Crystalline orientation and overhang control in collision based RF plasmas

Patent metadata

Field	Value
Publication number	US-9611539-B2
Application number	US-201313749791-A
Country	US
Kind code	B2
Filing date	Jan 25, 2013
Priority date	Jan 27, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

Methods and apparatus for depositing a metal-containing layer on a substrate are provided herein. In some embodiments, a method of processing a substrate in a physical vapor deposition (PVD) chamber includes applying RF power at a VHF frequency to a target comprising a metal disposed in the PVD chamber above the substrate to form a plasma from a plasma-forming gas; optionally applying a DC power to the target to direct the plasma towards the target; sputtering metal atoms from the target using the plasma while maintaining a first pressure in the PVD chamber sufficient to ionize a predominant portion of the sputtered metal atoms; and controlling the plasma sheath voltage between the plasma and the substrate to form a metal-containing layer having a desired crystal structure and or desired morphology on feature structures.

First claim

The invention claimed is:

1. A method of processing a substrate in a physical vapor deposition (PVD) chamber, comprising:
applying RF power at a VHF frequency to a target comprising a metal disposed in the PVD chamber above the substrate to form a plasma from a plasma-forming gas;
sputtering metal atoms from the target using the plasma while maintaining a first pressure in the PVD chamber sufficient to ionize a predominant portion of the sputtered metal atoms; and
controlling a plasma sheath voltage between the plasma and the substrate to reduce an ion energy of the sputtered metal atoms to form a metal-containing layer having a crystal orientation that is predominantly a <002> crystal orientation relative to a <100> crystal orientation or to increase an ion energy of the sputtered metal atoms to form a metal-containing layer having a crystal orientation that is predominantly a <100> crystal orientation relative to a <002> crystal orientation.

2. The method of claim 1 , further comprising:
applying a DC power to the target to direct the plasma towards the target.

3. The method of claim 1 , wherein controlling the plasma sheath voltage further comprises:
controlling impedance between the substrate and ground.

4. The method of claim 1 , wherein controlling the plasma sheath voltage further comprises:
applying an RF energy to the substrate.

5. The method of claim 1 , wherein controlling the plasma sheath voltage further comprises:
controlling impedance between a process kit shield and ground, wherein the process kit shield is disposed about a central region of the PVD chamber, the central region disposed between the substrate and the target.

6. The method of claim 1 , wherein forming the metal-containing layer comprises modulating the plasma sheath voltage to form an amorphous metal-containing layer having a mixture of crystalline orientations.

7. A method of processing a substrate in a physical vapor deposition (PVD) chamber, the substrate having an opening formed in a first surface of the substrate and extending into the substrate towards an opposing second surface of the substrate, the method comprising:
applying RF power at a VHF frequency to a target comprising a metal disposed in the PVD chamber above the substrate to form a plasma from a plasma-forming gas;
sputtering metal atoms from the target using the plasma while maintaining a first pressure in the PVD chamber sufficient to ionize a predominant portion of the sputtered metal atoms; and
controlling a plasma sheath voltage between the plasma and the substrate to reduce an ion energy of the sputtered metal atoms to form a metal-containing layer having a crystal orientation that is predominantly a <002> crystal orientation relative to a <100> crystal orientation or to increase an ion energy of the sputtered metal atoms to form a metal-containing layer having a crystal orientation that is predominantly a <100> crystal orientation relative to a <002> crystal orientation, wherein the metal-containing layer is formed on one or more surfaces of the opening while limiting overhang of the metal-containing layer across a mouth of the opening by controlling the plasma sheath voltage between the plasma and the substrate.

8. The method of claim 7 , further comprising:
applying a DC power to the target to direct the plasma towards the target.

9. The method of claim 7 , wherein the opening has an aspect ratio of height to width of at least 5:1.

10. The method of claim 7 , wherein forming the metal-containing layer comprises modulating the plasma sheath voltage to form an amorphous metal-containing layer having a mixture of crystalline orientations.

11. The method of claim 7 , wherein controlling the plasma sheath voltage further comprises:
controlling impedance between the substrate and ground.

12. The method of claim 7 , wherein controlling the plasma sheath voltage further comprises:
applying an RF energy to the substrate.

13. The method of claim 7 , wherein controlling the plasma sheath voltage further comprises:
controlling impedance between a process kit shield and ground, wherein the process kit shield is disposed about a central region of the PVD chamber, the central region disposed between the substrate and the target.

Assignees

• Applied Materials Inc

Inventors

• Ge Zhenbin
• Ritchie Alan
• Allen Adolph Miller

Classifications

• C23C14/351

  using a magnetic field in close vicinity to the substrate · CPC title

• H01J37/3299

  Feedback systems · CPC title

• H01J37/32706

  Polarising the substrate · CPC title

• C23C14/35 Primary

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• C23C14/3492

  Variation of parameters during sputtering · CPC title