title: Electron holographic mapping of two-dimensional doping areas in cross-sectional device specimens prepared by the lift-out technique based on a focused ion beam.
abstract: Recently, electron holography has been successfully applied to analyze two-dimensional (2D) dopant distribution in semiconductor devices with high resolution and high sensitivity. The preparation of proper specimens is a fundamental step for the practical application of electron holography in the semiconductor industry. Therefore, it is important to explore a reliable and quick specimen preparation method. In our current work, we have tried to use the lift-out technique based on a focused ion beam, to fabricate cross-sectional CMOS device specimens for electron holographic observation. Using the lift-out technique, specimens with a large area and uniform thickness can be prepared directly from integrated circuit wafers in a very short time. Specimens with a complex and unknown dopant distribution were examined using off-axis electron holography. In the reconstructed phase images, the different 2D doping areas in a CMOS device, such as source, drain, well and substrate, were revealed successfully. The advantages and disadvantages of the technique are discussed.
authors.affiliation: Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya 456-8587, Japan. wangzg@jfcc.or.jp
authors.forename: Zhou-Guang
authors.initials: ZG
authors.lastname: Wang
authors.forename: Naoko
authors.initials: N
authors.lastname: Kato
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Sasaki
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Hirayama
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Saka