TY - JOUR
T1 - Characterization of bending in single crystal Si beams and resonators
AU - Weigold, J. W.
AU - Juan, W. H.
AU - Pang, S. W.
AU - Borenstein, J. T.
PY - 1999/7
Y1 - 1999/7
N2 - Optical interferometry has been applied to determine the displacement of p++ Si beams. Clamped-clamped Si beams and cantilevered beams were fabricated with short and long B diffusion processes and characterized. Measurements of beam bending for released Si structures with length varying from 50 to 1000 μm, width varying from 5 to 15 μm, and thickness varying from 6 to 37 μm were obtained. By taking advantage of an etch-diffusion process, thicker beams can be fabricated which have less bending due to stress gradients. A 6.0-μm-thick cantilevered beam had a deflection of 11.2 μμm due to stress gradients, while a 36.7-μm-thick beam had a deflection of only 0.3 μm. Beams fabricated using a dissolved wafer process with a 12 h B diffusion were found to bend the same amount as those fabricated with a 4 h diffusion. This indicates that bending in doped Si beams not only depends on the gradients in the B concentrations, it could also be related to the distribution of dislocations. Using the deep-etch shallow-diffusion process, resonating elements that are 20 μm long, 4 μμm wide, and 28 μm thick were found to be perfectly flat without any bending.
AB - Optical interferometry has been applied to determine the displacement of p++ Si beams. Clamped-clamped Si beams and cantilevered beams were fabricated with short and long B diffusion processes and characterized. Measurements of beam bending for released Si structures with length varying from 50 to 1000 μm, width varying from 5 to 15 μm, and thickness varying from 6 to 37 μm were obtained. By taking advantage of an etch-diffusion process, thicker beams can be fabricated which have less bending due to stress gradients. A 6.0-μm-thick cantilevered beam had a deflection of 11.2 μμm due to stress gradients, while a 36.7-μm-thick beam had a deflection of only 0.3 μm. Beams fabricated using a dissolved wafer process with a 12 h B diffusion were found to bend the same amount as those fabricated with a 4 h diffusion. This indicates that bending in doped Si beams not only depends on the gradients in the B concentrations, it could also be related to the distribution of dislocations. Using the deep-etch shallow-diffusion process, resonating elements that are 20 μm long, 4 μμm wide, and 28 μm thick were found to be perfectly flat without any bending.
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-22644450120&origin=recordpage
U2 - 10.1116/1.590756
DO - 10.1116/1.590756
M3 - RGC 21 - Publication in refereed journal
VL - 17
SP - 1336
EP - 1340
JO - Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
JF - Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena
IS - 4
ER -