KR20060106170A - Method for making a poly crystalline silicon thin film and thin film transistor making method for having the same - Google Patents

Abstract

Disclosed are a method of manufacturing a polycrystalline silicon thin film and a method of manufacturing a thin film transistor having the same. A portion of the amorphous silicon thin film formed at the first edge of the substrate is irradiated with a laser beam having a long length and a narrow width to completely liquefy a portion of the amorphous silicon thin film. Silicon grains are grown in the amorphous silicon thin film completely liquefied by a laser beam to crystallize the amorphous silicon thin film. In order to increase the size of the silicon grain to form a polycrystalline silicon thin film, a laser beam having a long length and a narrow width is irradiated while moving to 1/2 or more of the width of the laser beam. In this way, by irradiating the laser beam while moving the laser beam in the first direction by 1/2 or more of the width of the laser beam, a polycrystalline silicon thin film can be produced more quickly.

Description

Method for manufacturing polycrystalline silicon thin film and method for manufacturing thin film transistor having the same {METHOD FOR MAKING A POLY CRYSTALLINE SILICON THIN FILM AND THIN FILM TRANSISTOR MAKING METHOD FOR HAVING THE SAME}

1 is a cross-sectional view showing a manufacturing apparatus for manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention.

2 is a conceptual diagram illustrating a method of manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention.

3 is an enlarged cross-sectional view of part A of FIG. 1.

4A through 4F are cross-sectional views illustrating a process of growing a polycrystalline silicon thin film by the manufacturing method illustrated in FIG. 2.

5A through 5C are plan views illustrating a process of growing a polycrystalline silicon thin film by the manufacturing method illustrated in FIG. 2.

FIG. 6 is a plan view schematically illustrating a polycrystalline silicon thin film completed by the manufacturing method illustrated in FIG. 2.

7A to 7C are plan views illustrating a process of growing a polycrystalline silicon thin film by the method of manufacturing a polycrystalline silicon thin film according to the second embodiment of the present invention.

8 is a plan view schematically illustrating a polycrystalline silicon thin film formed by the manufacturing method illustrated in FIGS. 7A to 7C.

9A to 9D are flowcharts showing in detail steps of a method of manufacturing a thin film transistor according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: laser 20: XY stage

100: substrate 110: transparent substrate

120: oxide layer 130: amorphous silicon thin film

132: solid-state amorphous silicon thin film 134: liquid silicon

140, 150 polycrystalline silicon thin film 142, 152 silicon grain

144 and 154 silicon grain boundaries 146 and 156 protrusions

200: laser beam 300: thin film transistor

310 substrate 320 oxide layer

330 polycrystalline silicon pattern 340 first insulating film

350: second insulating film 360: protective layer

370: pixel electrode G: gate electrode

S: source electrode D: drain electrode

The present invention relates to a method of manufacturing a polycrystalline silicon thin film and a method of manufacturing a thin film transistor having the same, and more particularly, to a method of manufacturing a polycrystalline silicon thin film and a method of manufacturing a thin film transistor having the same.

Conventional Liquid Crystal Display (LCD) has adopted Amorphous Silicon Thin Film Transistor (a-Si TFT) as a switching device, but recently, high quality display quality is required. Poly Crystalline Silicon Thin Film Transistors (poly-Si TFTs) with fast operation speeds are employed.

The polycrystalline silicon thin film transistor (poly-Si TFT) to form a polycrystalline silicon thin film is a method of forming a polycrystalline silicon thin film directly on the substrate, an amorphous silicon thin film is formed on the substrate and the heat treatment of the amorphous silicon thin film And a method of forming a polycrystalline silicon thin film.

In general, since the glass substrate used in the liquid crystal display (LCD) may be deformed in a general heat treatment process of 600 ° C. or more, the method of heat treating the amorphous silicon thin film is used as an excimer laser. Method is used. The Excimer Laser Annealing (ELA) method irradiates the amorphous silicon thin film with a laser beam having a high energy, and the amorphous silicon thin film is formed by instantaneous heating of several tens of nanoseconds (ns). Crystallization has an advantage of not damaging the glass substrate.

