Modern VLSI processes avoid wet etching, and use plasma etching instead. The plasma produces energetic radicals, neutrally charged, that react at the surface of the wafer. Since neutral particles attack the wafer from all angles, this process is isotropic. The source gas for the plasma usually contains small molecules rich in chlorine or fluorine. For instance, carbon tetrachloride (CCl₄) etches silicon and aluminium, and trifluoromethane etches silicon dioxide and silicon nitride. A plasma containing oxygen is used to oxidize ("ash") photoresist and facilitate its removal.

In Ion milling, or sputter etching, lower pressures, energetic ions of noble gases, often Ar+, bombards the wafer with which knock atoms from the substrate by transferring momentum. Because the etching is performed by ions, which approach the wafer approximately from one direction, this process is highly anisotropic. On the other hand, it tends to display poor selectivity. Reactive-ion etching (RIE) operates under conditions intermediate between sputter and plasma. Deep reactive-ion etching (DRIE) modifies the RIE technique to produce deep, narrow features.

The fabrication of an integrated circuit involves a sequence of processes that may be repeated many times before a circuit is complete. In this section, we have discussed about the first step involved in semiconductor device fabrication i.e. the cleaning of wafers. Briefly we also have studied about the etching of thin films. Generally, the next step involved is oxidation of the wafer surface and is discussed in the next section.