Preparation of TEM samples by focused ion beams

Abstract

The high spatial resolution available from TEM can be used with great advantage in the field of microelectronics to identify problems associated with the continually shrinking geometries of integrated circuit technology. In many cases the location of the problem can be the most problematic element of sample preparation. Focused ion beams (FIB) have previously been used to prepare TEM specimens, but not including using the ion beam imaging capabilities to locate a buried feature of interest. Here we describe how a defect has been located using the ability of a FIB to both mill a section and to search for a defect whose precise location is unknown. The defect is known from electrical leakage measurements to be a break in the gate oxide of a field effect transistor. The gate is a square of polycrystalline silicon, approximately 1μm×1μm, on a silicon dioxide barrier which is about 17nm thick. The break in the oxide can occur anywhere within that square and is expected to be less than 100nm in diameter.

Focused ion beam sample preparation of continuous fibre‐reinforced ceramic composite specimens for transmission electron microscopy

“…Despite the fact that the FIB produces large amounts of uniform thin area with no interfacial grooving and structurally intact interfaces, the use of the 30 kV gallium ion beam does introduce artefacts of its own (Ishitani & Yaguchi, 1996; Walker & Broom, 1997).…”

“…The ionic bombardment that produces sputtering also leaves a thin layer of damaged material on the sample surfaces milled by FIB (Ishitani & Yaguchi, 1996; Walker & Broom, 1997; Tanaka et al ., 1998). This limits the minimum sample thickness that can be produced while leaving some undamaged material for observation.…”

“…The aim of this paper is to demonstrate the utility of focused ion beam (FIB) specimen preparation for the production of TEM samples from a composite material system. The use of FIB sample preparation for microelectronics where the ability to produce site‐specific thin areas is critically important is well established (Szot et al ., 1992; Young, 1993; Stevie et al ., 1995; Walker et al ., 1995; Ishitani & Yaguchi, 1996).…”

Fabrication of nano structures in thin membranes with focused ion beam technology

“…In recent years specialised dedicated systems are commercially available for research in other disciplines. The technology makes it possible to carry out localized milling of almost any type of material, and deposition of conductors and insulators with high precision [1][2][3][4][5][6]. The possibility to image at high magnification and milling at a very specific site has made possible preparation of specimens for transmission electron microscopy (TEM).…”