In addition, the Excimer Laser Annealing (ELA) method has a fine grain of silicon atoms when the amorphous silicon thin film is melted in a liquid state and solidified into a solid phase. By rearranging in form, a silicon thin film having a relatively high electrical mobility is formed. That is, the polycrystalline silicon thin film transistor, which is formatted by the heat treatment method ELA by the excimer laser, has a high electric mobility when in the switch-on state.

However, in the heat treatment method using the excimer laser, the laser beam is irradiated with the amorphous silicon thin film several times to produce the polycrystalline silicon thin film. As the laser beam is irradiated with the laser beam several times, it is time to produce the polycrystalline silicon thin film. This is a problem that takes a lot.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a method of manufacturing a polycrystalline silicon thin film which reduces the manufacturing time by changing the moving interval of the laser beam.

Another object of the present invention is to provide a method for manufacturing a thin film transistor including the method for producing a polycrystalline silicon thin film.

In order to achieve the above object of the present invention, a method of manufacturing a polycrystalline silicon thin film according to an embodiment irradiates a laser beam having a long length and a narrow width to a portion of an amorphous silicon thin film formed at a first edge of a substrate, thereby providing the amorphous Completely liquefying a portion of the silicon thin film, growing silicon grain in the amorphous silicon thin film completely liquefied by the laser beam, crystallizing the amorphous silicon thin film, and increasing the size of the silicon grain to polycrystalline silicon Irradiating a laser beam having a long length and a narrow width while moving to at least one half of the width in a first direction to form a thin film.

In accordance with another aspect of the present invention, there is provided a method of manufacturing a thin film transistor, including forming an amorphous silicon thin film on a substrate, and forming the amorphous silicon thin film by using a laser beam generated by a laser. Changing to a thin film, etching a portion of the polycrystalline silicon thin film to form a polycrystalline silicon pattern, forming a first insulating film protecting the polycrystalline silicon pattern, and forming a gate electrode on the first insulating film Forming a second insulating film covering the gate electrode and the first insulating film, etching a portion of the first insulating film and the second insulating film to form a contact hole, and forming the contact hole through the contact hole. Forming a source electrode and a drain electrode electrically connected with the polycrystalline silicon pattern.

According to such a method of manufacturing a polycrystalline silicon thin film and a method of manufacturing a thin film transistor having the same, a polycrystalline silicon thin film can be produced more quickly by irradiating a substrate while moving the laser beam in a first direction at least 1/2 of the width of the laser beam. Can be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Example-1 of the polycrystalline silicon thin film manufacturing method>

1 is a cross-sectional view showing a manufacturing apparatus for manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention, Figure 2 is a conceptual diagram showing a method of manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention, 3 is an enlarged cross-sectional view of part A of FIG. 1.

1 to 3, a manufacturing apparatus for manufacturing the polycrystalline silicon thin film 140 includes a laser 10, an XY-stage 20, and a substrate 100.

The laser 10 generates the laser beam 200 intermittently to irradiate the laser beam 200 to the substrate. The laser 10 is preferably an excimer laser for generating a short wavelength, high power and high efficiency laser beam. The excimer laser includes, for example, an inert gas, an inert gas halide, a mercury halide, an inert gas acid compound, and a multiatomic excimer. At this time, the inert gas includes Ar2, Kr2, Xe2, and the like, and the inert gas halide includes ArF, ArCl, KrF, KrCl, XeF, XeCl, and the like. Inert gas acid compounds include ArO, KrO, XeO and the like, and the multiatomic excimer is Kr2F, Xe2F and the like.

The wavelength of the laser beam generated in the excimer laser is in the range of 200 nm to 400 nm, preferably the wavelength of the laser beam is 250 nm or 308 nm. The frequency of the laser beam is in the range of 300 Hz to 6000 Hz, preferably in the range of 4000 Hz to 6000 Hz.

