JP5286684B2 - Thin film layer peeling method, thin film device transfer method - Google Patents

Description

  The present invention relates to a thin film layer peeling method and a thin film device transfer method.

The following techniques have been proposed as a method for peeling the thin film layer by irradiating the light absorbing layer with light. For example, in Patent Documents 1 and 2, as a peeling method in the case of transferring a thin film layer formed on a substrate to a transfer destination substrate laminated via a separation layer, the separation layer is irradiated with a laser to perform the separation. A method for peeling a thin film layer from a substrate by causing peeling (interfacial peeling, intralayer peeling) in a layer is disclosed. In Patent Document 1, when laser irradiation is performed by square spot beam irradiation and line beam irradiation, a unit region is irradiated with a spot, and this spot irradiation is performed while shifting by about 1/10 of the unit irradiation region. Patent Document 2 describes a method of irradiating a line beam by intermittently scanning.
Japanese Patent Laid-Open No. 10-125929 JP-A-11-74533

  However, in the peeling method according to the prior art, many peeling defects that cannot be partially peeled are generated at the time of peeling, resulting in a decrease in yield.

  Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art, and is a peeling method capable of minimizing a peeling defect in a thin film layer peeling process using light irradiation, and a thin film using such a technique. The object is to provide a device transfer method.

According to the study by the applicant of the present application, it has been found that there are mainly two types of peeling defects that occur when light irradiation is performed. That is, a defect that cannot be peeled off because light is not irradiated to the transfer target, and a defect that cannot be peeled off because the defect occurrence rate is remarkably increased by light irradiation at the same location multiple times. In order to reduce these defects, the present invention employs the following light irradiation method.
The thin film layer peeling method of the present invention is a thin film layer peeling method in which a thin film layer existing on a substrate via a separation layer is peeled from the substrate in order to solve the above-described problem, and the separation layer is irradiated. When the light is irradiated a plurality of times to cause peeling at the inside and / or interface of the separation layer, and the thin film layer is detached from the substrate, the unit irradiation area by the irradiation light is a substantially regular hexagon, The irradiation light is irradiated such that one side of the unit irradiation region overlaps.
The thin film layer peeling method of the present invention is a thin film layer peeling method for peeling a thin film layer existing on a substrate via a separation layer from the substrate in order to solve the above-mentioned problem, and the separation layer is irradiated with irradiation light. When the film is irradiated a plurality of times to cause peeling at the inside and / or interface of the separation layer, and the thin film layer is detached from the substrate, the unit irradiation region by the irradiation light is substantially a regular hexagon.

  According to the method for peeling a thin film layer of the present invention, since the unit irradiation region is a substantially regular hexagon, it can be irradiated in a honeycomb shape along each side of each unit irradiation region, so there is no gap in the entire separation layer. Irradiation light can be irradiated. For example, when the present invention in which the unit irradiation area is substantially regular hexagon and the conventional unit irradiation area is substantially square, the area of each unit irradiation area and the overlapping width of adjacent unit irradiation areas are equal. The total area of the regular hexagonal sides is smaller than the total area of the square sides overlapping the entire transfer body. As described above, since the occurrence ratio of the overlapping portion in the entire irradiated region can be remarkably reduced as compared with the conventional case, it is possible to eliminate the peeling defect that cannot be partially peeled at the time of peeling, and the yield is improved.

Moreover, it is preferable to irradiate irradiation light so that one side of adjacent unit irradiation area | regions may overlap.
According to this method, irradiation light is irradiated such that one side of adjacent unit irradiation regions overlaps each other. In other words, since the entire irradiated area is irradiated so that one side of the subsequent unit irradiation area overlaps with one side of the previous unit irradiation area, the overlapping portion occurs only in the peripheral portion of each unit irradiation area. It becomes. In the entire irradiated region, the one-irradiation region around it is larger than the region of the overlapping portion described above, and therefore the peeling defect is not caused by the overlapping portion of the present invention. As described above, the region where the irradiation light overlaps can be remarkably reduced as compared with the conventional case, the occurrence of the peeling defect is prevented, and the yield is improved.

The number of times of irradiation of the irradiation light in the unit irradiation region is three times at the top where the irradiation of the predetermined unit irradiation region and the adjacent unit irradiation region overlaps, and the irradiation of the predetermined unit irradiation region and the adjacent unit irradiation region is performed. It is preferable that the irradiation is performed twice on the side where the two overlap each other and once on the side where the predetermined unit irradiation region and the adjacent unit irradiation region do not overlap.
According to this method, the portion irradiated with the most irradiation light at the overlapping portion of the unit irradiation regions is the top of the substantially regular hexagonal unit irradiation region. Since it is a point defect, it does not become a peeling defect that cannot be partially peeled at the time of peeling. That is, since the area of the overlapping portion is very small as compared with the conventional case, the overlapping portion is peeled off together with the irradiation portion irradiated once around the overlapping portion. Accordingly, it is possible to prevent the occurrence of peeling defects due to the overlapping portion, and the yield is improved.

Further, in the main scanning direction in which the irradiation light is irradiated, the center of gravity of the substantially regular hexagons of the adjacent unit irradiation areas are matched in the main scanning direction, and at least two sides of the unit irradiation areas are orthogonal to the main scanning direction. Irradiation is preferred.
According to this method, since the direction of the unit irradiation region is aligned in one direction in the entire irradiated region, the irradiation light can be irradiated to the entire irradiated region without any gap. Therefore, generation | occurrence | production of an unirradiated area | region is prevented and a thin film layer can be favorably peeled from a board | substrate.
Further, when the irradiation light is irradiated, the movement of the stage holding the substrate is only in one direction, so that the control becomes easy.

The width of the overlapping portion is preferably 1.64 times or more and 3 times or less of the sum of the side width deviation of the unit irradiation area, the area deviation of the unit irradiation area, and the scanning feed pitch.
According to this method, the width of the overlapping portion (the width in the direction orthogonal to the side of the unit irradiation region) is a value obtained by adding the side width deviation of the unit irradiation region, the region deviation of the unit irradiation region, and the scanning feed pitch. If it is .64 times or more, the occurrence of the unirradiated region can be suppressed to a much lower level than before. In addition, if the width of the overlapping portion is not more than three times the value obtained by adding the side width deviation of the unit irradiation region, the region deviation of the unit irradiation region, and the scan feed pitch, the occurrence of peeling defects due to the overlapping portion is generated. Can be minimized. Details will be described later.

