Initial stage oxidation on nano-trenched Si(100) surface

Y Sun and YL Liu and S Izumi and XF Chen and Z Zhai and SH Tian, JOURNAL OF PHYSICS D-APPLIED PHYSICS, 51, 015305 (2018).

DOI: 10.1088/1361-6463/aa99ab

As the size of an electronic element shrinks to nanoscale, trench design of Si strongly influences the performance of related semiconductor devices. By reactive force field molecular dynamics (ReaxFF MD) simulation, the initial stage oxidation on nano-trenched Si(100) angled 60 degrees, 90 degrees, 120 degrees, 150 degrees under temperatures from 300 K to 1200 K has been studied. Inhomogeneous oxidation at the convex- concave corners of the Si surface was observed. In general, the initial oxidation process on the Si surface was that, firstly, the O atoms ballistically transported into surface, then a high O concentration induced compressive stress at the surface layers, which prevented further oxidation. Compared to the concave corner, the convex one contacted a larger volume of oxygen at the very beginning stage, leading an anisotropic absorption of O atoms. Afterwards, a critical compression was produced at both the convex and concave corners to limit the oxidation. As a result, an inhomogeneous oxide film grew on nano- trenched Si. Meanwhile, due to enhanced O transport and compression relaxation by increasing temperature, the inhomogeneous oxidation was more obvious under 1200 K. These present results explained the observed experimental phenomena on the oxidation of non-planar Si and provided an aspect on the design of nano-trenched electronic components in the semiconductor field.

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