Bias Dependent Contrast Mechanisms in EBIC Images of MOS Capacitors

Abstract

Defects and inhomogeneities in the electrical properties of metal oxide silicon capacitors are analyzed by scanning electron microscopy, using the electron beam induced current technique (MOS/EBIC). All capacitors were analyzed in their as‐fabricated or prebreakdown condition. The collected signals and image contrast are found to be highly dependent on the gate‐to‐substrate bias applied during MOS/EBIC examination, and this bias‐dependence is shown to be correlated with the nature and physical location of the defect. Specific MOS defects were selected for this study according to their position in the substrate, in the oxide, or at the normalSi/SiO2 interface. Substrate defects examined were misfit dislocations in epitaxial Si(Ge) on Si. Interfacial inhomogeneities included thermally oxidized, reactive ion etched (RIE) Si surfaces, and SiO2 precipitates or “D‐defects” which extend to meet the Si surface. Oxide layer inhomogeneities were also detectable which exhibited a strong contrast dependence on the oxide electric field strength. © 1999 The Electrochemical Society. All rights reserved.

Nanometrology of Si Nanostructures Embedded in SiO2using Scanning Electron Microscopy

“…It is well known that the image of EBIC reveals inhomogeneities in the electrical properties of the material, such as the grain boundary of polycrystals and the defect in semiconductors. [19][20][21] However, there is no report on the yield peak in EBIC images with a width below 10 nm. Further experiments are needed for understanding the SE peak in the case of our technique.…”

Observation of Leakage Sites in High-k Gate Dielectrics in MOSFET Devices by Electron-Beam-Induced Current Technique

“…Many people have applied EBIC to image the leakage points but only a few reports exist. [12] One of the present authors has also tried to obtain EBIC image of leakage sites of SiO 2 but failed. The biggest difficulty was related to the breakdown mechanism of SiO 2 dielectric films.…”

(Invited) An Electron-Beam-Induced Current Investigation of Electrical Defects in High-k Gate Stacks

“…More than a decade ago, researchers attempted to detect the leakage sites in SiO 2 by EBIC. It was a very challengeable subject and only a few reports existed in the literature describing the extrinsic defects like oxide thinning in SiO 2 (13)(14)(15)(16). The difficult point originates from the abrupt breakdown phenomenon in SiO 2 film.…”