Wafer bonding activated by ion implantation

• US 7,939,424 B2
• Filed: 09/17/2008
• Issued: 05/10/2011
• Est. Priority Date: 09/21/2007
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated)
• Inventors: Erokhin, Yuri, Nunan, Peter, Sullivan, Paul, Walther, Steven R.
• Primary Examiner(s): EVERHART, CARIDAD
• Application Number:
  US12/212,386
• Publication Number:
  US 20090081848A1
• Time in Patent Office: 965 Days
• Field of Search: 438/799, 438/458, 257/E21.002, 257/E21.001, 257/E21.147, 257/E21.088, 250/492.21
• US Class Current: 438/458
• CPC Class Codes: H01J 2237/201 for mounting multiple objects
• CPC Class Codes: H01J 2237/202 Movement
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the objects or the material; Means for adjusting diaphragms or lenses associated with the support introducing the objects H01J37/18
• CPC Class Codes: H01J 37/3171 for ion implantation plasma immersion ion implantation H01J37/32412
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/26566 of a cluster, e.g. using a gas cluster ion beam
• CPC Class Codes: H01L 21/2658 of a molecular ion, e.g. decaborane
• CPC Class Codes: H01L 21/26593 at a temperature lower than room temperature
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H01L 2924/30105 Capacitance

Abstract

A method for wafer bonding two substrates activated by ion implantation is disclosed. An in situ ion bonding chamber allows ion activation and bonding to occur within an existing process tool utilized in a manufacturing process line. Ion activation of at least one of the substrates is performed at low implant energies to ensure that the wafer material below the thin surface layers remains unaffected by the ion activation.

Claims

1. A method for in situ bonding at least two substrates together comprising:

placing the substrates into an ion target chamber;

exposing at least one surface of a first of said at least two substrates to an ion beam to reduce the surface species of the at least one surface in preparation for bonding to a second of said at least two substrates;

aligning the first and second substrates at a desired temperature within said ion target chamber;

placing the exposed surface of said first substrate together and in contact with a surface of said second substrate to form bonded substrates; and

raising the temperature of said second chamber to initiate a post bond split layer of said bonded substrates.

2. The method of claim 1 further comprising removing the bonded substrates from said ion target chamber.

3. The method of claim 1 wherein said first substrate is a silicon wafer having a silicon dioxide layer.

4. The method of claim 1 further comprising exposing at least one surface of said second substrate to an ion beam to reduce the surface species of the at least one surface in preparation for bonding to said first substrate.

5. The method of claim 1 wherein said at least one surface of the first substrate is exposed to the ion beam having implant energies between 0.2 keV and 5 keV.

6. The method of claim 1 further comprising tilting the first substrate at an angle with respect to said ion beam when the first substrate is exposed to said ion beam.

7. The method of claim 1 further comprising creating a cleaved layer from said bonded substrates.

8. The method of claim 7 further comprising separating said post bond split layer from said cleaved layer.

9. A method for bonding at least two substrates together comprising:

placing the substrates into a first chamber;

exposing at least one surface of a first of said at least two substrates to an ion beam to reduce the surface species of the at least one surface in preparation for bonding to a second of said at least two substrates;

aligning the first and second substrates at a desired temperature within said first chamber;

moving said first and second substrates from said first chamber to a second chamber, said first and second chamber maintaining a vacuum environment therebetween;

placing the exposed surface of said first substrate together and in contact with a surface of said second substrate within said second chamber to form bonded substrates.

10. The method of claim 9 further comprising tilting the first substrate at an angle with respect to said ion beam when the first substrate is exposed to said ion beam.

11. The method of claim 9 further comprising raising the temperature of said second chamber to initiate a post bond split layer of said bonded substrates.

12. The method of claim 11 further comprising creating a cleaved layer from said bonded substrates.

13. The method of claim 12 further comprising separating said post bond split layer from said cleaved layer.

14. An ion implanter processing system comprising:

an ion source chamber configured to receive a feed gas and generate ions having a particular energy and mass, said ion source chamber having an aperture through which said ions are extracted;

a target chamber positioned downstream of said ion source configured to receive said ion beam;

a first chuck assembly positioned within said target chamber, said first chuck assembly configured to receive a first substrate aligned with said ion beam;

a second chuck assembly positioned within said target chamber, said second chuck assembly configured to receive a second substrate;

said ion beam having a particular implant energy such that ions activate a surface layer of said first substrate; and

a second chamber connected to said target chamber, said target chamber and said second chamber maintaining a vacuum environment therebetween, and wherein said first chuck assembly and said second chuck assembly are configured to move between said target chamber and said second chamber and are further configured-to position said first and second substrates in contact with one another within said second chamber.