Pressurized microbubble thin film separation process using a reusable substrate

• US 6,146,979 A
• Filed: 02/19/1998
• Issued: 11/14/2000
• 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): Whitehead, Jr., Carl
• Assistant Examiner(s): VOCKRODT, JEFF B
• Application Number:
  US09/026,032
• Time in Patent Office: 999 Days
• Field of Search: 438/455, 438/458, 438/464
• US Class Current: 438/458
• 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 (14) from a donor substrate (10). The technique has a step of introducing gas-forming particles (12) through a surface of a donor substrate (10) to a selected depth underneath the surface. The gas-forming particles form a layer of microbubbles within the substrate. A global heat treatment of the substrate then creates a pressure effect to separate a thin film of material from the substrate. Additional gas-forming particles are introduced into the donor substrate and a second thin film of material is then separated from the donor substrate. In a specific embodiment, the gas-forming particles are implanted using a plasma immersion ion implantation method.

Claims

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

introducing first gas-forming particles through a surface of the substrate to a first selected depth beyond said surface, said first gas-forming particles forming a layer of microbubbles to define a first layer of substrate material to be removed between about said first selected depth and said surface, and to define a first remaining portion of substrate material;

connecting the surface to a first stiffener to form a first assembly,

heating said first assembly to free said first layer of substrate material from the substrate to form a separated surface on said substrate, said surface having microblister damage;

planarizing said microblister damaged separated surface with a layer of silicon oxide;

introducing second gas-forming particles through said separated surface of said substrate to a second selected depth beyond said separated surface, said second gas-forming particles forming a second layer of microbubbles to define a second layer of substrate material to be removed between about said second selected depth and said separated surface, and to define a second remaining portion of substrate material;

connecting the separated surface to a second stiffener to form a second assembly; and

heating said second assembly to free said second layer of substrate material from the substrate.

2. The process of claim 1 wherein said second gas-forming particles are hydrogen ions.

3. The process of claim 1 wherein said second gas-forming particles are helium ions.

4. The process of claim 1 wherein said oxidized surface is prepared by polishing.

5. The process of claim 4 wherein said polishing comprises a chemical-mechanical polishing process.

6. The process of claim 1 wherein said substrate comprises single-crystal silicon with a principal crystallographic plane substantially parallel to the surface.

7. The process of claim 6 wherein said principal crystallographic plane is a {100} plane.

8. The process of claim 1 wherein said step of introducing first gas-forming particles includes plasma immersion ion implantation.

9. A process for forming films of material from a reusable silicon wafer, the silicon wafer having a {100} crystallographic plane substantially parallel to a surface of the silicon wafer, said process comprising steps of:

introducing first gas-forming particles trough the surface of the silicon wafer to a first selected depth underneath said surface, said first gas-forming particles forming a layer of microbubbles to define a first layer of silicon material to be removed above said first selected depth and to define a first remaining portion of wafer material below said first selected depth;

connecting the surface to a first stiffener to form a first assembly;

heating said first assembly to free said first layer of silicon material from the silicon wafer to form a separated surface on said silicon wafer, said separated surface having microblister damage;

forming a bonding layer on the separated surface, including providing a silicon oxide layer to planarize sad microblister damaged separated surface;

introducing second gas-forming particles through said separated surface of said silicon wafer to a second selected depth underneath said separated surface, said second gas-forming particles forming a second layer of microbubbles to define a second layer of silicon material to be removed above said second selected depth and to define a second remaining portion of silicon material below said second selected depth; and

connecting the bonding layer to a second stiffener to form a second assembly; and

heating said second assembly to free said second layer of silicon material from the silicon wafer.

10. The method of claim 9 wherein the bonding layer is formed on the separated surface prior to the step of introducing the second gas-forming particles.