Characterization of surface measurement techniques with latral and vertical calibration standards

In this thesis, the method of applying Siemens Tar and step height to evaluate the system resolution of different measurement technique is described. Furthermore, the design of and evaluation program that was used for distinguish of the ambiguous region of Siemens Star measurement is presented. Based on the results, obtained with the four measurement equipment’s and the evaluation program, some conclusions can be drawn.

The evaluation results of Siemens Stars states that it should be possible to sue Siemens Star structure which fabricated on sample surface to evaluate the vertical and lateral resolution of the measurements. Theory shows that the Siemens star can only be applied to evaluate the measurements with lateral resolutions worse than 0.28nm. The upper limitation of the Siemens star evaluation range is depends on the diameter of the star. Assuming the reasonable different between theoretical number and practical evaluation, it has been shown that the resolution computation from the experiment results is quite close to the theoretical resolution of WLI and CWL. Unfortunately, it is not successful to apply Siemens Star evaluation on the IFM.

The evaluation results of measuring Siemens Star by AFM show the interaction between the lateral and vertical resolution. A method of AW space which combines the lateral and vertical resolution is discussed. This method also offers a mathematical description of Siemens Star properties.

The program that was applied to distinguish the ambiguous region of Siemens Star measurement results is based on the AW space model. Some of the methods for the program reference the international standards for two dimensional Siemens Stars. Although the non-measured points cannot offer the height information of the measured surface, it is optimized for distinguish the two resolutions are discussed also. Measurements showed that the Siemens Stars fabricated by FIB and binary optics techniques have a good quality. These Siemens Stars can be applied to evaluate the sub-micron resolution of the measurements. The evaluation results are repeated for times to get an average number of the resolution. However, the large stanard deviation number needs to be considering that the evaluation is not stable under some conditions.

The step size measurement results show the good repeatability of different measurements on the vertical direction. These results once again that the vertical resolution and lateral resolution cannot be described independently. When steep structures are measured the interaction between vertical and lateral resolution is obvious. These can due to the incorrect measurement results on lateral or verical direction.

For the measurement results which cannot perform both lateral and vertical resolution at the same time but can be applied to distinguish the surface structure a new method of 'pseudo resolution' is proposed.

To conclude the evaluation results for the resolutions of different measurement techniques which are applied in this study, a Stedman map is drawn to give an overview. The specification of drawing Stedman map presents the method to explore the measuring range of different measurement techniques which have dissimilar physical theory. Summarizing the experimental verification of the theoretical resolution, it can be concluded that the methods of applying Siemens Star structure to evaluate measurement equipment’s' resolution is feasible.