Manufacturing method of semiconductor device
A method includes following steps. A first precursor is pulsed over a substrate such that first precursor adsorbs on a first region and a second region of the substrate. A first plurality of the first precursor adsorbing on the first region is then removed using a plasma, while leaving a second plurality of the first precursor adsorbing on the second region. A second precursor is then pulsed to the substrate to form a monolayer of a film on the second region and a material on the first region. The material is then removed using a plasma. The substrate is biased during removing the material.
1 . A method of forming a semiconductor device, comprising:
forming a conductive feature over a substrate;
forming a metal capping layer over the conductive feature;
forming a dielectric layer over the conductive feature;
etching the dielectric layer to form a via opening extending through the dielectric layer to expose the metal capping layer; and
forming a conductive via in the via opening, wherein forming the conductive via in the via opening comprises:
pulsing a first precursor over the substrate such that the first precursor comprises a first plurality of precursor molecules adsorbing on the metal capping layer and a second plurality of precursor molecules adsorbing on the dielectric layer;
performing a first purge after pulsing the first precursor;
after performing the first purge, performing a plasma removal procedure to the substrate to remove the second plurality of precursor molecules from the dielectric layer, while leaving the first plurality of precursor molecules on the metal capping layer;
pulsing a second precursor to react with the first plurality of precursor molecules to form a monolayer of a film; and
performing a second purge after pulsing the second precursor.
2 . The method of claim 1 , wherein performing the plasma removal procedure comprises:
applying a bias to the substrate.
3 . The method of claim 1 , further comprising:
prior to pulsing the first precursor over the substrate, treating the substrate with a plasma.
4 . The method of claim 3 , wherein treating the substrate with the plasma comprises:
applying a bias to the substrate.
5 . A method of forming a semiconductor device, comprising:
forming a conductive feature over a substrate;
forming a metal capping layer over the conductive feature;
forming a dielectric layer over the conductive feature;
etching the dielectric layer to form a via opening extending through the dielectric layer to expose the metal capping layer; and
forming a conductive via in the via opening, wherein forming the conductive via in the via opening comprises:
placing the substrate in a chamber;
introducing a first precursor to the chamber, wherein the first precursor comprises a first plurality of precursor molecules binding the metal capping layer with first bonds and a second plurality of precursor molecules binding the dielectric layer with second bonds;
purging the chamber with an inert gas;
breaking the second bonds that bind the second plurality of precursor molecules and the dielectric layer, while leaving the first bonds that bind the first plurality of precursor molecules and the metal capping layer intact;
introducing a second precursor to the chamber; and
purging the second precursor.
6 . The method of claim 5 , wherein the first bonds have a binding energy different from a binding energy of the second bonds.
7 . The method of claim 5 , wherein the first bonds have a binding energy greater than a binding energy of the second bonds.
8 . The method of claim 5 , wherein breaking the second bonds comprises:
applying a direct current (DC) bias, an alternating current (AC) bias, or a DC/AC superposed bias to the substrate.
9 . The method of claim 5 , wherein breaking the second bonds comprises:
applying a radio frequency (RF) bias to the substrate.
10 . The method of claim 5 , wherein breaking the second bonds comprises:
delivering a treatment gas to a plasma source connected to the chamber;
generating a plasma from the treatment gas; and
using the plasma to remove the second plurality of precursor molecules binding the dielectric layer.
11 . The method of claim 10 , wherein the treatment gas comprises He, Ne, Ar, Kr, Xe, Rn, or a combination thereof.
12 . The method of claim 5 , further comprising:
prior to introducing the first precursor to the chamber, performing a clean operation to the substrate, wherein the clean operation comprises:
delivering a treatment gas to a plasma source connected to the chamber;
generating a plasma from the treatment gas; and
using the plasma to clean the substrate.
13 . A method of forming a semiconductor device, comprising:
forming a conductive feature over a substrate;
forming a metal capping layer over the conductive feature, wherein the metal capping layer comprises Co, Cu, W, Al, Mn, Ru or a combination thereof;
forming a dielectric layer over the conductive feature;
etching the dielectric layer to form a via opening extending through the dielectric layer to expose the metal capping layer; and
forming a conductive via in the via opening, wherein forming the conductive via in the via opening comprises:
placing the substrate in a chamber;
introducing a first precursor to the chamber, wherein the first precursor comprises a first plurality of precursor molecules binding the metal capping layer with first bonds and a second plurality of precursor molecules binding the dielectric layer with second bonds;
purging the chamber with an inert gas;
breaking the second bonds that bind the second plurality of precursor molecules and the dielectric layer, while leaving the first bonds that bind the first plurality of precursor molecules and the metal capping layer intact;
introducing a second precursor to the chamber; and
purging the second precursor.
14 . The method of claim 13 , wherein the first bonds have a binding energy different from a binding energy of the second bonds.
15 . The method of claim 13 , wherein the first bonds have a binding energy greater than a binding energy of the second bonds.
16 . The method of claim 13 , wherein breaking the second bonds comprises:
applying a direct current (DC) bias, an alternating current (AC) bias, or a DC/AC superposed bias to the substrate.
17 . The method of claim 13 , wherein breaking the second bonds comprises:
applying a direct current (DC) bias to the substrate.
18 . The method of claim 13 , wherein breaking the second bonds comprises:
applying an alternating current (AC) bias to the substrate.
19 . The method of claim 13 , wherein breaking the second bonds comprises:
applying a DC/AC superposed bias to the substrate.
20 . The method of claim 13 , wherein breaking the second bonds comprises:
applying a radio frequency (RF) bias to the substrate.