The XY-stage 20 supports the substrate 100 and repeatedly moves the substrate 100 little by little at regular intervals. For example, the XY-stage 20 moves the substrate 100 little by little from right to left at regular intervals.

Each time the XY-stage 20 repeatedly moves the substrate 100 little by little, the laser beam 200 generated by the laser 10 is relatively the first end 102 of the substrate 100. ) Is irradiated to the substrate 100 while being moved little by little to the second end 104 of the substrate 100. In this case, the first end 102 of the substrate 100 refers to the left end of the substrate 100, and the second end 104 of the substrate 100 refers to the right end of the substrate 100. Alternatively, the XY-stage 20 may move the substrate 100 little by little from left to right at regular intervals.

The substrate 100 is disposed on the XY-stage 20 and includes a transparent substrate 110, an oxide layer 120, and an amorphous silicon thin film 130. The size of the substrate 100 varies depending on the application, but for example, has a size of 470 mm X 360 mm.

The transparent substrate 110 is disposed on the XY-stage 20 and formed of glass or quartz to allow light to pass through. The oxide layer 120 is formed on the transparent substrate 110 and improves an interface property between the transparent substrate 110 and the amorphous silicon thin film 130. The amorphous silicon thin film 130 is formed on the oxide layer 120 by chemical vapor deposition, and is made of amorphous silicon (a-Si).

The laser beam 200 generated by the laser 10 is irradiated onto the amorphous silicon thin film 130 to instantly melt a portion of the amorphous silicon thin film 130. The molten amorphous silicon thin film 130 rapidly causes solid phase crystallization, and as a result, a polycrystalline silicon thin film 140 composed of poly crystalline silicon (p-Si) is formed.

4A through 4F are cross-sectional views illustrating a process of growing a polycrystalline silicon thin film by the manufacturing method illustrated in FIG. 2. Specifically, FIG. 4A illustrates a process in which a portion of the amorphous silicon thin film is liquefied by a laser beam, FIG. 4B illustrates a process in which liquefied silicon is grown on both sides, and FIG. 4C is a lateral growth of liquefied silicon. 4d illustrates a process of liquefying the protrusion by again irradiating a laser beam, and FIG. 4e illustrates a process of growing liquefied silicon back to both sides, and FIG. 4f. Shows the process of forming the protrusion again in the center by the lateral growth of the liquefied silicon.

Referring to FIG. 4A, first, a substrate 100 on which the amorphous silicon thin film 130 is formed and a laser 10 generating the laser beam 200 are prepared. The substrate 100 is disposed on the XY-stage 20, and the laser beam 200 is preferably a beam having a narrow width and a long length.

Subsequently, the laser beam 200 generated by the laser 10 is irradiated onto a portion of the amorphous silicon thin film 130 formed at the first end 102 of the substrate 100. A portion of the amorphous silicon thin film 130 irradiated with the laser beam 200 is liquefied to cause phase deformation into liquid phase silicon 134, and other portions are not liquefied. The solid amorphous silicon thin film 132 is maintained.

In this case, the laser beam 200 preferably has an energy density capable of liquefying the amorphous silicon thin film 134 by one irradiation, but, alternatively, the laser beam 200 has the amorphous silicon thin film several times. 130 may be irradiated to liquefy the amorphous silicon thin film 130.

Referring to FIG. 4B, the liquid silicon 134 subsequently grows in a direction facing the solid amorphous silicon thin film 132 on both sides of the non-liquefied side, thereby performing solid phase crystallization. In this case, the solid amorphous silicon thin film 132 serves as a nucleus of silicon grains for growing the liquid silicon 134. That is, as the solid amorphous silicon thin film 132 acts as a nucleus in the growth of the silicon grain, the liquid silicon 134 is laterally grown by half of the width of the laser beam 200 from both sides. growth).

