Lamp Materials Quartz Materials and Fused Silica for Lamp Applications Lamp Materials Heraeus Conamic

Heraeus Conamic Lamp Materials ƒ Special lamps for analytical equipment ƒ High and ultra high pressure (UHP) for digital projection The origin of today’s global family-held company was Today, Heraeus Conamic routinely manufactures fused Using the expertise of over a century in fused quartz, ƒ Laser excitation and intense pulse lamps the innovative vision and entrepreneurial spirit of quartz and fused silica and has been doing so for over Heraeus Conamic has developed a number of fused ƒ Laser flow tubes Wilhelm Carl Heraeus, a pharmacist and chemist who 100 years. The know-how and excellence gained over quartz grades for demanding applications in the lamp ƒ Infrared lamps for industrial processing took over his father’s pharmacy “Einhorn-Apotheke” one century enables Heraeus Conamic to manufac- and lighting industry. ƒ Excimer UV lamps for surface cleaning in Hanau, Germany in 1851. ture quartz glass solutions to the most demanding (e. g. at flat panel display manufacturing) applications. Heraeus Conamic‘s Lamp Materials division offers ƒ Low pressure UV lamps In 1856 he succeeded in melting 2 kg of Platinum lamp tubing in snap cut and cut to length, annealed (e. g. for disinfection and water purification) in an oxyhydrogen flame and thus laid the basis of Heraeus Conamic, headquartered in Hanau, Germany, for reduced OH-content, with fire glazed ends or with ƒ Medium pressure Lamps (e. g. for UV-curing) today’s business of the Heraeus group. In 1899 is the technology leader in manufacturing high purity a closed end. Standard products are offered with an ƒ UV lamps for medical applications and ozone generation

Dr. Richard Küch followed in the success by fusing quartz materials and advanced quartz components. innovative diffuse reflector based on pure SiO2 ƒ i-line lamps for steppers used in semiconductor and rock crystal into a high grade vitreous silica (quartz (HRC®) as well. LCD manufacturing glass) by the same method. Heraeus Conamic supplies not only high quality fused quartz or fused silica but also specific know-how for The various quartz products manufactured by Heraeus For an indication which material grade is best suited for demanding applications. Conamic are used in many applications, such as: a specific application, please refer to the corresponding table. The experience of over a century has made Heraeus Conamic a global quartz glass producer with a large Properties and Applications variety of different grades and shapes of high-purity of Lamp Material grades fused quartz and fused silica. ®

310 300 130

(XP) ® ® ® ® ® ®

Because of its unique optical, mechanical and 200 210 270 235 250* 382 ® ® ® ® ® ® thermal properties quartz glass is an indispensable Properties HLQ HLQ HLQ HLQ HLQ HLQ M235 plus plus M382 Heralux plus Heralux VUV plus Suprasil Suprasil Suprasil Spectrosil Purasil material in the fabrication of high-tech products. highest UV and VUV transmission ● ● ● ● ● ● The industrial branches working with quartz glass highest resistance to VUV irradiation ◗ ● ● ● include semiconductor, telecommunications, lighting, deep UV blocking (Ozone free) ● ● ● solar, medical applications and chemical processing. UV blocking ● ● devitrification resistance ◗ ● ◗ ● ● highest temperature resistance ◗ ◗ ● high homogeneity ● ● ● ● ● ● ● ● ● ● ● best surface quality ● ● ● ● ● ● ● ● ● ● ● best chemical purity ◗ ● ● ● ● ● economic grade ● ● ●

Applications 172 nm excimer lamps ● ● low pressure lamps with 185 nm emission ● low pressure lamps (e.g. disinfection) ● ● ● ● high transmittance, long life sleeves ● for 185 nm and 254 nm applications sleeves for 254 nm disinfection ● medium pressure lamps ● ● ● ● metal halide lamps ● ● highest pressure lamps, HID lamps, UHP ● short arc lamps ● ◗ ● ● ● ● (e.g. i-line, cinema, stage/studio) long arc lamps (e.g. laser excitation) ● ● ● ● ● infrared lamps ● tanning lamps ◗ ● Heraeus Quarzglas GmbH & Co.KG, Heraeus Conamic, Heraeus Quartz North Amercia LLC., “Einhorn” pharmacy, Kleinostheim facility, Germany Buford facility, USA Hanau, Germany medical UV laser ◗ ● *FDA approved in system for tanning ● = fully applicable ◗ = partially applicable 2 3 Vitreous Silica Manufacturing of Vitreous Silica

