Multiple layer tungsten deposition process
AssigneeAT&T Corp.
InventorsSailesh M. Merchant, Arun K. Nanda, Pradip K. Roy
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Abstract
Tungsten plugs are formed in a manner which avoids the formation of unwanted tungsten volcanoes by depositing at least three and preferably five to seven layers of tungsten within a contact hole to form a layered plug. In particularly useful embodiments, the layers are deposited at alternating fast and slow rates of deposition.
Claims18
A method of forming a tungsten plug comprising:
- providing a nucleation layer;
- depositing at least three successive layers of tungsten on the nucleation layer within a contact hole,
- each layer being deposited at a rate of deposition different than the rate at which the previous layer was deposited,
- the layers being alternately deposited at a fast rate of deposition of greater than 40 .ANG./second and a slow rate of deposition of less than 40 .ANG./second.
A method of forming an electronic device comprising:
- providing a substrate having a conductive layer, a insulator layer formed on the conductive layer and a contact hole formed in the insulator layer to expose a portion of the conductive layer;
- providing a nucleation layer;
- depositing at least three layers of tungsten on the nucleation layer within the contact hole to at least substantially fill the contact hole, the at least three layers of tungsten being deposited at a rate of deposition different than the rate at which the previous layer was deposited,
- whereby a tungsten plug capable of providing electrical connection between the conductive layer of the substrate and another conductive element is formed.
A method of forming a tungsten plug within a contact hole formed in a substrate, the method comprising:
- (a) depositing a layer of tungsten by H.sub.2 reduction of WF.sub.6 at a rate of deposition greater than 40 .ANG./sec;
- (b) depositing a layer of tungsten by H.sub.2 reduction of WF.sub.6 at a rate of deposition less than 40 .ANG./sec;
- and
- (c) repeating steps (a) and (b) in an alternating manner a sufficient number of times to at least substantially fill the contact hole, whereby a layered tungsten plug is formed.
A method of forming a tungsten plug within a contact hole formed in a substrate, the method comprising:
- depositing a first layer of tungsten by H.sub.2 reduction of WF.sub.6 at a first rate of deposition;
- depositing a second layer of tungsten by H.sub.2 reduction of WF.sub.6 at a second rate of deposition, the second rate of deposition being slower than the first rate of deposition;
- and
- depositing a third layer of tungsten by H.sub.2 reduction of WF.sub.6 at a third rate of deposition, the third rate of deposition being faster than the second rate of deposition.
A method of forming an electronic device comprising:
- providing a substrate having a first layer, an insulator layer formed on the first layer and a contact hole formed in the insulator layer and exposing a portion of the first layer;
- depositing at least five layers of tungsten within the contact hole to at least substantially fill the contact hole, the at least five layers being deposited at alternating fast and slow rates of deposition.
Dependencies are inferred from the claim text.