Papers by Keyword: Chlorine Trifluoride

Abstract: A silicon carbide epitaxial reactor cleaning process was designed accounting for the exothermic reaction heat between silicon carbide and chlorine trifluoride gas. To avoid the peeling of the susceptor surface coating film, the spontaneous temperature increase due to the exothermic reaction heat was moderated by adding the nitrogen gas. The particle-type silicon carbide deposition could be effectively removed without causing any damage of susceptor.

Abstract: The in situ cleaning process of a silicon carbide epitaxial reactor was developed using chlorine trifluoride gas for removing the film-type silicon carbide deposition formed on a susceptor. By adjusting the etching temperature to less than 330 °C, the formed silicon carbide films could be removed without significant damage to the susceptor.

Abstract: The silicon carbide CVD reactor cleaning process was studied by means of detaching silicon carbide particles, which was formed on the silicon carbide coated carbon susceptor surface during the silicon carbide film deposition. The contact points between the particles and the susceptor surface were etched using chlorine trifluoride gas at temperatures lower than 290 °C for 120 min. During this process, the carbon susceptor covered with the silicon carbide coating film suffered from little damage while achieving cleaning.

Abstract: A SiC dry etcher using chlorine trifluoride (ClF₃) gas was evaluated, particularly about the etching rate distribution. At 100%, the etching rate was high in the center region and was low in the outer region. However, that at 20% showed the opposite profile. This difference was considered to be due to the chlorine trifluoride gas distribution which was built above the gas distributor.

Abstract: A SiC dry etching reactor using chlorine trifluoride (ClF₃) gas was designed and evaluated with the help of numerical calculations and experimental results. The etching rate was about 16 μm/min when the ClF₃ gas concentration, the total flow rate and the SiC substrate temperature were 90%, 0.3 slm and 500 °C, respectively. The gas stream above the substrate surface was concluded to significantly affect the etching rate profile.

Abstract: The C-face (0001) 4H-SiC surface morphology produced by etching using chlorine trifluoride gas was studied, focusing on the influence of the off-orientation. The etching pit at the 4^o off-oriented surface was formed at a temperature higher than 973 K, which was higher than 623 K for the on-axis surface. At 1073 K, the hexagonal-shaped etching pits were observed after the etching at the chlorine trifluoride gas concentration of less than 3 %. In the temperature range lower than 900 K, the mirror surface could be maintained after the etching. Thus, the mirror surface and the pitted surface are expected to be formed on the 4^o off-oriented surface by means of appropriately adjusting the parameters, such as the temperature and the chlorine trifluoride gas concentration.

Abstract: An etch pit shape of off-angled 4H-SiC Si-face formed by different halogen gases such as chlorine trifluoride (ClF3) and a mixed gas (O2+Cl2) of oxygen and chlorine in nitrogen (N2) ambience has been studied. One kind of etch pit with the crooked hexagon was formed at etching temperature under 500oC. The angle of etch pit measured by the cross-sectional atomic force microscope image was about 10o from the [11-20] view. A dislocation type of the etch pit was discussed in comparison with the etch pit shape and an X-ray topography image.

Abstract: The etching technology for 4H-silicon carbide (SiC) was studied using ClF3 gas at 673-973K, 100 % and atmospheric pressure in a horizontal reactor. The etch rate, greater than 10 um/min, can be obtained for both the C-face and Si-face at substrate temperatures higher than 723 K. The etch rate increases with the increasing ClF3 gas flow rate. The etch rate of the Si-face is smaller than that of the C-face. The etched surface of the Si-face shows many hexagonal-shaped etch pits. The C-face after the etching is very smooth with a very small number of round shaped shallow pits. The average roughness of the etched surface tends to be small at the higher temperatures.