Wafer thinning using magnetic mirror plasma

• US 20030186513A1
• Filed: 03/18/2003
• Published: 10/02/2003
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: iFire Technology Inc.
• Original Assignee: iFire Technology Inc.
• Inventors: Turner, Terry R., Banks, Richard M., Spain, James D.
• Granted Patent: US 6,794,272 B2
• Time in Patent Office: Days
• US Class Current: 438/462
• CPC Class Codes: H01L 21/304 Mechanical treatment, e.g. grinding, polishing, cutting H01L21/30625 takes precedence
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/76898 formed through a semiconductor substrate
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate

Abstract

A method for manufacturing integrated circuits uses an atmospheric magnetic mirror plasma etching apparatus to thin a semiconductor wafer. In addition the process may, while thinning, both segregate and expose through-die vias for an integrated circuit chip. To segregate, the wafer may be partially diced. Then, the wafer may be tape laminated. Next, the backside of the wafer may be etched. As the backside material is removed, the partial dicing and through-die vias may be exposed. As such, the method reduced handling steps and increases yield. Furthermore, the method may be used in association with wafer level processing and flip chip with bump manufacturing.

Claims

1. A method for segregating an integrated circuitry chip from a wafer, the method comprising:

circumscribing the integrated circuitry chip with at least one recess, said at least one recess having a particular depth extending into the wafer from a front side of the wafer; and

etching bulk wafer material from a back side of the wafer to achieve a particular thickness of the wafer, said thickness of the wafer being at most equal to said particular depth;

wherein said etching step comprises use of a magnetic mirror plasma.

2. The method of claim 1 wherein said step of removing bulk wafer material comprises etching at atmospheric pressure.

3. The method of claim 1 wherein said particular depth is at most equal to a depth of at least one integrated circuitry feature.

4. The method of claim 3 wherein said at least one integrated circuitry feature is a via.

5. The method of claim 1, the method further comprising the step of:

forming a recess extending from the front side of the wafer, the recess having a depth at least equal to said particular depth.

6. The method of claim 1, the method further comprising the step of removing through mechanical grinding a portion of the bulk wafer material from the back side of the wafer.

7. A system for segregating an integrated circuitry chip from a wafer, the system comprising:

means for circumscribing the integrated circuitry chip with at least one recess on a front side of the wafer, said at least one recess having a particular depth; and

etching means for removing bulk wafer material from a back side of the wafer to achieve a particular thickness of the wafer, said thickness of the wafer being at most equal to said particular depth;

wherein said etching means comprises a magnetic mirror plasma.

8. The system of claim 7 wherein said etching means comprises an atmospheric plasma etcher.

9. The system of claim 7 wherein said particular depth is at most equal to a depth of at least one integrated circuitry feature.

10. The system of claim 7, further comprising means for laminating said front side of the wafer.

11. The system of claim 7, further comprising means for transferring the integrated circuitry chip.

12. The system of claim 7, the system further comprising etching means for removing a residue material from said back side of the wafer.

13. The system of claim 7, the system further comprising means for forming a recess extending from the front side of the wafer, the recess having a depth at least equal to said particular depth.

14. A method for segregating an integrated circuitry chip from a wafer and exposing at least one integrated circuitry feature, the at least one integrated circuitry feature having a depth extending from a front side of the wafer, the method comprising:

circumscribing the integrated circuitry chip with at least one recess on the front side of the wafer, said at least one recess having a particular depth;

etching bulk wafer material from a back side of the wafer to achieve a particular thickness of the wafer, said thickness of the wafer being at most equal to said depth of the at least one integrated circuitry feature and at most equal to said particular depth;

wherein said etching step comprises use of a magnetic mirror plasma.

15. The method of claim 14 wherein said step of etching bulk wafer material comprises the step of etching at atmospheric pressure.

16. The method of claim 14 wherein said step of etching bulk wafer material comprises the step of etching with a plasma at atmospheric pressure.

17. The method of claim 14, further comprising the step of controlling said magnetic mirror plasma using a magnetic mirror field and an orthogonally rotating electric field.

18. The method of claim 14, further comprising the steps of:

controlling said magnetic mirror plasma using a magnetic mirror field and an orthogonally rotating electric field;

wherein the magnetic mirror plasma chamber is constructed of essentially non-ferrous materials.

19. The method of claim 14, further comprising the steps of:

controlling said magnetic mirror plasma using a magnetic mirror field and an orthogonally rotating electric field;

wherein the magnetic mirror plasma chamber is constructed of essentially non-ferrous materials;

wherein the plasma ions are created remote to the plasma chamber.

20. The system of claim 14 wherein said plasma chamber is constructed of essentially non-ferrous materials.