METHOD OF FABRICATING SILICON/DIELECTRIC MULTI-LAYER SEMICONDUCTOR STRUCTURES USING LAYER TRANSFER TECHNOLOGY AND ALSO A THREE-DIMENSIONAL MULTI-LAYER SEMICONDUCTOR DEVICE AND STACKED LAYER TYPE IMAGE SENSOR USING THE SAME METHOD, AND A METHOD OF MANUFACTURING A THREE-DIMENSIONAL MULTI-LAYER SEMICONDUCTOR DEVICE AND THE STACK TYPE IMAGE SENSOR

• US 20080160723A1
• Filed: 03/11/2008
• Published: 07/03/2008
• Est. Priority Date: 09/13/2005
• Status: Active Grant

• Current Assignee: Hanvision Co., Ltd., Lumiense Photonics, Inc.
• Original Assignee: Hanvision Co., Ltd., Lumiense Photonics, Inc.
• Inventors: Hannebauer, Robert Steven
• Granted Patent: US 7,977,145 B2
• Time in Patent Office: Days
• US Class Current: 438/455
• CPC Class Codes: H01L 21/30 Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 manufacture of electrodes thereon H01L21/28
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 27/1464 Back illuminated imager structures
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon

Abstract

Fabrication of a three-dimensional semiconductor structure is provided by the present disclosure. A buffer oxide film, a nitride film, and an ONO dielectric layer are formed on a handle wafer. A semiconductor layer and an oxide film are formed on a donor wafer, which is turned over and is then bonded to a handle wafer. Silicon of the donor wafer is then removed. In the same manner, blue, green, and red diode layers, and a transistor layer are sequentially formed. A metal layer is formed on the transistor layer. Inter-elements contact and pixel separation processes are performed and a support layer is bonded. The whole device is turned over and the nitride film is etched using an etch-stop layer, thus removing the handle wafer. After the elements are separated, packaging is performed to complete the device. Therefore, a back illuminated image sensor of a multi-layer structure can be provided.

Claims

1. A method of fabricating a silicon/dielectric multi-layer thin film for fabricating a semiconductor device of a multi-layer structure, the method comprising:

a step of preparing a handle wafer;

a donor wafer preparation step for layer transfer, of forming semiconductor layers in a donor wafer;

a layer transfer step of turning over the donor wafer so that the donor wafer is bonded to a top surface of the handle wafer, whereby the semiconductor layer remains but the remaining donor wafer is removed through layer transfer;

a step of forming a dielectric layer on the handle wafer on which the layer transfer has been performed; and

a step of repeating the donor wafer preparation step, the layer transfer step, and the dielectric layer formation step, thus forming a multi-layer silicon/dielectric layer.

2. The method of claim 1, wherein in the step of preparing the handle wafer, after the dielectric layer is formed on the handle wafer, the layer transfer step is performed on the dielectric layer.

3. The method of claim 1, wherein in the donor wafer preparation step, after another dielectric layer is formed on the donor wafer, the semiconductor layer is formed.

4. The method of claim 1, wherein the dielectric layer includes one or more dielectric layers.

5. The method of claim 4, wherein the dielectric layer includes any one of an oxide film, a nitride film, and an ONO filter stack layer, or a combination of them or any combination of dielectric films.

6. A method of fabricating a semiconductor device of a silicon/dielectric multilayer structure, the method comprising:

a handle wafer preparation step of sequentially buffer oxide film and a dielectric layer on a handle wafer, thus preparing a work substrate;

a donor wafer preparation step of forming a semiconductor layer for the semiconductor device in a donor wafer and preparing the donor wafer for layer transfer;

a layer transfer step of turning over the donor wafer, bonding the turned-over donor wafer to a top surface of the work substrate, and removing a silicon layer of the remaining donor wafer except for the semiconductor layer transferred by layer transfer;

a dielectric layer formation step of forming a dielectric layer on a top surface after the layer transfer step;

a multi-layer structure formation step of repeating the donor wafer preparation step, the layer transfer step, and the dielectric layer formation step, thereby laminating silicon/dielectric of a multi-layer structure on the handle wafer; and

a step of forming the highest layer of the semiconductor layer on which the layer transfer has been performed as a transistor layer, completing a transistor, connecting the transistor to semiconductor layers of an underlying multi-layer structure, separating pixels, forming solder bumps, and performing flip-chip packaging.

7. The method of claim 6, wherein the donor water preparation step comprises an oxide film formation step of forming an oxide film in the donor water and forming the semiconductor layer in the donor water below the oxide film.

8. The method of claim 6, wherein the semiconductor layer of the multi-layer structure includes a transistor layer at the highest layer and one or a plurality of photodiode layers at a lower side, thus forming an image sensor.

9. The method of claim 6, wherein the dielectric layer is termed of an optical tilter layer capable of helping to select colors of each color layer of the image sensor as an multi-layer dielectric filter stack.

10. The method of claim 6 in which the sensor is formed in a front illuminated mode without flipchip techniques or solder bumps on a support wafer.

