Pulsed nucleation deposition of tungsten layers

A method for depositing a tungsten nucleation layer on a substrate within a process chamber, comprising:

• (a) providing a flow of a gas mixture comprising a tungsten-containing precursor and a reducing gas into a process chamber for about 0.1 seconds to about 10 seconds to deposit a tungsten nucleation layer on a substrate;
• (b) removing reaction by-products generated during step (a) by providing a purge gas into the process chamber and evacuating both the purge gas and the reaction by-products therefrom;
• (c) providing a flow of the reducing gas into the process chamber for up to about 10 seconds to react with residual tungsten-containing precursor in the process chamber and deposit tungsten on the substrate;
• (d) removing reaction by-products generated during step (c) by providing a purge gas into the process chamber and evacuating both the purge gas and the reaction by-products therefrom;
• and
• (e) repeating steps (a)–(d) until a tungsten nucleation layer thickness of up to about 500 Å is deposited.

A method for depositing a tungsten nucleation layer on a substrate within a process chamber, comprising:

• (a) providing a flow of a gas mixture comprising tungsten hexafluoride and silane into a process chamber for about 0.1 seconds to about 10 seconds to deposit a tungsten nucleation layer on a substrate;
• (b) removing reaction by-products generated during step (a) by providing a purge gas into the process chamber and evacuating both the purge gas and the reaction by-products therefrom;
• (c) providing a flow of silane into the process chamber for up to about 10 seconds to react with residual tungsten hexafluoride in the process chamber and deposit tungsten on the substrate;
• (d) removing reaction by-products generated during step (c) by providing a purge gas into the process chamber and evacuating both the purge gas and the reaction by-products therefrom;
• and
• (e) repeating steps (a)–(d) until a tungsten nucleation layer thickness of up to about 500 Å is deposited.

A method for depositing a tungsten nucleation layer on a substrate within a process chamber, comprising:

• exposing a substrate to a gas mixture containing a tungsten precursor and a reducing gas for depositing a tungsten nucleation layer for about 0.1 seconds to about 10 seconds within a process chamber during a deposition step;
• exposing the process chamber to a first purge step that includes providing a purge gas into the process chamber and evacuating the process chamber;
• exposing the substrate to diborane or silane during a soak step;
• exposing the process chamber to a second purge step that includes providing the purge gas into the process chamber and evacuating the process chamber;
• and
• repeating the deposition step and the first purge step until the tungsten nucleation layer is formed with a predetermined thickness.

A method for depositing a tungsten nucleation layer on a substrate within a process chamber, comprising:

• exposing a substrate to a gas mixture containing a tungsten precursor and a reducing gas for about 0.1 seconds to about 10 seconds within a process chamber during a deposition step;
• exposing the process chamber to a purge step that includes providing a purge gas into the process chamber and evacuating the process chamber;
• repeating the deposition step and the purge step until a tungsten nucleation layer is formed with a predetermined thickness;
• and
• depositing a tungsten bulk layer on the tungsten nucleation layer during a second vapor deposition process.