The thin film device transfer method of the present invention includes a separation layer forming step of forming a separation layer on a substrate, a thin film layer forming step of forming a thin film layer on the separation layer, and a transfer of the thin film layer to the opposite side of the substrate. A separation step of irradiating the separation layer with light and separating the thin film layer from the substrate, and the separation step is performed using the above-described thin film layer peeling method. It is characterized by that.
According to the thin film device transfer method of the present invention, since the thin film layer peeling method described above is used in the separation step, the thin film layer can be peeled off from the substrate satisfactorily and reliably. Can be transferred easily. Therefore, good separation of the thin film layer from the substrate is always possible, and the yield is improved.

  In the present invention, when a transfer layer (thin film layer) formed on a substrate surface via a separation layer is transferred to a transfer body (transfer destination substrate) bonded to the substrate surface, the transfer layer (transfer destination substrate) is transferred from the back surface of the substrate to the separation layer. The present invention relates to a method of peeling a thin film layer from a substrate by causing peeling (interfacial peeling, intra-layer peeling) in the separation layer by irradiating a laser beam.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view showing a method for peeling a transferred layer (thin film layer) according to an embodiment of the present invention.
As shown in FIG. 1, a transfer body 180 is bonded to a substrate 100 on which a separation layer 120 and a transferred layer 140 are laminated in this order via an adhesive layer 160. When the layer to be transferred 140 on the substrate 100 is to be transferred to the transfer body 180 side, the separation layer 120 is irradiated with laser light as indicated by an arrow in the figure. When the area of the transferred layer is larger than the light irradiation region, the light irradiation is performed a plurality of times. If an unirradiated region is generated between a plurality of times of light irradiation, transfer is not performed. Therefore, when irradiating the separation layer 120 with laser light, if an attempt is made to avoid the generation of an unirradiated region, the next laser light is irradiated so as to overlap the region irradiated with the laser light first. A region (overlapping portion) where light is irradiated a plurality of times is generated. According to the applicant's research, it has been found that the occurrence rate of the peeling defect at the overlapping portion is remarkably higher than that in the region irradiated only once. That is, it has been clarified that the number of peeling defects can be reduced by reducing the ratio of the overlapping portion in the entire transfer target. Therefore, the present invention aims at minimizing the ratio of overlapping portions in order to minimize peeling defects, and has a feature with respect to laser light irradiation.
Below, the peeling method of the thin film layer in this embodiment is demonstrated.

(Laser light irradiation principle)
First, the principle of laser light irradiation will be described.
FIGS. 2A and 2B are explanatory views showing a laser irradiation method in the separation step, where FIG. 2A shows the beam scanning direction, and FIG. 2B shows an overlapping portion where the irradiations overlap. FIG. 3 is an explanatory diagram showing the number of times of irradiation in the unit irradiation region.
According to the analysis of the present inventor, it has been found that if the same place is irradiated a plurality of times in the irradiated region, the separation is remarkably reduced as compared with the case of one irradiation. For this reason, it has been found that the probability of occurrence of a peeling defect in the overlapping portion where the irradiation overlaps increases, and that the peeling defect occurs more frequently as the area of the overlapping portion in the irradiated region is larger than the one-time irradiation region. In order to eliminate such a peeling defect, it is necessary to minimize the ratio of overlapping portions.

Therefore, in this embodiment, the beam shape of the laser beam (laser beam irradiation shape) is set to a substantially regular hexagon so that the unit irradiation region of the laser beam is a substantially regular hexagon. This can be achieved, for example, by attaching a cover having a regular hexagonal hole at the tip of the beam irradiation section of the laser device.
The laser light irradiation is performed while shifting the unit irradiation region S with respect to the entire surface (irradiated region A) of the separation layer 120 (substrate).

  Specifically, as shown in FIG. 2A, scanning is performed in one direction of the irradiated area A (main scanning direction: a direction indicated by an arrow in the drawing). At this time, irradiation is performed by making the center of gravity G of the beam coincide with each other in the main scanning direction, and at least two sides of a beam shape (unit irradiation region) having a substantially regular hexagon are orthogonal to the main scanning direction. Then, as shown in FIG. 2B, irradiation is performed so that one side of the previous irradiation region S1 overlaps one side of the subsequent irradiation region S2, thereby scanning the i-th row shown in FIG. . The overlapping portion where the irradiation overlaps is a region indicated by hatching in FIG.

  After the irradiation of the i-th row is completed, the position is shifted in the sub-scanning direction and the i + 1-th row is irradiated. At this time, irradiation is performed so that one side of each irradiation region S adjacent to the i-th row in the sub-scanning direction overlaps. Thereby, as shown to Fig.2 (a), the two sides of the irradiation area | region S of the i + 1th line overlap with one side of each irradiation area | region S, S adjacent in the i-th line, respectively.

  Such scanning is repeated, and laser irradiation is performed up to the i + nth row. Then, as shown in FIG. 3, the number of times of irradiation in each irradiation region S is three times at the apex q where the irradiation overlaps, and twice at the side where the irradiation overlaps (for example, the side indicated by the thick solid line in the figure). Of course, it is once on the side where the irradiation does not overlap (for example, the side indicated by the thin solid line in the figure). The sides where the irradiation does not overlap are some sides in the irradiation region located at the end of the irradiated region (for example, the irradiation region S ′ in the figure), and there are no adjacent irradiation regions. Arise. In this irradiation region S ′, the apex q1 is located between a side where irradiation does not overlap (for example, a side indicated by a thin solid line in the figure) and a side where irradiation overlaps (for example, a side indicated by a thick solid line in the figure). The number of times of irradiation is 2 times, and the number of times of irradiation of the top portion q2 located between the sides where the irradiations do not overlap is one.

  As described above, the irradiation light is irradiated such that one side of the adjacent unit irradiation regions S, S overlaps each other. That is, as shown in FIG. 2B, since the entire irradiated area A is irradiated such that one side of the previous unit irradiation area S1 overlaps one side of the previous unit irradiation area S1, the overlapping portion is Only the peripheral portion of each unit irradiation region S is generated. Therefore, the region where the irradiation light overlaps can be remarkably reduced as compared with the conventional case, and the occurrence of a peeling defect is prevented, thereby improving the yield.

