Method of forming a contact in a semiconductor device
View Patent ↗Deterioration of yield may be prevented when a contact in a semiconductor device is made by a method including forming a contact hole by selectively removing an insulating layer from a semiconductor substrate, depositing a barrier layer on the insulating layer and on the surface of (or in) the contact hole, depositing an initial tungsten layer on the barrier layer to at least a predetermined thickness, removing particles generated during at least one of the depositing steps, and filling the contact hole with an additional tungsten layer.
1. A method of forming a semiconductor device, comprising the steps of:
forming a contact hole by selectively removing portions of an insulating layer on a semiconductor substrate;
depositing a barrier layer on the insulating layer and in the contact hole;
conformally depositing an initial tungsten layer with a predetermined thickness on the barrier layer, such that a horizontal gap having a width less than that of the contact hole remains in the contact hole after depositing the initial tungsten layer;
removing a portion of the initial tungsten layer up to a second thickness excluding particles generated during at least one of the depositing steps; and
filling the contact hole with an additional tungsten layer.
2. The method of claim 1 , wherein the initial tungsten layer is deposited with a thickness of 100 Å.
3. The method of claim 1 , wherein the second thickness is thinner than the first thickness.
4. The method of claim 1 , wherein the portion of the initial tungsten layer is removed using a plasma formed from a gas comprising SF 6 .
5. The method of claim 1 , wherein removing the portion of the initial tungsten layer comprises:
etching the portion of the initial tungsten layer using SF 6 in an etching chamber;
removing the particles using Cl 2 gas;
first out-gassing the etching chamber using Ar gas; and
second out-gassing the etching chamber using N 2 gas.
6. The method of claim 1 , wherein the initial tungsten layer has a thickness of less than half of the horizontal gap remaining in the contact hole.
7. The method of claim 1 , wherein the second thickness is about 10 Å.
8. A method of forming a semiconductor device, comprising the steps of:
selectively removing portions of an insulating layer on a semiconductor substrate to form a plurality of contact holes;
depositing a barrier layer on the insulating layer and in the contact holes;
conformally depositing an initial tungsten layer with a predetermined thickness on the barrier layer, wherein a horizontal gap having a width less than that of the contact hole remains in the contact hole;
etching a portion of the initial tungsten layer up to a second thickness less than the predetermined thickness such that a conformal tungsten layer remains in the contact hole; and
filling the contact hole with an additional tungsten layer.
9. The method of claim 8 , wherein the initial tungsten layer is deposited with a thickness of 100 Å.
10. The method of claim 8 , wherein the second thickness is about 10 Å.
11. The method of claim 8 , further comprising, after deposition of the initial tungsten layer, exposing the semiconductor device to a plasma comprising Cl 2 gas to remove particles.
12. The method of claim 8 , wherein removing the portion of the initial tungsten layer exposes particles generated during at least one of the depositing steps.
13. The method of claim 8 , wherein etching the portion of the initial tungsten layer comprises:
etching the portion of the initial tungsten layer in an etching chamber with a plasma comprising SF 6 ;
first out-gassing the etching chamber using Ar gas; and
second out-gassing the etching chamber using N 2 gas.
14. The method of claim 8 , wherein the initial tungsten layer has a thickness of less than half of the horizontal gap remaining in the contact hole.
15. A method of forming a semiconductor device, comprising the steps of:
selectively removing portions of an insulating layer on a semiconductor substrate to form a plurality of contact holes;
depositing a barrier layer on the insulating layer and in the contact holes;
conformally depositing an initial tungsten layer on the barrier layer, wherein the initial tungsten layer has a predetermined thickness and a horizontal gap having a width less than that of the contact hole remains in the contact hole;
plasma cleaning a portion of the initial tungsten layer in order to remove particles generated during the depositing from the semiconductor device; and
filling the contact hole with an additional tungsten layer.
16. The method of claim 15 , wherein the initial tungsten layer is deposited with a thickness of 100 Å.
17. The method of claim 15 , wherein the plasma cleaned tungsten layer by the plasma cleaning step has a thickness of about 10 Å.
18. The method of claim 15 , wherein plasma cleaning the portion of the initial tungsten layer comprises:
cleaning the initial tungsten layer in an etching chamber with a plasma comprising SF 6 ;
exposing the semiconductor device to a plasma comprising Cl 2 gas after the cleaning step;
first out-gassing the etching chamber using Ar gas; and
second out-gassing the etching chamber using N 2 gas.
19. The method of claim 15 , wherein the initial tungsten layer has a thickness of less than half of the horizontal gap remaining in the contact hole.