SIMS, Secondary Ion Mass Spectrometers, SIMS Workstation, Metallurgical Microscopes, Mumbai, India

Mass Spectrometers for Static and Dynamic SIMS

HAL EQS SIMS Systems

High Sensitivity
White triple stage mass filter and high transmission sector field energy filter.
Raster Control
For enhanced depth profiling capability.
Positive and Negative Ion Counting
Up to 2 X 107 cps.
SIMS Software Tuning
For optimum parameter adjustment via a dynamic display.

The HAL EQS is a state of the art secondary ion mass spectorometer for static and dynamic SIMS applications. Ionised species with masses up to 500 amu may be analysed. An integral electron impact ion source is utilized for conventional RGA, leak detection and Secondary Neutral Mass Spectrometry (SNMS). The HAL EQS employs a high performance triple quadrupole filter and a 45° sector field analyser with DC quadrupole input focusing lens. Ions passing through the instrument have simple curved trajectories with virtually 100% transmission within the pass band. The EQS has full high resolution ion energy analysis capability. Ion counts from 1 to 2 X 107 cps are made from an off axis,low background, high sensitivity detector.

Operating modes and example spectra


Positive and Negative SIMS spectra Detection of both positive and negative secondary ions is essential since both spectra contain important chemical information. Positive and negative histogram spectra from an amorphous metallic alloy of the composition CO(79%) B(7%) are shown, taken with a primary ion current of 1 nA. Neutrals Analysis Secondary Neutral Mass Spectrometry (SNMS) is routine since the EQS has an integral electron impact ion source mounted at the flight tube Mass peak profiles are shown for neutrals from a silicon surface. Trend Analysis This mode of operation is useful for studying changes in single intensity with time or depth as in Dynamic SIMS. This example shows secondary ions produced from a Yba2 Cu3DRA Electronics Division Malvern. Appl. Phys. Lett. 61(2), 1992). Map Mode This mode allows any of the controlled ion optical and ion source parameters routinely used in tuning to be scanned with respect to a specific mass for the optimization of instrument transmission. This facility may be used to obtain high resolution Ion Energy Distribution such as those shown here for PTFE sample.

Previous Investigations using the HAL EQS System

Mass Spectrum of Molybdenum Oxide
The example shown a spectrum obtained from a sample of molybdenum oxide on molybdenum metal employing a 5 KeV Ar+ ion beam with an O2 flood. The mass spectrum shows the molecular metal, around m/z 126 from the dioxide.

Depth Profile from a NiCr, Cu and NiFe layered sample
Dynamic SIMS employs a high current density ion beam to depth profile thin films, implants and multiplayer systems. A depth profile from a thin film NiCr, Cu and NiFe sample is shown opposite. In this example 99% of the surface area was masked. The ion gun and the acquisition parameters for the raster scanning were controlled directly by the HAL EQS controller.

Cleaning of a GaAs surface
Careful monitoring of surface cleanliness is vital in semiconductor device fabrication. Static SIMS performed at each stage of the cleaning process allows complete control over the surface preparation and the treatment of contaminants. This static SIMS spectrum was obtained from a GaAs surface prior to sputtering. Contaminate signals are reduced, while the intensity of the gallium and arsenic ion signals increases.

Negative Ion SIMS
The chemical nature of any surface, however complex, can be revealed from the positive and negative SIMS spectra. Here trace amounts of chloro-organic contaminants are detected on an oxidized aluminum sample.

HAL EQS Product Range

	HAL EQS 300	HAL EQS 500
Order Code	433030	435030
Mass Range (amu)	300	500
Energy Range (eV)	± 100	± 100
Ion Detection	+ve/-ve ions	+ve/-ve ions

Specifications

Energy Analyser	45° Sector field
Transmisssion	100% within Pass Band
Mass Filter	Triple filter -3F type
Pole Diameter	6.0 mm
Pole Material	Molybdenum
Filter Length	170 mm
Detector	Off axis air stable electron multiplier with pulse counting detector
Dynamic range	1cps to 2x10⁷cps

Maximum Operating Pressure	- 5x10-6 Extandable with optional differential pumping
Integral RGA Ion Source	- Electron impact Radically Symetric Twin-filament
Filament Type	- Thoriated iridium standard. Tungsten and rhenium optional.
Filament Degas	- Selectable single filament or simultaneous twin filament.

Performance Specification

From an oxidised molybdenum sample using a 5 keV Ar⁺ primary ion beam
Signal from ⁹⁸Mo⁺+⁹⁸MoO⁺ > 10⁴ cps per nA of primary beam.

Other Hiden Products for Surface Analysis include

HAL IDP Systems
The HAL IDP is a quadrupole mass spectrometer for the detection and analysis of low energy ions, positive and negative, generated from UHV surface science techniques, such as electron stimulated desorption (ESD) and photon stimulated desorption (PSD). It may also be used for thermal desorption studies where neutral species maybe ionized by post ionization.

HAL SIM Probes
The HAL SIM is a compact SIMS probes with an inline Bessel Box energy analyser. The Bessel Box essentially works in the same way as a cylindrical mirror analyser, a central stop elimating line of sight from source to detector. Two mass ranges are available and the probe comes as standard with an ion counting off-axis electron multiplier providing positive/negative ion detection.

IG20 and IFG200 Ion and FAB guns
The IG20and IFG200 are state of the art Ion and FAB guns for use in surface analysis. The IG20 provides an intense ion beam with 100 micron spot size while the IFG200 offers a 2 mm ion or fast atom beam.

Both guns operate over 0.5-5 KeV with oxygen or inert gases and have a 30 offset in the gun column for optimum rejection of neutrals. The IG20 and IFG200 are ideally suited for static and dynamic SIMS and other surface analysis applications.

SIMS Workstation


	Complete SIMS system comprising: Analysis chamber Primary Ion Gun Secondary Ion Mass Spectrometer Sample Manipulator UHV pumping system

/ SIMS (Secondary Ion Mass Spectrometers)