JP2003298029A - Apparatus and method for exfoliation transfer, semiconductor device and ic card - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for exfoliation transfer which can precisely conduct alignment regulation. <P>SOLUTION: The apparatus for exfoliation transfer comprises a holder (14), having a moving mechanism for grasping a transfer original board (11) including an element chip (12) to be release transferred and formed via a release layer so that its thickness direction perpendicularly crossing the vertical direction and alignment regulation, and a stage having an alignment mechanism for fixing a transfer destination board (13) for transferring the chip (12), formed on the board (11) so that its thickness direction perpendicularly crosses with the vertical direction and aligns with the board (11). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peeling transfer technique for thin film elements, and more particularly to an improved technique capable of highly accurate alignment adjustment.

[0002]

2. Description of the Related Art Conventionally, a transfer source substrate (first
A thin film element such as a thin film transistor formed on a substrate) is adhered to a transfer destination substrate (second substrate), and the peeling layer is irradiated with laser light to cause ablation in the peeling layer or at the interface to cause the inside of the layer. A technique for inducing peeling or interface peeling to transfer a thin film element to a transfer source substrate is known (Suftra: Surface Free Technology by Laser
Ablation, T.Shimada et al, Techn. Dig. IEDM1999. 28
9, S. Utsunomiya, et al, Dig Tech. Pap. SID2000,91
6, T.Shimada Proc.Asia Display / IDW 01,327, S Utsunom
iya, et al, ProcAsia Display / IDW '01 .339). According to this technique, since a material suitable for manufacturing a thin film transistor can be used as a transfer source substrate, high driving capability,
A highly reliable thin film transistor can be manufactured.
Further, as the transfer source substrate, as long as it is a substrate having an appropriate strength, it can be freely selected without being limited to a specific material, and since peeling transfer of a thin film transistor can be realized by a simple process, The manufacturing cost can be reduced.

FIG. 5 is a block diagram of a peeling transfer device using the same technique. In the figure, 11 is a transfer source substrate capable of transmitting laser light, 12 is an element chip (circuit element) including at least one thin film transistor, and 13 is an element chip 12
A transfer target substrate, 14 is a transfer source substrate 11,
A holder for finely adjusting the plane position, height, inclination, etc. of the transfer source substrate 11, and 15 is a transfer destination substrate 13 by vacuum suction.
Is a laser light source, and 17 is a camera for alignment adjustment. Further, the vertical direction in the drawing is assumed to be parallel to the vertical direction. The transfer source substrate 11 is a glass substrate having a relatively large area, and the element chip 12 is temporarily attached to the back surface (the surface facing the transfer destination substrate) via a release layer. Each of the transfer source substrate 11 and the transfer destination substrate 13 is provided with alignment marks for alignment, and the output signal from the alignment camera 17 is feedback-controlled so that a desired planar positional relationship can be obtained, and the holder 14 is moved. And finely adjust the horizontal movement of the stage 15. Since the transfer source substrate 11 is a transparent glass substrate, not only the alignment of the transfer source substrate 11 but also the alignment of the transfer destination substrate 13 through the transfer source substrate 11 is possible.

When the predetermined planar positional relationship between the transfer source substrate 11 and the transfer destination substrate 13 is obtained, the holder 14 is lowered to bring the transfer source substrate 11 and the transfer destination substrate 13 into close contact with each other. Since the adhesive is applied on the surface of the transfer destination substrate 11 in advance, the element chip 12 sandwiched between the transfer source substrate 11 and the transfer destination substrate 13 in the thickness direction with an appropriate pressure is used as the transfer destination substrate. Join to 13. Next, by irradiating the peeling layer with laser light from the laser light source 16 through the transfer source substrate 11, ablation is caused in the peeling layer or the interface,
The element chip 12 is peeled off from the transfer source substrate 13. As a result, the element chip 12 is transferred onto the transfer destination substrate 13.

