JP2007163640A - Manufacturing method and manufacturing apparatus for liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus of a liquid crystal display device, wherein a uniform ion implantation amount can be obtained over the entire surface of a TFT formation region of a substrate even when ion implantation is performed for every divided region of the TFT formation region and an expensive and large-sized apparatus is not needed. <P>SOLUTION: The apparatus implanting a prescribed ion by irradiating respective divided regions 4l and 4r formed by dividing the TFT formation region of the substrate 4 in the longitudinal direction of an ion beam whose sectional shape is a nearly oblong shape with the ion beam for every divided region 4l and 4r while the position in the short direction is sequentially changed is provided with a mask 15 forming the sectional shape of the ion beam between an ion source 2 of the ion beam and the surface of the substrate 4. The mask 15 is provided with oblong apertures 17 each having aperture amount reduced parts 18 at both end parts thereof and when the adjacent divided regions 4l and 4r are irradiated with the ion beam, at least a part of an irradiation reduced region irradiated with the ion beam by using one aperture amount reduced part 18 is irradiated again with the ion beam by using the other aperture amount reduced part 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a liquid crystal display device including, for example, a thin film transistor.

  In a liquid crystal display device in which a liquid crystal display (LCD) is driven by a driving circuit using thin film transistors (TFT), an amorphous silicon thin film is formed on a glass substrate, for example, in the manufacturing process, and this is formed into polysilicon. After forming the film (poly-Si film), the poly-Si film in the TFT formation region of the glass substrate is patterned, a gate insulating film is formed, and further, the gate electrode is formed and patterned. Subsequently, impurity ions such as boron (B) and phosphorus (P) are implanted into the poly-Si film in the TFT source-drain formation region using the gate electrode as a mask. Thereafter, the implanted ions are activated to form an insulating film, a pixel electrode, and the like.

  In the process of implanting impurity ions in the manufacturing process of such a liquid crystal display device, an ion source in which a cross-sectional shape longer than the lateral width of the TFT formation region of the glass substrate has a substantially thin rectangular shape (ribbon shape) is used and is opposed to the ion source. In this way, ions are implanted into the entire surface of the TFT formation region by scanning the ion beam in the short direction (longitudinal direction of the TFT formation region) once.

  Under these circumstances, there is a demand for manufacturing a liquid crystal display device using a large glass substrate for increasing productivity and a demand for an increase in the size of the display screen of the liquid crystal display device, and accordingly, the TFT formation region of the glass substrate is also large. It is necessary to. Under such circumstances, when ion implantation is performed using an ion beam having a substantially thin rectangular shape longer than the width of the TFT formation region, the ion source required for the ion implantation becomes large, and the ion source For ion beams emanating from, the ion density must be uniform over the long dimension. For this reason, the ion source becomes a large-sized facility and becomes very expensive.

  Therefore, a large TFT formation region is scanned using a substantially narrow rectangular ion beam shorter than the lateral width, and the divided regions divided in the longitudinal direction of the ion beam are sequentially scanned in the short direction for each divided region. It is conceivable to ion-implant the entire formation region. In order to perform ion implantation separately, a shutter mechanism having an opening for selectively setting the ion implantation region is provided in front of the semiconductor wafer, and an ion beam is applied to the ion implantation region of the wafer selected by the shutter mechanism. Is applied to the entire surface of the semiconductor wafer to allow ion implantation (see, for example, Patent Document 1).

However, when each of the divided regions obtained by dividing the large TFT formation region is scanned and ion implantation is performed as described above, depending on the scanning position of the ion beam, another portion ( The ion implantation is performed in a larger amount than the portion other than the boundary part), so that a non-uniform implantation portion such as a peak of the ion implantation amount is formed, and the effective TFT forming region where the ion implantation amount is uniform is reduced. There is a risk of it.
Japanese Patent Laid-Open No. 9-245722

  The present invention has been made in view of the above situation, and the object of the present invention is to provide a TFT formation region even if ion implantation is performed for each divided region of a divided region obtained by dividing the TFT formation region of the substrate. An object of the present invention is to provide a method and an apparatus for manufacturing a liquid crystal display device that can make the ion implantation amount uniform over the entire surface, are not large-sized equipment, and are not expensive.