Referring to FIG. 4C, as the liquid silicon 134 grows laterally from both sides, a protrusion 146 having a predetermined height is formed at the center of both sides. The protrusion 146 is formed as the side growth of the liquid silicon 134 meets at the centers of both sides, thereby reducing the electrical mobility of the polycrystalline silicon thin film 140. Thus, the protrusion 146 is preferably removed from the silicon thin film that requires high electrical mobility.

Referring to FIG. 4D, the laser beam 200 is moved from the first end 102 of the substrate 100 to the second end 104 by a predetermined interval to irradiate the substrate 100 again, thereby providing the protrusion. 146 is liquefied and removed. That is, as the laser beam 200 is irradiated to the substrate 100 again, not only the protrusion 146 is liquefied, but also a part of the polycrystalline silicon thin film and a part of the amorphous chamber silicon thin film are liquefied, and thus the Liquid silicon 134 is formed. At this time, the movement interval of the laser beam 200 preferably has a distance that can completely liquefy the protrusion 146.

Referring to FIG. 4E, the liquid silicon 134 formed by liquefaction again grows in a direction facing from the solid amorphous silicon thin film 132 on both sides, and solid crystallization is performed again. When the second solid phase crystallization is performed, the polycrystalline silicon thin film 142 disposed on the left side from the center of the liquid silicon 134 grows longer to the right side while absorbing the liquid silicon 134, whereas the liquid silicon The amorphous silicon thin film 132 disposed to the right from the center of 134 grows to the left by half the width of the laser beam 200.

Referring to FIG. 4F, as the liquid silicon 134 grows laterally from both sides, protrusions 146 having predetermined heights are formed at the centers of both sides.

As such, when the protrusion 146 is formed again, the laser beam 200 is again moved by a predetermined interval to liquefy the protrusion 146, and the liquefied liquid silicon 134 is further grown laterally. By repeating the process that occurs, it is possible to form the polycrystalline embodiment thin film 140 having a higher electrical mobility.

5A through 5C are plan views illustrating a process of growing a polycrystalline silicon thin film by the manufacturing method illustrated in FIG. 2. Specifically, FIG. 5A shows a simplified polycrystalline silicon thin film when the laser beam is first irradiated, and FIG. 5B shows a simplified polycrystalline silicon thin film when the laser beam is irradiated a second time, and FIG. 5C It is a simplified illustration of the polycrystalline silicon thin film when the laser beam is irradiated for the third time.

Referring to FIG. 5A, a laser beam 200 generated by the laser 10 is first irradiated onto a portion of the amorphous silicon thin film 130. A portion of the amorphous silicon thin film 130 irradiated with the laser beam 200 is instantly melted to change into the liquid silicon 134, and the liquid silicon 134 is the solid silicon thin film on both sides of the liquid layer that is not liquefied. Lateral growth occurs from 132.

When lateral growth of the liquid silicon 134 occurs, the solid silicon thin films 132 on both sides serve as nuclei for growth. As the nucleus of the silicon grows while absorbing the liquid silicon 134, a plurality of silicon grains 142 are generated. The silicon grains 142 are further grown while absorbing the liquid silicon 134 and meet each other. The silicon grains 142 meet each other, and the silicon grains 142 are disposed between the silicon grains 142. 144 are formed.

As the silicon grains 142 grow side by side, a protrusion 144 having a predetermined height is formed at the center of both sides. The protrusion 144 is formed almost straight along the center of both sides corresponding to half of the width of the laser beam 200.

Referring to FIG. 5B, the laser beam 200 is irradiated a second time to a portion of the polycrystalline silicon thin film 140 and a portion of the amorphous silicon thin film 130 by moving a predetermined interval. In this case, the first moving width D1 of the laser beam 200 preferably has an interval less than half of the width in the short axis direction of the laser beam 200 so as to liquefy and remove the protrusion 146. . For example, the moving width D1 of the laser beam 200 is in a range of 1 um to 4 um.