Quartz glass is the purest form of glass. It consists Characteristics Quartz glass is distinguished by its starting material.

only of silicon and oxygen (SiO2). The natural material If natural raw material (e.g. quartz sand or quartz Raw Material Raw Material Chemical that comprised only of those two elements is rock Mechanical Data electric flame synthetic crystal) is used, it is called fused quartz. If chemical Quartz Quartz Precursor, Density [g/cm³] 2.203 2.201 crystal. The difference between the two materials precursors (e.g. SiCl4) are used, it is called fused Sand Crystal e. g. SiCl4 (crystalline quartz and fused quartz) originates in the Mohs Hardness 5.5-6.5 silica. In addition to the raw material quartz glass is microstructure. Where crystalline quartz has a very Micro Hardness [N/mm²] 8600-9800 distinguished by the production route. There are three ordered structure with regular rings, fused quartz is Knoop Hardness [N/mm²] 5800-6100 5800-6200 established process groups that define the type of less ordered. In fused quartz the rings are of varying Modulus of elasticity (at 20°C) [N/mm²] 7.25 × 104 7.0 × 104 vitreous silica: Method Method Method size, may have dangling bonds and the bonds between Modulus of Torsion [N/mm²] 3.0 × 104 3.1 × 104 3.0 × 104 Electric Flame Soot the corresponding ions might be strained. ƒ electric fused quartz Fusion Fusion Process Poission’s ratio 0.17 ƒ flame fused quartz Compressive Strength (approx) [N/mm²] 1150 The unique properties of fused quartz is determined ƒ synthetic fused silica by either the chemical makeup (the SiO bond) or by Tensile Strength (approx) [N/mm²] 50 its microstructure. Bending Strength (approx) [N/mm²] 67 Torsional Strength (approx) [N/mm²] 30 Electric Fusion Process Fused Quartz Fused Silica The wide range of thermal stability, high optical trans- Sound velocity [m/s] 5720 mission and the high chemical resistance are a result Electric fusion is the most commonly used melting of the strong SiO bond. The amorphous structure is Thermal Data process for manufacturing quartz glass. Electric the reason for the low thermal expansion, excellent Softening temperature [°C] 1710 1730 1600 fusion is accomplished either by an electric gas dis- thermal shock resistance and high homogeneity of Annealing temperature [°C] 1220 1200 1100 charge (arc melting) or by applying heat generated by quartz glass. Strain temperature [°C] 1125 1080 1000 electric resistance. Fused Quartz Max working temp. continuous [°C] 1160 1050 950 Max working short term [°C] 1300 1350 1200 A further differentiation is made by selecting a continues or batch process. Single step electrically fused tubing is fabricated by pouring sand into the top Manufacturing processes of vitreous silica

Mean specific heat J/kg·K Electrical resistivity in Ω × cm of a vertical smelter that consists of a refractory metal crucible. 0 … 100°C 772 20°C 1018 0 … 500°C 964 400°C 1010 At temperatures exceeding 1800°C the ordered micro- 6 0 … 900°C 1052 800°C 6.3 × 10 structure of the raw material changes into the irregular 1200°C 1.3 × 105 glass network, glass is formed. Through an outlet in Heat conductivity W/m·K the bottom of the crucible the glass is pulled directly 20°C 1.38 Dielectric strength in kV/mm (sample thickness ≥ 5 mm) in the shape of tubes or as a solid, a so-called ingot. 100°C 1.47 20°C 25 … 40 200°C 1.55 500°C 4 … 5 Electric fused quartz has the highest temperature resis- 300°C 1.67 tance and highest viscosity of the vitreous silica types. 400°C 1.84 Dielectric loss angle (tg ) 1 kHz 5.0 × 10-4 950°C 2.68 δ 1 MHz 1.0 × 10-4 Mean expansion coefficient K-1 3 × 1010 Hz 4.0 × 10-4 0 … 100°C 5.1 × 10-7 0 … 200°C 5.8 × 10-7 Dielectric constant ( ) 20°C, 0 … 106 Hz 3.70 0 … 300°C 5.9 × 10-7 ε 8 0 … 600°C 5.4 × 10-7 23°C, 9 … 10 Hz 3.77 10 0 … 900°C 4.8 × 10-7 23°C, 3 × 10 Hz 3.81 -50 … 0°C 2.7 × 10-7

