Micro-optical structures for atom lithography studies

Erol C. Harvey, Tracy R. Mackin, Brian C. Dempster, Robert E. Scholten, Kevin H. Chau, Sima Dimitrijev
1999 Device and Process Technologies for MEMS and Microelectronics  
Slow neutral beams of metal atoms can be manipulated using the intensity gradient of near-resonant light-fields enabling the deposition of atoms onto a substrate in a processes often referred to as atom lithography. A suitably shaped light-field gradient is used to control the path of metal atoms using the dipole force created by the interaction between atoms and the strong, near-resonant optical intensity gradient. Relatively simple patterns such as lines and dots have been created using
more » ... l standing waves while more complex light-fields might be created using computer generated optical elements (CGOE) to manipulate the laser beam. In this paper we describe the microfabrication of spiral phase modulation structures used to create TEM* 01 fields, and diffractive optical structures used to create TEM 01 fields. Static mask projection is used to machine the diffractive structure, and two different excimer laser ablation techniques are investigated to create the spiral structures. In the first a set of 15 separate patterns are prepared on a chrome-on-quartz mask, and the laser used to ablate each pattern to the required depth. This replicates photolithographic multi-step fabrication in that the final structure resembles a spiral staircase. In the second technique a more smoothly varying spiral ramp is ablated using a single mask that rotates about one of its vertices, a process called mask dragging.
doi:10.1117/12.364493 fatcat:2ew646pdfbc3zonn6jodpai2vi