Depth profiling of Organic Films using mixed C60 + and Ar + Ion-Sputtering

Transcription

1 Principle of Depth Profile Depth profiling of rganic Films using mixed C6 + and Ar + Ion-puttering putter Ion Beam Jing-Jong hyue, Ph.D. Analysis Depth ".5-1 nm# Research Center for Applied ciences, Academia inica Department of Materials cience and Engineering, ational Taiwan University urface Layer ample Matrix Depth Profile Analysis 1 3 Principle of Depth Profile General Concepts of puttering composition depth profiling with surface analysis techniques?! erosion of specimen surface by energetic particle bombardment sputtering two possibilities for analysis:! freshly exposed surface (" XP, AE)! sputtered material (" IM) depth profiling! remove controlled thickness 2 4

2 XP Depth Profiling PHI 5 VersaProbe XM at inica (27/6/18) composition as a function of depth t in thin films XP signal is generated near the surface (~3nm) sputtering provides layer sectioning depth profiles are usually shown as signal intensity versus sputter time (not depth) further calibrations required! convert sputter time to depth! signal intensity to atomic concentration however, ion sputtering can causes change in the composition of the surface layers! surface segregation! preferential sputtering 5 7 puttering with C6 + Ions PHI 5 VersaProbe XM T=29ps Traditional ion sources such as Ar and Ga can impart significant damage to a samples surface C6 ions are more efficient in removing material and leave behind a relatively thin damage layer 15 kev Ga 15 kev C 6 C 6 bombardment calculations, Zbigniew Postawa; Enhancement of puttering Yields due to C 6 vs. Ga Bombardment of Ag{111} as Explored by Molecular Dynamics imulations, Z. Postawa, B. Czerwinski, M. zewczyk, E. J. miley,. Winograd and B. J. Garrison, Anal. Chem.y, 75, (23); Microscopic insights into the sputtering of Ag{111} induced by C 6 and Ga Bombardment,[ ibid., J. Phys. Chem., submitted January 24 1nm focused scanning XP microprobe (<1!m spot size) dual beam charge neutralization xyzrt five axis motorized sample manipulator floating column argon ion gun (-5kV) 1kV C6 sputter ion gun ptions:! UV light source for UP! electron gun for AE (<!m resolution)! dual anode X-ray source (Mg, Zr) 6 8

3 Depth Profile of PEDT:P on IT Glass: Ar Depth Profile of PEDT:P with Ar i2p beam voltage sputter time atomic concentration 3 kv.5 min 88%C, 3%, 9% 2 kv 1 min 88% C, 4%, 8% 1 kv 5 min 85%C, 6%, 9%.5 kv 15 min 85% C, 8%, 7% expected % C, 24%, 9% sputter time extended with lowering the beam energy significant lost of even at low beam energy! Ar is not suitable for analyzing organic films Depth Profile of PEDT:P on IT: Ar 3kV kV kV kV Depth Profile of PEDT:P on IT: C PEDT 3H P 67%C, 24%, 9% H PEDT P 67%C, 24%, 9%

4 Depth Profile of PEDT:P on IT: Peak Analysis of rganic Thin-Films with C6.5kV Ar kV C6 chemical composition is preserved through the thickness 35 3 chemical state of is preserved and the PEDT:P ratio does not change with sputtering H P PEDT PEDT 3H P it is also possible to analyze organic/inorganic hybrid thin film (i2/pedt:p)! constant i:pedt:p ratio through the thickness! uniform distribution of i2 nano-dots! preferential sputtering and sputtering-reduction did not be observed!! i2/pedt:p on IT Glass putter Depth Profile of Drug Distribution in a Biomedical Coating 1 i2p Rapamycin PLGA Coating Rapamycin Poly(lactic-co-glycolic acid) H PEDT P 67%C, 24%, 9% PEDT H P 16 Immunosuppressant Drug Biodegradable Host Polymer 14

5 putter Depth Profile of Drug Distribution in a Biomedical Coating LED Device Rapamycin PLGA Coating 1s (1x) i2p time 4 min 2 min ETL TPBi; 88%C, 11% EL CBP Host; 95%C, 5% Ir-containing Guest HTL PEDT:P; 67%C, 24%, 9% IT TPBi CBP putter time (min) C 6 + sputter depth profile reveals surface segregation of rapamycin 28 min Glass PEDT 3 H P 19 Perfluoropolyester on CaF2 LED Device: EL/HTL/IT CF 2 (~291.8eV) CF 2 - (~293 ev) x CF x 688 CF (~289.5eV) CaF C-CF x (~287.5eV) (surface) urface contaminants (surface) F(fluoride) 6 F(organic) Ca 2 C(CF2) C(CF2/CF3) 1 C(CF) C(C-CFx) (perfluoropolyester) C(CC/CH) (organic) putter time (min.) %C, 5% CBP PEDT 1s Ir4f (1x) H P 67%C, 24%, 9% 18

