Tin oxide film on a semiconductor substrate is etched selectively with an etch selectivity of at least 10 in a presence of silicon (Si), carbon (C), or a carbon-containing material (e.g., photoresist) by exposing the substrate to a process gas comprising hydrogen (H2) and a hydrocarbon (e.g., at a hydrogen/hydrocarbon ratio of at least 5), such that a carbon-containing polymer is formed on the substrate. In some embodiments an apparatus for processing a semiconductor substrate includes a process chamber configured for housing the semiconductor substrate and a controller having program instructions on a non-transitory medium for causing selective etching of a tin oxide layer on a substrate in a presence of silicon, carbon, or a carbon-containing material by exposing the substrate to a plasma formed in a process gas that includes H2 and a hydrocarbon.