Semiconductor structures formed on substrates and methods of manufacturing the same

• US 20070020884A1
• Filed: 07/25/2005
• Published: 01/25/2007
• Est. Priority Date: 07/25/2005
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Fairchild Semiconductor Corporation (ON Semiconductor Corporation)
• Inventors: Wang, Qi, Li, Minhua, Rice, Jeffrey
• Granted Patent: US 7,635,637 B2
• Time in Patent Office: Days
• US Class Current: 438/455
• 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 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate

Abstract

Processes used to transfer semiconductor structures from an initial substrate to a base substrate include bonding the initial substrate with a silicon dioxide layer to a doped silicon structure weakened sufficiently by hydrogen implantation for cleaving. After cleaving, a doped silicon layer remains, burying the silicon dioxide layer between the doped silicon layer and the initial substrate. Semiconductor structures are formed within/on an epitaxial layer disposed on the doped silicon layer forming an intermediate semiconductor structure. A process handle is temporarily bonded to the semiconductor structures for support. The initial substrate is thinned and removed by a mechanical thinning process followed by chemical etching using the buried silicon dioxide layer as an etch stop. The silicon dioxide layer is chemically removed from the doped silicon layer. A base substrate is formed on the doped silicon layer. The process handle is removed leaving the semiconductor structures disposed on the base substrate.

Claims

1. A method of transferring semiconductor structures from an initial substrate to a base substrate, the method comprising:

providing an initial substrate with an etch stop layer;

providing a doped silicon layer on the etch stop layer;

forming semiconductor structures on the doped silicon layer;

wherein the semiconductor structures, doped silicon layer, etch stop layer, and initial substrate form a semiconductor process;

supporting the semiconductor process with a removable support structure;

removing the initial substrate using a substrate removal process that removes the initial substrate up to the etch stop layer;

removing the etch stop layer with a chemical etching process; and

depositing a substrate material on the doped silicon layer to form a base substrate.

2. The method of claim 1, wherein forming semiconductor structures on the doped silicon layer comprises forming an epitaxial layer on the doped silicon layer.

3. The method of claim 1, wherein providing an initial substrate comprises forming the etch stop layer on the initial substrate having a thickness of between about 1 um and 2 um.

4. The method of claim 3, wherein the etch stop layer comprises silicon dioxide.

5. The method of claim 1, wherein providing a doped silicon layer comprises providing hydrogen atoms to a region of a doped silicon material, wherein the region has a sufficient concentration of hydrogen atoms to form a cleavable region.

6. The method of claim 5, wherein the providing hydrogen atoms comprises hydrogen ion implantation.

7. The method of claim 6, wherein the hydrogen ion implantation comprises implanting hydrogen ions with a implantation potential of about 170 kev.

8. The method of claim 1, wherein providing the doped silicon layer comprises bonding a doped silicon material to the etch stop layer.

9. The method of claim 8, wherein providing the doped silicon layer comprises cleaving the doped silicon material to leave a layer of the doped silicon material disposed on the etch stop layer.

10. The method of claim 9, wherein the cleaving comprises implanting hydrogen into a region of the doped silicon material and annealing the doped silicon material to fracture the doped silicon material along the hydrogen implanted region.

11. The method of claim 1, wherein supporting the body with the removable support structure comprises temporarily bonding the removable support structure to the semiconductor structures.

12. The method of claim 1, wherein removing the initial substrate comprises grinding a portion of the initial substrate away to a predetermined thickness.

13. The method of claim 12, further comprising chemically etching the initial substrate from the etch stop layer.

14. The method of claim 1, wherein removing the etch stop layer comprises chemically etching the etch stop layer with a HF solution.

15. A method of forming semiconductor structures on a metal substrate, the method comprising:

providing a initial substrate with an exposed silicon dioxide etch stop layer;

bonding a hydrogen implanted doped silicon material to the silicon dioxide etch stop layer;

determining a region of the doped silicon material sufficiently weakened by the hydrogen to allow cleaving the doped silicon material along the region;

cleaving the doped silicon material along the region leaving a doped silicon layer bonded to the silicon dioxide layer;

forming semiconductor structures on the doped silicon layer;

supporting the semiconductor structures, silicon dioxide layer, and initial substrate with a supporting device;

removing the initial substrate;

removing the silicon dioxide layer; and

providing a sufficient amount of metal to the doped silicon layer to form a metal substrate.

16. The method of claim 15, wherein forming semiconductor structures on the doped silicon layer comprises forming an epitaxial layer on the doped silicon layer.

17. The method of claim 15, wherein cleaving the doped silicon material comprises annealing the region of the doped silicon structure sufficiently to separate the doped silicon layer from the doped silicon material.

18. The method of claim 17, wherein annealing the region of the doped silicon structure comprises heating the region of the doped silicon structure to a temperature of between about 200 to 300 degrees Celsius for about 5 to 10 hours.

19. The method of claim 18, wherein heating the region of the doped silicon structure comprises heating the region of the doped silicon structure to 450 degrees Celsius for about 15 minutes.

20. The method of claim 15, wherein supporting the semiconductor structures, the silicon dioxide layer, and the initial substrate comprises temporarily bonding the supporting device to the semiconductor structures.

21. The method of claim 15, wherein removing the initial substrate comprises grinding the initial substrate to a predefined thickness.

22. The method of claim 15, wherein removing the initial substrate comprises chemically etching the initial substrate from the silicon dioxide etch stop layer.

23. The method of claim 15, wherein removing the initial substrate comprises forming a soluble material of SiO₂(OH)²⁻

.

24. The method of claim 15, wherein providing a sufficient amount of metal comprises electroplating the metal layer to the doped silicon layer.

25. The method of claim 24, wherein the metal layer comprises copper.

26-31. -31. (canceled)