Two-step process for nickel deposition
AssigneeAdvanced Micro Devices, Inc.
InventorsJacques J. Bertrand, George J. Kluth
Life of this patent
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Abstract
Sub-micron dimensioned, ultra-shallow junction MOS and/or CMOS transistor devices are fomxed by a salicide process wherein a blanket nickel layer is formed in contact with the exposed portions of the substrate surface adjacent the sidewall spacers, the top surface of the gate electrode, and the sidewall spacers. Embodiments include forming the blanket layer of nickel is formed by the sequential steps of: (i) forming a layer of nickel by sputtering with nitrogen gas; and, (ii) forming a layer of nickel by sputtering with argon gas. The two step process for forming the blanket layer of nickel advantageously prevents the formation of nickel silicide on the outer surfaces of the insulative sidewall spacers.
Claims11
A method of manufacturing a semiconductor device, which method comprises the steps of:
- (a) providing a semiconductor substrate of a first conductivity type and having a surface;
- (b) forming a gate insulator layer in contract with the substrate surface;
- (c) forming a gate electrode on a portion of the gate insulator layer, the gate electrode comprising first and second opposing side surfaces and a top surface;
- (d) forming a blanket layer of an insulative material on exposed portions of the gate insulator layer on the substrate surface and on the first and second opposing side surfaces and the top surface of the gate electrode;
- (e) removing the blanket layer of insulative material from the substrate surface portions and from the tops surface of the gate electrode, thereby forming a tapered width insulative sidewall spacer on each of the first and second opposing side surfaces of the gate electrode;
- and
- (f) forming a blanket layer of nickel in contact with the exposed portions of the substrate surface adjacent the sidewall spacers, the top surface of the gate electrode, and the sidewall spacers, wherein the blanket layer of nickel is formed by the sequential steps of:
- (i) forming a first layer of nickel by sputtering in a nitrogen gas atmosphere;
- and,
- (ii) forming a second layer of nickel on the first layer by sputtering in an argon gas atmosphere, whereby undesirable nickel silicide formation on the sidewall spacers during subsequent processing is substantially eliminated.
Dependencies are inferred from the claim text.