US 2014/0273451 A1 · TUNGSTEN DEPOSITION SEQUENCE

Abstract

Methods of filling gaps with tungsten are described. The methods include a tungsten dep-etch-dep sequence to enhance gapfilling yet avoid difficulty in restarting deposition after the intervening etch. The first tungsten deposition may have a nucleation layer or seeding layer to assist growth of the first tungsten deposition. Restarting deposition with a less-than-conductive nucleation layer would impact function of an integrated circuit, and therefore avoiding tungsten “poisoning” during the etch is desirable. The etching step may be performed using a plasma to excite a halogen-containing precursor while the substrate at relatively low temperature (near room temperature or less). The plasma may be local or remote. Another method may be used in combination or separately and involves the introduction of a source of oxygen into the plasma in combination with the halogen-containing precursor.

Claims19

Dependent claims

A method of depositing tungsten in a trench on a patterned substrate, the method comprising the sequential steps:

(i) depositing a first tungsten layer in the trench,
(ii) partially etching the first tungsten layer from the trench, and
(iii) depositing a second tungsten layer;
wherein the step of partially etching the tungsten from the trench occurs while the patterned substrate is in a substrate processing region of a substrate processing chamber, and partially etching the tungsten comprises:
flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a plasma in the remote plasma region to produce plasma effluents, and partially etching the first tungsten layer from the patterned substrate by flowing the plasma effluents into the substrate processing region, wherein a temperature of the substrate is below or about 40° C. during the step of partially etching the first tungsten layer.

2 more elements

Dependencies are inferred from the claim text.

Tungsten deposition sequence

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Tungsten deposition sequence

Life of this patent

Abstract

Claims19