Physical vapor deposition methods and systems to form semiconductor films using counterbalance magnetic field generators

Abstract

Embodiments relate generally to semiconductor device fabrication and processes, and more particularly, to systems and methods that implement magnetic field generators configured to generate rotating magnetic fields to facilitate physical vapor deposition (“PVD”). In one embodiment, a system generates a first portion of a magnetic field adjacent a first circumferential portion of a substrate, and can generate a second portion of the magnetic field adjacent to a second circumferential portion of the substrate. The second circumferential portion is disposed at an endpoint of a diameter that passes through an axis of rotation to another endpoint of the diameter at which the first circumferential portion resides. The second peak magnitude can be less than the first peak magnitude. The system rotates the first and second portions of the magnetic fields to decompose a target material to form a plasma adjacent the substrate. The system forms a film upon the substrate

1 . A method for processing a semiconductor substrate comprising:
 generating a first portion of a magnetic field having a first peak magnitude of magnetic field strength adjacent a first circumferential portion of a semiconductor substrate;   generating a second portion of the magnetic field having a second peak magnitude of magnetic field strength adjacent to a second circumferential portion of the semiconductor substrate, the second circumferential portion being at an endpoint of a diameter passing through an axis of rotation to another endpoint of the diameter at which the first circumferential portion resides, the second peak magnitude being less than the first peak magnitude;   rotating the first portion of the magnetic field and the second portion of the magnetic field about the axis of rotation;   decomposing a target material to form a plasma at a plasma processing region adjacent the semiconductor substrate within a chamber; and   forming a film upon the semiconductor substrate.   
     
     
         2 . The method of  claim 1  wherein generating the second portion of the magnetic field comprises:
 generating a minimum magnitude of magnetic field strength disposed between the second peak magnitude and the axis of rotation. 
 
     
     
         3 . The method of  claim 1  wherein rotating the first portion of the magnetic field and the second portion of the magnetic field about the axis of rotation comprises:
 rotating a first magnetic field generator to rotate the first portion of the magnetic field about the axis of rotation; 
 rotating a second magnetic field generator to rotate the second portion of the magnetic field about the axis of rotation to counterbalance the first magnetic field generator, 
 wherein the first magnetic field generator and the second magnetic field generator generate the first portion of magnetic field and the second portion of the magnetic field, respectively. 
 
     
     
         4 . The method of  claim 1  wherein the first magnetic field generator comprises a different cross-sectional area in a plane of rotation than the second magnetic field generator. 
     
     
         5 . The method of  claim 1  wherein rotating the first portion of the magnetic field and the second portion of the magnetic field about the axis of rotation comprises:
 rotating a first magnetic field generator having a periphery coextensive with a first sector in a plane of rotation about the axis of rotation, the first magnetic field generator including permanent magnet material of different magnetic characteristics to produce a magnetic strength profile from the first peak magnitude of magnetic field strength to an intermediate magnitude of magnetic field strength adjacent the axis of rotation; and 
 rotating a second magnetic field generator having a periphery coextensive with a second sector in the plane of rotation, the second magnetic field generator including other permanent magnet material of different magnetic characteristics disposed near the second circumferential portion to produce another magnetic strength profile from the intermediate magnitude of magnetic field strength adjacent to the axis of rotation to the second peak magnitude of magnetic field strength adjacent the second circumferential portion. 
 
     
     
         6 . The method of  claim 5  wherein the first sector comprises two radial peripheral portions offset by an angle that is less than another angle that offsets two radial peripheral portions of the second sector. 
     
     
         7 . The method of  claim 1  further comprising:
 including supplemental magnetic elements; and 
 modifying the first peak magnitude of magnetic field strength as a function of the magnetic characteristics of the supplemental magnetic elements. 
 
     
     
         8 . The method of  claim 1  further comprising:
 igniting the plasma. 
 
     
     
         9 . The method of  claim 8  wherein igniting the plasma further comprises:
 rotating a magnetic structure configured to receive the first portion of the magnetic field and the second portion of the magnetic field, the magnetic structure including triangular-shaped surface areas oriented parallel to a plane of rotation, 
 wherein a group of vertices of the triangular-shaped surface areas each lies on a line perpendicular to a radial line extending from the axis of rotation. 
 
     
     
         10 . The method of  claim 1  wherein generating the first portion of the magnetic field comprises:
 generating magnetic flux in a direction substantially circumferential relative to the axis of rotation, the magnetic flux extending between a first group of magnetic elements disposed on two principal radial lines and a second group of magnetic elements disposed between the two principal radial lines; and 
 generating magnetic flux in a direction substantially radial relative to the axis of rotation, the magnetic flux extending between a third group of magnetic elements disposed at a principal distal line coupled to the two principal radial lines and the second group of magnetic elements disposed between the two principal radial lines, 
 wherein the two principal radial lines and the principal distal line constitute portions of a periphery of a first magnetic field generator. 
 
     
     
         11 . The method of  claim 10  wherein generating the second portion of the magnetic field comprises:
 generating magnetic flux in another direction substantially circumferential relative to the axis of rotation, the magnetic flux extending between a fourth group of magnetic elements disposed on two secondary radial lines and a fifth group of magnetic elements disposed between the two secondary radial lines; and 
 generating magnetic flux in another direction substantially radial relative to the axis of rotation, the magnetic flux extending between a sixth group of magnetic elements disposed at a secondary distal line coupled to the two secondary radial lines and the fifth group of magnetic elements disposed between the two secondary radial lines, 
 wherein the secondary two radial lines and the secondary distal line constitute portions of a periphery of a second magnetic field generator. 
 
     
     
         12 . The method of  claim 1  wherein decomposing the target materials comprises:
 sputtering a chalcogenide material. 
 
     
     
         13 . The method of  claim 1  wherein modifying the non-metal film comprises:
 depositing one or more layers including germanium, antimony and tellurium (“GST”). 
 
     
     
         14 . The method of  claim 1  wherein decomposing the one or more non-metal target materials comprises:
 sputtering a material including germanium, antimony and tellurium (“GST”) in the form: Ge 2 Sb 2 Te 5 . 
 
     
     
         15 . The method of  claim 1  furthering comprising:
 biasing a wafer chuck configured to support the semiconductor substrate. 
 
     
     
         16 . The method of  claim 15  wherein biasing the wafer chuck comprising:
 generating a radio-frequency (“RF”) voltage signal to supply RF power; 
 matching impedance between the plasma including germanium, antimony and tellurium (“GST”) and a source generating the RF voltage; and 
 controlling the generation of the RF voltage to facilitate generation of the plasma to modify the non-metal film to deposit one or more layers of GST. 
 
     
     
         17 - 28 . (canceled)