In addition, when the laser beam 200 is excessively irradiated onto the amorphous silicon thin film 130, a shape in which the amorphous silicon thin film 130 is peeled off by the laser beam 200 may occur. In order to prevent the amorphous silicon thin film 130 from peeling off, an area where the first irradiated laser beam 200 and the second irradiated laser beam 200 overlap with each other is equal to the total area of the laser beam 200. It is preferable that it is 90% or less.

As the laser beam 200 is irradiated a second time, the protrusion 144, a part of the polycrystalline silicon thin film 140, and a part of the amorphous silicon thin film 130 are dissolved to form the liquid silicon 134 again. do. On the left side of the liquid silicon 134 is the polycrystalline silicon thin film 140 formed during the first irradiation of the laser beam 200, and on the right side of the liquid silicon 134, the existing solid-state amorphous silicon thin film ( 132).

In this case, the silicon grains 142 in the polycrystalline silicon thin film 140 grow longer to the right while absorbing the liquid silicon 134, and the solid amorphous silicon thin film 132 also forms the liquid silicon 134. Absorb and grow to form new silicon grains 142 to the left. As the silicon grains 142 grow laterally, new protrusions 146 having a predetermined height are formed at the center of both sides.

Referring to FIG. 5C, the laser beam 200 is moved again by a predetermined interval, and is irradiated to a part of the polycrystalline silicon thin film 140 and a part of the amorphous silicon thin film 130 for the third time. In this case, the second moving width D2 of the laser beam 200 preferably has the same size as the first moving width D2, and the new projection 146 is melted and removed so that the laser beam 200 is removed. Spacing less than half the width of

As the laser beam 200 is irradiated for the third time, a part of the polycrystalline silicon thin film 140 and a part of the amorphous silicon thin film 130 are dissolved to form the liquid silicon 134 again. In this case, the silicon grains 142 of the polycrystalline silicon thin film 140 on the left side of the liquid silicon 134 grow longer to the right while absorbing the liquid silicon 134, and the liquid silicon 134 The solid-state amorphous silicon thin film 132 on the right side of the γ grows by absorbing the liquid silicon 134 and forming new silicon grains 134 to the left. As these silicon grains 142 grow laterally, another new protrusion 146 having a predetermined height is formed at the center of both sides.

As described above, as the silicon grains 142 grow side by side while repeatedly generating and dissipating the protrusion 146, the polycrystalline execution cone thin film 140 having a higher electric mobility may be formed.

FIG. 6 is a plan view schematically illustrating a polycrystalline silicon thin film completed by the manufacturing method illustrated in FIG. 2.

Referring to FIG. 6, the polycrystalline silicon thin film 140 completed by the manufacturing method includes a plurality of silicon grains 142 and a plurality of silicon grain boundaries 144.

The silicon grains 142 have shapes grown in parallel from left to right or left to right, respectively. The silicon grain boundaries 144 are also formed in parallel directions by the shape of the silicon grains 142. Thus, the polycrystalline silicon thin film 140 has high electrical mobility from left to right or from right to left, while having low electrical mobility from top to bottom or bottom to top. As such, the reason why the polycrystalline silicon thin film 140 has low and high electrical mobility is due to the movement of electrons and holes due to the silicon grain boundaries 144 formed in parallel from left to right. Because it is disturbed.

According to the present exemplary embodiment, the laser beam 200 is moved at predetermined intervals and repeatedly irradiated onto the amorphous silicon thin film 130, thereby increasing the size of the silicon crystals 142. Can be formed.

<Example 2 of the polycrystalline silicon thin film manufacturing method>

Except for the polycrystalline silicon thin film, the method of manufacturing the polycrystalline silicon thin film according to the second embodiment of the present invention has the same configuration as the method of manufacturing the polycrystalline silicon thin film of the first embodiment described above, and thus the duplicated description thereof will be omitted. The same reference numerals and names are used for the components.

