2009 HORIBA, Ltd. All rights reserved HORIBA, Ltd. All rights reserved.

Transcription

1 2008 HORIBA, Ltd. All rights reserved.

2 Plasma Profiling Mass Spectrometry (PPMS) zur Analyse von Element- und Isotopenverteilungen in Oberflächen und Schichten Rainer Nehm, HORIBA Jobin Yvon GmbH, Unterhaching Anwendertreffen Analytische Glimmentladungsspektrometrie 23. und 24. November 2011, Dresden

3 A word on HJY nearly 200 Years History 1819: Jean Baptiste Soleil creates the Company, in Paris, 21 Rue de l Odéon 1848: Introduction of the Saccharimeter 1849: Henri Soleil, son of the founder, becomes Manager 1872: Léon Laurent, nephew of H. Soleil, takes charge of Ateliers Soleil and introduces his famous Polarimeter

4 Tradition of innovation. New facility in 2012 sfd

5 A European development New Elemental and Molecular Depth Profiling Analysis of Materials by Pulsed Radio Frequency Glow Discharge Time of Flight Mass Spectrometry (EMDPA). Start: 2006

6 Plasma Profiling Mass Spectrometry (PPMS) A new instrument for Depth Profile Analysis of Advanced Multilayered Materials

7 Motivations for the new technique Build on the success of the RF GD OES for depth profile analysis of thin/thick films Couple the fast plasma source to a more sensitive detection system (MS) Add new opportunities: elemental, isotopic and molecular depth profiling Target new applications and new markets

8 Advantages of TOF MS Why TOF-MS? TOF detection is simultaneous, therefore ideal for transient signals measurements. TOF MS is required for the ultra fast depth profiling of layers by the GD plasma source. The TOFMS instrument provides the entire MS spectrum from mass 1 (H) to mass xxx. TOFMS instrument is fast enough to record the entire spectrum at each depth (up to single spectra/s) Post data treatment and retrospective analysis is possible. Other

9 Advantages of TOF MS TOF MS versus OES Si Fe Si Si in Fe matrix Fe 2+ CO N 2 Ar PPMS: simple spectra, lower background, high sensitivity >> better DL

10 Components of the new technique PPMS consists of three different parts:

11 Components of the new technique PPMS consists of three different parts: Part 1: radio frequency glow discharge (RF GD) for the generation of the plasma and the sputtering of the sample

12 Components of the new technique PPMS consists of three different parts: Part 1: radio frequency glow discharge (RF GD) for the generation of the plasma and the sputtering of the sample Part 2: Small patented Quadrupol for Blanking interfering ions

13 Components of the new technique PPMS consists of three different parts: Part 1: radio frequency glow discharge (RF GD) for the generation of the plasma and the sputtering of the sample Part 2: Small patented Quadrupol for Blanking interfering ions Part 3: Time-of-flight mass spectro-metry (TOF MS) for the detection of the ions

14 Part 1: Radio frequency glow discharge NiO(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) Ni(10nm) Ti(10nm) SiC-Substrat NiO/Ti Ni (10 layers) / SiC Well known technique for surface analysis

15 Part 1: Radio frequency glow discharge Applying an RF tends to result of a negative charge of the sample Electrons can leave the surface of the sample and collide with Ar atoms in the source Ionized Ar atoms move towards the sample When ionized Ar atoms hit the surface they sputter the sample The sputtered atoms collide with electrons or metastable Ar atoms The sputtered atoms get ionized

16 Part 1: Radio frequency glow discharge Benefits of the RF source: Possibilty to analyze conductive and nonconductive samples Possibilty to run the source in an pulsed mode for analysis of fragile samples like thin glass or organic coatings

17 Part 2: Quadrupol Interface for Blanking (patented) Blanking of 4 masses simultaneously: Ar related ions and matrix ions tuneable for different masses Matrix 1 Matrix 2 Substrate Blanking Ar and Matrix 1 Blanking Ar and Matrix 2 Blanking Ar and Substrate Depth Advantages Blanking: Improved signal to noise on neighbouring ions Enhanced dynamic range Longer detector life time

18 Part 3: TOF - Time of Flight mass spectrometer Extraction Zone d Drift tube L Detector Source V mv 2 = 2 zev E=0 TOF = a+ b m/ z All ions need to start at the same time. Source of ions needs to be pulsed or the extraction of ions needs to be pulsed

19 Specifications of the TOF MS Flight Tube : 0.7 m (V mode) Flight time : µs Peak width : few ns Acquisition speed adjustable Typical 33 khz allows measurement of a mass range covering all elements of periodic table GD day - September 24, 2010

20 RF Generator TOFMS Acquisition pulse RFPeriod delay Acquisition Data acquisition 250 Hz 1 ms pulse / 4 ms period 30 khz 3 ms acq. / 4 ms RF full period 90 Mass Spectra Mass Spectra Intensity Intensity m/z m/z m/z m/z Source Profile Signal 0 Time/ RFpériod Depth Profile Integration over source profile region Analysis Time

21 Measurement in pulsed mode 500 Signal enhancement in afterglow up to 1 e continua pulsada (area afterpeak) pulsada (Máximo afterpeak) Sensitivity (cps/ppm) Lobo et al, Winter Conference B 12 C 24 Mg 27 Al 28 Si 31 P 32 S 48 Ti 51 V 53 Cr 55 Mn 59 Co 60 Ni 63 Cu 75 As 90 Zr 93 Nb 95 Mo 98 Mo 107 Ag 120 Sn 121 Sb 181 Ta 184 W 208 Pb Isotope

