Roughness scaling of three different deep reactive ion etched (DRIE) silicon surfaces is investigated using atomic force microscopy. At small distances, height-height correlations H reveal power-law behavior with equal scaling exponents for all surfaces, suggesting self-affine roughness inherent to the DRIE process. In contrast, at large distances, H is sensitive to the etch process; the resulting root mean square roughnesses vary by a factor of five and are inversely related to the characteristic fracture strengths from associated test structures. Such relationships are only possible after the regular DRIE features are considered, as this prevents inflation of the roughness metrics.
Citation: Journal of Applied Physics
Pub Type: Journals