SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

A substrate processing method using a substrate processing apparatus which comprises a process chamber in which a reaction space is formed to process a substrate in which a composite layer pattern having a plurality of first insulating layers and a plurality of second insulating layers alternately stacked thereon is formed, a substrate support unit, a gas distribution unit, and a plasma reactor, the method comprising the steps of: heating the substrate support unit and the gas distribution unit such that a temperature of the gas distribution unit is maintained equal to or lower than a temperature of the substrate support unit; supplying a reactive gas including a halogen-containing gas to the plasma reactor; generating radicals by applying power to the plasma reactor to activate the halogen-containing gas; and at least partially etching the plurality of first insulating layers in a lateral direction selectively with respect to the plurality of second insulating layers by supplying the radicals onto the substrate mounted on the substrate support unit through the gas distribution unit.