[0005]

By the way, in the conventional peeling transfer apparatus, the transfer source substrate 11 is maintained with its thickness direction substantially parallel to the vertical direction, and the four corners of the substrate 11 and the holder 14 are kept.
Since a large glass substrate is used as the transfer source substrate 11, the weight of the transfer source substrate causes the transfer source substrate to bend, making it difficult to perform accurate alignment adjustment. Further, since the holder 14 needs a movable mechanism for alignment, it cannot be made to have a robust structure, and there is a possibility that the transfer source substrate 11 is distorted due to gravity. When the transfer source substrate 11 and the holder 14 are bent or distorted, the transfer source substrate 11 and the transfer destination substrate 1
The accurate alignment adjustment of 3 becomes difficult.

Therefore, the present invention solves the above problems,
An object of the present invention is to provide a transfer device and a peeling transfer method capable of performing accurate alignment adjustment. Another object is to provide a semiconductor device and an IC card manufactured by using the same method.

[0007]

In order to solve the above-mentioned problems, the peeling transfer apparatus of the present invention has a transfer source substrate in which a thin film element to be peeled and transferred is formed with a peeling layer interposed therebetween in a thickness direction thereof. The gripping means is provided with a moving mechanism for gripping so as to be orthogonal to the vertical direction and performing alignment adjustment, and the transfer destination substrate for transferring the thin film element formed on the transfer source substrate has a vertical thickness direction. The fixing means includes an alignment mechanism that is fixed so as to be orthogonal to the direction and is aligned with the transfer source substrate.

With this structure, since the transfer source substrate is gripped so that the thickness direction thereof is perpendicular to the vertical direction and alignment adjustment with the transfer destination substrate is performed, the transfer source substrate may be bent due to its weight. Without, precise alignment adjustment can be performed.

Preferably, the transfer source substrate is a glass substrate.

Since a large glass substrate is particularly susceptible to distortion,
It is suitable for the present invention.

Preferably, the peeling layer includes a laser light source for inducing intralayer peeling or interfacial peeling.

Since the irradiation spot can be selectively formed by laser irradiation, it is suitable for peeling transfer of a thin film element.

In the peeling transfer method of the present invention, a step of gripping a transfer source substrate on which a thin film element to be peeled and transferred is formed via a peeling layer so that the thickness direction thereof is orthogonal to the vertical direction, Fixing the transfer destination substrate for transferring the thin film element on which the original substrate is formed so that the thickness direction thereof is perpendicular to the vertical direction; and performing the alignment adjustment between the transfer source substrate and the transfer destination substrate. A step of adhering the thin film element to a transfer destination substrate, a step of inducing intralayer peeling or interface peeling in the peeling layer, peeling the thin film element from the transfer source substrate, and transferring the thin film element to the transfer destination substrate. including.

Since the transfer source substrate is grasped so that the thickness direction thereof is perpendicular to the vertical direction and alignment adjustment with the transfer destination substrate is performed, the transfer source substrate does not bend due to its weight and is precise. Alignment can be adjusted.

In the semiconductor device of the present invention, the thin film element peeled and transferred by the peeling transfer method of the present invention is used as a circuit element.

Since the thin film element is transferred under the precise alignment adjustment, a highly reliable semiconductor device can be obtained.

Preferably, the thin film element is a thin film transistor having polycrystalline silicon manufactured by a low temperature process as an active layer.

A high performance semiconductor device can be obtained by using a thin film transistor having low temperature polycrystalline silicon as an active layer.

As such a semiconductor device, for example, I
C cards are preferred.

By manufacturing an IC card by the peeling transfer method of the present invention, a high-performance IC card can be manufactured at low cost, and since the thin film element is thin and easily bent, an IC card with high reliability against bending can be obtained. be able to.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present embodiment will be described below with reference to the drawings.

FIG. 1 is a block diagram of the peeling transfer device of this embodiment. In the figure, 11 is a transfer source substrate capable of transmitting a laser beam, 12 is an element chip including at least one thin film transistor, 13 is a substrate to which the element chip 12 is transferred, 14 is a source substrate 11 that holds the transfer source substrate 11, A holder for finely adjusting the position, height, inclination, etc. of the substrate 11, 15
Is a stage for fixing the transfer destination substrate 13 by vacuum suction, 16 is a laser light source, and 17 is a camera for alignment adjustment. As the transfer destination substrate 13, various substrates such as plastic substrates, films and foils can be used regardless of the material. For example, when manufacturing a liquid crystal display, the transfer destination substrate 13 is a TFT array substrate. Further, the vertical direction in the drawing is assumed to be parallel to the vertical direction. In this apparatus, the four corners of a transfer source substrate 11, which is a large glass substrate, are held by holders 14 so that the thickness direction thereof is substantially perpendicular to the vertical direction, and distortion occurs due to the weight of the substrate 11. It has been devised so that it does not occur. Further, the element chip 12 is formed on the surface of the substrate 11 facing the transfer destination substrate 13 with a release layer interposed therebetween.

