Lateral tip control effects in critical dimension atomic force microscope metrology: the large tip limit

Advances in the atomic force microscopy for critical dimension metrology

“…However, the effective tip width increases due to the lateral tip dither. A dither slope of 2.9 nm V −1 to 4.5 nm V −1 was measured for the CD-probes with different dimensions [93] and in a recent study dither slope has been concluded to be a 3 nm V −1 baseline response due to the cantilever base motion [94]. Murayama and colleagues proposed 'multi-angle step-in' algorithm for sidewall scanning using a flared probe [11,91].…”

Analysis for system errors in measuring the sidewall angle of a silica waveguide with confocal laser scanning microscope (CLSM)

“…In the current accurate profile measurements of micro/ nanostructure using the AFM technique as metrology tool, the CD-AFM and tilting-AFM metrologies have shown the advancements in accurately scanning the profiles of micro/ nanostructures. However, these two AFM-based metrologies are exposed to have their intrinsic limitations in the SWA measurements [12,[17][18][19][20][21][22][23]. In the top-down scanning CD-AFM metrology, the probe critically important to have high order measurement accuracies, so the flared probe is commonly adopted to have high contrast reconstructions of AFM images, but their applications are still limited by the aspect ratio of micro/nanostructures, including the vertical edge height (VEH), tip flare radius, tip overhang and undercut at bottom corner of line structure are the main contributing factors to the inaccessibility [12,[17][18][19][20].…”

“…In addition, the flared tip also causes a low spatial resolution on the horizontal surface, so the tilting-AFM were investigated to overcome the above limitations because of the sharp-tip and unique configuration in scanning process of surface measurements with an appropriately selected tilt angle and higher aspect ratio probes, and a recent establishment in SWA measurement uncertainty of ±0.86 was reported by Xie et al in 2015 [18]. The tilting-AFM has its operation limitations in installing setup and reaching feature footing and corners due to the vibration of scanning tip [21], further the matching between tilt-angle and SWA was modelled for defining the interaction force between the probe and featured surface determines the measurement accuracy since an inappropriate model generally results in the deterioration of measurement accuracy [12,[21][22][23]. Consequently, the matching of the probing angle and the SWA also generates the high measurement uncertainty.…”