The manufacturing method and the manufacturing apparatus of the liquid crystal display device of the present invention include:
A manufacturing method of a liquid crystal display device
In a manufacturing method of a liquid crystal display device having an ion implantation process of implanting predetermined ions by sequentially irradiating a thin film transistor forming region of a substrate with an ion beam having a substantially thin rectangular cross-sectional shape while sequentially changing the position in the lateral direction,
The ion implantation step irradiates a divided region obtained by dividing the thin film transistor formation region in the longitudinal direction of the ion beam with the ion beam while sequentially changing the position for each region. The cross-sectional area decreasing portion is provided on both side portions, and when the adjacent divided regions are respectively irradiated, the irradiation reduced region irradiated on one side of the cross-sectional area decreasing portion is set to the other of the next cross-sectional area decreasing portions. It is a method characterized by irradiating repeatedly using
Moreover, the manufacturing apparatus of a liquid crystal display device is
Irradiate each thin film transistor formation region of the substrate by dividing the ion beam in the longitudinal direction of the ion beam having a substantially thin rectangular shape while sequentially changing the position of the ion beam in each lateral region. A liquid crystal display manufacturing apparatus for injecting predetermined ions,
A mask for shaping the cross-sectional shape of the ion beam is provided between the ion source that emits the ion beam and the surface of the substrate, and the mask has a narrow rectangular opening having a reduced opening portion at both ends. When the adjacent divided regions are each irradiated with the ion beam, the irradiation reduced region irradiated with one of the opening amount reduced portions is overlapped at least partially using the other of the opening amount reduced portions. It is formed so that it may irradiate.

  According to the present invention, even if ion implantation is performed for each divided region of the divided region obtained by dividing the TFT formation region of the substrate, the ion implantation amount can be made uniform over the entire TFT formation region. The apparatus required for this is not a large-scale facility, and there is an effect that it is not expensive.

  An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view showing a schematic configuration of a manufacturing apparatus for a liquid crystal display device, FIG. 2 is a view for explaining the mask, FIG. 2A is a plan view schematically showing the mask, and FIG. (B) is a diagram schematically showing the ion amount of the shaped ion beam, FIG. 3 is a plan view showing a first step of ion implantation, and FIG. 4 is a plan view showing a second step of ion implantation. FIG. 5 is a view for explaining ion beams in the first and second steps of ion implantation. FIG. 5A is a view schematically showing the amount of ions irradiated in each step. b) is a diagram schematically showing the amount of synthesized ions in both steps, and FIG. 6 is a plan view schematically showing each modified form of the mask.

  First, in FIG. 1, an ion implantation apparatus 1 which is a manufacturing apparatus of a liquid crystal display device forms a thin film transistor (TFT) in an ion source 2 and a vacuum chamber 3, for example, a polysilicon film (polySi film) on the surface of a glass substrate. And a processing chamber body 5 for carrying out an ion implantation process by introducing a predetermined ion beam such as boron (B) or phosphorus (P) from the ion source 2. Configured. The ion source 2 extracts, for example, predetermined ions in the plasma generated by the plasma unit 6 by the electrode unit 7 or the like, and further externally as an ion beam having a substantially thin rectangular shape (ribbon shape) from the beam radiation opening 8. It is configured to radiate to.

  Further, the processing chamber body 5 is a substrate support base on which a substrate 4 on which a thin film transistor (TFT) is formed is placed in a vacuum chamber 3 maintained in a predetermined reduced pressure state with a poly Si film deposition surface as an upper surface side. 9, an X-direction advancing / retracting mechanism 11 for advancing and retreating the substrate supporting base 9 in the X-direction indicated by a double-pointed arrow while holding the X-direction guide rail 10 at a horizontal position, And a Y-direction advancing / retracting mechanism 13 for advancing and retracting in the Y-direction while holding the substrate support 9 in a horizontal position. Further, a beam introduction opening 14 is formed in the processing chamber body 5 in the ceiling portion of the vacuum chamber 3 above the substrate support 9 provided to be movable in the X and Y directions. Is provided so that the beam radiation opening 8 of the ion source 2 communicates, and the ion beam from the ion source 2 can be introduced into the vacuum chamber 3.

  On the other hand, in the vacuum chamber 3, a mask 15 made of a conductive material that shapes the cross-sectional shape of the introduced ion beam releases the charges charged when the ion beam is irradiated, and the substrate 4 on the substrate support 9 is released. Is attached to a mounting portion 16 projecting inward of the chamber in the vicinity of the beam introduction opening 14 in the ceiling portion so as to be disposed below the beam introduction opening 14 with a predetermined separation distance therebetween. . Further, as schematically shown in FIG. 2A, the mask 15 has a trapezoidal opening having a large ratio between the length in the short side and the length in the long side and having a flat left-right symmetrical shape that is a substantially thin rectangular shape. 17 is formed and is installed in the vacuum chamber 3 with its longitudinal direction coinciding with the X direction. Further, both ends of the opening 17 of the mask 15 have equal end lengths (dimensions in the longitudinal direction), and an opening amount reduction having an equal opening amount linearly decreased so as to gradually decrease the opening amount toward the tip of the end portion. A portion 18 is provided.