The peeling layer is preferably one that induces intra-layer peeling or interfacial peeling by absorbing irradiation light. More specifically, the light irradiation eliminates or reduces the interatomic or intermolecular distance of the substance. In other words, it is preferable that the ablation occurs to cause intralayer peeling or interfacial peeling. Alternatively, the gas may be released from the peeling layer by light irradiation to exhibit a separating effect. That is, the case where the component contained in the peeling layer is released as a gas, and the case where the peeling layer absorbs light and becomes a gas for a moment, and the vapor thereof is released may be separated. As such a peeling layer, amorphous silicon, silicon oxide, silicic acid compound, titanium oxide, titanic acid compound, zirconium oxide, zirconic acid compound, lanthanum oxide, lanthanum acid compound, PZ
T, PLZT, PLLZT, PBZT, silicon nitride, aluminum nitride, titanium nitride, organic polymer materials, aluminum, titanium, manganese, indium and the like are preferable.

Alignment marks for alignment are provided on each of the transfer source substrate 11 and the transfer destination substrate 13,
The output signal from the alignment camera 17 is feedback-controlled so that a desired planar positional relationship is obtained, and the vertical and horizontal movements of the holder 14 and the stage 15 are finely adjusted. Since the transfer source substrate 11 is a transparent glass substrate, not only the alignment of the transfer source substrate 11 but also the alignment of the transfer destination substrate 13 through the transfer source substrate 11 is possible. When the predetermined planar positional relationship between the transfer source substrate 11 and the transfer destination substrate 13 is obtained, the holder 14 is moved so as to be close to the transfer destination substrate 11 to bring the transfer source substrate 11 and the transfer destination substrate 13 into close contact with each other. . Since the adhesive is previously applied to the surface of the transfer destination substrate 11, the transfer source substrate 11
The element chip 12 sandwiched between the transfer target substrate 13 and the transfer target substrate 13 in the thickness direction with appropriate pressure is bonded to the transfer target substrate 13.

Next, by irradiating the peeling layer with laser light from the laser light source 16 through the transfer source substrate 11, ablation is caused in the peeling layer or the interface, and the element chip 1
2 is separated from the transfer source substrate 13. As a result, the element chip 12 is transferred onto the transfer destination substrate 13.
As the laser light, in particular, a wavelength of 100 nm to 350 nm
A degree of excimer laser light is preferred. By using a short-wavelength laser, it is possible to cause an action such as direct breaking of molecular bonds without thermal influence or gas evaporation in the peeling layer.

If a large glass substrate is used as the transfer source substrate 11, it is easy to bend and precise alignment adjustment becomes difficult. However, according to the present embodiment, the thickness direction of the transfer source substrate 11 is the vertical direction. Since the holder 14 is held so as to be orthogonal to each other, the same substrate 11 due to the influence of weight is used.
And the holder 14 can be prevented from being bent and the substrate 11 and the transfer destination substrate 13 can be precisely aligned. Further, by vertically arranging the peeling transfer device which has been conventionally placed horizontally, the occupied area can be saved and the space of the device can be saved.

The transfer source substrate 11 is not limited to a glass substrate as long as it is made of a light transmissive material, and a light transmissivity of 10% or more is desirable.
A light transmittance of 50% or more is more desirable. This is because if the light transmittance is too low, the light is greatly attenuated and a large amount of light is required to cause ablation in the peeling layer or the interface. The thickness of the transfer source substrate 11 is not particularly limited, but is preferably about 0.1 mm to 5.0 mm, more preferably about 0.5 mm to 0.5 mm. While it becomes unstable in strength when it is thin,
This is because if the thickness is too large, the attenuation of transmitted light will increase. Further, in order to perform alignment adjustment with high precision, a flat substrate is required.

