Reference nano-dimensional metrology by scanning transmission electron microscopy

Abstract

Traceable and accurate reference dimensional metrology of nano-structures by scanning transmission electron microscopy (STEM) is introduced in the paper. Two methods, one based on the crystal lattice constant and the other based on the pitch of a feature pair, were applied to calibrate the TEM magnification. The threshold value, which was defined as the half-intensity of boundary materials, is suggested to extract the boundary position of features from the TEM image. Experimental investigations have demonstrated the high potential of the proposed methods. For instance, the standard deviation from ten repeated measurements of a line structure with a nominal 100 nm critical dimension (CD) reaches 1σ = 0.023 nm, about 0.02%. By intentionally introduced defocus and larger sample alignment errors, the investigation shows that these influences may reach 0.20 and 1.3 nm, respectively, indicating the importance of high-quality TEM measurements. Finally, a strategy for disseminating the destructive TEM results is introduced. Using this strategy, the CD of a reference material has been accurately determined. Its agreement over five independent TEM measurements is below 1.2 nm.

P1.20 Design und Modellierung eines 3D-Nanotasters

“…2) bezeichnet, sind mit dem entsprechenden Tastkopf des Rasterkraftmikroskops, in der Lage als 2D-Sensor zu arbeiten. Es wird die Biegung und Torsion des Cantilevers detektiert [2,3].…”

Challenges in nanometrology: high precision measurement of position and size

“…In addition to the Si line features whose lattice parameter can provide a calibration for the TEM image magnification, a second method was applied. It uses a double line feature being imaged in the HR-TEM image as well whose distance has been calibrated by a metrological SPM before, for details see [34]. Figure 16 shows the basic scheme of the metrological approach, which was taken here, while fig.…”

Optimization of Nano-Grating Pitch Evaluation Method Based on Line Edge Roughness Analysis

“…Many nanofabrication methods have been utilized to fabricate lateral pitch structures, including e-beam lithography, multilayer gratings [2], [3], atom lithography [4]- [6], atom-based rulers [7]- [9], and so on. Before the nanoscale pitch structures can be used as transfer standards, pitch uncertainties need to be measured with metrological AFMs and estimated with the effective pitch evaluation methods [10].…”