  For this reason, the ion beam formed by the mask 15 having the opening 17 has a substantially rectangular shape (ribbon shape) having a cross-sectional area reduced portion formed on the opening amount reducing portion 18 on both side portions. Ion beam. For example, an ion beam is formed in which the total length in the longitudinal direction is 50 cm and the length of each cross-sectional area reduced portion on both side portions is 1 cm. In addition, when the ion beam thus shaped is irradiated, the ion amount is, as schematically shown in FIG. 2B, the ion amount on both sides of the range Da where the ion amount in the ion implantation range is uniform. Decreases in a range Db that gradually decreases toward the end of the range.

  And the ion implantation process to the board | substrate 4 by said ion implantation apparatus 1 is as showing below. That is, in the first step shown in FIG. 3, for example, a substrate 4 made of a square glass substrate with the entire surface being a TFT formation region is placed on a substrate support 9 in a vacuum chamber 3 in a predetermined reduced pressure state with each side It is placed so as to match the X and Y directions. Then, the substrate support 9 is shifted to the left side in the drawing, and the opening decreasing portion 18 on the right side in the drawing of the opening 17 of the mask 15 is positioned outside the right side of the substrate 4 so that the substrate 4 is positioned immediately below the opening 17 of the mask 15.

  Thereafter, the ion beam introduced from the ion source 2 into the vacuum chamber 3 is substantially elongated in cross-sectional shape having cross-sectional area reduced portions on both side portions by the openings 17 having the opening amount reducing portions 18 on both ends of the mask 15. The shaped ion beam is further irradiated onto the upper surface of the substrate 4 continuously. Simultaneously with the irradiation of the ion beam, the Y-direction advance / retreat mechanism 13 irradiates the substrate support 9 at a predetermined speed in the downward direction (short direction of the ion beam) in the figure to the upper side (not shown) of the substrate 4. Transport to be done.

  As a result, ion implantation is mainly performed on the divided region 4r in the right half of the substrate 4. Further, during this ion implantation, the other side of the opening 17 is scanned to irradiate a reduced range Db in which the amount of ions gradually decreases as shown on the right side of FIG. The irradiation reduced region 4p irradiated with the cross-sectional area reduced portion on the left side of the ion beam formed in the aperture reduced portion 18 is an ion implantation amount equal to or smaller than the ion implantation amount in the other divided region 4r. It gradually decreases toward the left end.

  For example, when irradiation is performed with an ion beam whose length in the longitudinal direction is about 50 cm and the length of the cross-sectional area reduction portion on both sides is 1 cm on the substrate 4 having a width of 73 cm, the length of the ion beam The right side portion of about 13 cm is located outside the right side of the substrate 4, and ions are implanted into a region having a width of 37 cm formed mainly by the divided region 4 r of the right half of the substrate 4. Further, the ion beam is irradiated on the left side of the 37 cm wide region where the ion implantation has been performed by the reduced cross-sectional area on one side of the ion beam.

  Further, after the ion implantation into the divided region 4r of the substrate 4 is completed, in the second step shown in FIG. 4, the substrate support 9 is returned to the initial position by the Y-direction advance / retreat mechanism 13 and at the same time by the X-direction advance / retreat mechanism 11 It is transferred in the right direction (longitudinal direction of the ion beam) in the figure and is shifted to the right side in the figure. Then, one opening amount decreasing portion 18 which is the right side of the opening 17 of the mask 15 in the drawing is located on the irradiation decreasing region 4p where the ion implantation has been performed previously, and the other opening amount decreasing portion 18 is the left side of the substrate 4. The lower left portion of the substrate 4 in the drawing is positioned directly below the opening 17 of the mask 15 so as to be located outside the side.

  Thereafter, as in the first step, the ion beam from the ion source 2 is shaped by the openings 17 having the opening amount reducing portions 18 at both ends, and the cross-sectional shape having the cross-sectional area reducing portions on both shaped side portions. However, the upper surface of the substrate 4 is continuously irradiated with a substantially thin rectangular ion beam. Simultaneously with the irradiation of the ion beam, the Y-direction advance / retreat mechanism 13 moves the substrate support 9 downward in the figure at a predetermined speed so that the irradiation is again performed to the upper side (not shown) of the substrate 4.

