The CVD diamond booklet - Diamond Materials - …

1 The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet available at: Content General properties of diamondGeneral properties of diamondGeneral properties of diamondGeneral properties of Diamond .. 3333 optical optical optical optical PropertiesPropertiesPropertiesProperties .. 5555 optical transparency .. 5 Absorption coefficient at m .. 6 Refractive index: n vs.. 7 Refractive index: nd vs. T .. 8 Refractive index: Thermal coefficient .. 9 X-ray absorption .. 10 THz dielectric properties .. 11 optical specifications of Diamond Materials .. 12 Surface finish, optical coatings and mounting .. 13 Thermal PropertiesThermal PropertiesThermal PropertiesThermal Properties .. 14141414 Thermal conductivity .. 14 Thermal conductivity vs. T .. 15 Specific heat vs. T.

2 16 Thermal expansion .. 17 Thermal specifications of Diamond Materials .. 18 Mechanical PropertiesMechanical PropertiesMechanical PropertiesMechanical Properties .. 19191919 Vickers-Hardness .. 19 Mechanical specifications of Diamond Materials .. 20 Examples of CVD Diamond appliExamples of CVD Diamond appliExamples of CVD Diamond appliExamples of CVD Diamond applicationscationscationscations .. 21212121 Useful formulaUseful formulaUseful formulaUseful formula .. 24242424 Bowing of a circular disk under 24 Thickness requirements .. 24 Contact Diamond MaterialsContact Diamond MaterialsContact Diamond MaterialsContact Diamond Materials .. 25252525 The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 1 The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 2 CVD Diamond wafers prepared by Microwave Plasma CVD: boron doped disk (blue), optical grade Diamond , mechanical grade, unpolished disk The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 3 General properties of diamondGeneral properties of diamondGeneral properties of diamondGeneral properties of Diamond The most important properties of CVD Diamond are the unsurpassed hardness extremely high thermal conductivity (>1800 W/mK, five times that of copper) broad band optical transparency extremely chemically inert.

3 Not affected by any acid or other chemicals Graphitization only at very high temperatures (T > 700 C in an oxygen containing and 1500 C in an inert atmosphere) The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 4 *highest value of all solid Materials PropertyPropertyPropertyProperty ValueValueValueValue Vickers hardness* 10,000 kg/mm2 Young's modulus* 1050 GPa Poisson's ratio Density g/cm3 Atom density* 1023 1/cm3 Thermal expansion coefficient 10-6/K @300K Sound velocity* 17,500 m/s Friction coefficient Specific heat @ 20 C J/gK Debye temperature* 1860 10K Bandgap eV Resistivity 1013 - 1016 cm The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 5 optical PropertiesOptical PropertiesOptical PropertiesOptical Properties optical transparency 11010001020304050607080 Transmission (%)Wavelength ( m)

4 optical transparency of CVD Diamond In the UV, Visible, IR and far IR The spectrum has not been corrected for reflection losses The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 6 Absorption coefficient at m Absorption coeff. (cm-1)Wavelength ( m) Absorption coefficient of CVD Diamond as measured by laser calorimetry. The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 7 Refractive index: n vs. Refractive indexWavelength ( m) The spectral variation of n is described by the Sellmeier equation:1 + + =nmxxnmxxn where x is the wavelength in nm 1 Peter, F. (1923), Z Phys, 15, pp 358 368 The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 8 Refractive index: nd vs.

5 T 020040060080010000246810121416 nd/nd (10-3)Temperature ( C) Variation of nd with temperature Patterson et our data measured at 633 nm wavelength 2 Pattersonet et al., Electrochem. Soc. Proc. 95-4, 503 (1995) The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 9 Refractive index: Thermal coefficient dn/dT (10-5/K)Temperature ( C) Thermal coefficient of the refractive index Measured by laser refraction of a Diamond prism Measured with laser interferometry Fontanella et 3 J. Fontanella et al., Appl. Opt. 16, 2949 (1977) The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 10 X-ray absorption Absorption Coefficient (1/ m)Energy (keV) X-ray absorption coefficient of various Materials .