7A to 7C are plan views illustrating a process of growing a polycrystalline silicon thin film by the method of manufacturing a polycrystalline silicon thin film according to the second embodiment of the present invention. Specifically, FIG. 7A illustrates a simplified polycrystalline silicon thin film when the laser beam is first irradiated, and FIG. 7B illustrates a simplified polycrystalline silicon thin film when the laser beam is irradiated a second time, and FIG. It is a simplified illustration of the polycrystalline silicon thin film when the laser beam is irradiated for the third time.

Referring to FIG. 7A, the laser beam 200 generated by the laser 10 is first irradiated onto a portion of the amorphous silicon thin film 130. A portion of the amorphous silicon thin film 130 irradiated with the laser beam 200 is instantly melted to change into the liquid silicon 134, and the liquid silicon 134 is the solid silicon thin film on both sides of the liquid layer that is not liquefied. Lateral growth occurs from 132.

When lateral growth of the liquid silicon 134 occurs, the solid silicon thin films 132 on both sides serve as nuclei for growth. As the nucleus of the silicon grows while absorbing the liquid silicon 134, a plurality of silicon grains 152 are generated. The silicon grains 152 are further grown while absorbing the liquid silicon 134 and meet each other, and silicon grain boundaries 154 are formed between the silicon grains 152 as the silicon grains 152 meet each other. do.

As the silicon grains 152 grow laterally, protrusions 154 having a predetermined height are formed at the centers of both sides. The protrusion 154 is formed almost straight along the center of both sides corresponding to half of the width of the laser beam 200.

Referring to FIG. 7B, the laser beam 200 is irradiated a second time to a portion of the polycrystalline silicon thin film 150 and a portion of the amorphous silicon thin film 130 by moving a predetermined interval. In this case, the first moving width B1 of the laser beam 200 is an interval between the width of the laser beam 200 and less than half the width of the laser beam 200 so as not to remove the protrusion 156. It is preferable to have.

As the laser beam 200 is irradiated for the second time, part of the polycrystalline silicon thin film 150 and part of the amorphous silicon thin film 130 are dissolved to form the liquid silicon 134 again. On the left side of the liquid silicon 134 is the polycrystalline silicon thin film 150 formed at the first irradiation of the laser beam 200, and on the right side of the liquid silicon 134, the existing solid-state amorphous silicon thin film ( 132).

In this case, the silicon grains 152 in the polycrystalline silicon thin film 150 grow to the right while absorbing the liquid silicon 134, and the solid amorphous silicon thin film 132 also absorbs the liquid silicon 134. Thereby forming new silicon grains 152 to the left. As the silicon grains 152 grow laterally, a new protrusion 156 having a predetermined height is formed at the center of both sides.

Referring to FIG. 7C, the laser beam 200 is irradiated to a portion of the polycrystalline silicon thin film 150 and a portion of the amorphous silicon thin film 130 by moving the predetermined distance again. In this case, the second moving width B2 of the laser beam 200 preferably has the same size as the first moving width B2, and the laser beam 200 does not remove the new protrusion 156. At least half of the width of the interval between the width of the laser beam 200 and less.

As the laser beam 200 is irradiated for the third time, a part of the polycrystalline silicon thin film 150 and a part of the amorphous silicon thin film 130 are dissolved to form the liquid silicon 134 again. At this time, the silicon grains 152 of the polycrystalline silicon thin film 150 on the left side of the liquid silicon 134 grow long to the right while absorbing the liquid silicon 134, and The solid amorphous silicon thin film 132 on the right side grows by absorbing the liquid silicon 134 and forming new silicon grains 134 to the left. As these silicon grains 152 grow laterally, another new protrusion 156 having a predetermined height is formed at the center of both sides.

As such, by removing the protrusion 156 formed by the lateral growth of the liquid silicon 134 and irradiating the amorphous silicon thin film 130 with the laser beam 200 having a larger moving width, The time required to form the polycrystalline silicon thin film 150 can be shortened.

