Method of depositing silicon oxide film by plasma enhanced atomic layer deposition at low temperature

A method of double-patterning by depositing a silicon oxide film on a resist pattern or etched lines formed on a substrate by plasma enhanced atomic layer deposition (PEALD), comprising:

• providing a substrate having a patterning layer on which adjacent lines constituted by a resist pattern or etched lines are formed in a PEALD reactor, said resist pattern or etched lines being formed of an organic film susceptible to deformation by heat;
• controlling a temperature of a susceptor on which the substrate is placed at less than 50° C. or lower as a deposition temperature;
• introducing a silicon-containing precursor and an oxygen-supplying reactant to the PEALD reactor and applying RF power therein in a cycle, while the deposition temperature is controlled substantially at a constant temperature of less than 50° C., thereby depositing a silicon oxide atomic layer over the lines while inhibiting deformation of the lines, each line having a top and two side walls;
• repeating the cycle multiple times substantially at the constant temperature to deposit a silicon oxide film in contact with and fully covering the lines;
• etching the silicon oxide film to expose each line from the silicon oxide film only at the top and to expose the patterning layer between the adjacent lines, so that the silicon oxide film is left only on the two side walls of each line on the patterning layer, constituting double-patterning spacers;
• removing the lines to leave only the double-patterning spacers;
• etching the patterning layer in its thickness direction using the double-patterning spacers as an etch mask to form a pattern corresponding to the double-patterning spacers in the patterning layer;
• and
• removing remaining double-patterning spacers, if any, on the tops of the pattern.