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Inductively coupled plasma (ICP) reactive ion etching of SiC was investigated using SF6 plasmas. Etch rates were studied as a function of substrate bias voltage (−3 to −500 V), ICP coil power (500–900 W), and chamber pressure (1–6 mT). The highest etch rate (970 nm/min) for SiC yet reported was achieved. Anisotropic etch profiles with highly smooth surfaces free of micromasking effects were obtained. The addition of O2 to the SF6 plasma was found to slightly increase the etch rate.

By using deep-level transient spectroscopy (DLTS), deep centers have been characterized in unintentionally doped n-GaN samples grown by metalorganic chemical-vapor deposition and subjected to inductively coupled plasma reactive ion etching. At least six DLTS traps exist in the control sample: A1 (∼0.90 eV), Ax (∼0.72 eV), B (0.61 eV), C1 (0.44 eV), D (0.25 eV), and E1 (0.17 eV), with B dominant. Then, as the etching bias-voltage increases from −50 to −150 V, trap D increases strongly and becomes dominant, while traps A1, C (0.34 eV), and E1 increase at a slower rate. Trap B, on the other hand, is nearly unchanged. Previous electron-irradiation studies are consistent with the E1 traps being N-vacancy related. It is likely that the D traps are also, except that they are in the regions of dislocations.

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The effects of energetic ion-induced damage on deep traps in n-GaN have been investigated using deep level transient spectroscopy. The energetic ions were produced in an inductively coupled plasma reactive ion etching (ICP-RIE) system. The electrons captured at the trap levels E1 (0.25 eV) and E2 (0.62 eV), in a control sample, were found to depend logarithmically on the duration of the filling pulse, indicating a relationship to dislocations. The dramatic increase in the concentration of deep level E1 traps, as a function of etching-bias voltage, is thought to indicate the introduction of a VN-related complex. On the other hand, the concentration of deep level E2 traps shows an initial increase at an etching-bias of −50 V, followed by a decrease at higher etching-bias voltages. This trend was also observed in the room-temperature yellow luminescence spectra and x-ray photoelectron spectroscopy, which suggests that the deep level E2 is associated with point defects in the form of VGa-impurity complexes.