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The success of the helium ion microscope has encouraged extensions of this technology to produce beams of other ion species. A review of the various candidate ion beams and their technical prospects suggest that a neon beam might be the most readily achieved. Such a neon beam would provide a sputtering yield that exceeds helium by an order of magnitude while still offering a theoretical probe size less than 1-nm. This article outlines the motivation for a neon gas field ion source, the expected performance through simulations, and provides an update of our experimental progress.

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We have studied the kinetic mechanism of the adsorption-induced-desorption (AID) reaction, H+D/Si(100) --> D2. Using a modulated atomic hydrogen beam, two different types of AID reaction are revealed: one is the fast AID reaction occurring only at the beam on-cycles and the other the slow AID reaction occurring even at the beam off-cycles. Both the fast and slow AID reactions show the different dependence on surface temperature Ts, suggesting that their kinetic mechanisms are different. The fast AID reaction overwhelms the slow one in the desorption yield for 300 K < or = Ts < or = 650 K. It proceeds along a first-order kinetics with respect to the incident H flux. Based on the experimental results, both two AID reactions are suggested to occur only on the 3x1 dihydride phase accumulated during surface exposure to H atoms. Possible mechanisms for the AID reactions are discussed.

We have observed low-energy electron diffraction patterns of Cu(001) clean surface using field-emitted electrons from tungsten tips. Only elastically scattered electrons contribute to diffraction patterns. Tip-sample distance, bias voltage, electron beam opening angle and tip apex structure determine the probing diameter and symmetry of diffraction patterns. The emission current, bias voltage and estimated probing diameter for the observed diffraction patterns were 0.15 nA, 75 -82 V, and 4 -40 mm, respectively.

Soon after its development in 1955, the gas field ion source (GFIS) was pursued as the source of positive ions for focused ion beam (FIB) instruments [1]. Within the semiconductor industry, such FIB instruments are of critical importance for their failure analysis (FA), circuit edit (CE), and TEM sample preparation. However the GFIS development efforts were hampered by issues related to the source lifetime, and the short and long term temporal stability. The commercial gallium liquid metal ion source (Ga-LMIS) has served as the ion source of choice for the past 30 years with some recognized shortcomings arising from the probe size, electrical contamination, optical opacity, etc [2]. These shortcomings have produced a growing interest in FIBs with other ion species. In the past decade, the helium GFIS performance was vastly advanced -permitting the development of the helium ion microscope (HIM). In the past year, these same advances were applied to a neon GFIS.The challenges arising from a neon beam can be attributed to the fundamentally different characteristics of the neon atom compared to a helium atom. Neon atoms will field ionize at an electric field strength of 3.5 V/Å, or about 20% less than the field required for the field ionization of helium [3]. The reduced field strength gives rise to a limited lifetime of the emitter atoms due to field assisted chemical processes. Previous neon results show drastic changes in the apex of the emitter after typically a few minutes of operation [3]. The neon gas also is much more polarizable in the presence of a strong non-uniform electric field. This has the effect of making the gas atoms attracted to the emitter, and augmenting their normally small van der Waals forces to the point where they tend to adhere to the emitter [4]. As an indirect consequence, the emission current tends to fluctuateas muh as 30% over very short time periods (Figure 1a). Additionally, the location of the emission sites tends to jump between a small set of metastable states (Figure 1b).Most recently, the stability and lifetime of the neon GFIS has been improved to the point where it has become a suitable source for a neon ion microscope (NIM). Both the fluctuations in the brightness, and the motion of the emission sites, have been reduced by a factor of 5. Further improvements allow for the operation over long periods of time (~10 hours). Under these conditions, the NIM can be used for imaging (Fig. 2) and nano-machining applications.[1] A