STM-study of triangular defect structures induced on WSe2

Electrical field induced growth of triangular nanometer structures on WSe2

“…Figure 2 shows the length of one edge of a triangle as function of time for a typical run. It is found that the edge length increases linearly, as reported in the preceeding paper [5], corresponding to a constant growth velocity v , 7.5 · 10\ nm/s in this case. It turned out that v varies considerably from day to day, as already observed in other experiments [2,5], with values between 0.01 and 1 nm/s in our experiments.…”

“…It is found that the edge length increases linearly, as reported in the preceeding paper [5], corresponding to a constant growth velocity v , 7.5 · 10\ nm/s in this case. It turned out that v varies considerably from day to day, as already observed in other experiments [2,5], with values between 0.01 and 1 nm/s in our experiments. Figure 3 shows the evolution of another triangle, but now the scanning was interrupted several times: for 700 s, as the triangle had reached a size of about 40 nm (interval I), for 600 s at a size of 60 nm (interval II), and for 2500 s at a size of 80 nm (interval III).…”

“…Some of them have shown that it is possible to ''etch'' structures with nanometer dimensions in lateral direction and a depth of a single molecular layer [2][3][4][5]. Whereas this etching process has been shown for different metal chalcogenides [2,3], the details of the process are not clear at all.…”

“…Motivated by the previous results [2][3][4][5] we have studied in detail the conditions for the etching of such structures with the STM on WSe . Our measurements demonstrate that the etching process is controlled via the electric field at the surface of the semiconductor.…”

“…Some of these materials (but not the WSe examined here) can be etched with the atomic force microscope (AFM) as well [4]. The application of this etching process towards a production of individual structures on a nanometer scale so far is hampered by the fact that scanning over the structures leads to further growth and therefore to a change of the structures [2,5].…”