Method for forming a gap filling refractory metal layer having reduced stress
AssigneeApplied Materials, Inc.
InventorsSteve Ghanayem, Maitreyee Mahajani
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Abstract
A method for forming a refractory metal layer that features two-stage nucleation prior to bulk deposition of the same. The method includes placing a substrate in a deposition zone, flowing, into the deposition zone during a first deposition stage, a silicon source, such as a silane gas, and a tungsten source, such as tungsten-hexafluoride gas, so as to obtain a predetermined ratio of the two gases therein. During a second deposition stage, subsequent to the first deposition stage, the ratio of the two gases is varied. Specifically, in the first deposition stage there is a greater quantity of silane gas than tungsten-hexafluoride gas. In the second deposition stage there may be a greater quantity of tungsten-hexafluoride than silane.
Claims34
A method for nucleating a substrate, said method comprising:
- placing a substrate in a deposition zone;
- during a first deposition stage flowing, into said deposition zone, a silicon source and a tungsten source so as to obtain a flow ratio of said silicon source to said tungsten source;
- and
- during a second deposition stage, subsequent to said first deposition stage, decreasing said ratio of said silicon source to said tungsten source.
A chemical vapor deposition process for depositing a tungsten layer on a substrate, said method comprising:
- placing a substrate in a deposition zone;
- during a first deposition stage flowing, into said deposition zone, a tungsten source and a silicon source at a first flow ratio of said silicon source to said tungsten source;
- during a second deposition stage, subsequent to said first deposition stage, flowing said tungsten source and silicon source into said deposition zone at a second flow ratio of said silicon source to said tungsten source, wherein said second flow ratio is less than said first flow ratio;
- during a third deposition stage, subsequent to said second deposition stage:
- (i) flowing, into said deposition zone, a process gas including a tungsten compound and a reduction agent;
- and
- (ii) maintaining said deposition zone at process conditions suitable for depositing a tungsten layer on said substrate.
A chemical vapor deposition process for depositing tungsten over a substrate disposed in a substrate processing chamber, said process comprising:
- depositing a first layer of tungsten over said substrate by flowing a first process gas comprising a tungsten source and a silicon source into said chamber, said first process gas having a first flow ratio of said silicon source to said tungsten source during deposition of a first strata of said first layer and having a second flow ratio of said silicon source to said tungsten source during deposition of a second strata of said first layer deposited over said first strata, wherein said second flow ratio is less than said first flow ratio flow ratio;
- and
- thereafter, depositing a second layer of tungsten on said first layer by flowing a second process comprising a tungsten source and reducing agent into said chamber.
Dependencies are inferred from the claim text.