Method of nucleating tungsten on titanium nitride by CVD without silane
First Claim
1. A method of nucleating tungsten in a tungsten CVD process performed in a vacuum chamber without the use of silane to deposit elemental tungsten onto a substrate, the method comprising the steps of:
- injecting hydrogen into the chamber and bringing the chamber to a pressure and temperature sufficient to produce a hydrogen dissociation reaction at the substrate before the introduction of WF6 into the chamber; and
then injecting WF6 into the chamber in a ratio with H2 and at a pressure and temperature to produce a reduction reaction resulting in tungsten deposition onto the substrate.
2 Assignments
0 Petitions
Accused Products
Abstract
Nucleation of a refractory metal such as tungsten is initiated on a substrate of TiN without the use of silane by introducing hydrogen into a CVD reactor before the introduction of the reactant gas containing the metal, brought to reaction temperature and to reaction pressure. The process is most useful for CVD of tungsten onto patterned TiN coated silicon semiconductor wafers. Alternatively, hydrogen is introduced in a mixture with the metal containing gas, such as WF6, and maintained at subreaction pressure, of for example 100 mTorr, until the substrate is stabilized at a reaction temperature of approximately 400° C. or higher, to cause the dissociation of hydrogen on the wafer surface, then elevated to a relatively high reaction pressure of, for example, 60 Torr at which nucleation is achieved. Also, the reduction reaction that deposits the tungsten film proceeds without the need for a two step nucleation-deposition process.
110 Citations
20 Claims
-
1. A method of nucleating tungsten in a tungsten CVD process performed in a vacuum chamber without the use of silane to deposit elemental tungsten onto a substrate, the method comprising the steps of:
-
injecting hydrogen into the chamber and bringing the chamber to a pressure and temperature sufficient to produce a hydrogen dissociation reaction at the substrate before the introduction of WF6 into the chamber; and then injecting WF6 into the chamber in a ratio with H2 and at a pressure and temperature to produce a reduction reaction resulting in tungsten deposition onto the substrate. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of nucleating tungsten in a tungsten CVD process performed in a vacuum chamber without the use of silane to deposit elemental tungsten onto a substrate, the method comprising the steps of:
-
injecting a gas mixture of hydrogen and WF6 into the chamber and maintaining the chamber at a subreaction pressure below that for a WF6 reduction reaction at the temperature of the substrate; and before increasing the pressure from the subreaction pressure, maintaining the temperature of the substrate at least at that for the dissociation of hydrogen; and then increasing the pressure in the chamber to a WF6 reduction reaction pressure. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. A method of nucleating tungsten in a CVD process performed by reduction of WF6 in a vacuum chamber without the use of silane to deposit a metal onto a substrate, the method comprising the steps of:
-
injecting a gas including hydrogen into the chamber; injecting a gas including WF6 into the chamber with or following the introduction of hydrogen into the chamber; elevating the pressure of the gas within the chamber from a subreaction pressure to at least a minimum reaction pressure; elevating the temperature of the substrate and the gases within the chamber to at least a minimum reaction temperature before WF6 gas within the chamber is raised to the minimum reaction pressure. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
Specification