Publication
Title
Fabrication of conductive atomic force microscope probes and their evaluation for carrier mapping
Author
Abstract
Scanning Spreading Resistance Microscopy (SSRM) and Scanning Capacitance Microscopy (SCM) are two techniques based upon the atomic force microscope (AFM), which are used to obtain two-dimensional carrier maps of a semiconductor device's cross-section. As all AFM techniques, they require probes with sharp tips to get good resolution images. Additionally, a hard and wear resistant tip material is needed to withstand the extreme mechanical stress tips are submitted to while a good conductivity is necessary for the characterization of highly doped areas of modem devices. In this work, several types of materials are evaluated based upon their mechanical and electrical characteristics: metals, hardmetals, conductive oxides and doped diamond. Commercial metal and diamond coated silicon tips are currently used (only diamond for SSRM). However, tips with thin metal coatings wear fast while the high resistivity of diamond limits the dynamic range. In both cases, the radius of curvature of coated tips is fairly large limiting the resolution. Probes with tips made out of TiN, a hardmetal, were manufactured using the molding technique. Using these tips, an ohmic point contact was obtained on Si. In SSRM mode, resistivity contrast was observed for the first time for a metallic tip. TiN tips also proved to be hard enough to penetrate the oxide and obtain SSRM images on InP. A good contrast and a monotonic behavior on n-type silicon in the absence of bias were obtained in SCM. The wear rate of TiN tips is lower than that of coated Si tips. However, despite their high hardness, TiN tips wore fast under high pressure and the tips died after a few SSRM scan lines on Si, and after a few images on InP.
Language
English
Source (journal)
SMART SENSORS, ACTUATORS, AND MEMS, PTS 1 AND 2
Source (book)
Conference on Smart Sensors, Actuators, and MEMS, MAY 19-21, 2003, MASPALOMAS, SPAIN
Publication
2003
ISBN
0-8194-4976-8
Volume/pages
5116(2003), p. 607-616
ISI
000184053200069
Full text (Publisher's DOI)
UAntwerpen
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 03.01.2013
Last edited 15.11.2017
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