Tutorial: SIMS Basics

Transcription

1 Tutorial: SIMS Basics Ovrviw of SIMS Sputtring procss Elctron-gun Mass spctrum Dtctors WiscSIMS modification Isotop Analyss Noriko Kita (WiscSIMS, UW-Madison) Plas stop m anytim for qustions!

2 Scondary Ion Mass Spctromtr (SIMS) Ø Surfac chmical and isotop analyss Ø High snsitivity ( ppb) Ø Mdium latral rsolution (50 nm-20 µm) Ø Dpth rsolution 2-30 nm TOF SIMS Ø Dstructiv Analysis Dynamic SIMS IMS 1280: 2µm -20µm NanoSIMS: 50 nm Goscinc applications: Isotop ratios Trac lmnts Volatil lmnts

3 Principl of Scondary Ion Mass Spctromtr Primary Ions: Cs +, O /O 2 : highr snsitivity O 2+, Ar + Ga + : nm-scal spot sizs Clustr ions (Ar n+, C 60+ ): lss sampl damag Mass Spctromtr: Magntic Sctor: High prcisions Tim of Flight (TOF): pulsd bam, surfac analysis Fourir Transform Ion Cyclotron Rsonanc (FT-ICR) Ion Trap (Orbitrap) Analysis typs: Spot isotop/chmical analysis Ion imaging (scanning/ dirct) Dpth profil 3D imaging

4 Ion Sputtring Procss and Scondary Ionization 1. Primary ions ar implantd to th intrior of sampl. 2. Atoms ar displacd by collision cascad. 3. Atoms, molculs, ions, lctrons ar jctd from sampl surfac. Mass Spctromtr should Sparat molcular isobaric intrfrnc by high mass rsolving powr (M/ M) 2000 Compnsation of surfac charging Focus ions with variabl initial kintic nrgy Mostly nutral atoms and molculs Primary Ion Scondary Ions (<10%) nutral atoms, molculs (>90%) atomic and molcular ions (+/ ) scondary lctrons ( ) amorphous layr (~30 nm)

5 IMS 1280: Magntic Sctor Doubl-focusing MS Elctrostatic Lns Primary Ion Sourcs (Cs+/O-) Elctrostatic Dflctor Aprtur or Slit Cs- Duo- Sourc Plasmatron Primary Bam Mass Filtr Normal Incidnc Elctron Gun IMS 1280 Airlock Sampl Stag ESA Sampl Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Primary Ions + Cs Scondary Ions O Sampl Enrgy Slit Elctron Bam -gun Scondary Ion Production from sampl surfac Collctor Motion Axis Dtctors Magnt Flight Tub Ion Dtction Mass Spctromtr should Sparat molcular isobaric intrfrnc by high mass rsolving powr (M/ M) 2000 ü Larg radius sctor magnt Compnsation of surfac charging ü lctron gun Focus ions with variabl initial kintic nrgy ü Doubl-focusing MS

6 Doubl Focusing Mass Spctromtrs SIMS usd for Goscinc Larg radius (high mass rsolution: M/ΔM 5,000) Sctor Magnt radius Ø IMS 1270/1280/1280-HR/1300-HR 3 : Stabl isotop, Gochronology, Nuclar fornsic R = 585 mm Ø SHRIMP: Gochronology (zircon U-Pb ags) R = 1,000 mm Ø NanoSIMS: High spatial rsolution (50nm bam) Imaging, biological applications Convntional SIMS (low mass rsolution): IMF 7f/ 7fGo: R = 120 mm TOF (Tim of flight): Shallow dpth analysis, thin film

7 SIMS Analysis Spots Cs+ primary bam µm spots Larg Spot Cs+ primary bam 1-2 µm spots Small Spot Foraminifra; Kozdon t al. (2011) Primary Ion intnsity ~ 2 na Prcisions of oxygn isotop ratios ~ 0.3 Comt sampl rturn; Nakashima t al. (2012) 3 pa 1-2

8 Most of lmnts in priodic tabl ar ionizd Ionization fficincy varis significantly from 0.1 to 10% O /Sc(+) Highr ionization tndncy: Mg+, Ca+, Primary Ions Cs: +10kV O : 13kV Sampl Scondary Ions ±10kV Cs+/Sc( ) Highr lctrongativity: O, C, S, Si Pb+ - Nobl gass do not ioniz. - Nitrogn in carbon baring phas: CN Modifid from Evans Analytical Group:

9 Scondary Ions: Ionization Efficincy Ionization fficincis = (N of scondary ions)/ (N of atoms sputtrd) O in silicat, carbonats, oxid minrals ~10% C in carbonats 0.3% Si in quartz ~ 1% Instrumntal bias on isotop ratio = ( 18 O / 16 O ) SIMS /( 18 O/ 16 O) Tru Scondary Ion intnsitis Calcit (CaCO 3 ) C = cps O = cps Ca ~0 (ionizd as CaO ) Quartz (SiO 2 ) O Si = cps = cps oxygn isotop ( 18 O/ 16 O) in silicat, carbonats, oxid minrals: ±10 carbon isotop ( 13 C/ 12 C) in calcit: 40 silicon isotop ( 30 Si/ 28 Si) in quartz: 30

10 Ion sputtring and lctron gun

11 Sputtring of sampls Ion Sourcs Elctrostatic Lns Elctrostatic Dflctor Aprtur or Slit Cs + +10kV O 13kV Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Magnt Flight Tub Impact Enrgy kv Primary Bam Mass Filtr Primary Ions + Cs Scondary Ions O Collctor Motion Axis Sampl 10kV +10kV Normal Incidnc Elctron Gun Airlock Sampl Stag Sampl Sampl Elctron Bam Dtctors IMS 1280

12 Entranc of scondary optics (Main chambr door is opnd) Sampl holdr Insulator Sampl holdr is hld at ± 10kV Sampl holdrs (original 25mm and nw 32 mm) 20 mm 22 mm

13 Analysis of insulator: scondary lctrons Scondary lctrons jction Scondary Ions 0V 0V Primary Ion Ion Extraction Fild ±10kV Minimum charging M+ +10kV M 10kV Charg built up -9.9kV Elctrons rturns to sampl surfac Elctrons scap from sampl surfac nutral atoms, molculs (>90%) atomic and molcular ions (+/ ) scondary lctrons ( ) Positiv scondary Ion Ngativ scondary Ion

14 Analysis of insulator: scondary lctrons kv Elctrostatic discharg! on your sampl 0V Minimum charging M+ +10kV Elctrons rturns to sampl surfac Positiv scondary Ion M 10kV 0V Elctrons scap from sampl surfac Ngativ scondary Ion Charg built up -9.9kV

15 Elctron Gun for Charg Compnsation Elctrostatic Lns Elctrostatic Dflctor Aprtur or Slit Magnt Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Flight Tub Primary Bam Mass Filtr Primary Ions + Cs Scondary Ions O Collctor Motion Axis Elctron Gun Normal Incidnc Elctron Gun Airlock Elctron Bam Dtctors Sampl Stag Sampl Sampl IMS 1280

16 Elctron Gun for Charg Compnsation Primary Ions + Cs Scondary Ions O Acclration voltag: -10kV Currnt: 50 µa Elctron Bam Dclration 0V Sampl Elctron gun: -10 kv Sampl acclration: -10 kv Sampl Elctron Cloud ( µm): lctron nrgy =0 V -9.9kV Whn charg build up by sputtring lctron is attractd to sampl surfac until th charg is compnsatd. -10kV

17 Doubl Focusing Mass Spctromtr

18 Doubl Focusing Mass Spctromtr Elctrostatic Lns Elctrostatic Dflctor ESA Aprtur or Slit Magnt Magnt Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Flight Tub Primary Bam Mass Filtr Primary Ions + Cs Scondary Ions O Collctor Motion Axis Normal Incidnc Elctron Gun Airlock Elctron Bam Dtctors Sampl Stag Sampl Sampl IMS 1280

19 IMS 1280: Magntic Sctor Doubl-focusing MS mv 2 /R E qe = mv 2 /R E mv 2 /R M qe Elctrostatic Lns Elctrostatic Dflctor E : lctrostatic fild (ESA) R : radius B : magntic fild qvb Aprtur or Slit qb = mv/r M Magnt qv = mv 2 /2 0V Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Flight Tub ±10kV Sampl q = lctron charg V = ±10 kv m = mass of ion v = vlocity of ion Primary Bam Mass Filtr Normal Incidnc Elctron Gun IMS 1280 Airlock Sampl Stag Sampl Primary Ions + Cs Scondary Ions O Sampl Elctron Bam Collctor Motion Axis Dtctors 16 O 18 O Multipl Dtctors

20 Initial Kintic Enrgy of Scondary Ions Trajctory of ions with variabl nrgis and angls will b diffrnt Sputtring procss may provid initial kintic nrgy to ions v = v i + v 0 v i m i v i2 /2 =q V s 0V Acclration by lctrostatic fild V s v 0 Ion with initial kintic nrgy and angls Ion without initial kintic nrgy -10kV Sampl

