Thin film device transfer method, thin film device, thin film integrated circuit device, active matrix board, liquid crystal display, and electronic apparatus

• US 6,521,511 B1
• Filed: 02/26/1999
• Issued: 02/18/2003
• Est. Priority Date: 07/03/1997
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Inoue, Satoshi, Shimoda, Tatsuya, Miyazawa, Wakao
• Primary Examiner(s): Lee, Eddie
• Assistant Examiner(s): RICHARDS, NORMAN DREW
• Application Number:
  US09/242,923
• Time in Patent Office: 1,453 Days
• Field of Search: 438/455, 438/458, 438/149, 438/155, 438/464
• US Class Current: 438/458
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/57 the laser beam entering a face of the workpiece from which it is transmitted through the workpiece material to work on a different workpiece face, e.g. for effecting removal, fusion splicing, modifying or reforming
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• 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 21/76264 SOI together with lateral isolation, e.g. using local oxidation of silicon, or dielectric or polycristalline material refilled trench or air gap isolation regions, e.g. completely isolated semiconductor islands
• CPC Class Codes: H01L 21/76275 Vertical isolation by bonding techniques
• CPC Class Codes: H01L 21/76283 Lateral isolation by refilling of trenches with dielectric material
• CPC Class Codes: H01L 21/76289 Lateral isolation by air gap
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1266 the substrate on which the devices are formed not being the final device substrate, e.g. using a temporary substrate
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence

Abstract

A thin film device fabrication method in which a thin film device formed on a substrate are transferred to a primary destination-of-transfer part and then the thin film device is transferred to a secondary destination-of-transfer part. A first separation layer (120) made of such a material as amorphous silicon is provided on a substrate (100) which allows passage of laser. A thin film device (140) such as TFTs are formed on the substrate (100). Further, a second separation layer (160) such as a hot-melt adhesive layer is formed on the thin film devices (140), and a primary destination-of-transfer part (180) is mounted thereon. The bonding strength of the first separation layer is weakened by irradiation with light, and the substrate (100) is removed. Thus, the thin film device (140) is transferred to the primary destination-of-transfer part. Then, a secondary destination-of-transfer part (200) is attached onto the bottom of an exposed part of the thin film device (140) via an adhesive layer (190). Thereafter, the bonding strength of the second separation layer is weakened by such means as thermal fusion, and the primary destination-of-transfer part is removed. In this manner, the thin film device (140) can be transferred to the secondary destination-of-transfer part (200) while maintaining layering relationship with respect to the substrate (100).

Claims

1. A device transfer method comprising:

a first step of forming a first separation layer on a substrate;

a second step of forming an object-of-transfer layer containing the device on said first separation layer;

a third step of forming a second separation layer on said object-of-transfer layer;

a fourth step of attaching a primary destination-of-transfer part to said second separation layer;

a fifth step of irradiating said first separation layer with light to cause exfoliation in an inner-layer and/or interface of said first separation layer, and then removing said substrate from said object-of-transfer layer while retaining said first separation layer on said object-of-transfer layer using said first separation layer as a boundary;

a sixth step of removing said first separation layer from said said object-of-transfer layer;

a seventh step of attaching a secondary destination-of-transfer part to the bottom of said object-of-transfer layer; and

an eighth step of removing said primary destination-of-transfer part and said second separation layer from said object-of-transfer layer using said second separation layer as a boundary,

whereby said object-of-transfer layer containing said device is transferred to said secondary destination-of-transfer part.

2. The device transfer method as defined in claim 1, wherein:

said substrate transmits light; and

said first separation layer is irradiated with light through said substrate which transmits light.

3. The device transfer method as defined in claim 1, wherein:

said second separation layer is made of an adhesive material; and

said eighth step includes a step of melting said adhesive material.

4. The device transfer method as defined in claim 1, wherein said eighth step includes a step of irradiating said second separation layer with light to cause exfoliation in an inner-layer part and/or interface of said second separation layer.

5. The device transfer method as defined in claim 4, wherein:

said primary destination-of-transfer part transmits light; and

said second separation layer is irradiated with light through said primary destination-of-transfer part which transmits light.

6. The device transfer method as defined in claim 1, wherein said second step includes a step of forming an electrode for conduction of said device after formation of said device.

7. The device transfer method as defined in claim 1, wherein said secondary destination-of-transfer part is transparent.

8. The device transfer method as defined in claim 1, wherein said secondary destination-of-transfer part is made of a material having a glass transition temperature (Tg) of softening point which is lower than or equal to a maximum temperature T_max used in formation of said object-of-transfer layer.

