Substrate processing apparatus, signal source device, method of processing material layer, and method of fabricating semiconductor device

A method of processing a material layer, the method comprising:

• positioning a substrate comprising a polycrystalline material layer on a susceptor in a processing chamber;
• converting an upper portion of the polycrystalline material layer into an amorphous material layer;
• and
• removing the amorphous material layer by using radicals,
• wherein the converting of the upper portion of the polycrystalline material layer into the amorphous material layer comprises:
• supplying a sinusoidal wave signal and a non-sinusoidal wave signal to the susceptor to provide radicals and ions to the upper portion of the polycrystalline material layer.

A method of fabricating a semiconductor device, the method comprising:

• forming a plurality of active regions on a substrate extending in a first direction and a device isolation film defining the active regions;
• forming a dummy gate line extending in a second direction intersecting the active regions on the device isolation film;
• forming source-drain regions in portions of the active regions exposed on both sides of the dummy gate line;
• forming an insulating film covering the device isolation film and the source-drain regions around the dummy gate line;
• removing the dummy gate line to form a gate trench extending between the source-drain regions;
• forming a gate insulating film and a polycrystalline gate material layer in the gate trench;
• converting an upper portion of the polycrystalline gate material layer into an amorphous material layer;
• and
• removing the amorphous material layer by using radicals.