Plasma processing apparatus including gas distribution plate

A plasma processing method, comprising:

• a preparing plasma processing apparatus including a main gas supplier, an additional gas supplier, and a chamber,
• wherein the chamber comprises:
• a support;
• a main splitter connected to the main gas supplier;
• an additional splitter connected to the additional gas supplier;
• and
• a gas distribution plate (GDP) on the support and connected to the main splitter and the additional splitter,
• wherein the GDP comprises reservoirs and nozzles, each connected to a respective reservoir,
• wherein the reservoirs comprise:
• a first reservoir and a second reservoir connected to the main splitter and not connected to the additional splitter;
• and
• a third reservoir between the first reservoir and the second reservoir and connected to both the main splitter and the additional splitter, and
• wherein the first reservoir, the second reservoir, and the third reservoir are separated from each other;
• and
• placing a substrate on the support;
• and
• forming a plasma between the substrate and the GDP using a process gas and an additional gas,
• wherein the process gas supplied from the main gas supplier to the chamber is sprayed onto the substrate after passing through the main splitter, the first reservoir, and the second reservoir,
• wherein the additional gas supplied from the additional gas supplier to the chamber is sprayed onto the substrate after passing through the additional splitter and the third reservoir, and
• wherein the additional gas is an acceleration gas for increasing a plasma density of the process gas or a deceleration gas for decreasing the plasma density of the process gas.