Surface morphology of a single-crystalline 4H-silicon carbide (SiC) etched by chlorine trifluoride gas was studied over the wide temperature range of 570–1570 K at atmospheric pressure in a horizontal cold wall reactor. The etch rate of both the Si-face and C-face 4H-SiC at the substrate temperatures between 720 and 1570 K was simultaneously measured to be nearly flat at ca. 5μmmin−1 . The Si and C faces showed pitted surfaces at low temperatures. The pits tended to become small and shallow with the increasing substrate temperature. This temperature-dependent behavior was expressed using the rate theory accounting for the slightly low activation energy at the spot causing the pit. The etch pits formed at low temperature may be related to crystalline defects.

The etch rate of single-crystalline 4H–SiC is studied using chlorine trifluoride gas at 673–973 K and atmospheric pressure in a cold wall horizontal reactor. The 4H–SiC etch rate can be higher than 10 µm/min at substrate temperatures higher than 723 K. The etch rate increases with the chlorine trifluoride gas flow rate. The etch rate is calculated by taking into account the transport phenomena in the reactor including the chemical reaction at the substrate surface. The flat etch rate at the higher substrate temperatures is caused mainly by the relationship between the transport rate and the surface chemical reaction rate of chlorine trifluoride gas.

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.

Dry etching of 4H-silicon carbide (SiC) is studied using chlorine trifluoride gas at 673-973K and atmospheric pressure in a horizontal reactor. The etch rate of C-face and Si-face of 4H-SiC can be greater than 10 um/min at substrate temperatures higher than 723 K. The etch rate of Si-face is lower than that of C-face. The etch rate increases with the chlorine trifluoride gas flow rate. The etched surface of Si-face shows many pits having a hexagonal edge shape and tends to be rough. However, the C-face maintains a very smooth surface after the etching. The average roughness of the etched surface tends to be low at the higher temperatures. The etch rate behavior is discussed from the view points of the transport phenomena in the reactor and the chemical process at the substrate surface; their rate constants are obtained.

The morphology of a single-crystalline 4H-silicon carbide (SiC) substrate surface after etching by chlorine trifluoride (ClF3) gas was studied over the wide temperature range of 673-1573 K at atmospheric pressure in a horizontal cold wall reactor. The Si-face and C-face showed pitted surfaces at low temperatures; the pits tended to become small and shallow with the increasing substrate temperature. The etching for 0.5 min at the substrate temperature of 1573K and at the ClF3 gas concentration of 1% could maintain a specular surface on both the Si-face and C-face 4H-SiC, the root-mean-square roughness of which was comparable to that of the substrate before etching.