8 is a plan view schematically illustrating a polycrystalline silicon thin film formed by the manufacturing method illustrated in FIGS. 7A to 7C.

Referring to FIG. 8, the polycrystalline silicon thin film 150 completed by the manufacturing method includes a plurality of silicon grains 152, a plurality of silicon grain boundaries 154, and a plurality of protrusions 150.

Each of the protrusions 150 are formed in parallel in parallel from top to bottom. The silicon grains 152 may be formed to have a predetermined size between the protrusions 150. The silicon grain boundaries 154 are formed in a direction perpendicular to the protrusions 150 or in a slightly oblique direction between the protrusions 150. In addition, the silicon grains 152 and the silicon grain boundaries 154 are also formed at the edge of the polycrystalline silicon thin film 150.

Since the polycrystalline silicon thin film 150 includes the protrusion 156, the polycrystalline silicon thin film 150 has a lower electric mobility than the polycrystalline execution cone thin film that does not include the protrusion 156. Therefore, the polycrystalline silicon thin film 150 is preferably used to manufacture a PMOS device that does not require very high characteristics.

According to the present embodiment, by irradiating the amorphous silicon thin film 130 with the laser beam 200 to have a larger moving width, the polycrystalline silicon thin film 150 that does not require high characteristics can be manufactured at a faster time. have.

<Example of Manufacturing Method of Thin Film Transistor>

9A to 9D are flowcharts showing in detail steps of a method of manufacturing a thin film transistor according to an exemplary embodiment of the present invention. Specifically, FIG. 9A illustrates a process of forming a polycrystalline silicon pattern on a substrate, and FIG. 9B illustrates a process of forming a first insulating film and a drain electrode on the polycrystalline silicon pattern, and FIG. 9C illustrates a second insulating film on a drain electrode. And a contact hole are formed, and FIG. 9C illustrates a process in which a source electrode and a drain electrode are formed through the contact hole.

Referring to FIG. 9A, a thin film transistor manufacturing method first forms an oxide layer 320 on a transparent substrate 310, and then forms an amorphous silicon thin film on the oxide layer 320.

The amorphous silicon thin film is converted into a polycrystalline silicon thin film by a laser beam. The process of forming the polycrystalline silicon thin film will be described in detail. First, a substrate 310 on which the amorphous silicon thin film is formed and a laser for generating the laser beam are prepared. The laser beam preferably has a long length and a narrow width. Subsequently, the laser beam is irradiated to a portion of the amorphous silicon thin film formed at the first end of the substrate 310 to liquefy a portion of the amorphous silicon thin film. Silicon grains are grown in the liquefied amorphous silicon thin film to solidify the liquefied amorphous silicon thin film. By repeatedly irradiating the laser beam from the first end to the second end facing the first end at a predetermined interval, the size of the silicon grain is increased to form a polycrystalline silicon thin film.

In the polycrystalline silicon thin film formed by the laser beam, a portion of the polycrystalline silicon thin film is removed by plasma etching or the like to form a polycrystalline silicon pattern 330.

Referring to FIG. 9B, a first insulating layer 340 is formed to cover the polycrystalline silicon pattern 330 to protect the polycrystalline silicon pattern 330. The first insulating layer 340 may be formed by, for example, plasma enhanced chemical vapor deposition (PECVD).

Subsequently, a gate electrode G is formed on the first insulating layer 340. The gate electrode G is preferably disposed at the center of the polycrystalline silicon pattern 330. The gate electrode G is formed by, for example, etching after a metal material is deposited.

Referring to FIG. 9C, a second insulating layer 350 is formed to cover the gate electrode G and the first insulating layer 340. The second insulating film 350 may be formed by PECVD, and the thickness of the second insulating film 350 may have a predetermined thickness or more for improving reliability of the thin film transistor 300 and preventing crosstalk. In one example, the thickness of the second insulating film 350 is 6000 Å or more.

