The Hyperion™ Ion Probe for Next Generation FIB, SIMS and Nano-Ion, Implantation

Abstract

A high performance ion source (Hyperion TM ) has been developed that significantly advances the capabilities of many ion beam techniques used by material scientists and engineers. Hyperion TM has been developed to provide focused beams as small as 10nm, beam currents up to several microamps and with a broad range of ion species that include He + , O 2 + , Xe + and H 3 + . This paper summarizes a few applications that have been explored with this new system, along with some of the enhanced capabilities anticipated for surface engineering, sample preparation and surface analysis. HyperionTM is a high density, non-thermal plasma ion source that exhibits very high brightness, low energy spread and is able to operate reliably with a broad range of ion species [1,2]. This technology provides state-of-the-art performance in many areas of surface science and engineering that include FIB Milling, Nano Implantation and High Resolution Surface Analysis.This new ion source provides a useable current that extends to many micro-amps with an energy normalized brightness of >1x10 4 Am -2 sr -1 V -1 with xenon, 6.7x10 3 Am -2 sr -1 V -1 with helium, 4.5x10 3 Am -2 sr -1 V -1 with oxygen and 2.7x10 3 Acm -2 sr -1 with hydrogen. Unlike point ion sources (eg the liquid-metal ion source), the effective beam brightness at the target can be maintained from picoAmps up to many micro-Amps. The combination of high brightness, low energy spread and very high angular intensity provides this broad range of operating currents. A comparison of the typical gallium FIB performance with the Hyperion TM FIB is shown in figure 1. Hyperion TM excels at beam currents >50nA, while still having the brightness to provide <25nm resolution for imaging at 30keV. This system finds a broad array of applications, that includes large area cross-sectioning of next generation 3D IC technologies. In the coming years, critical interconnects and vertically stacked circuitry will often need to be excavated by deep FIB milling for failure analysis. Figure 2 shows a cross-section of a 'Through Silicon Via' (TSV), anticipated in the industry to replace external wire interconnects for these new high density devices. Once the fabrication process has been further developed for these 3D devices, over 10 5 TSV's are anticipated for some stacked die.Applications such as prototyping MEMS and embedded circuit components have been demonstrated with this high current FIB. Figure 3 shows a micro-scale spiral RF antenna, often used on RF IC's, that has been fabricated here in <60 minutes. A 5µm thick layer of copper has been locally sputter deposited over a ~250x250µm area of silicon oxide with a 3µA Xe + beam hitting a copper target and creating a conformal deposit in ~25minutes. A bitmap has been uploaded to the FIB pattern generator, directing a 250nA, 25keV Xe + beam to mill away the excess copper. The deposited copper has a measured electrical conductivity that is within a factor of 3 of bulk copper, such that this 2.5nH (calculated) inductor would have a quality factor (Q) ...

Bright focused ion beam sources based on laser-cooled atoms

“…92 Typically a plasma is created in a chamber with a gas inlet and a small (0.1 mm to 0.2 mm) exit orifice by subjecting it to a strong radio-frequency (RF) field created by an antenna wrapped around the exterior. The RF frequency is chosen to be high enough to be well above the plasma ion resonance, but also below the electron resonance.…”

“…Unlike the LMIS and the GFIS, the inductively coupled plasma source does not obtain its ions from a sharp tip, but rather from a more conventional approach of ionizing a gas via electron currents induced in a plasma. 92 Typically a plasma is created in a chamber with a gas inlet and a small (0.1 mm to 0.2 mm) exit orifice by subjecting it to a strong radio-frequency (RF) field created by an antenna wrapped around the exterior. The RF frequency is chosen to be high enough to be well above the plasma ion resonance, but also below the electron resonance.…”

Ion Sources Used for Secondary Ion Mass Spectrometry

“…A commercial ion source is being produced and has been described by Smith et al 23 Figure 3.2 shows the basic geometry that is common to all inductively coupled systems. …”

“…The RF coils (red) are external to the plasma and are often cooled along with the quartz vessel.RF-driven plasma sources have been developed and used by Ji et al16 for the production of noble gas atomic ion beams with FIB applications. Recently, Smith et al23 have demonstrated a commercial version of an RF ion source. Claims of very high brightness have been made by Smith et al but as yet have not been confirmed when compared with other ion sources under similar operating conditions.…”

High resolution isotopic analysis of U-bearing particles via fusion of SIMS and EDS images

“…6,7 Implementation of the two-step pre-screen then re-analysis SIMS process for screening U-bearing particle populations is advantageous for nuclear safeguards because it signicantly decreases the analysis time for precision isotopic ratio measurements, however it is not without its limitations. SIMS measurements are a product of (1) the primary ion interrogation area, which is governed by the inverse relationship between ion beam current and the ability to ultimately focus that ion beam [8][9][10] and (2) the secondary ions impacting the ion detectors. Once a particle has been identied by the pre-screening step, generally, a defocused higher current primary ion beam is used to obtain an accurate and precise isotopic ratio of that particle.…”