4 Electric fusion process 5 Tube Production

Flame Fusion Process Single Step Tubing Multi Step Tubing

Flame fusion is the most traditional form to fuse The pulling of tubing directly from the melt is the most In this process a pre-form (usually a cylinder) is locally Crystal grains quartz. A H2/O2-flame is used to fuse crystalline cost efficient production process. It is available only for heated and redrawn into tubing. The cylinder is either Vitreous silica particles to fused quartz. Heraeus chemist Dr. Richard electric fused quartz. formed directly or an ingot is reshaped into a cylinder. Küch was the first to use this method on an industrial Because the reforming of glass is independent on the scale over 100 years ago. For a continues process The outlet of the crucible is ring shaped and the size actual production route of the quartz glass, multistep small grains of the raw material are constantly trickled of the forming tool determines the available dimensions tubing is available in electric and flame fused quartz as into a flame and fused onto a glass rod, that is slowly of tubing (outer diameter, wall thickness). Because a well as synthetic fused silica. Furthermore, the addi- removed as it grows. change of the forming tool is not possible once the tional process-steps homogenize the material usually process started, the range of tube sizes per run is limit- resulting in a lower bubble content. The available Flame fused quartz has better homogeneity and solari- ed. A large amount of tubes must be drawn in order to finished sizes depend solely on the size of the starting sation resistance compared to electric fused quartz. justify using this process. cylinder.

H2 + 02 Tubes produced in the single step process have tight The advantage of the multistep process is the high tolerances and are most economic. flexibility regarding starting material and finished sizes, as well as a relatively small batch size.

Soot Process Bait tube Soot body In this process chemical precursors (e.g. silicon

tetra-chloride, SiCl4) are oxidized (burned) in a H2/

O2 flame. The forming SiO2 is deposited on a rotating bait tube like smoke off a candle deposits on a stick above the flame. The soot body is then vitrified into a transparent glass body in a second process step.

Because the precursors are made in an industrial chemical process, the raw materials have exceptionally high purity. Glass made of these precursors has an Hydrogen-oxygen flame Chemical Precursor, alkali- and metal ion content in the parts per billion loaded with silica (SiO ) nanoparticles e. g. SiCl 2 4 (ppb) range. H2 + 02

Synthetic fused silica has the best transmission, the highest purity and the best solarisation resistance of all vitreous silica types.

6 7 Chemical Characteristics

Fused quartz is outstandingly resistant to most liquids Aluminum, as the most prevalent impurity, bonds Hydroxyl Content (metals, solutions, acids etc.). It is corroded by hydro- directly into the quartz glass by substituting silicon fluoric and phosphoric acid as well as bases. Quartz atoms. Thus it has very low mobility even at high tem- In addition to the metallic impurities, fused quartz glass is sensitive to traces of alkaline and alkaline peratures which makes it almost impossible to remove and fused silica also contain water present as OH- earth metals, because they hasten devitrification at at any stage of the production process. groups. Incorporation of OH-groups into the glass elevated temperatures. Devitrification is the (local) re- network resulting in a lower viscosity and thus lower verting of the amorphous structure to the regular crys- Small amounts of aluminum increase the viscosity of working temperatures. Other physical properties are talline structure. This takes place at higher tempera- the quartz glass, allowing higher working temperatures. also affected, such as the optical transmission by tures and is visible only when the quartz body is cooled the formation of absorption bands in the infrared below 275°C, when the crystalline parts flake off. (IR). Each production route corresponds to a typical hydroxyl content. Quartz glass is a very pure material consisting of

