Dr. Eva-Maria Zerbe Profile

Dr. Eva-Maria Zerbe

Metrology Engineer at Advanced Mask Technology Ctr

SPIE Involvement:

Author

Publications (2)

Proceedings Article | 30 October 2007 Paper

Calibration of contact areas: the influence of corner rounding

Jan Richter, Eva-Maria Zerbe, Thomas Marschner

Proceedings Volume 6730, 67303B (2007) https://doi.org/10.1117/12.740407

KEYWORDS: Calibration, Photomasks, Critical dimension metrology, Standards development, Scanning electron microscopy, Semiconducting wafers, Scanners, Etching, Scatterometry, Roads

Read Abstract +

The precise reporting of critical dimension (CD) features on photolithographic masks is an essential part of the mask production process. A wide range of external (standardization by national institutes) and internal (standardization within mask houses to match different tools) methods has been set up to ensure calibration consistency for the simple one dimensional case. One of the current developments is to expand these concepts to area measurements. This is to achieve better reproducibility of CD tools and to achieve a better characterization of contacts with respect to their imaging behaviour in wafer scanners. Here, we report some very fundamental constrains of this approach that have to be taken into account regardless of the actual measurement strategy. The major result is that for two dimensional contacts the shape has to be considered. This is due to the fact that the usually constant offset for calibration of critical dimensions in one dimension is no longer a constant but depends on the absolute size of the contact and the value of the corner rounding. For standard values of 200 nm contacts with corner rounding of 75 nm and calibration offsets around 20 nm maximum systematic differences of about 2nm will be obtained. Given the fact that even 40 nm calibration differences for photomask standards can be observed even for national institutes, these systematic errors can be easily as large as 6 nm for 200 nm structures. This systematic error clearly exceeds the road map targets for critical dimension off-target specifications for the coming technology node. This statement is even emphasized by the fact that in future contact layer specifications will be smaller than for lines/space layers. Once tool independent characterization of contact areas has to be achieved, area measurement in each mask house needs a second thought to implement these systematic constrains. Here, we show that the additional measurement of the corner rounding ís a relatively easy method to accomplish this.

Proceedings Article | 14 May 2007 Paper

Matching of different CD-metrology tools for global CD signature on photomasks

E.-M. Zerbe, T. Marschner, J. Richter, C. Utzny

Proceedings Volume 6607, 660729 (2007) https://doi.org/10.1117/12.728992

KEYWORDS: Critical dimension metrology, Photomasks, Scanning electron microscopy, Metrology, Standards development, Semiconducting wafers, Calibration, Electron beams, Molecules

Read Abstract +

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years