Reactive Ion Etching Techniques

In this Chapter, we will review the chemical, ion sputtering, plasma-assisted and reactive ion etching techniques for SiC. These processes can be used in fabricating SiC devices. 

Reactive ion etching techniques can also be used to fabricate structures that lead to dramatically reduced optical losses. In Fig. 29, we show such a structure developed by Steier and co-workers [104] that reduces mode size mismatch by exploiting the concept of mode expansion due to reduction of the difference in index of refraction between core and cladding. 

Finally, the metallisation layer usually requires patterning, which can be done by reactive ion etching (RIE) or back-sputtering. The two processes are similar. In both techniques accelerated ions hit the substrate and forcibly detach atoms or molecules from the surface. RIE uses reactive gases such as chlorine, Cl or trichlorofluoromethane [75-69-4] CCl E. Inert gases such as argon or neon are used in back-sputtering. 

The device was realized by deep reactive ion etching (DRIE) using the SU-8 technique, producing vertical side walls [72-74]. This fabrication route was chosen to avoid crystallization, which is known to occur at sharp channel edges. Using DRIE smooth, curved corners can be realized, unlike by conventional silicon wet etching. 

Figure 13 Schematic representation of the bilevel resist process employing an oxygen reactive ion etching pattern transfer technique.

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