  Furthermore, since irradiation is performed so that at least two sides of the regular hexagonal unit irradiation region S are orthogonal to the scanning direction, the direction of the unit irradiation region S is aligned in one direction in the entire irradiation region A. Irradiation light can be irradiated to the entire irradiation region A without a gap. Therefore, generation of an unirradiated region is prevented, and the transferred layer 140 can be peeled from the substrate 100 satisfactorily.

  In addition, since the portion where the irradiation light is irradiated most in the overlapping portion of the unit irradiation regions S is the top portion q (spot-like defect) of the substantially regular hexagonal unit irradiation region S, At the time of peeling, it does not become a peeling defect that cannot be partially peeled. That is, since the area of the overlapping portion is very small as compared with the conventional case, the overlapping portion is peeled off together with the irradiation portion irradiated once around the overlapping portion. Accordingly, it is possible to prevent the occurrence of peeling defects due to the overlapping portion, and the yield is improved.

  Therefore, according to the peeling method of this embodiment, an unirradiated region does not occur in the main scanning direction and the sub-scanning direction, and the entire irradiated region A can be irradiated reliably. Furthermore, since the generation of overlapping portions where irradiation overlaps can be significantly reduced as compared with the conventional case, peeling defects at the overlapping portions can be eliminated.

  Hereinafter, the occurrence ratio of the overlapping portion in the laser irradiation method of the present embodiment and the conventional laser irradiation method will be described.

[Comparison between this embodiment and the prior art]
Next, the ratio of the conventional irradiation method (line beam, rectangular beam) and the irradiation method of this embodiment (regular hexagonal beam) will be described.
Here, the beam irradiation region is S, the area of the object to be peeled (irradiation region) is A, and the width (overlap width) of the overlap between the previous beam irradiation region and the subsequent beam irradiation region is d. Here, the overlapping width d is a width in a direction orthogonal to each side of the beam irradiation region S.

である。被照射領域上でのビーム照射領域の重なり部の発生割合Ｒ_ｌは、下記の式２より求められる。

通常、ビーム幅Ｗは０．１ｍｍ〜０．５ｍｍで、重なり幅ｄも０．１ｍｍ〜０．５ｍｍであることから、被照射領域のほとんど全ての領域でレーザー光が２回以上照射される。被照射領域上での重なり部の発生割合Ｒ_ｌは上式より０．８以上となり、８０％以上の確立で発生することになる。 (Comparative Example 1: Line beam)
In the beam irradiation region S, when the width of the line beam is W, the length of the side in the longitudinal direction is L, and the overlap width is d,

It is. The generation ratio R _l of the overlapping portion of the beam irradiation region on the irradiated region can be obtained from the following equation 2.

Usually, since the beam width W is 0.1 mm to 0.5 mm and the overlap width d is also 0.1 mm to 0.5 mm, the laser beam is irradiated twice or more in almost all the irradiated area. Occurrence rate R _l overlap portion on the illuminated region is 0.8 or more from the above equation, it will occur over 80% of the established.

である。被照射領域上でのビーム照射領域Ｓの重なり部の発生割合Ｒ_Ｓは、下記の式４より求められる。

ここで、重なり部の割合Ｒｓが最少となるのは、Ｌ＝Ｗの正方形の場合で、その際の重なり部の割合Ｒｓは、下記の式（５）より求められる。

ちなみにラインビームと正方形ビームとでは、どちらが重なり部の割合が減るかを調べるために両者の差を取ると、

と記述されるので、

を満たしたときに、ラインビームの方が重なり部の割合を減らすことになる。 (Comparative Example 2: Rectangular beam)
In the beam irradiation region S, when the width of the rectangular beam is W and the length of the side in the longitudinal direction is L,

It is. The generation ratio R _S of the overlapping portion of the beam irradiation region S on the irradiated region can be obtained from the following Equation 4.

Here, the overlapping portion ratio Rs is minimized in the case of a square of L = W, and the overlapping portion ratio Rs at that time is obtained from the following equation (5).

By the way, in order to investigate which of the line beam and the square beam is reduced, the difference between the two is

Because it is described as

When the above condition is satisfied, the line beam reduces the ratio of overlapping portions.

In the case of an excimer laser currently on the market, since the irradiation area is about 100 mm ^2, if the length L of the line beam is about 20 mm or less, the line beam reduces the ratio of overlapping portions. However, since the size of the irradiated region is usually much larger than 20 mm, the ratio of the overlapping portion is reduced in the square beam than in the line beam.

したがって、被照射領域上でのビーム照射領域の重なり部の発生割合Ｒ_Ｈは、

となる。 (This embodiment: regular hexagonal beam)
When the length of one side of the regular hexagonal beam is L, the area (irradiation region) S of the regular hexagonal beam can be obtained by Expression (7).

Therefore, the generation ratio _RH of the overlapping portion of the beam irradiation region on the irradiated region is

It becomes.

(Effect 1) As described above, when the method according to the present embodiment is used, the ratio of the overlapped portion is 0.93 as compared with the case where the square beam which is the best in the conventional technique is used in the same irradiation area (irradiation region) S. It is possible to lower it twice, thus reducing the peeling defects.

(Effect 2) In this embodiment, three times of laser irradiation overlap each vertex of the irradiation area | region which exhibits a regular hexagon. On the other hand, in the case of a square beam, the number of times of laser light irradiation is 4 at each vertex. As described above, according to the applicant's research, when the number of laser irradiations increases once, the occurrence rate of peeling defects (overlapping portions) increases by 10 times or more. In the square beam, the number of vertices existing in the irradiated region is A / S, whereas in the regular hexagonal beam, the number of vertices in the irradiated region is doubled to 2 A / S. However, since the separation defect occurrence rate at each vertex is different by 10 times or more, the number of separation defects caused by the vertex is reduced to 1/5 or less in the regular hexagonal beam as compared with the square beam.

(Effect 3) Since the regular hexagonal beam has higher laser use efficiency than the square beam, the beam irradiation area is widened, and the ratio of overlapping portions can be further reduced.

である。したがって、円形ビームの利用効率Ｅｓは、

となり、約６４％である。 The excimer laser has a circular shape with a radius r immediately after transmission. A square is cut out from this circle (see FIG. 4).
The length L of one side of the square inscribed in the circle of radius r is

It is. Therefore, the utilization efficiency Es of the circular beam is

It is about 64%.