11. A method of fabricating a semiconductor device of a silicon/dielectric multilayer structure, the method comprising:

a handle water preparation step of forming an etch-stop layer and a dielectric layer on a handle wafer;

a donor water preparation step of forming a semiconductor layer for the semiconductor device in a donor wafer and preparing the donor wafer for layer transfer;

a layer transfer step of turning over the donor wafer, bonding the turned-over donor wafer to a top surface of the work substrate, and removing a silicon layer of the remaining donor wafer except for the semiconductor layer through layer transfer;

a dielectric layer formation step of forming a dielectric layer on a top surface of the work substrate after the layer transfer step;

a multi-layer structure formation step of repeating the donor wafer preparation step, the layer transfer step, and the dielectric layer formation step, thus forming silicon/dielectric in a multi-layer structure;

a pixel separation and contact step of forming the highest layer of the semiconductor layer as a transistor layer, completing transistors, allowing the transistors to bring in contact with semiconductor layers of an underlying multi-layer structure, separating pixels in the semiconductor layer of the multi-layer structure, and forming a metal layer and solder bumps on an upper surface;

a support layer preparation step of preparing a support layer and forming an oxide film and a metal layer in which circuits are patterned on the support layer;

a support layer bonding step of turning over the support layer and aligning and bonding the solder bumps and the metal layer;

and a handle wafer removing step of turning over the support layer so that the support layer is located at a lower side, etching the handle wafer using an etch-stop layer, removing the etch-stop layer, and then performing dicing and packaging.

12. The method of claim 11, wherein the handle wafer preparation step comprises a buffer oxide film formation step of forming a thick buffer oxide film in the handle wafer and forming a nitride film as the etch-stop layer on the buffer oxide film.

13. The method of claim 11, wherein the donor wafer preparation step comprises an oxide film formation step of forming an oxide film on the donor wafer and forming the semiconductor layer below the oxide film.

14. The method of claim 11, further comprising an edge sealing step after the support substrate bonding step.

15. The method of claim 11, wherein in the semiconductor layer of the multi-layer structure, a transistor layer is formed at one or more photodiode layers and the highest layer, thus forming an image sensor.

16. The method of claim 11, wherein in the semiconductor device of the silicon/dielectric multi-layer structure, the semiconductor layer of the highest layer is formed to have a MOS semiconductor structure.

17. The method of claim 16, wherein the MOS semiconductor includes a transistor fabricated using a bulk semiconductor process.

18. The method of claim 16, wherein the MOS semiconductor includes a SOI Si transistor that is partially or entirely depleted.

19. The method of claim 16, wherein the MOS semiconductor includes a Junction Field Effect Transistor (JFET) that is isolated by dielectric.

20. The method of claim 16, wherein the MOS semiconductor includes either a Bipolar Junction Transistor (BJT) that is isolated by dielectric or a flip-fet transistor that is isolated by dielectric.

21. The method of claim 16, wherein the transistor includes a transistor having four kinds of terminals, including a source, a drain, a top side gate, and a back side gate.

22. A three-dimensional stack type image sensor, comprising:

a blue photodiode formed to a predetermined thickness using silicon;

a first oxide layer provided on the blue photodiode;

a green photodiode formed on the first oxide layer and formed to predetermined thickness using silicon;

a second oxide layer provided on the green photodiode;

a red photodiode formed on the second oxide layer and formed to a predetermined thickness using silicon;

a third oxide layer provided on the red photodiode; and

a transistor layer formed on the third oxide layer and having formed a transistor therein.

23. The three-dimensional stack type image sensor of claim 22, wherein optical filters for helping to select colors of each photodiode are provided on and below each photodiode.

24. The three-dimensional stack type image sensor of claim 23, wherein the optical titer is formed of an dielectric filter stack.

25. A three dimensional multi-layer semiconductor device, comprising:

an upper layer in which a MOS semiconductor is formed; and

a lower layer having a three-dimensional structure in which silicon and dielectric are laminated in multiple layers, wherein the lower layer has a multi-layer structure having a semiconductor junction, or has a MEMS structure.

26. The three-dimensional multi-layer semiconductor device of claim 25, wherein the lower layer has a structure in which an optical filter layer is laminated as a dielectric layer and a photodiode layer is laminated as a silicon layer.

27. A stack type image sensor, comprising:

solder bumps for flip-chip bonding;

a metal layer connected to the solder bumps;

a transistor layer contacting the metal layer;

a multi-layer photodiode layer having a multi-layer structure in which an oxide film, an ONO dielectric layer, and a photodiode layer are repeatedly formed below the transistor layer and the photodiode layers are brought in contact with the transistor and a metal layer; and

an oxide film and a dielectric layer formed on the multi-layer photodiode layer.

28. A stack type image sensor, comprising:

a support layer having formed a dielectric insulation film and a patterned metal layer thereon;

a wire bonded to the metal layer and solder bumps connected to the metal layer;

a Back-End-Of-The-Line (BEOL) having a metal connected to the solder bumps, a metal layer, and an Inter Layer Dielectric (ILD) layer;

a transistor layer formed on the ILD layer in a turned-over shape and brought in contact with the metal layer;

a multi-layer photodiode layer having a multi-layer structure in which an ONO dielectric layer and a photodiode layer are repeatedly formed on the turned-over transistor layer and the photodiode layers are brought in contact with the transistor and the metal layer; and

an ONO dielectric layer formed on the multi-layer photodiode layer.

29. The stack type image sensor of claim 28, further comprising oxide films between the ONO dielectric layer and the transistor layer and between the ONO dielectric layer and the photodiode layers respectively.

30. A stack type image sensor, comprising:

a support layer being a complete water substrate having formed in it active circuits comprised of transistors and interconnects with solder bumps connected to the metal layer;

a Back-End-Of-The-Line (BEOL) having a metal connected to the solder bumps, a metal layer, and an Inter Layer Dielectric (ILD) layer;

31. A stack type image sensor, comprising:

patterned layers in the substrate from which it is formed which are patterned during fabrication of the multilayer three dimensional substrate.