Semiconductor systems and methods may include methods of performing selective etches that include modifying a material on a semiconductor substrate. The substrate may have at least two exposed materials on a surface of the semiconductor substrate. The methods may include forming a low-power plasma within a processing chamber housing the semiconductor substrate. The low-power plasma may be a radio-frequency (“RF”) plasma, which may be at least partially formed by an RF bias power operating between about 10 W and about 100 W in embodiments. The RF bias power may also be pulsed at a frequency below about 5,000 Hz. The methods may also include etching one of the at least two exposed materials on the surface of the semiconductor substrate at a higher etch rate than a second of the at least two exposed materials on the surface of the semiconductor substrate.