21 Elctrostatic Analyzr (ESA) Ions with variabl angls: Focus Ions with variabl nrgy: Disprsion Ions with variabl angls ESA Focus Elctrostatic Lns Elctrostatic Dflctor Aprtur or Slit ESA Magnt Enrgy Slit Cs- Duo- Sourc Plasmatron Primary Bam Mass Filtr Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Enrgy slit Primary Ions Scondary Ions + Cs O Collctor Motion Axis Flight Tub fastr ions Normal Incidnc Elctron Gun Airlock Elctron Bam Dtctors ESA Disprsion IMS 1280 Sampl Stag Sampl Sampl slowr ions Enrgy Slit Ions with variabl nrgy

22 Sctor Magnt: Ions with diffrnt masss Magnt sparat ions with diffrnt mass Elctrostatic Lns Elctrostatic Dflctor Aprtur or Slit Magnt Magnt Magnt Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Flight Tub Primary Bam Mass Filtr Primary Ions Scondary Ions + Cs O Collctor Motion Axis Normal Incidnc Elctron Gun Airlock Exit slit Elctron Bam Dtctors m-1 m+1 IMS 1280 Sampl Stag Sampl Sampl Exit slit m

23 Sctor Magnt: Ions with th sam mass Ions with diffrnt angls: Focus Ions with diffrnt nrgy: Disprsion Similar to ESA diffrnt nrgy diffrnt angls Elctrostatic Lns Elctrostatic Dflctor Aprtur or Slit Magnt Magnt Magnt Magnt Cs- Duo- Sourc Plasmatron Elctrostatic Analyzr (ESA) Fild Aprtur Entranc Slit and Contrast Aprtur Enrgy Slit Flight Tub Primary Bam Mass Filtr Primary Ions Scondary Ions + Cs O Collctor Motion Axis Normal Incidnc Elctron Gun Airlock Exit slit slowr fastr Elctron Bam Dtctors IMS 1280 Sampl Stag Sampl Sampl Exit slit Exit slit Disprsion Focus

24 Doubl focusing mass spctromtr Disprsions mad by ESA and Magnt ar coupld to focus ions with variabl nrgy. ESA Enrgy slit Magnt lns Entranc slit Ions jctd with variabl angls From Camca IMS manual Exity slit Ions jctd with variabl angls and nrgy Focus ions with variabl angls Focus Ions with variabl initial nrgy

25 Dtaild schmatics of IMS 1280 Primary Column Magnt (PBMF) Lns: 5 Dflctor: 7 Stigmator: 2 Aprtur: 2 Elctron Gun Coil: 2 Lns: 1 Dflctor: 2 Quadrapol: 1 Scondary optics Magnt ESA Lns: 10 Dflctor: 6 Stigmator: 3 Hxapol: 3 Slit: 3 Aprtur: 2 Dtctors FC: 6 EM: 4 MCP ESA: 6

26 Mass Spctrum and Ion Dtction

27 Mass Spctrum and Stability (NMR) MRP=(M/ΔM): mass rsolving powr 17 O: MRP ~ 4,000; 16 O, 18 O: MRP ~2,200 Magntic fild is rgulatd by NMR snsor. Drift (ΔB) <5 ppm for 12 hours *Hall Prob stability: ~30 ppm for 1 hour 16 O 18 O 30 ppm Flight Tub Hall Prob 17 O amu 10% hight Multi-collctors 16 OH amu NMR Prob NMR Probs NMR (Nuclar Magntic Rsonanc) snsors btwn lctro-magnts

28 Ion Transmission Rlativ transmission Transmission vs. Mass rsolution 18 O/ 16 O IMS 6f (Cs+) IMS 1270 (Cs+) 17 O WiscSIMS IMS 1280 Oxygn 2 isotop >90% C isotop >90% Oxygn 3 isotop >70% Larg radius SIMS Nanosims 50 (C-) 0.01 Small radius SIMS Mass rsolution CAMECA

29 Ion Dtctors FC (Faraday cup): Dirct ion currnt masurmnts >10 6 cps Ion currnt cps = A R =10 11 ohm Amp 3V V = I R EM (lctron multiplir): Puls counting <10 6 cps Stabl Gain Slowr rspons (sc) Thrmal nois (~1000 cps) Sris of dynods (N~20): ach jcts 2-3 lctrons 10 8 lctrons producd pr singl ion dtctd as an lctronic puls Low nois <0.01 cps Fast rspons (20-70 ns) Gain drift

30 Ion dtction systm Magnt Ø Singl collctor: 2 FC, 1EM (switch by dflctors) Ø Multi-collctors: 4 FC, 3 EM Multi-collction FC systm is originally dsignd by Finnigan MAT. Vry similar to modrn ICP-MS and TIMS instrumnts. Ø Multi-channl plat (MCP) Dirct imag, tuning!

