LOW DAMAGE THERMALLY ASSISTED ELECTRON-CYCLOTRON-RESONANCE ETCH TECHNOLOGY FOR WIDE BANDGAP II-VI MATERIALS

A flexible and low damage dry etch technology for the fabrication of Z nSe-based nanostructures is presented. Thermally assisted electron cyc lotron resonance etching using gas mixtures of chlorine compounds and Ar and N-2, respectively, combines plasma etching at low ion energies with process temperatures between 60 and 250 degrees C. With increasin g process temperatures, rising etch rates and reduced surface roughnes s indicate a thermal activation of the etching process; The etch profi le can be controlled by varying the plasma power causing a transition from partially physical to prevailing chemical etch properties. High q uantum efficiencies in CdZnSe/ZnSe quantum wires with lateral sizes do wn to 20 nm were obtained, indicating a significantly reduced etch dam age compared to conventionally dry etched II-VI nanostructures. The po tential of the etch technology is demonstrated by realizing quantum wi res with a blue shift of the photoluminescence signal (e.g., 8 meV for 20-nm-wide wires) caused by lateral carrier confinement effects. (C) 1997 American Vacuum Society.