である。したがって円形ビームの利用効率Ｅｓは、

となり、約８３％となる。 On the other hand, the length L (see FIG. 5) of one side of a regular hexagon inscribed in a circle with a radius r is

It is. Therefore, the utilization efficiency Es of the circular beam is

And about 83%.

  Therefore, in the case of irradiation with the same energy density, the unit hexagonal beam of the present invention has a unit irradiation region S of 0.827 / 0.636 = 1.300, which is 30% larger than that of the conventional square beam. Become. As a result, the number of times A / S applied to the entire irradiated area A is reduced by 1 / 1.300 = 0.76 times. Therefore, according to the present embodiment, productivity is improved and the ratio of overlapping portions is further reduced, so that peeling defects can be reduced.

  6A and 6B show the side width deviation of the beam shape (irradiation region) of the present invention. (A) is a view focusing on one side of the beam shape, and (b) is an enlarged view of (a). Here, when the length L of one side of the beam shape is 8.4 mm, the side width deviation Δw is 40 μm.

  The reason why the peeling defect occurs is that an unirradiated region that is not irradiated with laser light is generated and that irradiation is performed a plurality of times at an overlapping portion for each irradiation. Therefore, in the present invention, the overlap width at the time of laser irradiation is 1.64 times to 3 times (standard deviation of beam side width + standard deviation of beam size + standard deviation of feed pitch).

Next, the reason why the overlap width at the time of laser irradiation is 1.64 times to 3 times (standard deviation of side width + standard deviation of beam size + standard deviation of feed pitch) will be described.
First, consider the probability that an unirradiated area will occur.
For 1.64-fold the sides difference, shot probability of the non-irradiated regions occurs between the shot 0.050.050.05 = 1.2510 ^-4 becomes even a laser to 2000 shots Not The number of irradiation regions (expected value) is less than 0.5, and no unirradiated region appears in the irradiated region. Since the irradiation region of 10 cm ² degree from 1 cm ^2, if 2000 ^shots, the area of 2000cm 2 (= 40cm50cm second generation glass) 20000 cm from the ² (> ^120cm130cm fifth generation glass) can be processed in one.

In the case of an overlap width three times as large as each deviation, the probability is 0.0015 × 0.0015 × 0.0015 = 3.375 × 10 ⁻⁹ . This is because the probability of deviating from three times the standard deviation is 0.15%, and each deviation is an independent event. In short, an unirradiated region is generated once after irradiation of 300 million times. For example, using a low power laser such as solid-state lasers, even on the assumption that the unit irradiation area is very small and 0.3cm × 0.3cm = 0.09cm ^2, unirradiated and irradiated with 27 million cm ² The probability that a region will appear once. This is no longer sufficient in terms of suppressing the occurrence of unirradiated areas, and it can be said that over-irradiation is over spec. If the overlap width is further increased, the peeling defect caused by the overlap portion cannot be ignored, and the yield is reduced.

  The sum of the deviations varies depending on the type of laser and the optical system, but according to the experience of the present inventors, it is generally about 50 μm to 200 μm. Therefore, when the sum of the deviations is 200 μm which is the largest, the triple is 600 μm. By the way, according to the experiment by the present inventor, the minimum overlap width d when a peeling defect (linear peeling defect) due to the overlapping portion occurs is about 0.8 mm, and the peeling defect due to the overlapping of each vertex (three times). The minimum point diameter when a point-like peeling defect) occurs is about 0.5 mm. This means that if the overlap width is smaller than 0.8 mm, the occurrence of defects can be prevented to some extent even if the probability of occurrence of peeling defects at the overlap portion increases. Further, even if the probability of occurrence of a peeling defect is increased by irradiation three times at the apex, if the overlap width d is 0.5 mm or less, it means that the occurrence of the defect can be suppressed to some extent.

  Of course, when mass production is considered, the ratio of the overlapping portion should be minimized as in the present embodiment. However, if the overlapping width is very narrow, the irradiation irradiated only once around the overlapping portion. A part is peeled off together with the part. In order to reduce the occurrence of linear defects, the width of the overlapping portion is preferably 0.8 mm or less, and in order to reduce the occurrence of point-like defects when irradiated three times, It may be 0.5 mm or less. Therefore, it is preferable to set the overlap width for each irradiation to about 0.6 mm or less. As described above, when the sum of the deviations is 200 μm, which is the largest, 0.6 mm is three times the deviation. Therefore, even from this point, the maximum overlapped portion for each irradiation is 3 of the sum of the deviations. Should be less than double.

  Needless to say, the ideal situation is that there is no overlap or non-irradiation area for each irradiation, but in reality this is not possible, so the beam shape is a regular hexagon and the overlap for each irradiation is as narrow as possible. Minimize the ratio of overlap to the whole body.

As described above, if the overlap width d overlaps 1.67 times or more of the sum of the deviations, the occurrence of the peeling defect due to the unirradiated region can be ignored. On the other hand, if the overlap width d is not more than three times the sum of the deviations, it is possible to minimize the occurrence of peeling defects caused by the overlap portion.
Therefore, with respect to the overlap width, no peeling defect due to the unirradiated region occurs (more than 1.64 times the sum of the deviations), and the peeling defect due to the overlapping portion is minimum (less than 3 times the sum of the deviations). Must be.

である。 (Example)
Excimer laser 1 shot energy: 1J
Energy density required for peeling: 450 mJ / cm ²

Circular beam area (irradiation region) S1 immediately after excimer laser transmission
S = (1J) / (450 mJ / cm ² ) = 2.2222 cm ² ,

Radial beam radius immediately after excimer laser transmission: r
πr ² = 2.2222 cm ² r = 0.842 cm

Side length of regular hexagon inscribed in circular beam: L
L = r = 0.841cm

Due to the above conditions, this regular hexagonal beam area (irradiation region) S2 is

It is.

The standard deviation of the beam side width is 40 μm, the standard deviation of the beam size is 10 μm, the standard deviation of the feed pitch is 40 μm, the total is 90 μm, and the overlap width is doubled to be d = 180 μm. Since it is twice, the probability that an unirradiated area occurs between shots is
It is 0.0220.0220.022 = 1.0610 < ^-5 >.