As a result, ion implantation into the left half of the divided region 4l of the substrate 4 is performed. During this ion implantation,
In order to scan while irradiating a reduced range Db in which the amount of ions gradually decreases as shown on the left side of FIG. 5A to the right side portion of the divided region 4l, it is formed at one opening amount decreasing portion 18 of the opening 17. The irradiation reduced region 4q irradiated with the reduced cross-sectional area on the right side in the figure of the ion beam has an ion implantation amount equal to or less than the ion implantation amount in the other divided region 41 and gradually decreases toward the right end. It has become.

  However, this irradiation reduced region 4q overlaps with the irradiation reduced region 4p in which the ion implantation is performed in the first step, and the amount of ions when the irradiation is performed by the cross-sectional area reduced portions on both sides of the ion beam, that is, overlap. Since the integrated value of the amount of ions at the time of irradiation and the amount of ions in the portion other than the portion where the cross-sectional area is reduced are substantially equal, the irradiation reduced region 4q is formed by two irradiations as shown in FIG. The amount of ions is synthesized, and the amount of ion implantation is substantially equal to the amount of ions implanted in the divided regions 4r and 4l irradiated at portions other than the portion where the cross-sectional area decreases.

  For example, as in the first step, when the width of the substrate 4 is 73 cm, the total length of the ion beam is about 50 cm, and the length of the reduced cross-sectional area of both sides is 1 cm, the left side of the ion beam length of about 13 cm The portion is located outside the left side of the substrate 4, and ions are implanted into a region having a width of 37 cm formed mainly by the left half of the divided region 4 l of the substrate 4. In the first step and the second step, overlapping irradiation is performed on the portion having a width of 1 cm on the right side of the 37 cm wide region where the ion implantation has been performed, by the reduced cross-sectional areas of the ion beam.

  Thus, the substrate 4 whose entire surface is the TFT formation region is ion-implanted substantially evenly, the ions implanted in the subsequent steps are activated, and the formation of the insulating film, the formation of the pixel electrode, and the like are performed.

  As a result, even if ion implantation is performed on each of the divided regions 4l and 4r in the divided regions 4l and 4r obtained by dividing the substrate 4 whose entire surface is the TFT formation region into two parts, ion implantation is performed at the boundary between the divided regions 4l and 4r. Therefore, the ion implantation amount over the entire surface can be made substantially uniform. For this reason, an effective TFT formation region can be made large, and the discard portion can be minimized. In addition, since the ion beam used for this is not of a long size, a large ion source is not required, the ion density can be easily made uniform in the entire region, and the apparatus is large and expensive. It does not become equipment.

  In the above embodiment, the opening 17 of the mask 15 has a flat trapezoidal shape. However, the present invention is not limited to this, and the shape of the reduced cross-sectional area at both end portions of the opening is the same. The ion beam formed at step 1 is irradiated with the cross-sectional area reduced portions on both side portions, and the integrated value of the ion amount when the position is appropriately set and overlapped one by one, and the portion other than the cross-sectional area reduced portion is 1 What is necessary is just to make the amount of ions equal to the number of times of irradiation.

  For example, as shown in FIG. 6A, each of the parallelograms has an opening amount decreasing portion 18a having the same opening amount and an opening amount linearly decreasing toward the end portion. The mask 15a in which the opening 17a is formed may be used. Further, as shown in FIG. 6 (b), the opening amounts are decreased in a curved manner toward the end portions at both ends, for example, when the end edges of both opening amount decreasing portions 18b are connected to each other. The mask 15b in which the opening 17b having the opening amount decreasing portion 18b such that the curves of FIG.

  Further, as shown in FIG. 6 (c), an opening 17c having an opening amount reducing portion 18c at both end portions is a plurality of small openings having, for example, a slit shape in which the opening area is changed in the opening amount reducing portion 18c and other portions. For example, a mask 15c having a configuration in which 19 is distributed in a flat trapezoidal shape may be used. Further, as shown in FIG. 6 (d), the openings 17d having the opening decreasing portions 18d at both ends reduce, for example, a plurality of small circular openings 20 having the same diameter toward the tip at both ends, and are flat trapezoidal. The mask 15d having a configuration in which the small aperture distribution density is changed so as to have a distribution of the above.

  Further, in the above-described embodiment, the ion implantation process to the substrate 4 by the ion implantation apparatus 1 is performed by transferring the ion beam to the substrate 4 while transferring the substrate support base 9 in one direction in both the first process and the second process. In the second step, the substrate 4 is irradiated with an ion beam while being transferred in the opposite direction to the first step, and the reciprocating process of the substrate support 9 is used. You may make it shorten the time which an ion implantation process requires.