22 Prototypes In total three prototypes: HORIBA Jobin Yvon S.A.S. Chilly Mazarin, Frankreich University of Oviedo Oviedo, Spanien EMPA Swiss Labs for Materials Science and Technology Thun, Switzerland

23 Horizontal sample mounting (photo of prototype) SAMPLE ¼ 10 inch Si wafer RF APPLICATOR

24 Design of the final product Delivery of the first PPMS beginning of 2012

25 Surface analysis with Plasma Profiling Mass Spectrometry Examples for elemental and isotopic information

26 Example 1: Analysis of ultra-thin layers - minor elements Al 98.5 Co Nb/Al (100-x) Co x /Si x= 1.5, 3.5, 4.5, 9.0, 35 % Constant thickness of internal layer, but variation of the Al-Co stoichiometry 50 nm 6 nm Ion Signal Intensity (counts) Sputtering starts 28 CO + 93 Nb + 27 Al + 59 Co + (x10) 28 Si Time (s) Co + Ion Signal Intensity (counts) 26 Pisonero et al, Winter Plasma Conference 2011

27 Example 1: Analysis of ultra-thin layers - minor elements 40 Nb/Al (100-x) Co x /Si x= 1.5, 3.5, 4.5, 9.0, 35 % Constant thickness of internal layer, but variation of the Al-Co stoichiometry 50 nm 6 nm Co Atomic Concentration (%) y = (0.002± )x R² = Co + ion signal intensity (counts) Calibration of Co atomic concentration in 6 nm AlCo layers Pisonero et al, Winter Plasma Conference 2011

28 Example 2: Analysis of ultra-thin layers - minor elements R. Valledor et al. Anal, Bioanal. Chem. 396 (2010) 2881 Nb/Al/Si t: 50, 20, 5, 2, 1 nm 50 nm t nm GD day - September 24, 2010

29 Example OVERVIEW 3: Analysis of Multilayered Metal Nanowires Template filled with trilayer nanowires (3.5 µm nanopore length) Pulsed rf-gd-tofms qualitative depth profile SEM cross-sectional view Au + (x11) Ni + (x44) 197 Au + (x11) 27 Al + ions sputtering time (s) Au(--)/Ni(1.9 µm)/au(0.9 µm)/substrate Pulsed rf-gd-tofms allows a fast and reliable depth characterization of nanopores quality, of critical importance to assist the optimization of electrodeposition procedures as well as to evaluate their routine manufacturing quality (e.g. evaluating the possible failure in electrodeposion process)

30 Example 4: 10 B in Si Quantitative depth profil with SIMS (reference technique) Quantitative depth profile with PPMS atoms/cm 3 1E19 1E18 1E17 1E16 1E15 10 B 11 B 29 Si 30 Si Maximale 10 B Konzentration 100 µg/g bei einer Tiefe von 300 nm counts/s Concentration (µg/g) B Concentration 10B Concentration 1E14 0,0 0,2 0,4 0,6 0,8 1,0 Depth (µm) Depth (nm) Pisonero et al, Solar Energy Materials and Solar Cells, 94, 1352 (2010)

31 Example 5: Isotopic Analysis W Ta 2 18 O 5 Ta 2 16 O 5 Ta 2 18 O 5 Ta 2 16 O 5 Ta 2 18 O 5 Ta 2 16 O 5 Ta Al 2 O 3 Al Substrat 50 nm 50 nm 50 nm 50 nm 50 nm 50 nm 6. Steps 4 & 5 repeated, on top W surface with 25 nm thickness 5. Ta 2 18 O 5 Anodisation in sodium tungstate prepared with 18 O enriched H 2 O 4. Ta 2 16 O 5 Anodisation in sodium tungstate (Na 2 WO 4 ) 3. Ta Sputtering deposition 2. Al 2 O 3 Anodisation in ammonium pentaborate (NH 4 B 5 O 8 4H 2 O) 1. Al Substrate: pure foil 0.3 mm thick

32 Example 5: 18 O enriched thin tantalum oxide bilayers Intensity (ions) Ta 18 O 16 O 16 O 2 H 3 Ta Ta 16 OH 2 Al H 3 x O x500 Al 16 O 2 x O 18 O x500 Ta W x1000 Ta 16 O x50 Ta 18 O x 100 Ta 2 16 O 5 Analysis Conditions Plasma 600 Pa, 45 W Puls mode 0.8 ms /4 ms Ta 2 18 O 5 Ta 2 18 O 5 Ta 2 16 O 5 Ta 18 2 O 5 Ta 16 2 O 5 Ta 16 O 18 O Depth(nm) Al 2 O nm Al Detection of marker W on top surface with expected thickness ~ 25 nm Resolution of labeled layers 18 O (looking at 16 O 18 O and Ta 18 O) Detection of H at the interface oxide/ metal A. Tempez et al, Surface and Interface Analysis, 41, 966 (2009).

33 Example 6: C, Al und Zn auf Si Substrat Messung Cornel Venzago (AQura), Probe von Vladimir Sivakov (IPHT Jena) und REM Bild und Ausarbeitung von Sebastian Schmitt (MPI Erlangen)

34 Conclusion Plasma Profiling Mass Spectrometry allows the analysis of conductive and non-conductive samples therefore a large field of applications simulteneous analysis is compared with other surface techniques like SIMS, XPS or Auger spectroscopy a fast technique and therefore well suited for industrial labs higher sensitivity than classical GD-OES for layers from a few nm up to several µm provides elemental, isotopic and molecular information

35 Thank you. PPMS Isotopic Information Elemental Information Molecular Information List with publications available!