of a smooth (roughness 250 A) electroinsulating layer on a polycrystalline, monocrystalline or amorphous substrate (roughness is not >500 angstroms) by high-frequency cathodic sputtering, a part of the deposited material (re-emission coefft.) is removed by the ion bombardment with the loss of a part of the electric energy. The process is improved by forming a first layer of the insulating material at an energy loss coefft. of =1:12 or less (pref, between 1:12-35) and a re-emission coefft. of =0.35 (pref. 0.35-0.15); and then a second layer of the insulating material at an energy loss coefft. of >=1:5 (pref. 1:5-1.5), and a re-emission coefft. of >=0.6 (pref. 0.6-0.8). Different surfaces can be smoothly coated. This is of special importance whom a very thin magnetic layer is to be applied onto the insulating layer, as the properties of such magnetic layers greatly depend on the smoothness of the substrate (e.g. in magnetic heads).