Semiconductor-on-insulator silicon wafer

• US 7,217,636 B1
• Filed: 02/09/2005
• Issued: 05/15/2007
• Est. Priority Date: 02/09/2005
• Status: Expired due to Fees

• Current Assignee: IQE, PLC
• Original Assignee: Translucent Inc. (Silex Systems Ltd.)
• Inventors: Atanackovic, Petar B.
• Primary Examiner(s): HOANG, QUOC DINH
• Application Number:
  US11/054,579
• Time in Patent Office: 825 Days
• Field of Search: 438/311, 438/455, 438/459, 438/464, 438/478, 438/479, 438/517, 438/149, 257/347
• US Class Current: 438/455
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

A method of fabricating a semiconductor-on-insulator semiconductor wafer is described that includes providing first and second semiconductor substrates. A first insulating layer is formed on the first substrate with a first predetermined stress and a second insulating layer is formed on the second substrate with a second predetermined stress different than the first predetermined stress. The first insulating layer is bonded to the second insulating layer to form a composite insulating layer bonding the first substrate to the second substrate and a portion of the one substrate is removed to form a thin crystalline active layer on the composite insulating layer. The first and second insulating layers are formed with different stresses to provide a desired composite stress, which can be any stress from compressive to unstressed to tensile, depending upon the desired application.

Claims

1. A method of fabricating a semiconductor-on-insulator semiconductor wafer comprising the steps of:

providing a first semiconductor substrate;

selecting a first material from a group consisting of SiO₂, Si₃N₄, poly Si, and combinations thereof;

forming a first insulating layer of the first material on a surface of the first semiconductor substrate, forming the first insulating layer with a first predetermined stress;

providing a second semiconductor substrate;

selecting a second material from a group consisting of TiSi₂, CoSi₂, TaSi₂, rare earth oxides, rare earth nitrides, rare earth phosphides, rare earth silicides, and combinations thereof;

forming a second layer of the second material on a surface of the second semiconductor substrate, forming the second layer with a second predetermined stress different than the first predetermined stress;

bonding the first insulating layer to the second layer to form a composite insulating layer bonding the first semiconductor substrate to the second semiconductor substrate; and

removing a portion of one of the first semiconductor substrate and the second semiconductor substrate to form a thin crystalline active layer on the composite insulating layer.

2. A method as claimed in claim 1 wherein the steps of selecting a first material and selecting a second material include selecting a method of formation of each of the first insulating layer and the second layer from the selected materials.

3. A method as claimed in claim 2 wherein the steps of selecting a method of formation for each of the first insulating layer and the second layer each include selecting a method of formation from a group of processes including thermal, CVD, TEOS, plasma, sputtered, LPCVD, and commercial CMOS.

4. A method as claimed in claim 2 wherein the steps of forming the first insulating layer with the first predetermined stress and forming the second layer with the second predetermined stress each include selecting a layer thickness that provides the predetermined stress.

5. A method as claimed in claim 1 wherein the step of providing the second semiconductor substrate includes providing a crystalline germanium substrate.

6. A method as claimed in claim 5 wherein the step of removing a portion of one of the first semiconductor substrate and the second semiconductor substrate includes removing a portion of the crystalline germanium substrate to form a thin crystalline active germanium layer.

7. A method of fabricating a semiconductor-on-insulator semiconductor wafer comprising the steps of:

providing a first silicon substrate;

forming a layer including a first material selected from a group consisting of SiO₂, Si₃N₄, poly Si, and combinations thereof on a surface of the first silicon substrate, forming the layer of first material with a first predetermined stress;

providing a second silicon substrate;

forming a layer including a second material selected from a group consisting of TiSi₂, CoSi₂, TaSi₂, rare earth oxides, rare earth nitrides, rare earth phosphides, rare earth silicides, and combinations thereof on a surface of the second silicon substrate, and forming the layer of second material with a second predetermined stress different than the first predetermined stress;

bonding the layer of first material to the layer of second material using Van der Waal'"'"'s bonding to form a composite insulating layer bonding the first silicon substrate to the second silicon substrate; and

removing a portion of the second silicon substrate to form a thin crystalline active layer on the composite insulating layer.

8. A method as claimed in claim 7 wherein the steps of providing the first silicon substrate and providing the second silicon substrate include providing a high quality silicon substrate for the second silicon substrate and providing a lower quality silicon substrate for the first silicon substrate.

9. A method as claimed in claim 7 wherein the steps of forming a layer of first material and forming a layer of second material each include selecting a method of formation of the layer of first material and the layer of second material from a group of processes including thermal, CVD, TEOS, plasma, sputtered, LPCVD, and commercial CMOS.

10. A method as claimed in claim 7 wherein the steps of forming the layer of first material with the first predetermined stress and forming the layer of second material with the second predetermined stress each include selecting a layer thickness that provides the predetermined stress.

11. A method as claimed in claim 7 wherein the steps of forming the layer of first material with the first predetermined stress includes forming the layer of first material with a compressive stress and forming the layer of second material with the second predetermined stress includes forming the layer of second material with a tensile stress substantially equal to the compressive stress.