Area A of transferred object (second generation glass): 2000 cm ²
Then,
Laser irradiation number: A / S2 is
The ^{A / S2 = 2000cm 2 /1.837cm 2} = 1089 times.
As a result, the number (expected value) of unexposed areas between shots is
1.0610 ⁻⁵ 1089 = 0.01. Therefore, an unirradiated area does not appear on the transfer object.

となり、被照射領域全体の２．４７％である。 The occurrence ratio _RH of the overlapping portion in the transferred body is

This is 2.47% of the entire irradiated area.

(Comparative Example 1: Square beam)
In the prior art square beam irradiation, the overlap width was 0.5 mm to 1 mm. However, in order to clarify the superiority of the present invention, the overlap width is the same as that of the present embodiment.

この正方形ビーム面積（照射領域）：Ｓ４

被転写体（第二世代ガラス）の面積Ａ：２０００ｃｍ^２
レーザー照射数：Ａ／S４
Ａ／Ｓ４＝２０００ｃｍ^２／１．４１４ｃｍ^２＝１４１４回
となる。 Excimer laser 1 shot energy: 1J
Energy density required for peeling: 450 mJ / cm ²

Circular beam area (irradiation area) immediately after excimer laser transmission: S3
S3 = (1J) / (450 mJ / cm ² ) = 2.2222 cm ²

Radial beam radius immediately after excimer laser transmission: r
πr ² = 2.2222 cm ² r = 0.842 cm

Side length of square inscribed in circular beam: L

This square beam area (irradiation area): S4

Area A of transferred object (second generation glass): 2000 cm ²
Number of laser irradiation: A / S4
The ^{A / S4 = 2000cm 2 /1.414cm 2} = 1414 times.

The number (expected value) in which an unirradiated area occurs between shots is 1414/1089 = 1.30
That is 30% higher than the present invention. Also, productivity is inferior by 30%.

である。重なり部の発生割合は、０．０３０３／０．０２４７＝１．２３となり、本願発明よりも２３％多い。その分、剥離欠陥も生じやすい。 The occurrence ratio _RH of the overlapping portion in the transferred body is

It is. The generation ratio of the overlapping portion is 0.0303 / 0.0247 = 1.23, which is 23% higher than the present invention. Accordingly, peeling defects are likely to occur.

  Thus, according to the peeling method of this invention, since unit irradiation field S is a regular regular hexagon, separation layer 120 (irradiation field A) is irradiated by irradiating along each side of each unit irradiation field S. Laser light can be irradiated on the entire surface without any gap, and the occurrence of overlapping portions where the laser light overlaps can be significantly reduced as compared with the prior art. Therefore, the occurrence of peeling defects is prevented, and the transfer of the thin film layer 140 to the transfer body 180 is favorably performed, and the yield is improved.

Next, a thin film device transfer method using the thin film layer peeling method of the present invention will be described in detail with reference to the drawings.
"Transfer method for thin film devices"
FIGS. 7 to 12 are process cross-sectional views for explaining a process until a thin film device is transferred to another substrate after the thin film device is formed on the substrate.

[Step 1: Separation layer forming step]
As shown in FIG. 7, a separation layer (light absorption layer) 120 is formed on the substrate 100.

Hereinafter, the substrate 100 and the separation layer 120 will be described.
The substrate 100 preferably has a light-transmitting property that allows light to pass therethrough.

  In this case, the light transmittance is preferably 10% or more, and more preferably 50% or more. If this transmittance is too low, the attenuation (loss) of light increases, and a larger amount of light is required to peel off the separation layer 120.

  The substrate 100 is preferably made of a highly reliable material, and particularly preferably made of a material having excellent heat resistance. The reason is that, for example, when forming the transfer layer 140 and the intermediate layer 142 described later, the process temperature may be high (for example, about 350 to 1000 ° C.) depending on the type and formation method. This is because if the substrate 100 is excellent in heat resistance, the range of setting of film forming conditions such as the temperature condition is widened when forming the transferred layer 140 or the like on the substrate 100.

  Therefore, the substrate 100 is preferably made of a material having a strain point equal to or higher than Tmax, where Tmax is the maximum temperature when the transfer layer 140 is formed. Specifically, the constituent material of the substrate 100 preferably has a strain point of 350 ° C. or higher, and more preferably 500 ° C. or higher. As such a thing, heat resistant glass, such as quartz glass, Corning 7059, Nippon Electric Glass OA-2, is mentioned, for example.

  Further, the thickness of the substrate 100 is not particularly limited, but it is usually preferably about 0.1 to 5.0 mm, and more preferably about 0.5 to 1.5 mm. If the thickness of the substrate 100 is too thin, the strength is reduced, and if it is too thick, light attenuation tends to occur when the transmittance of the substrate 100 is low. When the light transmittance of the substrate 100 is high, the thickness thereof may exceed the upper limit value. Note that the thickness of the substrate 100 is preferably uniform so that light can be uniformly irradiated.

  The separation layer 120 has such a property that it absorbs irradiated light and causes peeling (hereinafter referred to as “in-layer peeling” or “interfacial peeling”) in the layer and / or at the interface. It is preferred that the bonding force between atoms or molecules of the substance constituting the separation layer 120 disappears or decreases due to light irradiation, that is, ablation occurs, leading to in-layer separation and / or interfacial separation.

  Furthermore, the gas may be released from the separation layer 120 by light irradiation, and the separation effect may be exhibited. That is, there are a case where the component contained in the separation layer 120 is released as a gas, and a case where the separation layer 120 absorbs light and becomes a gas for a moment, and its vapor is emitted, contributing to the separation. . Examples of the composition of the separation layer 120 include those described in the following A to E.

A. Amorphous silicon (a-Si)
This amorphous silicon may contain hydrogen (H). In this case, the content of H is preferably about 2 atomic% or more, and more preferably about 2 to 20 atomic%. Thus, when a predetermined amount of hydrogen (H) is contained, hydrogen is released by light irradiation, and an internal pressure is generated in the separation layer 120, which becomes a force for peeling the upper and lower thin films. The content of hydrogen (H) in the amorphous silicon is adjusted by appropriately setting conditions such as film formation conditions such as gas composition, gas pressure, gas atmosphere, gas flow rate, temperature, substrate temperature, and input power in CVD. can do.

B. Various oxide ceramics such as silicon oxide or silicate compound, titanium oxide or titanate compound, zirconium oxide or zirconate compound, lanthanum oxide or lanthanum oxide compound, electrical conductor (ferroelectric), or semiconductor , SiO ₂ and Si ₃ O ₂ , and examples of the silicate compound include K ₂ SiO ₃ , Li ₂ SiO ₃ , CaSiO ₃ , ZrSiO 4, and Na ₂ SiO ₃ .

