Physical Vapor Deposition (PVD)

Sputtering

Sputtering is the dominant PVD technique in semiconductor manufacturing. It physically ejects atoms from a solid target material using energetic ion bombardment:

• A plasma is created from an inert gas (usually argon)
• Argon ions are accelerated toward the target (a disk of the desired material)
• Ions knock atoms off the target surface (like billiard balls)
• Ejected atoms travel across the vacuum chamber and deposit on the wafer

Common sputtered films in semiconductor fabs:

• TaN/Ta: Barrier/liner for copper interconnects
• Copper seed: Thin copper layer for electroplating
• Titanium/TiN: Contact barriers and hard masks
• Aluminum: Bond pads and some interconnect layers