SCHOTT Pharma AG & Co. KGaA · XETR:1SXP
SCHOTT Pharma AG & Co. KGaA — Schott Lithotec — Technical Presentation (September 2003)
16 slides from SCHOTT Pharma AG & Co. KGaA's technical presentation, Sep 23, 2003
Slide 1: Mechanisms of radiation induced defect generation in fused silica
Mechanisms of radiation induced defect generation in fused silica Ute Natura1, Oliver Sohr2, Rolf Martin1, Michael Kahlke1, Gabriele Fasold1 1Schott Lithotec AG, Jena, D-07745, Otto-Schott-Str. 13, 2Schott Glas, Mainz, D-55122, Hattenbergstr. 10 Boulder 09/23/2003 © Schott Lithotec AG 1
Slide 2: Mechanisms of radiation induced defect generation in fused silica
Mechanisms of radiation induced defect generation in fused silica 0. Introduction 1. Previous model of defect generation 2. Measurements of transmission and hydrogen consumption 3. Advanced model of defect generation 4. Advanced model and the change of the refractive index 5. Summary Boulder 09/23/2
Slide 3: 0. Introduction
0. Introduction Radiation induced defects: - absorption - hydrogen consumption - refractive index change Experiments: - marathon experiments were carried out with the KrF-excimer laser (248nm) and the ArF-excimer laser (193nm) Measurements: - transmission - IR measurements - raman spectroscopy (hydr
Slide 4: 1. Previous Model of Defect Generation
1. Previous Model of Defect Generation ( Si ! )* ( Si O ! )* λ = 260 nm λ = 210 nm ( Si O Si )* λ Fl = 650 nm σ ? 2KrF Si ! σ Si O ! 2ArF (E') (NBOH) c1 eV c ArF : 6,4 eV 2 H2 H2 KrF : 5 Si H Si OH Process 1 Si O Si Process 2 - precursors are stretched Si-O bonds - defects are generated by two- and
Slide 5: 2. Measurement of H2-Consumption (248nm)
2. Measurement of H2-Consumption (248nm) absolute consumption relative consumption 18 3 H2 Content (10 Mol./cm ): 2 H2-Consumption (10 Mol./cm ) H = 25mJ/cm 3 2,7 H2-Consumption / H2-Content 2 2,5 2,3 H = 14mJ/cm 1,0 2 H = 7mJ/cm 2,0 1,7 18 1,5 0,5 1,0 2 H = 25mJ/cm 2 0,5 H = 14mJ/cm H = 7mJ/cm 2 f(
Slide 6: 2. Measurement of Transmission and H2-Consumption (248nm)
2. Measurement of Transmission and H2-Consumption (248nm) Ind. Absorption H2 - Consumption 2 H = 25mJ/cm H2-Consumption / H2-Content 2 0,03 H = 40 mJ/cm2 H = 14mJ/cm Ind. Abs. in 1/cm (base 10) 1,0 2 H = 20mJ/cm2 H = 7mJ/cm H = 18 mJ/cm2 0,02 0,5 0,01 f(x) = AKrF*(1-exp(-σ2KrF*H*H*x)) f(x)=BKrF*(1-e
Slide 7: 2. Measurement of Transmission and H2-Consumption (193nm)
2. Measurement of Transmission and H2-Consumption (193nm) Ind. Absorption H2 - Consumption f(x) = AArF*(1-exp(-σ2KrF*H*H*x)) Ind. Abs. in 1/cm (base 10) 0,03 2 ng 6,3 mJ/cm H2-Consumption / H2-Content 2 1,0 n eli H = 3 mJ/cm 2 4,8 mJ/cm n 2 H = 1,5 mJ/cm cha 0,8 3,9 mJ/cm 2 2 ro 0,02 H = 0,5 mJ/cm 2
Slide 8: 3. Advanced Model of Defect Generation
3. Advanced Model of Defect Generation two fundamental defect generation processes ( Si ! )* ( Si O ! )* (≡ Si-OH)*initial λ = 260 nm λ = 210 nm ( Si O Si )* λ Fl = 650 nm σ ArF : 6,4 eV 2KrF Si ! σ Si O ! KrF : 5 eV 2ArF (E') (NBOH) H2 c1 eV c σ4’ ArF : 6,4 eV 2 σ3’ H2 H2 σ4 σ3 KrF : 5 Si OH Si H (
