Pattern profile control utilizing shadowing effect in oblique ion-beam etching

A new pattern profile control technique utilizing an ion-beam shadowing effect has been developed. A tapered sidewall is obtained by oblique ion-beam etching with a sublayer deposition on a layer to be etched before or after photolithography. Metal or photoresist can be used as a sublayer. Tapered pattern angle is controlled mainly by varying ion-bean angle and initial mask thickness. Sublayer thickness is chosen to eliminate discontinuous sidewall formation arising from an ion-beam shadowing effect. Since the chemical etching process can be completely eliminated in these processing steps, pattern profiles for all the materials are easily controlled with good reproducibility.