Fault Isolation of Sub-Surface Leakage Defects Using Electron Beam Induced Current Characterization in Next-Generation Flash Memory Technology Development

2010 ◽  
Author(s):  
Go Nagatani ◽  
Kenneth Yu ◽  
Amalia Del Rosario ◽  
Max Sidorov ◽  
Richard E. Stallcup ◽  
...  
Keyword(s):  
Electron Beam ◽  
Flash Memory ◽  
Technology Development ◽  
Physical Structure ◽  
Fault Isolation ◽  
Induced Current ◽  
Structure Modification ◽  
Electron Beam Induced Current ◽  
Emission Microscopy ◽  
Surface Leakage

Abstract This paper covers methods used to isolate single leaky junctions in a test structure designed for Flash memory technology development. It may be possible to isolate this failure through micro probing or a combination of electrical testing and physical structure modification by FIB, but at the expense of spending numerous days. The paper shows that a combination of emission microscopy (EMMI), electron beam induced current (EBIC) characterization and a SEM nano-probing can drastically simplify the fault isolation process. Results of nano-probing are also shown to prove the level of leakage detected in the faulty junction. A combination of EMMI and EBIC characterization was able to pinpoint the problematic junction from approximately 2500 junctions in the structure. Furthermore, the nano-probing IV characterization proved the identified junction to be indeed high in leakage current, providing further confidence for physical failure analysis.

scholarly journals P-N Junction Analysis using Electron Beam Induced Current (EBIC) Technique

2021 ◽  
Author(s):  
Lori L. Sarnecki ◽  
Regina Kuan
Keyword(s):  
Electron Beam ◽  
Cross Section ◽  
Integrated Circuit ◽  
Resolution Enhancement ◽  
Three Dimensional ◽  
Potential Method ◽  
Fault Isolation ◽  
Induced Current ◽  
Cross Sectional ◽  
Electron Beam Induced Current

Abstract The integrity of a P-type or N-type epitaxial layer, implanted wells, or dopants (i.e. P-epi, N-well, P-imp, N-imp, etc.) oftentimes can affect the performance of an integrated circuit (IC), especially in analog/mixed signal devices. At onsemi, we had encountered a poor P-N junction of a Zener diode that caused a Cross-Coupled-Switched-Cap voltage doubler to have a lower output voltage which eventually affected the performance of the IC. The integrity of any P-N junction can be electrically verified through curve tracing with in-SEM nano-probing and fault isolation (PEM, OBIRCH, etc.) techniques. However, physical defect revelation using junction stain, either top-down or in cross section, can be challenging due to the three-dimensional (3D) form of any P-N junction. With Electron Beam Induced Current (EBIC), we can easily identify an abnormal P-N junction through both topdown and cross section. This paper is to characterize EBIC analysis on IC cross sectional view in mapping the P-N junctions and provide the information of its doping profiles. In this paper, limitation of both chemical etching and EBIC will be discussed as well as introducing the use of ion mill after FIB cross section during cross sectional EBIC sample prep as a potential method for resolution enhancement. These findings add to the understanding in using this technique and further improvement to its application in failure analysis.

Electron beam induced current study of thin silicon layers on insulator substrate

1990 ◽  
Vol 48 (4) ◽  
pp. 618-619
Author(s):  
A. Buczkowski ◽  
Z. J. Radzimski ◽  
J. C. Russ ◽  
G. A. Rozgonyi
Keyword(s):  
Electron Beam ◽  
Energy Loss ◽  
Beam Energy ◽  
Collection Efficiency ◽  
Silicon Layer ◽  
Depletion Layer ◽  
Incident Electron Energy ◽  
Induced Current ◽  
Electron Hole ◽  
Electron Beam Induced Current

If a thickness of a semiconductor is smaller than the penetration depth of the electron beam, e.g. in silicon on insulator (SOI) structures, only a small portion of incident electrons energy , which is lost in a superficial silicon layer separated by the oxide from the substrate, contributes to the electron beam induced current (EBIC). Because the energy loss distribution of primary beam is not uniform and varies with beam energy, it is not straightforward to predict the optimum conditions for using this technique. Moreover, the energy losses in an ohmic or Schottky contact complicate this prediction. None of the existing theories, which are based on an assumption of a point-like region of electron beam generation, can be used satisfactorily on SOI structures. We have used a Monte Carlo technique which provide a simulation of the electron beam interactions with thin multilayer structures. The EBIC current was calculated using a simple one dimensional geometry, i.e. depletion layer separating electron- hole pairs spreads out to infinity in x- and y-direction. A point-type generation function with location being an actual location of an incident electron energy loss event has been assumed. A collection efficiency of electron-hole pairs was assumed to be 100% for carriers generated within the depletion layer, and inversely proportional to the exponential function of depth with the effective diffusion length as a parameter outside this layer. A series of simulations were performed for various thicknesses of superficial silicon layer. The geometries used for simulations were chosen to match the "real" samples used in the experimental part of this work. The theoretical data presented in Fig. 1 show how significandy the gain decreases with a decrease in superficial layer thickness in comparison with bulk material. Moreover, there is an optimum beam energy at which the gain reaches its maximum value for particular silicon thickness.

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