267 results about "Tungsten film" patented technology

A tungsten nucleation film is formed on a surface of a semiconductor substrate by alternatively providing to that surface, reducing gases and tungsten-containing gases. Each cycle of the method provides for one or more monolayers of the tungsten film. The film is conformal and has improved step coverage, even for a high aspect ratio contact hole.

Embodiments of the invention provide an improved process for depositing tungsten-containing materials. The process utilizes soak processes and vapor deposition processes, such as atomic layer deposition (ALD) to provide tungsten films having significantly improved surface uniformity and production level throughput. In one embodiment, a method for forming a tungsten-containing material on a substrate is provided which includes positioning a substrate within a process chamber, wherein the substrate contains an underlayer disposed thereon, exposing the substrate sequentially to a tungsten precursor and a reducing gas to deposit a tungsten nucleation layer on the underlayer during an ALD process, wherein the reducing gas contains a hydrogen / hydride flow rate ratio of about 40:1, 100:1, 500:1, 800:1, 1,000:1, or greater, and depositing a tungsten bulk layer on the tungsten nucleation layer. The reducing gas contains a hydride compound, such as diborane, silane, or disilane.

Improved methods for depositing low resistivity tungsten films are provided. The methods involve depositing a tungsten nucleation layer on a substrate and then depositing a tungsten bulk layer over the tungsten nucleation layer to form the tungsten film. The methods provide precise control of the nucleation layer thickness and improved step coverage. According to various embodiments, the methods involve controlling thickness and / or improving step coverage by exposing the substrate to pulse nucleation layer (PNL) cycles at low temperature. Also in some embodiments, the methods may improve resistivity by using a high temperature PNL cycle of a boron-containing species and a tungsten-containing precursor to finish forming the tungsten nucleation layer.

Methods of improving the uniformity and adhesion of low resistivity tungsten films are provided. Low resistivity tungsten films are formed by exposing the tungsten nucleation layer to a reducing agent in a series of pulses before depositing the tungsten bulk layer. According to various embodiments, the methods involve reducing agent pulses with different flow rates, different pulse times and different interval times.

Methods of forming low resistivity tungsten films with good uniformity and good adhesion to the underlying layer are provided. The methods involve forming a tungsten nucleation layer using a pulsed nucleation layer process at low temperature and then treating the deposited nucleation layer prior to depositing the bulk tungsten fill. The treatment operation lowers resistivity of the deposited tungsten film. In certain embodiments, the depositing the nucleation layer involves a boron-based chemistry in the absence of hydrogen. Also in certain embodiments, the treatment operations involve exposing the nucleation layer to alternating cycles of a reducing agent and a tungsten-containing precursor. The methods are useful for depositing films in high aspect ratio and / or narrow features. The films exhibit low resistivity at narrow line widths and excellent step coverage.

In one embodiment, a method for depositing a tungsten-containing film on a substrate is provided which includes depositing a barrier layer on the substrate, such as a titanium or tantalum containing barrier layer and depositing a ruthenium layer on the barrier layer. The method further includes depositing a tungsten nucleation layer on the ruthenium layer and depositing a tungsten bulk layer on the tungsten nucleation layer. The barrier layer, the ruthenium layer, the tungsten nucleation layer and the tungsten bulk layer are independently deposited by an ALD process, a CVD process or a PVD process, preferably by an ALD process. In some examples, the substrate is exposed to a soak process prior to depositing a subsequent layer, such as between the deposition of the barrier layer and the ruthenium layer, the ruthenium layer and the tungsten nucleation layer or the tungsten nucleation layer and the tungsten bulk layer.

Embodiments of the invention provide an improved process for depositing tungsten-containing materials. The process utilizes soak processes and vapor deposition processes to provide tungsten films having significantly improved surface uniformity while increasing the production level throughput. In one embodiment, a method is provided which includes depositing a tungsten silicide layer on the substrate by exposing the substrate to a continuous flow of a silicon precursor while also exposing the substrate to intermittent pulses of a tungsten precursor. The method further provides that the substrate is exposed to the silicon and tungsten precursors which have a silicon / tungsten precursor flow rate ratio of greater than 1, for example, about 2, about 3, or greater. Subsequently, the method provides depositing a tungsten nitride layer on the tungsten suicide layer, depositing a tungsten nucleation layer on the tungsten nitride layer, and depositing a tungsten bulk layer on the tungsten nucleation layer.

In a fabrication method for forming an electrical interconnection of CVD tungsten film, a contact hole is formed in a dielectric layer. A lower conductive layer is formed in the contact hole and over the dielectric layer. A portion of the lower conductive layer is removed. As a result, the dielectric layer is exposed. An upper conductive layer is formed over the lower conductive layer and over the dielectric layer. The lower conductive layer has a rough surface and the upper conductive layer has a smooth surface. In this manner, following patterning of conductive stripes over the conductive layer, residue is mitigated, and thus, inadvertent interconnection of neighboring stripes is eliminated.

Novel low-resistivity tungsten film stack schemes and methods for depositing them are provided. The film stacks include a mixed tungsten / tungsten-containing compound (e.g., WC) layer as a base for deposition of tungsten nucleation and / or bulk layers. According to various embodiments, these tungsten rich layers may be used as barrier and / or adhesion layers in tungsten contact metallization and bitlines. Deposition of the tungsten-rich layers involves exposing the substrate to a halogen-free organometallic tungsten precursor. The mixed tungsten / tungsten carbide layer is a thin, low resistivity film with excellent adhesion and a good base for subsequent tungsten plug or line formation.