Dry etching process and method for manufacturing magnetic memory device

• US 20070026681A1
• Filed: 08/26/2004
• Published: 02/01/2007
• Est. Priority Date: 08/27/2003
• Status: Active Grant

• Current Assignee: Seiji Samukawa, Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Samukawa, Seiji, Tatsumi, Tetsuya, Shiraiwa, Toshiaki
• Granted Patent: US 7,473,646 B2
• Time in Patent Office: Days
• US Class Current: 438/709
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/01 Manufacture or treatment

Abstract

Provision of a process capable of preferably etching particularly PtMn used for a pin layer of an MRAM is an object: a dry etching method for performing dry etching on a layer including platinum and/or manganese by using pulse plasma and a production method of an MRAM, wherein the dry etching method is applied to processing of the pin layer. The MRAM is configured to have a memory portion comprising a magnetic memory element composed of tunnel magnetoresistive effect element formed by stacking a magnetic fixed layer having a fixed magnetization direction, a tunnel barrier layer and a magnetic layer capable of changing the magnetization direction.

Claims

1. A dry etching method for performing dry etching on a layer including platinum and/or manganese by using pulse plasma.

2. A dry etching method as set forth in claim 1, wherein on/off time of said pulse plasma is 10 to 100 μ

s.

3. A dry etching method as set forth in claim 1, wherein a plasma source capable of turning on/off generation of said plasma is used.

4. A dry etching method as set forth in claim 3, wherein electron cyclotron resonance (ECR), inductively-coupled plasma (ICP) or a helicon wave is used as said plasma source.

5. A dry etching method as set forth in claim 1, wherein a gas capable of generating negative ions is used as an etching gas.

6. A dry etching method as set forth in claim 5, wherein at least one kind of gases including at least chloride atom or a mixed gas thereof is used as said etching gas.

7. A dry etching method as set forth in claim 1, wherein plasma processing for preventing corrosion by a gas including at least hydrogen atom is added.

8. A dry etching method as set forth in claim 7, wherein at least one kind of gases including at least hydrogen atom, a mixed gas thereof, or a mixed gas obtained by adding a rare gas to any one of them is used as said gas.

9. A production method of a magnetic memory device having a memory portion comprising a magnetic memory element composed of a tunnel magnetoresistive effect element formed by stacking a magnetic fixed layer having a fixed magnetization direction, a tunnel barrier layer and a magnetic layer capable of changing the magnetization direction, wherein

when at least a part of said magnetization fixed layer is composed of a layer including platinum and/or manganese, the layer is formed by dry etching by pulse plasma.

10. A production method of a magnetic memory device as set forth in claim 9, wherein on/off time of said pulse plasma is 10 to 100 μ

s.

11. A production method of a magnetic memory device as set forth in claim 9, wherein a plasma source capable of turning on/off generation of said plasma is used.

12. A production method of a magnetic memory device as set forth in claim 11, wherein electron cyclotron resonance (ECR), inductively-coupled plasma (ICP) or a helicon wave is used as said plasma source.

13. A production method of a magnetic memory device as set forth in claim 9, wherein a gas capable of generating negative ions is used as an etching gas.

14. A production method of a magnetic memory device as set forth in claim 13, wherein at least one kind of gases including at least chloride atom or a mixed gas thereof is used as said etching gas.

15. A production method of a magnetic memory device as set forth in claim 9, wherein plasma processing for preventing corrosion by a gas including at least hydrogen atom is added.

16. A production method of a magnetic memory device as set forth in claim 15, wherein at least one kind of gases including at least hydrogen atom, a mixed gas thereof, or a mixed gas obtained by adding a rare gas to any one of them is used as said gas.

17. A production method of a magnetic memory device as set forth in claim 9, for producing a magnetic memory device configured that an insulation layer or a conductive layer is sandwiched by said magnetization fixing layer and said magnetic layer, information is written by magnetizing said magnetic layer in a predetermined direction by a magnetic field induced by flowing currents respectively to a bit line and word line provided to an upper surface and lower surface of said memory element, and the written information is read by a tunnel magnetoresistive effect via said tunnel barrier layer.