Titanium _{oxide, TiO, Ti 2 0 3,} Ti0 2 , and examples of titanate compounds, for _{example, BaTi0 4, BaTiO 3, Ba} 2 Ti 9 O 20, BaTi 5 O11, CaTiO 3, SrTiO 3, PbTiO ₃ , MgTiO ₃ , ZrTiO ₂ , SnTiO ₄ , Al ₂ TiO ₅ , FeTiO ₃ .

Examples of the zirconium oxide include ZrO ₂ , and examples of the zirconate compound include BaZrO ₃ , ZrSiO ₄ , PbZrO ₃ , MgZrO ₃ , and K ₂ ZrO ₃ .

C. Ceramics or dielectrics such as PZT, PLZT, PLLZT, PBZT (ferroelectric)

D. Nitride ceramics such as silicon nitride, aluminum nitride, titanium nitride Organic polymer materials Organic polymer materials include -CH-, -CO- (ketone), -CONH- (amide), -NH- (imide), -COO- (ester), -N = N- (azo ), A bond having a bond such as —CH═N— (Schiff) (these bonds are cleaved by light irradiation), particularly any one having a large number of these bonds. The organic polymer material may have an aromatic hydrocarbon (one or more benzene rings or condensed rings thereof) in the structural formula.

  Specific examples of such organic polymer materials include polyolefins such as polyethylene and polypropylene, polyimides, polyamides, polyesters, polymethyl methacrylate (PMMA), polyphenylene sulfide (PPS), polyethersulfone (PES), epoxy resins, and the like. Is mentioned.

F. Examples of the metal include Al, Li, Ti, Mn, In, Sn, Y, La, Ce, Nd, Pr, Gd, Sm, or an alloy containing at least one of them.

  The thickness of the separation layer 120 varies depending on various conditions such as the purpose of peeling, the composition of the separation layer 120, the layer structure, and the formation method, but it is usually preferably about 1 nm to 20 μm, and about 10 nm to 2 μm. More preferably, it is about 40 nm to 1 μm. If the thickness of the separation layer 120 is too small, the uniformity of film formation may be impaired, and peeling may be uneven. If the thickness is too thick, good separation of the separation layer 120 is ensured. In addition, it is necessary to increase the light power (light quantity), and it takes time to remove the separation layer 120 later. Note that the thickness of the separation layer 120 is preferably as uniform as possible.

  The formation method of the separation layer 120 is not particularly limited, and is appropriately selected according to various conditions such as a film composition and a film thickness. For example, CVD (including MOCVD, low pressure CVD, ECR-CVD), vapor deposition, molecular beam vapor deposition (MB), sputtering, ion plating, PVD and other various vapor deposition methods, electroplating, immersion plating (dipping), Various plating methods such as electroless plating, Langmuir Projet (LB) method, spin coating, spray coating, roll coating and other coating methods, various printing methods, transfer methods, ink jet methods, powder jet methods, etc. Two or more of them can be combined to form.

  In the case where the separation layer 120 is made of a sol-gel ceramic or an organic polymer material, it is preferable to form the film by a coating method, particularly spin coating.

Next, the thickness of the separation layer 120 will be described.
As described above, when the separation layer 120 is irradiated with light, ablation occurs. Here, ablation means that the fixing material that absorbs the irradiation light (the constituent material of the separation layer 120) is excited photochemically or thermally, and the bonds of atoms or molecules inside the surface or inside are cut and released. In general, all or part of the constituent material of the separation layer 120 appears as a phenomenon that causes a phase change such as melting or transpiration (vaporization). In addition, the phase change may result in a minute firing state, which may reduce the binding force.

  And it has been found that the absorbed energy required to reach this ablation is lower as the film thickness is thinner. Therefore, by reducing the thickness of the separation layer 120, the energy of the irradiation light can be reduced, and the light source device can be reduced in size while saving energy.

[Step 2: Transferred layer forming step]
Next, as illustrated in FIG. 8, a transfer target layer (thin film device layer) 140 is formed on the separation layer 120.

An enlarged cross-sectional view of a portion K (a portion surrounded by a one-dot chain line in FIG. 8) of the thin film device layer 140 is shown on the right side of FIG. As shown in the figure, the thin film device layer 140 includes, for example, a TFT (thin film transistor) formed on a SiO ₂ film (intermediate layer) 142, and this TFT introduces an n-type impurity into the polysilicon layer. The source / drain layer 146, the channel layer 144, the gate insulating film 148, the gate electrode 150, the interlayer insulating film 154, and the electrode 152 made of, for example, aluminum are formed.

In this embodiment, the SiO 2 film is used as an intermediate layer provided in contact with the separation layer 120, but other insulating films such as Si ₃ N ₄ can also be used. The thickness of the SiO 2 film (intermediate layer) is appropriately determined according to the purpose of formation and the function that can be exhibited, but it is usually preferably about 10 nm to 5 μm, and preferably about 40 nm to 1 μm. More preferred. The intermediate layer is formed for various purposes, for example, a protective layer that physically or chemically protects the transferred layer 140, an insulating layer, a conductive layer, a laser light shielding layer, a barrier layer for preventing migration, or a reflective layer. That exhibit at least one of these functions.

In some cases, the transfer layer (thin film device layer) 140 may be formed directly on the separation layer 120 without forming an intermediate layer such as a SiO ₂ film.

  The transferred layer 140 (thin film device layer) is a layer including a thin film device such as a TFT as shown on the right side of FIG.

  As the thin film device, in addition to the TFT, for example, a thin film diode, a photoelectric conversion element (photosensor, solar cell) or a silicon resistance element composed of a silicon PIN junction, other thin film semiconductor devices, electrodes (eg, ITO, mesa) Transparent electrodes such as films), actuators such as switching elements, memories, piezoelectric elements, micromirrors (piezo thin film ceramics), magnetic recording thin film heads, coils, inductors, thin film highly magnetically permeable materials, and micromagnetic devices combining them, There are filters, reflective films, dichroic mirrors, etc.

  Such a thin film device is usually formed through a relatively high process temperature in relation to its formation method. Therefore, in this case, as described above, the substrate 100 needs to have a high reliability that can withstand the process temperature.