6 Full LED Device puttering Rate of Cluster Ion Beam 1 9 1s Ir4f7 (1x) %C, 11% TPBi 95%C, 5% 2 CBP Electron Transporting Layer: TPBi 1kV1nA C6 +.5kV22nA Ar TPBi slower sputtering rate, damage to chemical structure 22 24

7 1kV1nA C kV3nA Ar + Depth Profile with Ar + /C6 + Co-sputtering beam voltage sputter time atomic concentration min 67% C, 24%, 9% kv, 75 na.1 kv, 3 na 4.24 min 67% C, 24%, 9% 4.87 min 67% C, 24%, 9% kv, 3 na.1 kv, 6 na.2 kv, 6 na.25 kv, 6 na 3.76 min 67% C, 24%, 9% 4.87 min 67% C, 24%, 9% 4.29 min 67% C, 24%, 9% 4.3 min 7% C, 21%, 9% kv, 6 na 4.49 min 72% C, 2%, 8% kv, 6 na 5.56 min 78% C, 14%, 8% sputter time decreased with high dose and low dose Ar higher sputtering rate, no observable damage to chemical structure 25 lost of at >.25 kv Ar! dose of Ar is optimized with minimize damage and enhance sputtering rate 27 puttering with.2kv3na Ar + puttering Rate of Mixed C6 + /Ar + Ion Beam extremely slow sputtering rate, still damage the chemical structure 26 28

8 putter Damage Thickness in i (Angle-Resolved XP) putter Induced Topography (AFM) -.5 Top Layer(2.34 nm) -.5 Top Layer(1.68 nm) -.5 Top Layer(1.63 nm) Depth (nm) i2p(96 %) Ar2p(4 %) Depth (nm) i2p(83 %) (17 %) Depth (nm) i2p(83 %) (17 %) KV Ar KV C KVAr + +1KV C6 +.2KV Ar nm RM 1KV C nm RM.2 KVAr + +1KV C nm RM putter Damage Thickness in i (TEM) putter of Hard Materials (Zn4!nH2) 1 9.5KV Ar + 1 Zn2p3 9.2 KVAr + +1KV C6 + Zn2p KV Ar + 5~7 nm thick 1KV C6 + 4~6 nm thick.2 KVAr + +1KV C6 + 2~4 nm thick shallower sampling depth in hard materials overall damage thickness is comparable using cluster ion beams have no benefit 3 32

9 Depth Profile of LED Vertical Array of Ti2 anotube Polymer-based Inverted olar Cell Vertical Array of Ti2 anotube 34 36

10 Ti2 anotube Infiltrated with Polymer Conclusion XP is widely used to study the surface chemical composition of materials to probe below the surface, Ar ion sputtering is typically used to remove material but it is generally not possible to apply to organic materials because of the high level of damage C6 ion sputtering has been demonstrated to remove organic materials while causing minimal damage to the surface however, the sputtering rate decreased with sputtering time due to the C deposition Depth Profile of a olar-cell Conclusion CH 3 to avoid excessive damage to the surface while maintaining a steady sputtering rate, combination of high-energy C6 and low-energy Ar beams are used concurrently the surface is eroded by the C6 beam and the residual carbon is removed by Ar HREM and ARXP revealed thiner and more localized damage layer with co-sputtering however, the surface roughness is higher with C6 beams and interface broadening was observed thick organo-electronic devices can be analyzed with this technique 38 4

11 Acknowledgments Dr. John Hammond, Physical Electronics, UA Mr. Wensly Yip (!"#), ULVAC-PHI, Japan Prof. Jwo-Huei Jou ($%&), DME, THU Prof. Chih-Wei Chu ('()), RCA, Academia inica Dr. Bang-Ying Yu (*+,), RCA, Academia inica Miss. Ying-Yu Chen (-.!), RCA, Academia inica Mr. Wei-Ben Wang (/1), DME, THU Mr. Mao-Fen Hsu (234), DME, THU Miss. hu-ping Tsa (567), RCA, Academia inica Mr. Mark Cheng (89:), Veeco, Taiwan ponsorship by Academia inica and C (through M-2-18 and M-1-12-MY2) 41