Prakt. Met. Sonderband 38 (2006) 403
MODIFICATION AND CHARACTERIZATION OF METALLIZED
TIPS FOR SCANNING PROBE MICROSCOPY
we
tückstreu- Y. Ritz*, A. Masalska**, M. Hecker*, T. Gotszalk**, and E. Zschech*
A I AMD Saxony LLC & Co. KG, D-01330 Dresden, Germany
* Wroclaw University of Technology, Faculty of Microsystem Electronics and Photonics,
ot P-50372 Wroclaw, Poland
ie“, Deut-
terferenz-
Hilfe der ABSTRACT
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The characterization of nanoscale regions in present and future device structures of
e im Hin- leading-edge microelectronic products requires probes with dedicated features tailored on
the nanoscale. SPM tips are used not only for conventional AFM characterization, but also
warmfes- for electrical, thermal and optical investigation of devices. Particular applications are the
Ausgabe measurement of strain in strained silicon channels of metal-oxide-semiconductor field
effect transistors (MOSFETs) with high spatial resolution using aperture-less NanoRaman
spectroscopy and conductive or current sensing AFM. For these applications, highly
reproducible metal tips or metallized tips are needed. In this paper, new approaches to
tailor those tips using the FIB technique, and to characterize the tips using dedicated
structures and adapted AFM methods are described. Based on a numerical procedure, the
tip quality is described quantitatively. The described preparation and calibration techniques
offer new possibilities for the routine application of nanostructures and nanodevices as
needed for advanced SPM techniques and nanosensors.
1. INTRODUCTION
Nanoscale characterization of electronic and optical device structures is a challenge to
physical analytics. Scanning probe microscopy (SPM) techniques provide a high spatial
resolution, however the manufacturing of metallized tips (that have to be mounted on a
cantilever) as needed for conductive or current sensing atomic force microscopy (C-AFM),
and for Nano-Raman spectroscopy is still challenging [1-4]. It has been reported that pure
metal tips and metal-coated tips can be sharpened or re-sharpened applying the focused
ion beam (FIB) technique in combination with micromanipulators [5]. However, the
quantitative description of the tip size and shape is still challenging.
In this paper, a method is proposed that allows the geometrical characterization and
calibration of SPM tips using particularly designed calibration-test samples. These
samples are prepared on dedicated film stacks utilizing FIB milling and marking
techniques. For comparison with the SPM measurements a scanning electron microscopy
(SEM) investigation of the structures is used. Geometrical parameters that describe the tip
shape are determined applying a numerical procedure for tip/sample deconvolution of the
measured AFM signal.
