Apparatus for selectively etching first region made of silicon nitride against second region made of silicon oxide

An apparatus for selectively etching a first region relative to a second region on a main surface of a substrate, the first region being made of silicon nitride, the second region being made of silicon oxide, the apparatus comprising:

• a chamber having a gas inlet and a gas outlet;
• a substrate support disposed within the chamber and including an electrode;
• a gas supply configured to supply a gas into the chamber;
• an RF supply configured to supply a RF signal to the electrode;
• and
• a controller configured to cause:
• (a) placing the substrate on the substrate support;
• (b) forming a first plasma from a first gas containing hydrogen with the RF signal,
• (c) exposing the substrate to the first plasma to modify the first region;
• (d) forming a second plasma from a second gas containing fluorine without the RF signal;
• (e) exposing the substrate to the second plasma to remove the modified first region,
• wherein the first region has a plurality of protruded regions, of which heights are different from each other,
• a first film is formed on the first region, and
• a second film is formed on the first film.

A plasma processing apparatus equipped with an ICP (Inductively Coupled Plasma) type plasma source, comprising:

• a chamber having a gas inlet and a gas outlet;
• a substrate support disposed within the chamber;
• a plasma generator;
• and
• a controller configured to cause:
• (a) placing a substrate, on the substrate support, including a first region made of silicon nitride, a second region made of silicon oxide and a third region made of silicon;
• (b) modifying the first region by a hydrogen plasma generated from a first gas;
• and
• (c) after (b), removing the modified first region by a fluorine plasma generated from a second gas,
• wherein the second region is provided at both sides of the third region, and the third region is protruded above the second region,
• the first region is provided to cover the second region and the third region, and
• the first gas further includes an oxygen-containing gas.