selektor 1975-04

A new process for etchi;1g semiconduc- tor surfaces is proposed by the Inter- national Plasma Corporation. The `plasma tunnel` etches at up to twice the speed of conventional processes, and at the same time it is less hard on the protecting mask. This means that the etching can be deeper and at the same time more precise. The mask itself is scarcely changed by the plasma etching process, so that it can easily be removed later by conventional techniques. These advantages are the result of the unique design of the etching tunnel. A perforated aluminium cylinder inside the cylindrical plasma chamber. encloses the components and protects them against ultra-violet and ionising radi- ation, but the plasma particles which do the actual etching can pass through the perforated cylinder and reach the com- ponents.