用于晶体管静电势离轴电子全息术的传统和背侧聚焦离子束铣削。

Conventional and back-side focused ion beam milling for off-axis electron holography of electrostatic potentials in transistors.

作者信息

Dunin-Borkowski Rafal E, Newcomb Simon B, Kasama Takeshi, McCartney Martha R, Weyland Matthew, Midgley Paul A

机构信息

Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK.

出版信息

Ultramicroscopy. 2005 Apr;103(1):67-81. doi: 10.1016/j.ultramic.2004.11.018. Epub 2005 Jan 12.

DOI:10.1016/j.ultramic.2004.11.018

PMID:15777601

Abstract

Off-axis electron holography is used to characterize a linear array of transistors, which was prepared for examination in cross-sectional geometry in the transmission electron microscope (TEM) using focused ion beam (FIB) milling from the substrate side of the semiconductor device. The measured electrostatic potential is compared with results obtained from TEM specimens prepared using the more conventional 'trench' FIB geometry. The use of carbon coating to remove specimen charging effects, which result in electrostatic fringing fields outside 'trench' specimens, is demonstrated. Such fringing fields are not observed after milling from the substrate side of the device. Analysis of the measured holographic phase images suggests that the electrically inactive layer on the surface of each FIB-milled specimen typically has a thickness of 100 nm.

摘要

离轴电子全息术用于表征晶体管的线性阵列，该阵列是通过聚焦离子束（FIB）从半导体器件的衬底侧进行铣削，以制备用于透射电子显微镜（TEM）横截面几何形状检查的样品。将测量的静电势与使用更传统的“沟槽”FIB几何形状制备的TEM样品所获得的结果进行比较。展示了使用碳涂层来消除样品充电效应，这种效应会在“沟槽”样品外部产生静电边缘场。从器件的衬底侧进行铣削后未观察到这种边缘场。对测量的全息相位图像的分析表明，每个FIB铣削样品表面上的电惰性层通常具有100 nm的厚度。