SiO2. Traces of other elements are called impurities or The lowest values are achieved by electric fusion dopant if induced intentionally. Despite their very low because the glass is melted in vacuum or in a slightly concentrations, these impurities can have a signifi- reducing atmosphere (~100 ppm). The hydroxyl cant effect on quartz glass. Purity is predominantly content in electric fused quartz can be reduced in an determined by the raw material used. Additional pos- additional annealing step (<1-30 ppm). sibilities for contamination arise from the manufactur- ing method and the handling procedures. Precautions Flame fusion results in significantly higher hydrox- at all stages of the production process assure a high yl levels (150-200 ppm), since fusion occurs in a level of purity. hydrogen/oxygen flame. This hydroxyl level cannot be reduced by annealing. The most common impurities are metals (such as Al, Na and Fe among others) and water (present as OH- Synthetic fused silica produced by flame hydrolysis groups). These foreign elements are mainly integrat- of chemical precursors has the highest hydroxyl content ed in the glass network and effect viscosity, optical (up to 1000 ppm). This can be reduced, for instance absorption and electrical properties. They can also by further process including chemical treatments. influence the properties of materials in contact with the quartz glass during the end user application (e.g. Lamp electrodes). Lamp Material Grades, typical impurity content (ppm) The purity of fused quartz and fused silica is out- standingly high. Synthetic fused silica from Heraeus Li Na K Mg Ca Fe Cu Cr Mn Al Ti OH contains a total metallic contamination below 1 part HLQ® 200 E 0.6 0.3 0.4 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 1.1 * per million (ppm). For fused quartz the amount is HLQ® 210 E 0.6 0.3 0.4 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 1.1 *

® approximately 20 ppm and consists primarily of Al2O3 HLQ 270 E 0.05 0.05 0.1 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 1.1 * with much smaller amounts of alkali oxides, earth HLQ® 235 E 0.6 0.3 0.4 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 doped * alkali oxides, Fe O , TiO and ZrO . 2 3 2 2 HLQ® 250 E 0.6 0.3 0.4 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 doped * Metallic impurities originate mostly from natural ® E 0.6 0.3 0.4 0.05 0.5 0.1 < 0.05 < 0.05 < 0.05 15 doped * quartz. Very carefully controlled processes are used HLQ 382 to greatly reduce impurities in raw materials from 200 Heralux® plus / VUV F 1 1 0.1 0.1 0.1 0.2 0.1 0.1 0.05 10 0.1 130-220

ppm to less than 20 ppm (SiO2-purity of 99.998%). M235 plus F 1 1 0.1 0.1 0.1 0.2 0.1 0.1 0.05 10 doped 130-220 M382 plus F 1 1 0.1 0.1 0.1 0.2 0.1 0.1 0.05 10 doped 130-220 Suprasil® 130 S 0.1 0.2 0.1 0.05 0.2 0.05 0.05 0.05 0.05 0.5 0.2 100-300 Suprasil® 300 S 0.01 0.05 0.01 0.005 0.05 0.02 0.01 0.005 0.005 0.05 0.05 < 1 Suprasil® 310 S 0.01 0.05 0.01 0.005 0.05 0.02 0.01 0.005 0.005 0.05 0.05 typic. 200 Spectrosil® S < 0.01 < 0.01 < 0.01 < 0.01 < 0.015 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 < 1350 Purasil® / Purasil® XP S 0.02 < 0.05 < 0.02 0.05 0.02 < 0.05 0.01 0.01 0.01 0.5 0.2 * *

* as drawn ~100 ppm, reduceable through annealing ** Purasil: OH ≤1ppm / Purasil XP: OH 150-300 ppm 8 9 Doping of Transmission Quartz Solarization

Even though vitreous silica has a very good transmis- Undoped fused Quartz has a very broad window of sion over a broad area of the light spectrum; high en- optical transmission ranging from approx. ergy electromagnetic radiation can damage the glassy Electric Fused Quartz 170 nm to 3.5 µm with an absorption band at