[Process 3: Joining process]
Next, as shown in FIG. 9, the thin film device layer 140 is bonded (adhered) to the transfer body 180 via the adhesive layer 160.

  Preferable examples of the adhesive constituting the adhesive layer 160 include various curable types such as a reactive curable adhesive, a thermosetting adhesive, a photocurable adhesive such as an ultraviolet curable adhesive, and an anaerobic curable adhesive. An adhesive is mentioned. The composition of the adhesive may be any, for example, epoxy, acrylate, or silicone. The adhesive layer 160 is formed by, for example, a coating method.

  In the case of using the curable adhesive, for example, a curable adhesive is applied on the transfer layer (thin film device layer) 140, and the transfer body 180 is bonded thereon, followed by curing according to the characteristics of the curable adhesive. The curable adhesive is cured by a method, and the transfer target layer (thin film device layer) 140 and the transfer body 180 are bonded and fixed.

  When the adhesive is a photo-curing type, light is irradiated from the outside of one of the light-transmitting substrate 100 and the light-transmitting transfer body 180 (or from both the outside of the light-transmitting substrate and the transfer body). As the adhesive, a light curable adhesive such as an ultraviolet curable adhesive that does not easily affect the thin film device layer is preferable.

  Unlike the illustration, an adhesive layer 160 may be formed on the transfer body 180 side, and a transfer target layer (thin film device layer) 140 may be adhered thereon. For example, when the transfer body 180 itself has an adhesive function, the formation of the adhesive layer 160 may be omitted.

  Although it does not specifically limit as the transfer body 180, A board | substrate (plate material), especially a transparent substrate are mentioned. Such a substrate may be a flat plate or a curved plate. Further, the transfer body 180 may be inferior to the substrate 100 in characteristics such as heat resistance and corrosion resistance. The reason for this is that in the present invention, a transfer layer (thin film device layer) 140 is formed on the substrate 100 side, and then the transfer layer (thin film device layer) 140 is transferred to the transfer body 180. This is because the properties, particularly heat resistance, do not depend on the temperature condition or the like when forming the transferred layer (thin film device layer) 140.

  Therefore, when the maximum temperature in forming the transfer layer 140 is Tmax, a material having a glass transition point (Tg) or a softening point equal to or lower than Tmax can be used as the constituent material of the transfer body 0. For example, the transfer body 180 can be made of a material having a glass transition point (Tg) or a softening point of preferably 800 ° C. or lower, more preferably 500 ° C. or lower, and further preferably 320 ° C. or lower.

  Further, the mechanical properties of the transfer body 180 are preferably those having a certain degree of rigidity (strength), but may also be flexible and elastic. In particular, the mechanical characteristics of the transfer body 180 may be determined in consideration of the following points.

  When the separation layer 120 is irradiated with light, the substance constituting the separation layer 120 is photochemically or thermally excited, the surface or internal molecules or atoms are cleaved, and the molecules or atoms are released to the outside. The It is preferable to ensure the yield strength by the mechanical strength of the transfer body 180 so that the stress that acts on the upper layer of the separation layer 120 with the release of molecules or atoms can be received by the transfer body 180. This is because deformation or destruction of the upper layer of the separation layer 120 is prevented.

  Such a proof stress is not limited only to the mechanical strength of the transfer body 180, but is a layer positioned above the separation layer 120, that is, any one of the transferred layer 140, the adhesive layer 160, and the transfer body 180. What is necessary is just to ensure by the mechanical strength of one or several layers. In order to ensure such proof strength, the material and thickness of the layer to be transferred 140, the adhesive layer 160, and the transfer body 180 can be appropriately selected.

  Examples of the constituent material of the transfer body 180 include various synthetic resins or various glass materials. In particular, various synthetic resins and normal (low melting point) inexpensive glass materials are preferable, and the thickness is set in consideration of the above-mentioned proof stress. It can also be determined.

  The synthetic resin may be either a thermoplastic resin or a thermosetting resin. For example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified Polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate, poly- (4-methylbenten-1), ionomer, acrylic resin, polymethyl methacrylate, acrylic-styrene copolymer (AS Resin), butadiene-styrene copolymer, polio copolymer (EVOH), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester such as precyclohexane terephthalate (PCT), poly Ether, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyfluoride Various types of thermoplastic elastomers such as vinylidene fluoride, other fluorine resins, styrene, polyolefin, polyvinyl chloride, polyurethane, fluoro rubber, chlorinated polyethylene, epoxy resins, phenol resins, urea resins, melamine resins, Saturated polyesters, silicone resins, polyurethanes, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these, may be mentioned, and one or more of these may be combined (for example, two layers) As a laminate of the upper) it can be used.

  Examples of the glass material include silicate glass (quartz glass), alkali silicate glass, soda lime glass, potash lime glass, lead (alkali) glass, barium glass, borosilicate glass, and the like. Of these, glass other than silicate glass is preferable because it has a lower melting point than silicate glass, is relatively easy to mold and process, and is inexpensive.

  When the transfer body 180 made of synthetic resin is used, the large transfer body 180 can be integrally formed, and even a complicated shape such as a curved surface or an uneven surface can be easily formed. In addition, various advantages such as low material cost and low manufacturing cost can be obtained. Therefore, the use of a synthetic resin is advantageous in manufacturing a large and inexpensive device (for example, a liquid crystal display).

  The transfer body 180 is a part of a device such as a liquid crystal cell that constitutes an independent device, such as a color filter, an electrode layer, a dielectric layer, an insulating layer, or a semiconductor element. May be included.

  Further, the transfer body 180 may be a substance such as metal, ceramics, stone, or wood paper, or on an arbitrary surface constituting a certain item (on a watch surface, on an air conditioner surface, on a printed circuit board, etc.). ), Or on the surface of a structure such as a wall, pillar, ceiling, or window glass.

[Step 4: Separation step]
Next, as shown in FIG. 10, light is irradiated from the back side of the substrate 100. This light is applied to the separation layer 120 after passing through the substrate 100. Thereby, in-layer peeling and / or interface peeling occurs in the separation layer 120, and the bonding force is reduced or disappears.

  The principle that separation and / or interfacial separation occurs in the separation layer 120 is that the constituent material of the separation layer 120 is ablated, the gas contained in the separation layer 120 is released, and the melting that occurs immediately after irradiation is performed. It is estimated that this is due to phase change such as transpiration.

