Effective removal of hydrogen resists used to pattern devices in silicon using scanning tunneling microscopy

摘要

We present a high resolution scanning tunneling microscope (STM) study of the thermal desorption of hydrogen resist layers used for STM-based lithography on the Si(001)2 X 1 surface. From this study we determine the optimum annealing conditions for removing the hydrogen resist in one step. We demonstrate that this thermal process can completely remove the hydrogen resist from a phosphorus doped surface structure created using STM-lithography, without disturbing the lithographically defined structure. We investigate the effectiveness of the removal process by performing electrical measurements of a buried STM-patterned device created using the optimized thermal desorption process and demonstrate that we can achieve phase coherence lengths of ～40 nm, comparable to that in P in Si delta-doped layers where no hydrogen resist or STM patterning has been used.