Patent ID: 7855145

Claim:
A method for filling a gap, comprising: forming an insulating layer on a substrate; forming a gap region in the insulating layer; and forming a phase change material layer pattern in the gap region, the phase change material layer pattern including a plurality of sub phase change material layer patterns having a substantially flat surface, the sub phase change material layer patterns being sequentially stacked in the gap region, wherein the plurality of sub phase change material layer patterns are formed by repeatedly forming a phase change material layer and etching the phase change material layer in a plasma processing apparatus, and includes: supplying a process gas and a source gas to a process chamber of the plasma processing apparatus; independently supplying a voltage to an upper electrode and a lower electrode respectively located in an upper portion and a lower portion of the process chamber; providing a first power of about 100 W or less to the upper electrode and grounding the lower electrode during forming the phase change material layer; and providing a second power higher than the first power provided to the upper electrode to the lower electrode during etching the phase change material layer.