Method of forming phase change memory devices in a pulsed DC deposition chamber

• US 7,888,240 B2
• Filed: 10/10/2007
• Issued: 02/15/2011
• Est. Priority Date: 10/10/2006
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Lee, Sean Jong, Lim, Chong W., Chang, Kuo-Wei, Hamamjy, Roger
• Primary Examiner(s): Smith; Bradley K
• Assistant Examiner(s): Movva; Amar
• Application Number:
  US11/974,168
• Publication Number:
  US 20080102560A1
• Time in Patent Office: 1,224 Days
• Field of Search: 438/469, 257/E29.17
• US Class Current: 438/469
• CPC Class Codes: C23C 14/06 characterised by the coating material C23C14/0021 , C23C14/04 take precedence
• CPC Class Codes: C23C 14/0623 Sulfides, selenides or tellurides
• CPC Class Codes: C23C 14/3435 Applying energy to the substrate during sputtering
• CPC Class Codes: H10B 63/24 of the Ovonic threshold switching type
• CPC Class Codes: H10N 70/026 by physical vapor deposition, e.g. sputtering
• CPC Class Codes: H10N 70/066 by filling of openings, e.g. damascene method
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/8828 Tellurides, e.g. GeSbTe

Abstract

A phase change memory including an ovonic threshold switch is formed using a pulsed direct current (DC) deposition chamber using pulsed DC. Pulsed DC is used to deposit a chalcogenide film. Pulsed DC may be also used to deposit a carbon film.

Claims

1. A method, comprising:

providing a deposition chamber;

moving a substrate into the deposition chamber;

forming a chalcogenide layer directly or indirectly on the substrate in the deposition chamber; and

depositing a carbon film directly or indirectly on the substrate using a 350 kHz direct current pulser.

2. The method of claim 1, wherein a pulsed direct current device is operated at a frequency of about 100 kHz to form at least a portion of the chalcogenide layer.

4. The method of claim 1, further comprising:

forming a pair of conductive layers in the deposition chamber such that the chalcogenide layer is between the conductive layers so as to form an ovonic threshold switch.

5. The method of claim 1, further comprising:

using an electrostatic chuck in the deposition chamber during the formation of at least a portion of the chalcogenide layer.

6. The method of claim 1, further comprising:

after moving the substrate into the deposition chamber, holding the substrate using a clamp ring, and the clamp ring comprises ceramic.

7. The method of claim 1, further comprising:

providing a cluster tool, the cluster tool including a plurality of reaction chamber and a robot, one of the reaction chambers is the deposition chamber; and

wherein the substrate is moved into the deposition chamber using the robot.

8. The method of claim 1, wherein forming the chalcogenide layer includes forming a self-ionization plasma.

9. The method of claim 8, further comprising:

maintaining a chamber pressure of the deposition chamber below 3 milliTorr during the formation of the self-ionization plasma; and

delivering argon gas into the deposition chamber while maintaining the chamber pressure.

3. A method, comprising:

providing a deposition chamber;

moving a substrate into the deposition chamber;

forming a chalcogenide layer directly or indirectly on the substrate in the deposition chamber using a pulsed direct current device;

operating the pulsed direct current device at a first frequency to form at least a portion of the chalcogenide layer; and

operating the pulsed direct current device at a second frequency that is greater than the first frequency to deposit a carbon layer, wherein the second frequency is about 350 kHz.

10. A method, comprising:

providing a pulsed direct current deposition chamber;

forming at least a portion of a phase change memory element including a chalcogenide film using the pulsed direct current deposition chamber; and

depositing a carbon film of the phase change memory element in the pulsed direct current deposition chamber using a 350 kHz direct current pulser.

11. The method of claim 10, further comprising:

depositing the chalcogenide film using a 100 kHz direct current pulser.

12. The method of claim 10, further comprising:

using an electrostatic chuck in the pulsed direct current deposition chamber while the forming of the at least the portion of the phase change memory element.

13. The method of claim 10, further comprising:

using a deposition chamber with a ceramic clamp ring to form another portion of the phase change memory element.

14. A method of forming a memory device, comprising:

providing a cluster tool having a plurality of reaction chambers;

forming a portion of a phase change memory device in one of the reaction chambers using a direct current pulser, the portion of the phase change memory device comprising chalcogenide;

depositing a carbon layer of the phase change memory device in one of the reaction chambers using a 350 kHz direct current conductive pulser.

15. The method of claim 14, wherein the portion of the phase change memory device and the carbon layer are formed in the same reaction chamber of the cluster tool.

16. The method of claim 14, wherein the portion of the phase change memory device and the carbon layer are formed using substantially different pulse frequencies.

17. The method of claim 16, wherein the portion of the phase change memory device comprising chalcogenide is formed using the direct current pulser operating at a frequency that is less than 350 kHz.

18. The method of claim 17, further comprising:

providing a pulser that is the direct current pulser and the direct current conductive pulser.

19. The method of claim 14, wherein the carbon layer is a carbon film.