SiC coated graphite PERMA KOTE™

SicCoat_img.jpg With the rapid progress in higher density semiconductor products, high purified graphite has grown in demand so as to reduce gas desorption of carbon surfaces as well as the amount of dust and impurities. Made by depositing a SiC layer on isotropic graphite using CVD process, PERMA KOTE™ is widely used in the semiconductor manufacturing industry.

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Pancake susceptor

SicCoat_Pancakesusceptor.jpgThe susceptors used in processes that form the epitaxial layer on semiconductor wafers, whether pancake type or barrel type, barrel, require an SiC coated graphite.

Barrel susceptor

SicCoat_Pancakesusceptor.jpgPERMA KOTE™ is a graphite product coated with high purified SiC, which has high heat and corrosion resistance.

Characteristics

  • The silicon carbide layer has excellent oxidation resistance, corrosion resistance and chemical resistance.
  • The silicon carbide layer is stable at high temperatures and is extremely hard.
  • Prevents the parting and scattering of graphite particles, and the emission of gas and impurities from the graphite substrate.
  • Both the graphite substrate and silicon carbide layer are of high purity.
  • Both the graphite substrate and silicon carbide layer have a high thermal conductivity, and excellent heat distribution properties.
  • Material is designed so that cracks and delamination do not occur.

Application

  • Susceptor for silicon epitaxial growth
  • Single crystal silicon manufacturing equipment
  • MOCVD susceptors
  • Heaters
  • Heat spreaders
  • Oxidation resistance components

PERMA KOTE™ Properties

Crystal structure
β-SiC (Cubic system) Structure β-SiC(Cubic system) Structure
Bulk density 3.2 Mg/m3
Decomposition Temperature 2700℃ or higher
Hardness 2800HK
Electrical Resistivity 0.2 Ω・m (through the fall-of-potential method)
Flexural Strength 170 MPa (through 3-point bending)
Young's Modulus 320 GPa (through the deflection method)

* The figures above are extracted from other publications or are measurement examples, and are not guaranteed.

Coating Thickness

The standard thickness is 120 μm; however this can be modified within a range of 20 to 500 μm.

SEM Photograph of PERMA KOTE™ Surface

SEM photograph of perma kote surface

Corrosion Resistance

Name Chemical formula Concentration(%) Temperature(℃) Time(h) Change in mass(g/m2)
Hydrofluoric acid HF 47 80 144 -1.0
Hydrochloric acid HCl 36 Boiling point 144 0
Sulfuric acid H2SO4 97 110 144 0
Nitric acid HNO3 61 Boiling point 144 0
Hydrofluoric acid + nitric acid HF+HNO3 (1:1) 100 80 288 -1.0
Nitric acid + sulfuric acid HNO3+H2SO4 (1:1) 100 25 288 -1.0
Sodium hydroxide NaOH 20 80 288 0
Phosphoric acid H3PO4 100 100 192 -1.0
Nitrohydrochloric acid HCl+HNO3 (3:1) 100 80 192 0

Reactivity with various substances (in a vacuum)

Reactant Chemical Formula 1200℃×3h 1600℃×3h
Aluminum Al
Boron B
Cobalt Co ×
Chromium Cr ×
Copper Cu
Iron Fe × ×
Molybdenum Mo
Nickel Ni ×
Lead Pb ×
Silicon Si
Tin Sn
Tantalum Ta
Titanium Ti
Vanadium V ×
Tungsten W
Alumina Al2O3 ×
Boron oxide B2O3
Chromium oxide (Ⅲ) Cr2O3 ×
Iron oxide (Ⅲ) Fe2O3 × ×
Magnesium oxide MgO
Manganese oxide (Ⅳ) MnO2 ×
Lead oxide(Ⅱ) PbO
Silicon oxide SiO2
Titanium oxide (Ⅳ) TiO2
Vanadium oxide (Ⅴ) V2O5
Zirconium oxide (Ⅳ) ZrO2

※ ◎...No reaction ○...Slight reaction
  △...Reaction ×...Significant reaction

Impurity analysis example mass ppm

Element Content
B 0.15
Na 0.02
Al 0.01
Cr < 0.1
Fe 0.02
Ni < 0.01

*Measurement method: Glow Discharge Mass Spectrometry
*The figures above are measurement examples and are not to be guaranteed.
Before actually using one of our products, please refer to our catalogue and be sure to contact our sales department to consult on selecting the most appropriate grade.

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