  Furthermore, the entire surface of the substrate 4 as a TFT formation region is divided into two in the longitudinal direction of the ion beam by an ion beam having a transverse cross-sectional shape of a substantially thin rectangular shape having cross-sectional area reduction portions on both side portions, and each divided region 4l. , 4r are continuously scanned in the lateral direction, but the substrate having a wider TFT formation region is not shown, but the number of the divided regions is increased in accordance with the length dimension of the ion beam. Similarly, if the region is continuously scanned in the short direction, ions can be implanted into a larger TFT formation region without using a long ion beam. Although not shown, a shutter is provided so as to cross the irradiation path of the ion beam, and when each of the divided regions 4l and 4r is scanned, the ion beam irradiation is intermittently performed by the shutter during the scanning. Only the region that requires implantation may be selectively irradiated.

It is a cross-sectional view which shows schematic structure of the manufacturing apparatus of the liquid crystal display device which is one Embodiment of this invention. 2A and 2B are diagrams for explaining a mask according to an embodiment of the present invention, in which FIG. 2A is a plan view schematically illustrating the mask, and FIG. 2B is a schematic diagram illustrating an ion amount of a formed ion beam. FIG. It is a top view which shows the 1st process of the ion implantation in one Embodiment of this invention. It is a top view which shows the 2nd process of the ion implantation in one Embodiment of this invention. FIG. 5A is a diagram for explaining an ion beam in the first and second steps of ion implantation in one embodiment of the present invention, and FIG. 5A schematically shows the amount of ions irradiated in each step. (B) is a figure which shows typically the synthetic ion amount in both processes. It is a top view showing typically each modification of a mask concerning one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ion implantation apparatus 2 ... Ion source 4 ... Substrate 4l, 4r ... Divided area 11 ... X direction advance / retreat mechanism 13 ... Y direction advance / retreat mechanism 15 ... Mask 17 ... Opening 18 ... Opening amount reduction | decrease part

Claims (7)

In a manufacturing method of a liquid crystal display device having an ion implantation process of implanting predetermined ions by sequentially irradiating a thin film transistor forming region of a substrate with an ion beam having a substantially thin rectangular cross-sectional shape while sequentially changing the position in the lateral direction,
The ion implantation step irradiates a divided region obtained by dividing the thin film transistor formation region in the longitudinal direction of the ion beam with the ion beam while sequentially changing the position for each region. The cross-sectional area decreasing portion is provided on both side portions, and when the adjacent divided regions are respectively irradiated, the irradiation reduced region irradiated on one side of the cross-sectional area decreasing portion is set to the other of the next cross-sectional area decreasing portions. A method of manufacturing a liquid crystal display device, characterized by irradiating with a plurality of layers.   The integral value of the ion amount in the irradiation reduced region when the cross-sectional area reduced portion is irradiated in an overlapping manner is substantially equal to the ion amount in a region other than the irradiation reduced region irradiated with the ion beam. A method for manufacturing a liquid crystal display device according to claim 1. Irradiate each thin film transistor formation region of the substrate by dividing the ion beam in the longitudinal direction of the ion beam having a substantially thin rectangular shape while sequentially changing the position of the ion beam in each lateral region. A liquid crystal display manufacturing apparatus for injecting predetermined ions,
A mask for shaping the cross-sectional shape of the ion beam is provided between the ion source that emits the ion beam and the surface of the substrate, and the mask has a narrow rectangular opening having a reduced opening portion at both ends. When the adjacent divided regions are each irradiated with the ion beam, the irradiation reduced region irradiated with one of the opening amount reduced portions is overlapped at least partially using the other of the opening amount reduced portions. An apparatus for manufacturing a liquid crystal display device, characterized by being formed so as to irradiate.   4. The apparatus for manufacturing a liquid crystal display device according to claim 3, wherein the opening amount decreasing portion has the same length at both end portions of the opening, and the opening amount gradually decreases toward the tip of each end portion.   4. The apparatus for manufacturing a liquid crystal display device according to claim 3, wherein the opening amount decreasing portion has the same opening amount at both ends.   4. The apparatus for manufacturing a liquid crystal display device according to claim 3, wherein at least a part of the opening is formed by a plurality of small openings.   The ion beam irradiation is performed while changing the sequential position for each of the divided regions by placing the substrate on a substrate support and moving the substrate support. 3. An apparatus for manufacturing a liquid crystal display device according to item 3.

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