CREATION OF MAGNETIC FIELD (VECTOR POTENTIAL) WELL FOR IMPROVED PLASMA DEPOSITION AND RESPUTTERING UNIFORMITY
A physical vapor deposition (PVD) system includes a chamber and a target arranged in a target region of the chamber. A pedestal has a surface for supporting a substrate and is arranged in a substrate region of the chamber. A transfer region is located between the target region and the substrate region. N coaxial coils are arranged in a first plane parallel to the surface of the pedestal and below the pedestal. M coaxial coils are arranged adjacent to the pedestal. N currents flow in a first direction in the N coaxial coils, respectively, and M currents flow in a second direction in the M coaxial coils that is opposite to the first direction, respectively.
1 . A physical vapor deposition (PVD) system, comprising:
a chamber;
a target arranged in a target region of the chamber;
a pedestal having a surface for supporting a substrate and arranged in a substrate region of the chamber, wherein a transfer region is located between the target region and the substrate region;
N coaxial coils arranged in a first plane parallel to the surface of the pedestal and below the pedestal; and
M coaxial coils, where N and M are integers greater than zero, and
wherein N currents flow in a first direction in the N coaxial coils, respectively, and M currents flow in a second direction in the M coaxial coils that is opposite to the first direction, respectively.
2 . The PVD system of claim 1 , wherein the M coaxial coils are arranged in a second plane that is parallel to the surface of the pedestal and above the surface of the pedestal.
3 . The PVD system of claim 1 , wherein the M coaxial coils are arranged in a second plane that is parallel to the surface of the pedestal and below the surface of the pedestal.
4 . The PVD system of claim 1 , wherein:
at least some of the M coaxial coils are arranged in a second plane that is parallel to the surface of the pedestal and below the surface of the pedestal, and
remaining ones of the M coaxial coils are arranged in a third plane that is parallel to the surface of the pedestal and above the surface of the pedestal.
5 . The PVD system of claim 1 , wherein the N coaxial coils and the M coaxial coils create a magnetic field well in the chamber above the substrate.
6 . The PVD system of claim 5 , wherein:
the magnetic field well is generally “U”-shaped and is centered on the surface of the pedestal;
a magnetic null is located inside the magnetic field well; and
a strong magnetic field is located outside of the magnetic field well.
7 . The PVD system of claim 1 , wherein:
at least one of the N coaxial coils has a first diameter,
at least one of the M coaxial coils has a second diameter, wherein the second diameter is greater than the first diameter.
8 . The PVD system of claim 1 , wherein N is greater than one and wherein at least one of the N currents has a different magnitude than another one of the N currents.
9 . The PVD system of claim 1 , wherein the target includes a hollow cathode magnetron (HCM).
10 . The PVD system of claim 1 , wherein a smallest one of the M currents is greater than a greatest one of the N currents.
11 . The PVD system of claim 10 , wherein a smallest one of the M currents is greater than or equal to approximately two times a greatest one of the N currents.
12 . The PVD system of claim 2 , wherein the N coaxial coils and the M coaxial coils are arranged 0-6 inches below and above the surface of the pedestal, respectively.
13 . The PVD system of claim 4 , wherein the N coaxial coils and the at least some of the M coaxial coils are coplanar.
14 . The PVD system of claim 13 , wherein the N coaxial coils and the at least some of the M coaxial coils are arranged 0-6 inches below the surface of the pedestal.
15 . The PVD system of claim 14 , wherein the N coaxial coils and the at least some of the M coaxial coils are arranged approximately 1 inch below the surface of the pedestal.
16 . The PVD system of claim 1 , wherein the PVD system is used to deposit a tantalum/tantalum nitride barrier film.
17 . A method of operating a physical vapor deposition (PVD) system, comprising:
arranging N coaxial coils in a first plane parallel to a substrate-supporting surface of a pedestal in a chamber of a PVD system and below the pedestal;
arranging M coaxial coils adjacent to the pedestal, where N and M are integers greater than zero; and
creating a magnetic field well above a substrate by supplying N currents to the N coaxial coils, respectively, and M currents to the M coaxial coils, respectively,
wherein the N currents flow in a first direction in the N coaxial coils and the M second currents flow in a second direction in the M coaxial coils that is opposite to the first direction.
18 . The method of claim 17 , wherein arranging the M coaxial coils includes arranging the M coaxial coils in a second plane that is parallel to the surface of the pedestal and above the surface of the pedestal.
19 . The method of claim 17 , wherein arranging the M coaxial coils includes arranging the M coaxial coils in a second plane that is parallel to the surface of the pedestal and below the surface of the pedestal.
20 . The method of claim 17 , wherein arranging the M coaxial coils includes:
arranging at least some of the M coaxial coils in a second plane that is parallel to the surface of the pedestal and below the surface of the pedestal; and
arranging remaining ones of the M coaxial coils in a third plane that is parallel to the surface of the pedestal and above the surface of the pedestal.
21 . The method of claim 17 , wherein:
the magnetic field well is generally “U”-shaped and is centered on the substrate-supporting surface of the pedestal;
a magnetic null is located inside the magnetic field well; and
a strong magnetic field is located outside of the magnetic field well.
22 . The method of claim 18 , wherein:
at least one of the N coaxial coils has a first diameter, and
at least one of the M coaxial coils has a second diameter, wherein the second diameter is greater than the first diameter.
23 . The method of claim 22 , wherein N is greater than one and wherein at least one of the N currents has a different magnitude than another one of the N currents.
24 . The method of claim 18 , wherein the PVD system includes a hollow cathode magnetron (HCM) target.
25 . The method of claim 18 , wherein a smallest one of the M currents is greater than a greatest one of the N currents.
26 . The method of claim 19 , wherein the N coaxial coils and the M coaxial coils are arranged 0-6 inches below and above the surface of the pedestal, respectively.
27 . The method of claim 18 , wherein the N coaxial coils and the at least some of the M coaxial coils are coplanar.
28 . The method of claim 27 , wherein the N coaxial coils and the at least some of the M coaxial coils are arranged 0-6 inches below the surface of the pedestal.
29 . The method of claim 28 , wherein the N coaxial coils and the at least some of the M coaxial coils are arranged approximately 1 inch below the surface of the pedestal.
30 . The method of claim 18 , further comprising depositing a tantalum/tantalum nitride barrier layer.