9. The device transfer method as defined in claim 1, wherein said secondary destination-of-transfer part has a glass transition temperature (Tg) or softening point which is lower than or equal to a maximum temperature used in formation of said device.

10. The device transfer method as defined in claim 1, wherein said secondary destination-of-transfer part is made of a synthetic resin or glass material.

11. The device transfer method as defined in claim 1, wherein said substrate is resistant to heat.

12. The device transfer method as defined in claim 1, wherein said substrate is made of a material having a distortion point which is higher than or equal to a maximum temperature T_max used in formation of said object-of-transfer layer.

13. The device transfer method as defined in claim 1, wherein said device includes a thin film transistor (TFT).

16. A device transferred to said secondary destination-of-transfer part using the device transfer method defined in claim 1.

17. An integrated circuit comprising a device transferred to a secondary destination-of-transfer part using the transfer method defined in claim 1.

18. An active matrix board comprising a pixel portion which includes thin film transistors (TFTs) arranged in a matrix and pixel electrodes connected with respective ends of said thin film transistors,

wherein the method defined in claim 1 is used in transferring said thin film transistors of said pixel portion for fabrication of the active matrix board.

20. A liquid crystal display device manufactured by using the active matrix board defined in claim 18.

21. An electronic apparatus comprising a t device transferred to said secondary destination-of-transfer part using the device transfer method defined in claim 1.

22. The electronic apparatus as defined in claim 21, wherein said secondary destination-of-transfer part is provided as a casing part of said electronic apparatus and said device is transferred on at least one of the inside and outside of said casing part.

14. A device transfer method comprising:

a first step of forming a first separation layer on a substrate;

a second step of forming an object-of-transfer layer containing devices on said first separation layer;

a third step of forming a second separation layer on said object-of-transfer layer;

a fourth step of attaching a primary destination-of-transfer part to said second separation layer;

a fifth step of irradiating said first separation layer with light to cause exfoliation in an inner-layer and/or interface of said first separation layer, and then removing said substrate from said object-of-transfer layer while retaining said first separation layer on said object-of-transfer layer using said first separation layer as a boundary;

a sixth step of removing said first separation layer from said object-of-transfer layer;

a seventh step of attaching a secondary destination-of-transfer part which is larger than said substrate to the bottom of said object-of-transfer layer; and

an eighth step of removing said primary destination-of-transfer part from said object-of-transfer layer using said second separation layer as a boundary,

whereby said plurality of object-of-transfer layers are transferred to said secondary destination-of-transfer part by repeating said first to eighth steps a plural number of times.

15. The device transfer method as defined in claim 14, wherein a design rule level of at least one of said devices transferred to said secondary destination-of-transfer part is different from that of the other devices.

19. An active matrix substrate comprising:

a pixel portion which includes thin film transistors (TFTs) connected with scanning lines and signal lines arranged in a matrix, and pixel electrodes connected with respective ends of said thin film transistors; and

a driver circuit for supplying signals to said scanning lines and signal lines,

wherein the method defined in claim 15 is used in thin film transistor fabrication based on a second design rule level for said driver circuit.

24. A device transferred to said secondary destination-of-transfer part using the device transfer method defined in claim 14.

25. An integrated circuit comprising a device transferred to a secondary destination-of-transfer part using the transfer method define in claim 14.

26. An active matrix substrate comprising a pixel portion which includes thin film transistors (TFTs) arranged in a matrix and pixel electrodes connected with respective ends of said thin film transistors,

wherein the method defined in claim 15 is used in transferring said thin film transistors of said pixel portion for fabrication of the active matrix board.

27. A liquid crystal display device manufactured by using the active matrix board defined in claim 26.

28. An electronic apparatus comprising a device transferred to said secondary destination-of-transfer part using the device transfer method defined in claim 14.

29. The electronic apparatus as defined in claim 28, wherein said secondary destination-of-transfer part is provided as a casing part of said electronic apparatus and said device is transferred on at least one of the inside and outside of said casing part.

23. A device transfer method comprising:

a first step of forming a first separation layer on a substrate;

a second step of forming an object-of-transfer layer containing the device on said first separation layer;

a third step of irradiating said first separation layer with light to cause exfoliation in an inner-layer and/or interface of said first separation layer, and then removing said substrate from said object-of-transfer layer while retaining said first separation layer on said object-of-transfer layer using said first separation layer as a boundary; and

a fourth step of removing said first separation layer from said object-of-transfer layer;

a fifth step of attaching a destination-of-transfer part to the bottom of said object-of-transfer layer,

whereby said object-of-transfer layer containing said device is transferred to said destination-of-transfer part.