Development of 3D MetA-SIMS for organic materials using Dual FIB ToF-SIMS

Abstract

Three-dimensional microanalysis of the microstructure of organic materials is important in the development and progress of novel materials on the micro-to-nanometer scales. We have developed the three-dimensional microanalysis method using focused ion beams (FIBs) for section processing (shave-off scanning) and mapping for time-of-flight secondary ion mass spectrometry (ToF-SIMS). Shave-off scanning can effectively create an arbitrary section on a sample set against composite materials with a wide variety of shapes; three-dimensional sample images are then obtained by alternately operating two FIBs. From the simulation results, we could set the optimum condition of beam irradiation. In this study, we confirmed the enhancement of secondary ion intensity by Au deposition under ToF-SIMS mapping with the optimized condition, and examine the usefulness of the simulation. The enhanced maps of characteristic polystyrene (PS) fragment ions were obtained. In addition, we observed the distribution of Au deposition by mapping results. These maps showed same tendency. The intensity of PS fragment ions was enhanced according to existence of deposited Au particles. These results indicated that a precise analysis of 3D MetA-SIMS can be realized.

Study of Thickness Distributions of Sputtered Gold Particles Deposited on a Perpendicular Section for Enhancement of 3D MetA-SIMS

“…Three-dimensional metal-assisted SIMS (3D MetA-SIMS) is a novel 3D analysis method that intends to enhance the signal yields of organic samples by irradiating a gold plate set at the rear of a target sample [1]. This method adopts a unique processing technique called "shave-off", which uses a lateral focused ion beam (FIB) and completely sputters the surface of the sample to create a slightly damaged new section parallel to the FIB [2].…”

Angular Distribution of Secondary Ions under FIB-shave-off Condition -Toward Development of Three-Dimensional Secondary Ion Image System-

“…It has been reported that shave-off cross-sectioning is an efficient micro-machining method to achieve highly precise depth profiling with nanometer-dimensional depth resolution, which would provide spatial distribution of materials compounds [3,4]. Different heights of two W-wires were taken as model material to investigate their shave-off cross-sectioning shape and/or angle by using Ga-FIB micro-machining method.…”

“…1). Prof. Owari's group has taken several approaches to get 3D images not only of inorganic and organic/polymer materials [1][2][3][4] but also for biological samples by using the 2D shave-off cross-sectioning FIB-SIMS technique [5]. Fig.…”

Secondary ion mass spectrometry depth profiling of ultrathick films using an argon gas cluster source: Crater shape implications on the analysis area as a function of depth

“…Its inert chemistry and large cluster size also combine to minimize damage accumulation and topography development, providing depth resolutions approaching a few nanometers. These features have enabled ToF‐SIMS characterization of thin film structures for evaluating device efficiency and performance, such as investigating defects at interfaces of polymer nanostructures in organic electronics and optoelectrical devices …”