PRODUCTION OF PATTERNS IN THE SURFACES OF SOLID BODIES BY ION ETCHING OR SPUTTER ETCHING

摘要

1513218 Ion or sputter etching SIEMENS AG 20 July 1976 [18 Aug 1975] 30095/76 Heading B6J [Also in Division B3] To produce an etched pattern in a surface of a solid body the surface is subjected to ion or sputter etching through a mask which will itself disintegrate under ion bombardment, the rate of disintegration of the mask increasing at an intermediate point in the total duration of the etching step. The increase may be achieved by using a mask consisting of a metallic layer, e.g. of Al, Ti, Cr, Mn, Mo, Ta, Zr or V and a photosensitive lacquer with the metallic layer which disintegrates more slowly outermost. Alternatively both layers may be metal with the layer which is slower to disintegrate outermost. A reactive gas may be supplied during the latter part of the etching step to increase the disintegration rate. Alternatively or in addition, a reactive gas, such as O 2 or carbon tetrafluoride may be added to the ion etching atmosphere of e.g. argon atoms at a pressure of 10SP-4/SP-10SP-3/SP Torr to reduce the disintegration rate in the earlier stages and then cut off. As shown, Fig. 1, a mask, comprising a photosensitive lacquer or aluminium layer 3 and a titanium layer 4, on an SiO 2 coating 2 on a silicon substrate 1 is subjected to an ion beam 5, or sputter etching using argon is carried out. The SiO 2 is removed faster than the titanium layer 4, straight-sided recesses being formed in the layer 2. When the titanium layer 4 has been removed, the layer 3 disintegrates more quickly, bevelled edges being formed on the mask and the recesses in the SiO 2 layer. Similar edge formations are achieved when a reactive gas supply is cut off during the etching operation to increase the disintegration rate.