  Whether the separation layer 120 causes in-layer separation, interfacial separation, or both depends on the composition of the separation layer 120 and various other factors, and one of the factors is irradiation. Conditions such as the type of light, wavelength, intensity, and reaching depth are included.

  The light to be irradiated may be any light that causes separation and / or interfacial separation in the separation layer 120. For example, X-rays, ultraviolet rays, visible light, infrared rays (heat rays), laser light, millimeter waves , Microwave, electron beam, radiation (α ray, β ray, γ ray) and the like. Among these, a laser beam is preferable because it easily causes separation (ablation) of the separation layer 120.

  Examples of the laser device that generates the laser light include various gas lasers, solid-state lasers (semiconductor lasers), and the like. Excimer lasers, Nd-YAG lasers, Ar lasers, CO2 lasers, CO lasers, He-Ne lasers, and the like. Among them, an excimer laser is particularly preferable.

  Since the excimer laser outputs high energy in a short wavelength region, it can cause ablation in the separation layer 120 in a very short time, and thus hardly causes a temperature increase in the adjacent transfer body 180 or the substrate 100. That is, the separation layer 120 can be peeled without causing deterioration or damage.

  Further, when the ablation is caused in the separation layer 120, the wavelength of the irradiated laser light is preferably about 100 nm to 350 nm if there is a wavelength dependency of the light.

  In addition, when the separation layer 120 is given a separation characteristic by causing a phase change such as outgassing, vaporization, and sublimation, the wavelength of the irradiated laser light is preferably about 350 to 1200 nm.

In addition, the energy density of the irradiated laser light, particularly in the case of an excimer laser, is preferably about 10 to 5000 mJ / cm ^2, and more preferably about 100 to 1000 mJ / cm ² . The irradiation time is preferably about 1 to 1000 nsec, more preferably about 10 to 100 nsec. When the energy density is low or the irradiation time is short, sufficient ablation or the like does not occur, and when the energy density is high or the irradiation time is long, the transferred layer 140 is adversely affected by the irradiation light transmitted through the separation layer 120. There is a risk of effect.

  As represented by such laser light, the irradiation light 7 is preferably irradiated so that its intensity is uniform.

  Next, as shown in FIG. 11, a force is applied to the substrate 100 to release the substrate 100 from the separation layer 120. Although not shown in FIG. 11, the separation layer 120 may adhere to the substrate 100 after the separation.

  Next, the remaining separation layer 120 is removed by a method such as cleaning, etching, ashing, polishing, or a combination thereof. As a result, the transfer target layer (thin film device layer) 140 is transferred to the transfer body 180 as shown in FIG.

  If a part of the separation layer 120 is attached to the detached substrate 100, it is removed in the same manner. When the substrate 100 is made of an expensive material such as quartz glass or a rare material, the substrate 100 is preferably used for recycling (recycling). That is, since the present invention can be applied to the substrate 100 that is to be reused, it is highly useful.

  Through the above steps, the transfer of the transfer target layer (thin film device layer) 140 to the transfer body 180 is completed. Thereafter, removal of the SiO 2 film adjacent to the transferred layer (thin film device layer) 140, formation of a conductive layer such as wiring on the transferred layer 140, or a desired protective film can be performed.

  In the thin film device transfer method of the present embodiment, since the thin film layer peeling method described above is used, the transferred layer can be peeled off from the substrate satisfactorily and reliably, and the transferred layer is transferred to the transfer body. can do. Therefore, good separation of the transfer layer from the substrate is always possible, and the yield is improved.

  In the present invention, the layer to be transferred (thin film device layer) 140 itself, which is the object to be peeled, is not peeled directly, but is peeled off at the separation layer bonded to the layer to be transferred (thin film device layer) 140. Regardless of the characteristics, conditions, etc. of the object (transfer target layer 140), it can be peeled (transferred) easily, reliably and uniformly, and damage to the object (transfer target layer 140) due to the peeling operation is also possible. Therefore, the high reliability of the transferred layer 140 can be maintained.

  The preferred embodiments according to the present invention have been described above with reference to the accompanying drawings. However, it goes without saying that the present invention is not limited to such examples, and the above embodiments may be combined. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

It is explanatory drawing which shows the peeling method of the to-be-transferred layer which concerns on one Embodiment of this invention. It is explanatory drawing which shows the laser irradiation method in a isolation | separation process, Comprising: (a) shows a beam scanning direction, (b) shows the overlapping part which irradiation overlaps. It is explanatory drawing which shows the frequency | count of irradiation in an irradiation area | region. It is a figure which shows the conventional beam shape. It is a figure which shows the beam shape of this embodiment. It is a figure which shows the side width deviation of the beam shape of this embodiment. It is process drawing which shows the transfer method of the thin film device of this embodiment. It is process drawing which shows the transfer method of the thin film device following FIG. It is process drawing which shows the transfer method of the thin film device following FIG. It is process drawing which shows the transfer method of the thin film device following FIG. It is process drawing which shows the transfer method of the thin film device following FIG. FIG. 12 is a process diagram illustrating a thin film device transfer method following FIG. 11;

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Substrate, 120 ... Separation layer, 7 ... Laser light (irradiation light), A ... Irradiation area, S ... Irradiation area, G ... Gravity center, 140 ... Transfer target layer (thin film device layer)

Claims (2)

A thin film layer peeling method for peeling a thin film layer existing on a substrate via a separation layer from the substrate,
When the separation layer is irradiated with irradiation light a plurality of times to cause peeling at the inside and / or the interface of the separation layer, and when the thin film layer is detached from the substrate, the unit irradiation region by the irradiation light is substantially a regular hexagon. Yes,
The width of the overlapping part of the irradiation light irradiated a plurality of times is 1.64 times or more and 3 times or less of the sum of the side width deviation of the unit irradiation area, the area deviation of the unit irradiation area, and the scanning feed pitch. A thin film layer peeling method characterized by the above. A separation layer forming step of forming a separation layer on the substrate;
A thin film layer forming step of forming a thin film layer on the separation layer;
A bonding step of bonding a transfer body to the opposite side of the thin film layer from the substrate;
Irradiating the separation layer with light to separate the thin film layer from the substrate, and
A method for transferring a thin film device, wherein the separation step is performed using the method for peeling a thin film layer according to claim 1 .

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