PATTERN PROFILE CONTROL UTILIZING SHADOWING EFFECT IN OBLIQUE ION-BEAM ETCHING

A new pattern profile control technique using an ion-beam shadowing effect was 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-beam 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.