Subsequently, a portion of the first insulating layer 340 and a portion of the second insulating layer 350 are etched to form a contact hole. The contact hole includes a first contact hole 352 formed to be spaced a predetermined distance to the left of the gate electrode G and a second contact hole 354 formed to be spaced a predetermined distance to the right of the gate electrode G. .

Referring to FIG. 9D, a source electrode S and a drain electrode D are electrically connected to the polycrystalline silicon pattern 340 through the contact hole. In this case, the source electrode S is electrically connected to the polycrystalline silicon pattern 340 through the first contact hole 352, and the drain electrode D is connected through the second contact hole 354. It is electrically connected to the polycrystalline silicon pattern 340.

Subsequently, a protective layer 360 covering and protecting the source electrode S and the drain electrode D is formed on the second insulating layer 350. After being formed on the second insulating layer 350, a portion of the second insulating layer 350 is etched to form a pixel contact hole 362. A transparent pixel electrode 370 is formed on the passivation layer 360 to be electrically connected to the drain electrode D by the pixel contact hole 362.

According to the present exemplary embodiment, the thin film transistor 300 having higher electrical characteristics may be manufactured by forming the polycrystalline silicon pattern 340 having high electrical mobility by the laser beam.

Although the thin film transistor 300 illustrated in FIGS. 9A to 9D has been described as a top gate thin film transistor as an example, the thin film transistor 300 may also be applied to a bottom gate thin film transistor.

According to such a method of manufacturing a polycrystalline silicon thin film and a method of manufacturing a thin film transistor having the same, the polycrystalline silicon thin film which does not require high characteristics by moving a laser beam to at least 1/2 of the width of the laser beam by irradiating an amorphous silicon thin film. Can be prepared at a faster time.

Although the detailed description of the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described below. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (5)

Irradiating a laser beam having a long length and a narrow width on a portion of the amorphous silicon thin film formed at the first edge of the substrate to completely liquefy a portion of the amorphous silicon thin film; Growing silicon grains in the amorphous silicon thin film completely liquefied by the laser beam to crystallize the amorphous silicon thin film; And And irradiating a laser beam having a long length and a narrow width in a first direction while moving at least 1/2 of the width to increase the size of the silicon grain to form a polycrystalline silicon thin film. Method for producing a silicon thin film. The method of claim 1, wherein the moving distance of the laser beam is smaller than a width of the laser beam and is larger than 1/2 of the width of the laser beam. The method of claim 1, wherein the laser beam has a moving distance in a range of about 1 μm to about 4 μm. The method of claim 1, wherein a length of the laser beam is the same as a length of one side of the substrate. Forming an amorphous silicon thin film on a substrate; Moving a laser beam to at least 1/2 the width of the beam to irradiate the amorphous silicon thin film to form a polycrystalline silicon thin film; Etching a portion of the polycrystalline silicon thin film to form a polycrystalline silicon pattern; Forming a first insulating film to protect the polycrystalline silicon pattern; Forming a gate electrode on the first insulating film; Forming a second insulating film covering the gate electrode and the first insulating film; Etching a portion of the first insulating film and the second insulating film to form a contact hole; And A method of manufacturing a thin film transistor comprising forming a source electrode and a drain electrode electrically connected to the polycrystalline silicon pattern through the contact hole. Forming the polycrystalline silicon thin film Irradiating a laser beam having a long length and a narrow width to a portion of the amorphous silicon thin film formed at the first edge of the substrate to completely liquefy a portion of the amorphous silicon thin film; Growing silicon grains in the amorphous silicon thin film completely liquefied by the laser beam to crystallize the amorphous silicon thin film; And And irradiating a laser beam having a long length and a narrow width in a first direction while moving at least 1/2 of the width in order to increase the size of the silicon grain to form a polycrystalline silicon thin film. Method for manufacturing a transistor.

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