Slide 9: 3. Advanced Model of Defect Generation (IR-Spectroscopy)
3. Advanced Model of Defect Generation (IR-Spectroscopy) Absorption (base 10) 0,04 Difference irradiated - unirradiated Absorption (base 10) d = 1mm 1,0 0,02 SiOH 0,00 0,8 -0,02 0,6 -0,04 3800 3600 3400 3200 Wavenumber (1/cm) 0,4 unirradiated 0,2 irradiated 0,0 3800 3600 3400 3200 Wave number (1/cm)
Slide 10: 3. Advanced Model of Defect Generation (Modelling of Absorption Data)
3. Advanced Model of Defect Generation (Modelling of Absorption Data) 248nm Standard Samples 193nm 0,004 0,010 Ind. Abs. in 1/cm (base 10) Ind. Abs. in 1/cm (base 10) 2 2 H= 1,7 mJ/cm H = 20 mJ/cm 0,002 0,005 Model function Model function 0,000 0,000 0 1000 2000 0 500 1000 1500 6 6 10 Pulses 10 Puls
Slide 11: 4. Advanced Model and the Change of the Refractive Index
4. Advanced Model and the Change of the Refractive Index 1. Compaction due to excitation and relaxation of the network 2. Rarefaction due to defect generation processes 1 and 2 Irradiation by KrF- Irradiation by ArF- excimer laser (248nm) excimer laser (193nm) Compaction ~(NH2/τ)0,6..0,7 ~(NH2/τ)0,6
Slide 12: 4. Advanced Model and the Change of the Refractive Index (193nm)
4. Advanced Model and the Change of the Refractive Index (193nm) 2 H(mJ/cm ): 20 H = 4..7 mJ/cm 2 tion H = 0,6..1,5 mJ/cm 2 ompac C 15 H < 0,25 mJ/cm 2 only ion t a r efac i on +R dn (nm/mm) c t 10 o mpa C 5 - H = 4 mJ/cm 2 2 - H = 1,5 mJ/cm 0 2 - H = 0,7 mJ/cm 2 - H = 0,2 mJ/cm -5 0 1000 2000 3000
Slide 13: 4. Advanced Model and the Change of the Refractive Index (248nm)
4. Advanced Model and the Change of the Refractive Index (248nm) ct ion 10 pa om yC onl dn in nm/mm 1 a c ti o n f 0,1 R ar e s) n d s it i e a c t ion y d en o mp a e n erg 0,01 C r e nt f e ( di f 1E-3 1E-4 1 10 100 1000 10000 100000 2 2 2 Dose (D=N*H /τ) in MPulse*(mJ/cm ) /ns In case of a certai
Slide 14: 5. Summary
5. Summary Previous Model: - only process 1 - could not explain discrepancies between measured data of absorption, hydrogen consumption and the decrease of the index of refraction Advanced Model: - consists of 2 fundamental processes: - Process 1: generation of absorbing defects E‘, NBOHC (small H2-
Slide 15: Acknowledgement
Acknowledgement The authors would like to thank Carl Zeiss Oberkochen and the Institute for Physical High Technology Jena (IPHT) for their help in the design of the experimental setups and many helpful discussions. This work was partly supported by the BMBF-project CHOCLAB II (contract-no. 13EU0155)
Slide 16: 3. Advanced Model of Defect Generation (Raman-Spectroscopy)
3. Advanced Model of Defect Generation (Raman-Spectroscopy) unirradiated 10 Difference Intensitäty (a.u.) 300 irradiated - unirradiated irradiated 5 0 Intensity (a.u.) -5 200 SiOH -10 -15 H2 SiOH -20 4200 4000 3800 3600 3400 3200 100 Wave number of Ramanshift (1/cm) H2 0 4200 4000 3800 3600 3400 320
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