Controlled cleavage thin film separation process using a reusable substrate

• US 6,159,825 A
• Filed: 02/19/1998
• Issued: 12/12/2000
• Est. Priority Date: 05/12/1997
• Status: Expired due to Term

• Current Assignee: Silicon Genesis
• Original Assignee: Silicon Genesis
• Inventors: Henley, Francois J., Cheung, Nathan W.
• Primary Examiner(s): Mulpuri, Savitri
• Application Number:
  US09/026,113
• Time in Patent Office: 1,027 Days
• Field of Search: 438/459, 438/977, 438/514, 438/528, 438/455, 438/460, 438/476, 438/928, 438/959, 438/4, 148/33.1, 148/33.2
• US Class Current: 438/460
• CPC Class Codes: B81C 1/0038 Processes for creating layers of materials not provided for in groups B81C1/00357 - B81C1/00373
• CPC Class Codes: B81C 2201/0191 Transfer of a layer from a carrier wafer to a device wafer
• CPC Class Codes: B81C 2201/0192 by cleaving the carrier wafer
• CPC Class Codes: H01L 21/187 by direct bonding
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 21/2236 from or into a plasma phase
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/2658 of a molecular ion, e.g. decaborane
• CPC Class Codes: H01L 21/304 Mechanical treatment, e.g. grinding, polishing, cutting H01L21/30625 takes precedence
• CPC Class Codes: H01L 21/7624 using semiconductor on insulator [SOI] technology H01L21/76297 takes precedence; manufacture of integrated circuits on insulating substrates H01L21/84; silicon on sapphire [SOS] technology H01L21/86
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 21/7813 leaving a reusable substrate, e.g. epitaxial lift off
• CPC Class Codes: Y10S 117/915 Separating from substrate
• CPC Class Codes: Y10S 156/93 Semiconductive product delaminating, e.g. delaminating emiconductive wafer from underlayer
• CPC Class Codes: Y10S 438/974 Substrate surface preparation
• CPC Class Codes: Y10S 438/977 Thinning or removal of substrate
• CPC Class Codes: Y10T 156/11 Methods of delaminating, per se; i.e. , separating at bonding face
• CPC Class Codes: Y10T 156/1158 Electromagnetic radiation applied to work for delamination [e.g., microwave, uv, ir, etc.]
• CPC Class Codes: Y10T 156/19 Delaminating means
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank
• CPC Class Codes: Y10T 428/24893 : including particulate material
• CPC Class Codes: Y10T 428/249956 : Void-containing component is inorganic

Abstract

A technique for forming films of material (12) from a donor substrate (10). The technique has a step of introducing energetic particles (22) through a surface of a donor substrate (10) to a selected depth (20) underneath the surface, where the particles have a relatively high concentration to define donor substrate material (12) above the selected depth. Energy is provided to a selected region of the substrate to cleave a thin film of material from the donor substrate. Particles are introduced again into the donor substrate underneath a fresh surface of the donor substrate. A second thin film of material is then cleaved from the donor substrate.

Claims

1. A process for forming films of material from a substrate, said process comprising steps of:

introducing first particles through a surface of the substrate to a first selected depth underneath said surface, said first particles being a first concentration at said first selected depth to define a first layer of substrate material to be removed above said first selected depth and to define a first remaining portion of substrate material below said first selected depth;

freeing said first layer of substrate material from the substrate to form a cleaved surface on said substrate by applying energy to a selected region of said substrate thereby cleaving said first laver from said substrate in a controlled fashion;

introducing second particles through said cleaved surface of said substrate to a second selected depth underneath said cleaved surface, said second particles being at a second concentration at said second selected depth to define a second layer of substrate material to be removed above said second selected depth and to define a second remaining portion of substrate material below said second selected depth; and

freeing said second layer of substrate material from the substrate.

2. The process of claim 1 further comprising a step, prior to said step of freeing said first layer, of attaching said surface to a first stiffener.

3. The process of claim 2 further comprising a step, prior to said step of freeing said second layer, of attaching said surface to a second stiffener.

4. The process of claim 1 further comprising steps, after said step of freeing said second layer, of implanting particles and freeing additional layers.

5. The process of claim 1 further comprising a step of preparing said cleaved surface prior to said step of introducing second particles.

6. The process of claim 5 wherein said cleaved surface is prepared by polishing.

7. The process of claim 6 wherein said polishing comprises a chemical-mechanical polishing process.

8. The process of claim 5 wherein said cleaved surface is prepared by forming a planarized layer on said cleaved surface.

9. The process of claim 8 wherein said planarized layer comprises silicon oxide.

10. The process of claim 5 wherein said cleaved surface is prepared by cleaning.

11. The process of claim 1 wherein said substrate comprises single-crystal silicon.

12. The process of claim 11 wherein said substrate has a major crystallographic plane parallel to said surface of said substrate.

13. The process of claim 12 wherein said major crystallographic plane is a {100} plane.

14. The process of claim 12 wherein said major crystallographic plane is a {110} plane.

15. The process of claim 12 wherein said major crystallographic plane is a {111} plane.

16. A process for forming films of material from a single-crystal silicon substrate, said process comprising steps of:

introducing first hydrogen ions through a surface of the substrate to a first selected depth underneath said surface, said first hydrogen ions being at a first concentration at said first selected depth to define a first layer of substrate material to be removed above said first selected depth and to define a first remaining portion of substrate material below said first selected depth;

freeing said first layer of substrate material from the substrate to form a cleaved surface on said substrate by applying energy to a selected region of said substrate thereby cleaving said first layer from said substrate in a controlled fashion;

preparing the cleaved surface;

introducing hydrogen ions through said planarized layer to a second selected depth underneath said cleaved surface, said second hydrogen ions being at a second concentration at said second selected depth to define a second layer of substrate material to be removed above said second selected depth and to define a second remaining portion of substrate material below said second selected depth; and

freeing said second layer of substrate material from the substrate.

17. The process of claim 16 further comprising a step, prior to said step of freeing said first layer, of attaching said surface to a stiffener.