FIG. 2 is a process explanatory view of the peeling transfer method in this embodiment. Here, for convenience of description, it is assumed that the left-right direction in the drawing is set in a direction parallel to the vertical direction. First, as shown in FIG.
Plasma chemical vapor deposition (PE) using H ₄ as a source gas
CVD) or low pressure chemical vapor deposition (LPCVD) using disilane (Si ₂ H ₆ ) as a source gas to deposit the amorphous silicon film 22 on the transfer source substrate 21. . A quartz substrate, a glass substrate, or the like can be used as the transfer source substrate 21. Next, the thin film transistor 23 and the pad 24 are sequentially formed on the amorphous silicon film 22. Further, as shown in FIG. 6B, the transfer source substrate 21 and the transfer destination substrate 25 are aligned with each other under precise alignment adjustment, and the thin film transistor 23 is placed between the transfer source substrate 21 and the transfer destination substrate 25. The thin film transistor 23 is bonded to the transfer destination substrate 25 via the pad 24 by sandwiching the thin film transistor 23 in the thickness direction with an appropriate pressure bonding force. Next, the thin film transistor 23 scheduled for peeling transfer is irradiated with a laser beam from the laser light source 26 to induce intralayer peeling of the amorphous silicon film 22. Then, as shown in FIG. 6C, hydrogen in the amorphous silicon film 22 irradiated with the laser beam is released, and the pressure inside the film is increased, so that the amorphous silicon film 22 is destroyed. . As a result, the thin film transistor 23 is separated from the transfer source substrate 21, and the transistor 23 is transferred to the transfer destination substrate 25.

As described above, by dividing the transfer destination substrate 25 on which the thin film transistor 23 is transferred into appropriate sizes, a desired semiconductor device (for example, an IC card described later) is obtained.
Can be obtained. The thin film transistor 23 transferred to the transfer destination substrate 25 under precise alignment adjustment has no positional deviation with respect to the wiring pattern, and a high-performance semiconductor device can be obtained.

FIG. 3 is a manufacturing process diagram of a thin film transistor for transfer to a transfer destination substrate using the peeling transfer technique of the present invention. Here, a manufacturing process of a thin film transistor manufactured by a low temperature process will be described. First, as shown in FIG. 3A, plasma chemical vapor deposition (PECVD) using monosilane (SiH ₄ ) as a source gas and low pressure chemical vapor deposition using disilane (Si ₂ H ₆ ) as a source gas. Law (L
The transfer source substrate 3 is formed by using various film forming techniques such as PCVD).
An amorphous silicon film 32 is deposited on the surface 1. Transfer source substrate 3
As 1, it is possible to use a quartz substrate, a glass substrate, or the like. Next, laser light 3 is applied to the amorphous silicon film 32.
Irradiation 3 is carried out, and melt crystallization is performed to obtain a polycrystalline silicon film. Next, as shown in FIG. 3B, a predetermined region of the polycrystalline silicon film 32 to be an active layer in a subsequent step is patterned by a photolithography process, and a gate insulating film 34 is further formed thereon. A gate electrode 35 is formed on the gate insulating film 34 and etched into a predetermined wiring pattern.
Finally, as shown in FIG. 3C, using the gate electrode 35 as a mask, impurities such as phosphorus and boron are implanted in a self-aligned manner and activated to form the source / drain regions 36 of the CMOS structure. Further, an interlayer insulating film 37 is formed, a contact hole is opened, and a source electrode / drain electrode 38 is formed. Since the active layer of the thin film transistor obtained in the above manufacturing process is low temperature polycrystalline silicon,
A high performance CMOS field effect transistor can be obtained.

FIG. 4 is a plan view of an IC card manufactured by using the peeling transfer technique of the present invention. The IC card 41 is configured to include a terminal / circuit section 42, a text display section 43, and an image display section 44 which are transferred onto a plastic substrate by using the above-mentioned peeling transfer technique. The terminal / circuit section 42 is an external interface circuit including the above-mentioned thin film transistor. The text display section 43 and the image display section 44 are displays for text display and image display each including the above-mentioned thin film transistor, a liquid crystal display element, an electrophoretic element, an organic EL element, and a light emitting polymer element. These circuit elements are connected to each other to realize the function as an IC card. Since the IC card 41 is manufactured by using the peeling transfer technique described above, a high-performance IC card can be manufactured at low cost. Further, since the element chip is thin and easy to bend, it is possible to obtain the IC card 41 with high reliability against bending.

