Synthetic Fused Silica Optical and technical grades

Transcription

1 SCHOTT LITHOTEC FUSED SILICA Synthetic Fused Silica Optical and technical grades

2 Schott Lithotec Fused Silica LithosilTMQ is available in six different quality grades: LithosilTMQT is not specified concerning homogeneity, striae and striations. This grade is recommended for technical applications. Lithosil Q is characterized by TM its high three-dimensional opti- LithosilTMQ/1-E193 cal homogeneity. Free of stria- LithosilTMQ/1-E248 tions in any spatial direction, it The excimer grade equivalents of is recommended for high-end LithosilTMQ and LithosilTMQ1 for resolution requirements in such 248 nm (LithosilTMQ/1-E248) or optical elements as prisms and 193 nm (LithosilTMQ/1-E193) excimer lenses. laser applications present remarkable laser damage resistance, high UV-trans- Lithosil Q1 exhibits high homo- mission, extremly low bulk defect level geneity and has no striations in and low fluorescence behavior. These one spatial direction. Typical properties make LithosilTMQ-E the first applications are optical elements choice material for excimer laser such as lenses, windows and applications and laser machining. TM wafers. LithosilTMQ2 is not specified concerning homogeneity. This grade is recommended for optics in the visible spectral range or optics in the UV with less stringent demands on transmission. Typical values of internal transmittance at selected wavelengths per 1 mm sample thickness Internal transmittance λ = 193 nm λ = 2 nm λ = 248 nm Lithosil Q Lithosil Q Lithosil Q Lithosil QT.97 Lithosil Q/1-E Lithosil Q/1-E

3 Optical properties of Synthetic Fused Silica Grade Bubbles and inclusions Homogeneity Stress birefringence OH content Bubbles according to bubble class DIN Max. bubble diameter [mm] Striae 1) according to ISO Striations 1) Refractive index change n 2) Standard Special products 5% outer edge exclusion [nm/cm] [ppm] Lithosil Q Lithosil Q1 Lithosil Q2 <.1 none 3D none none in functional direction H1 not specified H2H5 5 3) 1 3) appr. 12 Lithosil QT...1 <.6 not specified 2 appr. 1 Lithosil Q-E193 4) Lithosil Q1-E193 4) Lithosil Q-E248 4) Lithosil Q1-E248 4) ArF - excimer grade: selected from Lithosil Q or Q1; see qualification method on Lithosil Q-E KrF - excimer grade: selected from Lithosil Q or Q1; see qualification method on Lithosil Q-E Notes 1) Shadow method, polarizer and interferometer are used for striae and striation detection. 2) Homogeneity n is tested interferometrically (5% outer edge exclusion). Classification according to Schott Glas nomenclature. 3) Lower values with respect to size and processing available on request. 4) Max. LIF factor (fluorescence signal ratio at 65 nm of Lithosil Q-E to reference) can be individually agreed and guaranteed on request. Class H1 H2 H3 H4 H5 Maximum deviation of refractive index ± ± ± ± ± Typical Transmission of Lithosil Q/Q1 including Fresnel reflection losses (1 mm path length) transmission [%] wavelength [nm] transmission [%] wavelength [nm]

4 Refractive Indices (at 2 C and 113 mbar) λ [nm] (vacuum wavelength) n n n n 153 n 16 n t n s n r n C n C n He-Ne n D n d n e n F n F n g n h n i n n n n 28.4 n n KrF n n ArF All refractive indices are interpolated from values measured under dry nitrogen atmosphere Tolerances of refractive indices ± Constants of Dispersion Formula B B B C C C Typical Trace Contaminants [ppm] Trace Lithosil Lithosil elements Q/Q1 Q2 Al Na Ca K Fe Ti Cu Cr Mn n d = v d = n F n C =.675 n e = v e = n F n C =.68 Relative Partial Dispersion P s,t.329 P C,s.578 P d,c.397 P e,d.239 P g,f P i,h Deviation of Relative Partial Dispersions from Normal Line P C,t P C,s P F,e P g,f P i,g Temperature Coefficients of relative Refractive Index +2/+4 C n/ T [1-6 /K] n C n d n e n F n g n h n i Thermal Properties Strain point T [ C] Annealing point T [ C] Softening point T [ C] Mean specific heat c p (2 1 C) [J/g K] Heat conductivity λ (32 C) [W/(m K)] Linear thermal expansion coefficient α (25 1 C) [1 6 /K] Mechanical Properties Young s modulus (25 C) [GPa] Shear modulus (25 C) [GPa] Compressive strength [N/mm 2 ] Bending strength [N/mm 2 ] Poisson s ratio µ Knoop HK.1/2 Mohs Density ρ [g/cm 3 ] Stress optical coefficient [1/Pa] Longitudinal ultrasonic velocity [m/s] Transversal ultrasonic velocity [m/s] Internal damping (25 5 C) D D 1 D 2 E E 1 λ TK [µm] Formula for Dispersion and dn/dt according to Schott Optical Glass catalogue Constants of Formula for dn/dt +2/+4 [ C] Electrical Properties Dielectric constant ε r Dielectric loss angle ϕ (25 C/1MHz) tan δ (δ = 9 ϕ) (25 C/1MHz) Electrical resistivity (2 C) [Ω cm] ± ±.3 (14 ± 5)

5 Lithosil Q-E Excimer Grade Fused Silica with Low Fluorescence Inquire for Excellent transmission at 193 nm and 248 nm Low laser induced fluorescence (LIF) fluorescence signal [arbitrary units] Example of LIF-Spectrum Lithosil Q Lithosil Q-E average Measurements performed at IPHT Jena wavelength [nm] Control Unit Radiation conditions on customer request: 193 nm Excimer Laser Detector 1 Detector 1 LIF Signal Detector 1 LIF Signal Reference Laser wavelength 193 nm Energy density 1-25 mj/cm 2 Repetition rate 1-3 Hz Detector 2 Detector 2 Reference Detector 2 Measurement of LIF Energy level diagram Red fluorescence indicates the excimer laser radiation induced defects Measurement of Transmission 3 LIF 2 1 Two-photon absorption bridges the energy gap Additional one-photon absorption generates defects like E and NBOH centers NBOH centers emit red fluorescence (LIF) from the excited state * Glass Science and technology (Glastechnische Berichte) Bd. 71C (1998) 67-72

6 SCHOTT North America, Inc. 4 York Avenue Duryea, PA USA Phone: Fax: david.fritz@us.schott.com