Refractory carbide layer
AssigneeSgl Carbon SE
InventorsCharles Wijayawardhana, Christian Militzer, Jing-Jia Huang, Urban Forsberg, Henrik Pedersen
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Abstract
A chemical vapor deposition (CVD) method for preparing a layer comprising refractory carbide crystals, in particular silicon carbide crystals. At least a portion of the layer is formed from a gas mixture containing a silicon source and an aromatic carbon source. The molar C/Si ratio in the gas mixture is from about 0.85 to about 1.45. Also, layers obtainable by the method, as well as their uses and applications in various industries.
Claims5
A chemical vapor deposition (CVD) method for preparing a layer comprising silicon carbide crystals, wherein at least part of the layer is formed from a gas mixture containing a silicon source and an aromatic carbon source, wherein the molar C/Si ratio in said gas mixture is from about 0.85 to about 1.45;
- wherein in SEM image analysis of a cross section of the layer, at most about 20% of the surface of the cross section area has a pattern of parallel lines tilted by more than 15° with respect to a portion of a surface of the layer which is closest to the respective image;
- wherein a surface of the layer has a mean linear intercept surface grain size in a range of 0.2-25 μm;
- wherein the surface of the layer comprises refractory carbide crystal tops having a regular hexagonal pyramid shape;
- wherein a distribution of silicon carbide crystal orientations is such that an orientational quality Q is at least about 0.95,
- wherein the orientational quality Q is calculated from maximum peak intensities of an X-ray diffractogram detected with Cu k-alpha radiation at 1.5406 Å wavelength, according to the following formula
- Q
- =
- I
- 111
- +
- I
- 2
-
- 2
-
- 2
- +
- I
- 3
-
- 3
-
- 3
- /
- 5
-
- 1
-
- 1
- I
- 1
-
- 1
-
- 1
- +
- I
- 2
-
- 0
-
- 0
- +
- I
- 2
-
- 2
-
- 0
- +
- I
- 311
- +
- I
- 2
-
- 2
-
- 2
- +
- I
- 4
-
- 0
-
- 0
- +
- I
- 3
-
- 3
-
- 1
- +
- I
- 4
-
- 2
-
- 0
- +
- I
- 3
-
- 3
-
- 3
- /
- 5
-
- 1
-
- 1
- +
- I
- 4
-
- 2
-
- 2
- wherein
- I111 is the maximum intensity at 2θ ranging from 34.6° to 36.6°,
- I200 is the maximum intensity at 2θ ranging from 40.4° to 42.4°,
- I220 is the maximum intensity at 2θ ranging from 59.0° to 61.0°,
- I311 is the maximum intensity at 2θ ranging from 70.8° to 72.8°,
- I222 is the maximum intensity at 2θ ranging from 74.5° to 76.5°,
- I400 is the maximum intensity at 2θ ranging from 89.0° to 91.0°,
- I331 is the maximum intensity at 2θ ranging from 99.8° to 101.8°,
- I420 is the maximum intensity at 2θ ranging from 103.4° to 105.4°,
- I333/511 is the maximum intensity at 2θ ranging from 132.4° to 134.4°,
- I422 is the maximum intensity at 2θ ranging from 119.0° to 121.0°.
Dependencies are inferred from the claim text.