structure. In the irregular network of vitreous silica 100 2.73 µm depending on OH content. some chemical bonds between the network partners 90 can be strained or in other ways mismatched. These 80 The IR-absorption edge arises from lattice vibrations strained bonds can react with high energy photons 70 and its position depends on the thickness of the resulting in an increasing number of lattice defects. 60 glass. The forming of defects by high energy photons is 50 40 called Solarization. These defects as well as defects [OH]: 130 ppm The exact position of the UV-absorption edge ransmission (%) formed by impurities can act as absorption centers T 30 [OH]: 30 ppm is strongly influenced by the chemical elements in for photons, resulting in a decreased transmission in 20 [OH]: 5 ppm the glass network (impurities or dopants) and is [OH]: 1 ppm 10 selected areas of the energy spectrum. (A number of lowest for synthetic material. 0 scientific papers have been published dealing with 150 200 250 300 350 400 1000 2000 3000 4000 5000 solarization in vitreous silica). Wavelength (nm) With its good understanding of vitreous silica and the associated processes, Heraeus Conamic has devel- HLQ®-200, -210, -270 HLQ®-235 HLQ®-250 HLQ® 382 HLQ® 382 annealed The defects generated by high energy irradiation oped a broad variety of material grades suitable for (Solarization) not only affect transmission but result most applications. Choosing the right one depends As mentioned earlier, depending on concentration, in a weakened structure, and ultimately in a break- Flame Fused Quartz on a number of different aspects. For further infor-

impurities have an influence on transmission. For ing of the glass piece. For the reasons given above 100 mation and support in your decision making process, specific applications foreign elements are intentional- annealed synthetic grades show the best resistance 90 please get in contact with your local sales represen- ly put into the glass. to solarization. 80 tative (see the information on the backside of this 70 brochure). The raw material is mixed with oxides before the 60 fusion process. This process is called doping. Doped 50 quartz is commonly used in applications where the 40 ransmission (%) high transmission or thermal stability of fused quartz T 30 is required but a specific region of the light spectrum 20 is either not wanted or even harmful to the process 10 0 performed by the lamp. The most commonly known 150 200 250 300 350 400 1000 2000 3000 4000 5000 doping effect is doping with titanium to eliminate Wavelength (nm) deep UV-radiation, while transmitting UV-A and UV-B ® radiation. Transmission of different quartz glass types Heralux plus M 235 plus M 382 plus M 382-S plus at 172 nm as a function of irradiation time 1.0 Synthetic Silica

100 0.8 90 Suprasil® 310 80 70 0.6 60 50 plasma fused quartz glass 0.4 40 ransmission (%)

T 30 electrically fused quartz glass

transmission (a.u.) [%] 20 0.2 (synthetic grain) 10 0 natural fused quartz glass 150 200 250 300 1000 2000 3000 4000 5000 (natural quartz grain) 0 Wavelength (nm) 0 500 1000 1500 2000 2500 time of 172 nm irradiation [hours] Suprasil®310 Suprasil®130 Suprasil®300

A. Schreiber, B Kühn, E. Arnold, F-J Schilling, H-D. Witzke, Radiation resistance of quartz glass 10 for VUV discharge lamps, J. Phys. D: Appl. Phys. 38 (2005) 3242–3250 11 [email protected] 6181 +49 Phone 35-6234 Hanau 63450 Quarzstr. 8, Materials Lamp Conamic Heraeus KG &Co. GmbH Quarzglas Heraeus Europe [email protected] +1 Phone (240) 690-3852 States United 28405 Wilmington, NC, 3016 St. Boundary Conamic Heraeus LLC. America, North Quartz Heraeus USA [email protected] Xuhui District Shanghai Building Gui Lin Road, 406 5, No. Phone +86 (21) +86 Phone 5175 3357 Heraeus Conamic Conamic Heraeus Shanghai,Heraeus China China (Mainland) China China 1-22-2 Nishi-Shinjuku, Shinjuku-Ku, Shinjuku-Ku, Nishi-Shinjuku, 1-22-2 Japan Tokyo Tokyo [email protected] Shinjuku San-ei Bidg. Shinjuku San-ei Phone +81 (3)Phone 3348-1916 Shin-Etsu Quartz Prod. Co., Ltd. Co., Prod. Quartz Shin-Etsu 〒 160-0023 Japan 160-0023

The Heraeus logo, Heraeus, Conamic, Heralux, HLQ, Purasil, Spectrosil and Suprasil are trademarks or registered trademarks of Heraeus Holding GmbH or its affiliates. All rights reserved. For more specific information, visit www.herae.us/conamic-trademarks.

The data given in this brochure are valid for April 2021. Subject to alterations. HCA-PTN-LM_8.2/EN/04.2021