| Etching reactions of polycrystalline and single crystal Cu surfaces by gas-phase Br2 and Cl2 were characterized in ultra-high vacuum (UHV) using surface science analytical techniques. Macroscopic reaction kinetics were obtained using temperature programmed desorption (TPD), while changes in the macroscopic surface structure were monitored with low energy electron diffraction (LEED). Following the macroscopic studies, atomic and nanometer-scale mechanisms were characterized using scanning tunneling microscopy (STM). A custom high-speed, variable temperature UHV-STM was designed and built to monitor the etching reactions in situ. By recording images at a constant rate while exposing the sample to halogens, STM movies were generated to study the processes involved in Cu etching reactions. The implications of the results as they relate to Cu etching for microelectronics applications is discussed. |
