Compositional Analysis

Fraunhofer-Center Nanoelektronische Technologien

Compositional Ana

Secondary Ion Mass Spectrometry (SIMS)/Tof-SIMS

SIMS
Buried particles in C deposition on Si bulk


SIMS
Al2O3 for Flash Memory application: Quantitative study of Si diffusion into high-k layer


SIMS
Series of samples and standards in a single sample holder ready to be analyzed

Secondary Ion Mass Spectrometry (SIMS) is a very versatile and well established destructive surface analysis technique providing qualitative and quantitative information about local elemental, isotopic and molecular composition.

 
Applications
 
A solid sample is sputtered by a beam of primary ions under ultra high vacuum conditions, removing neutral and ionized particles from the sample. The secondary ions are subsequently analyzed in a mass spectrometer. SIMS can be used in static or dynamic mode. Surface images and spectra are obtained in the static mode. Here, a low dose of high energy primary ions removes some characteristic ions from the upper monolayers only. Alternatively, an unlimited dose of primary ions can be used to sputter into the sample. Dynamic SIMS thus yields depth information about the sample composition within a depth range from a few nanometers up to several microns and a depth resolution below one nanometer.


Cameca IMS WF (magnetic sector SIMS)
A magnetic sector field mass analyzer yields information about ions of one or a few specific masses with very high mass resolution and sensitivity. It excels at depth profiling of e.g. dopants or contaminations, layer stacks and alloys and the analysis of buried artifacts. The quantification of data via reference standards for various elements used in semiconductor industry is possible.


ION-TOF ToF-SIMS 300R
TA ToF-SIMS features a Time-of-Flight mass spectrometer and is hence capable of analyzing ions in a broad mass range up to 10.000 amu simultaneously and thus excels at the analysis of contaminations or complex materials. It can operate without any prior information about the sample.
Static Mode: Local surface maps with high lateral resolution: structures, defects, surface contaminations, e.g. particles and unknown organics
Dynamic Mode: Depth profiling of implants, contaminations, layer stacks or alloys. Quantification via reference samples or sensitivity factors is only feasible in special cases.

 
Technical Specification
 
CAMECA IMS WF
Depth resolution: 1-10 nm
Sputtered Area:  (50-500 μm)²
Mass resolution: up to 25000
Mass range: 1-560 amu
Primary Ions: (Cs+, O2+): 250eV – 10keV
Temperature: ~20°C
Pressure (UHV): 1e-10 mbar  - 1e-8 mbar
Sample Size:   up to 300 x 300 mm
Environment: Laboratory

IONTOF TOF.SIMS 300R
 
Depth resolution: 1-10 nm
Sputtered Area: (2-500 μm)²
Lateral resolution: <100nm
Mass resolution: up to 7000
Mass range: 1-10.000 amu
Primary Ions: Cs+   250eV – 2keV
O2+   500 eV – 2keV
Bi+, Bi3+  25keV
Temperature: ~20°C
Pressure (UHV): 1e-10 mbar  - 1e-8 mbar
Sample Size: up to 300 x 300 mm
Environment: Cleanroom, Class 1000
   
Research Areas
 
• NVMs: non-volatile memory cell stacks (SONOS, TANOS, TAZOS, …): 
» Layer thickness comparison for different depositions 
» Elemental composition, layer stack, interface sharpness 
» Diffusion monitoring of e.g. Al, Si and Zr after heat treatment

• Epitaxial SiGe films
» Layer thickness
» Ge content, relative Ge changes for different processes
» Oxygen and carbon contamination

• Wafer and substrate monitoring, e.g. for semiconductor or solar industry applications
» Applicable to almost all solid materials and coatings (semiconductors, metals, glasses, oxides, organics…)
» High spatial resolution, surface images, particle characterization
» Organic contamination (oils, fatty acids, …)
» Metallic contamination (Al, Fe, Cu, …)

• Silicide formation for contact implants
» Monitoring of silicide formation, elemental identification
» Redistribution of contact implants during silicidation