31 Typs of analyss using SIMS Spot analysis: High prcision stabl isotop analyss Trac lmnt analyss Scanning Ion Imaging (SII): NanoSIMS Trac lmnt, isotop mapping Rsolution = Primary bam siz (0.5µm - 3 µm) Dirct Ion Imag: IMS 1280/7f sris works as ion microscop. MCP dtction SCAPS dtctor (Hokkaido 1270 and Hawaii 1280) Rsolution = Optical rsolution (~0.5 µm) Exampl of SII (Ushikubo t al. 2008)

32 Modification and upgrad

33 Modifications and upgrad of WiscSIMS IMS 1280 WiscSIMS IMS 1280 prforms as good as nwr instrumnts; IMS 1280-HR and 1300-HR 3 Analytical improvmnt FC amplifir pump (2010) Exit slit modifications (2010, 2016) Larg sampl holdr (2012) FC amplifir upgrad (2016, Camca) RF Plasma Sourc (2017, Camca) Small spot ( 2 µm) analyss Turbo pump damprs (2011) NanoDflctor (2014) Mostly in-hous modifications Efficincy and asy oprations Sampl chambr camra (2008) Six sampl airlock (2009, Camca Sampl navigation and imaging Blu light illumination (2009) UV light illumination (2011) Softwar Badgrscop (2012) Adaptd to nwst IMS 1300-HR 3

34 Modification of WiscSIMS IMS 1280 (UV light microscop, 2011) IMS 1280 Optical microscop Original: Whit halogn lump Rsolution ~3.5 µm Chromatic abbration UV light optics 356 nm LED HD camra Rsolution ~1.3 µm * Rplacd multipl optical componnts. Kita t al. (2015, JAAS)

35 Nw sampl viwing softwar Badgrscop (2012) Nw softwar to viw HD-camra Imag procssing Kita t al. (2015, JAAS)

36 NanoDflctor (2014) Accuracy of aiming 1 µm Stag minimum stp =1 µm Primary bam dflction minimum = 1µm Apply additional voltag to bam dflctor Rsolution: 0.1 µm Comt particl analyss (Dfouilloy t al. 2017; EPSL) (a) SEM imag of comt particl with FIB mark SIMS 16 O - ion imags of th FIB mark with 10 µm rastring. (b) bfor adjustmnt (c) aftr displacmnt of th stag (d) aftr adjustmnt with th NanoDflctor () SEM imag of comt particl aftr SIMS analysis In-hous microprocssor board attachd to Camca original dflctor board

37 RF Plasma Sourc for O /O 2 ions (coming soon!) x10 incras in intnsity Mg isotop analyss of xtratrrstrial matrials Oxygn isotop analysis Cs + : 1-2 µm, 3pA 30 min /spot Duoplasmatron Mg isotop analysis (MgO~0.5%) O : 2-3 µm, 3pA 11 h /spot Mg isotop analyss of comt particl (Nakashima t al. 2015) Smallr spots 2 µm Fastr analyss 1h

38 RF Plasma Sourc for O /O 2 ions (coming soon!) x10 incras in intnsity Ø Cosmochmistry 26 Al- 26 Mg xitinct nuclid chronology Mg isotop fractionation by vaporation Ø U-Pb gochronology (zircon) Duoplasmatron Ø Trac lmnt analyss Othr isotop systm in carbonats Mg isotop fractionation Ca isotop fractionation Sr isotop ( 87 Sr/ 86 Sr)

39 Finally,.. SIMS analysis is asy

40 Oxygn isotop analyss Instrumnt is fully tund including dtctor positions and magntic fild. click - Mov to standard grain in your sampl. - Mov to your analysis position.

41 Oxygn isotop analyss Instrumnt is fully tund including dtctor positions and magntic fild. Acquisition taks 3min - Mov to standard grain in your sampl. - Mov to your analysis position. - Prss START

42 During first 1 min, thr will b sris of scanning. This is calld DTFA Scan that adjustmnt of primary bam misalignmnt against scondary ion optical axis. O- Oxygn isotop analyss DTFA-Scan Cs+ DTFA (XY)

43 Aftr th analysis: import nw data to xcl sht Click Macro-button Slct nxt row

44 Aftr th analysis: import nw data to xcl sht

45 Oxygn isotop analyss Instrumnt is fully tund including dtctor positions and magntic fild. click - Mov to standard grain in your sampl. - Mov to your analysis position. - Mov to nxt position Rpat this 12 hours