6 Data from The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 11 THz dielectric properties 100 11010 2030405060708090 100 CVD DiamondAbsorption Coefficient [cm-1]Frequency [THz]Wavenumbers [cm-1] Refractive IndexWavenumbers [cm-1] data from Peter Uhd Jepsen, University of Freiburg The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 12 optical specifications of Diamond Materials The core competences of Diamond Materials include the manufacturing of high purity CVD Diamond disks with properties approaching those of perfect natural Diamond crystals. PropertyPropertyPropertyProperty ValueValueValueValue Transmission 225nm to far IR , > 70% @ 10 m Refractive index @ 10 m, @ 500nm Absorption coefficient cm-1 @ 10 m Bandgap eV Tensile strength ( thick) Nucleation surface in tension 600 MPa Growth surface in tension 400 MPa Loss tangent (tan @140 GHz) < 10-5 Dielectric constant Properties of optical grade CVD- Diamond by Diamond Materials The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 13 Surface finish, optical coatings and mounting PropertyPropertyPropertyProperty ValueValueValueValue Dimensions Thickness 10 - 2000 m Diameter up to 100 mm Surface finish Shape flat, spherical (convex & concave)

7 Roughness < 5 nm* Flatness 1 fringe/cm* Wedge 0 1 * Antireflection Coatings (visible and infrared) Spec. Transmission at m > % Wavefront distortion < 4 fringes at 633 nm over 30 mm* Mounting Diamond windows mounted in UHV flanges (bakeable at 250 C, vacuum tight < 10-10 mbar l/s)* *specifications available upon request The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 14 Thermal PropertiesThermal PropertiesThermal PropertiesThermal Properties Thermal conductivity 0500100015002000 SapphireSiliconAlNCopperCVD Diamond Thermal Conductivity (W/mK)Material The thermal conductivity of Diamond in comparison to other Materials . The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 15 Thermal conductivity vs. T -200-10001002003000500100015002000250030 0035004000450050005500 Thermal Conductivity (W/mK)Temperature ( C) Thermal conductivity of CVD Diamond vs.

8 Temperature CVD Diamond Theory Copper The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 16 Specific heat vs. T 50100 150 200 250 300 350 400 450 Specific heat (kJ/KgK)Temperature (K) The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 17 Thermal expansion Thermal Expansion (10-6/K)Temperature ( C) Thermal expansion vs. temperature High quality CVD Diamond Medium quality CVD Diamond Values recommended by Slack4 4 Slack and Bartram, J. Appl. Phys. 46, 89 (1975) The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 18 Thermal specifications of Diamond Materials Optimized CVD- Diamond as provided by Diamond Materials reaches a thermal conductivity of up to 2000 W/mK it exceeds that of copper by a factor of five.

9 In contrast to metals, where heat is conducted by electrons, lattice vibrations are responsible for the high thermal conductivity of Diamond . PropertyPropertyPropertyProperty ValueValueValueValue Thermal conductivity @300 K > 1200 W/mK* > 1500 W/mK* > 1800 W/mK* Thermal expansion coefficient @300 K +/- 10-6/K @700 K +/- 10-6/K Specific heat @ 20 C J/gK Debye temperature 1860 10K * various thermal grades are available upon request The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 19 Mechanical PropertiesMechanical PropertiesMechanical PropertiesMechanical Properties Vickers-Hardness 0200040006000800010000 TalcGypsumCalciteFluoriteAptiteCorundumT opazQuartzOrthocalseCVD Diamond Vickers-Hardness (kg/mm2)Material The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 20 Mechanical specifications of Diamond Materials CVD Diamond manufactured by Diamond Materials exhibits an exceptional wear resistance and a low coefficient of friction.

10 Highly demanding applications such as cutting tools, surgical knives and wear resistant components have been demonstrated. PropertyPropertyPropertyProperty ValueValueValueValue Vickers hardness 10,000 kg/mm2 Young's modulus 1050 GPa Poisson's ratio Thermal expansion coefficient 10-6/K @300K Tensile strength ( thick) Nucleation surface in tension 1100 MPa Growth surface in tension 500 MPa Density g/cm3 The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 21 Examples of CVD Diamond applicationsExamples of CVD Diamond applicationsExamples of CVD Diamond applicationsExamples of CVD Diamond applications CVD Diamond window beam splitter for space application CVD Diamond UHV window The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 22 Ultra-high precision Diamond balls CVD Diamond laser windows for high-power CO2 lasers The CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond bookletThe CVD Diamond booklet Page 23 CVD Diamond wafers (80 mm )