FABRICATION OF DRY-ETCHED CDZNSE ZNSE QUANTUM WIRES BY THERMALLY ASSISTED ELECTRON-CYCLOTRON-RESONANCE ETCHING/

A low damage dry etch technology suitable for in situ processing was d eveloped for the fabrication of ZnSe-based nanostructures. Thermally a ssisted electron cyclotron resonance etching combines plasma etching a t low ion energies with process temperatures between 80 degrees C and 210 degrees C. Due tea variation of the process parameters, i.e., plas ma power and sample temperature, a transition from partially physical to prevailing chemical etch properties is obtained. Therefore an accur ate control of etch profile, surface morphology, and etch rate is poss ible. Optically active CdZnSe/ZnSe quantum wires with lateral sizes do wn to 20 nm were realized, indicating a significantly reduced influenc e of optically inactive layers compared to conventionally dry etched n anostructures. In narrow wires, a systematic blue shift of the photolu minescence signal with decreasing wire width clearly demonstrates late ral carrier confinement effects. (C) 1997 American Institute of Physic s.