[0032]

According to the present invention, the transfer source substrate is grasped so that the thickness direction thereof is perpendicular to the vertical direction and the alignment adjustment with the transfer destination substrate is performed. Precise alignment adjustment can be performed without bending.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a peeling transfer device of the present invention.

FIG. 2 is an explanatory diagram of a peeling transfer process of the present invention.

FIG. 3 is a manufacturing process diagram of the thin film transistor of the invention.

FIG. 4 is a plan view of the IC card of the present invention.

FIG. 5 is a configuration diagram of a conventional peeling transfer device.

[Explanation of symbols]

11, 21, 31 ... Transfer source substrate 12, 27 ... Element chip 13, 25 ... Transfer destination substrate 14 ... Holder 15 ... Stage 16, 26 ... Laser light source 17 ... Alignment camera 22 ... Amorphous silicon film 23 ... Thin film transistor 24 ... Pad 32 ... Polycrystalline silicon film 33 ... Laser light 34 ... Gate insulating film 35 ... Gate electrode 36 ... Source region / drain region 37 ... Interlayer insulating film 38 ... Source electrode / drain electrode 41 ... IC card 42 ... Terminal / circuit part 43 ... Text display section 44 ... Image display section

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fukumi Dobashi             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation (72) Inventor Tomoyuki Kamakura             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation (72) Inventor Masashi Kasuga             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F-term (reference) 5B035 BA03 BB09 CA01                 5F110 AA01 AA17 BB04 BB20 CC02                       DD01 DD24 GG02 GG13 GG45                       GG47 HJ01 HJ13 HJ23 NN02                       PP03 QQ16

Claims (10)

[Claims] 1. A moving mechanism for gripping a transfer source substrate on which a thin film element to be peeled and transferred is formed via a peeling layer so that the thickness direction thereof is perpendicular to the vertical direction and for performing alignment adjustment. The gripping means and the transfer destination substrate for transferring the thin film element formed on the transfer source substrate are fixed so that the thickness direction thereof is orthogonal to the vertical direction, and alignment is performed with the transfer source substrate. And a fixing unit having a mechanism. 2. The peeling transfer device according to claim 1, wherein the transfer source substrate is a glass substrate. 3. The peeling transfer device according to claim 1, further comprising a laser light source for inducing intralayer peeling or interfacial peeling in the peeling layer. 4. A step of gripping a transfer source substrate on which a thin film element to be peeled and transferred is formed via a peeling layer so that the thickness direction thereof is orthogonal to the vertical direction, and the transfer source substrate is formed. Fixing the transfer destination substrate for transferring the thin film element so that the thickness direction thereof is orthogonal to the vertical direction; adjusting the alignment between the transfer source substrate and the transfer destination substrate; and transferring the thin film element. A peeling transfer method comprising: a step of adhering to a first substrate; and a step of inducing intra-layer peeling or interfacial peeling in the peeling layer, peeling the thin film element from the transfer source substrate, and transferring the thin film element to the transfer destination substrate. . 5. The peeling transfer method according to claim 4, wherein the transfer source substrate is a glass substrate. 6. The peeling transfer method according to claim 4, wherein the peeling layer is irradiated with a laser beam to induce intra-layer peeling or interfacial peeling in the peeling layer. 7. A semiconductor device, comprising a thin film element peeled and transferred by the method according to any one of claims 4 to 6 as a circuit element. 8. The semiconductor device according to claim 7, wherein the thin film element is a thin film transistor using polycrystalline silicon manufactured by a low temperature process as an active layer. 9. An IC card, wherein a circuit element is a thin film element peeled off and transferred by the method according to any one of claims 4 to 6. 10. The IC card according to claim 9, wherein the thin film element is a thin film transistor using polycrystalline silicon manufactured by a low temperature process as an active layer.