Copper alloy for semiconductor interconnections, fabrication method thereof, semiconductor device having copper alloy interconnections fabricated by the method, and sputtering target for fabricating copper alloy interconnections for semiconductors
AssigneeKabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
InventorsMasao Mizuno, Takashi Onishi
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Abstract
A Cu alloy for semiconductor interconnections contains at least one selected from the group consisting of 0.10 to 10 atomic percent of Sb, 0.010 to 1.0 atomic percent of Bi, and 0.01 to 3 atomic percent of Dy, with the balance being Cu and inevitable impurities. The Cu alloy can be reliably embedded in narrow trenches and/or via holes for interconnections.
Claims5
A Cu alloy comprising:
- at least one selected from the group consisting of:
- 0.10 to 10 atomic percent of Sb,
- 0.010 to 1.0 atomic percent of Bi, and
- 0.01 to 3 atomic percent of Dy,
- with the balance being Cu and inevitable impurities.
A Cu alloy for semiconductor interconnections, being deposited by sputtering and comprising at least one selected from the group consisting of Sb, Bi and Dy with the balance being Cu and inevitable impurities,
- wherein the Cu alloy has an average size of crystal grains of 0.01 to 0.15 μm immediately after deposition by sputtering at room temperature, and
- wherein, when the Cu alloy is subjected to heat treatment, the Cu alloy has an increased average size of the crystal grains of 0.5 μm or more after heat treatment.
A sputtering target for fabricating Cu alloy interconnections for semiconductors, comprising:
- at least one selected from the group consisting of:
- 0.10 to 12 atomic percent of Sb,
- 0.020 to 3 atomic percent of Bi, and
- 0.02 to 3.5 atomic percent of Dy,
- with the balance being Cu and inevitable impurities.
Dependencies are inferred from the claim text.