KR101949389B1 - Method of forming pattern using mask-less exposure equipment - Google Patents

Abstract

A pattern forming method using a maskless exposure apparatus having an exposure head unit including a digital micro-mirror device, the pattern forming method comprising: a first region where light is not irradiated onto a substrate through the digital micro-mirror device; A second region where light is irradiated with a first energy density per unit area and a third region where light is formed with a second energy density smaller than the first energy density per unit area, Wherein the data pattern type applied to the digital micro-mirror device controlling the irradiation is one or more bar-shaped patterns having a first width and a first spacing, The beam spots spaced apart from each other by the pattern information having the bar shape applied to the substrate And the third region is largely changed with respect to the third region.

Description

[0001] The present invention relates to a pattern forming method using a maskless exposure apparatus,

The present invention relates to a pattern forming method using a maskless exposure apparatus, and more particularly, to a method of forming an exposure pattern having different thicknesses by one exposure and a method of manufacturing an array substrate for a display using the method.

In recent years, as the society has become a full-fledged information age, a display field for processing and displaying a large amount of information has rapidly developed, and various flat panel display devices have been developed in response to this.

Specific examples of such flat panel display devices include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display (FED) (ELD), organic light emitting diodes (OLED), and the like. These flat panel display devices are excellent in performance of thinning, light weight, and low power consumption, and can be applied to a conventional cathode ray tube ).

Meanwhile, in such a flat panel display manufacturing process, a thin film deposition process for forming a thin film layer of a predetermined material on the substrate surface, a photolithography process for exposing a selected portion of the thin film, An etching process for patterning in a desired shape is repeated several times, and numerous processes such as cleaning and cutting are carried out.

Here, in the photolithography process, a photoresist (hereinafter referred to as PR) is coated on a substrate on which a thin film is deposited, and then an exposure mask having a pattern of a desired shape is faced to expose and develop a PR pattern having the same shape as the pattern of the mask is formed, and a material pattern of a desired shape is formed by etching a material layer located under the pattern using a specific type of PR pattern thus formed.

However, the exposure process using the exposure mask used in such a photolithography process is very complicated and complicated, requiring a long manufacturing time and requiring a high manufacturing cost. That is, the unit cost of the fine patterned exposure mask itself is very expensive, and when a desired pattern shape is changed, a separate exposure mask is newly required, which ultimately raises the manufacturing cost of the display device.

On the other hand, as a display device with a high resolution is required in recent years, the manufacturing cost and the management cost of a mask for exposing a high-resolution fine circuit pattern are also increased, so that the manufacturing cost of the mask type exposure process increases exponentially.

Therefore, in order to solve the problem of the exposure method using the exposure mask, a mask-less exposure process which can realize an ultrafine circuit without requiring a separate exposure mask, This is a trend.

In this case, the maskless exposure process has pattern information made of a control signal using a DMD (Digital Micro-mirror Device), in which a plurality of micromirrors of the DMD transmit a beam incident at a predetermined angle at a desired angle, The other beam can be sent at different angles to form a pattern through a method of selectively reaching only the necessary beam to the substrate.

Here, in the maskless exposure apparatus using the DMD, the exposure beam is modulated by on / off control of each of the micro mirrors of the DMD based on control signals generated according to pattern data designed using a CAD or the like, The modulated exposure beam is selectively irradiated onto the PR layer formed on the substrate.

Therefore, maskless exposure using the DMD has a great advantage in terms of manufacturing cost compared to the exposure method using a conventional exposure mask in that it does not require an exposure mask for each pattern.

However, since maskless exposure using such a DMD selectively irradiates light at a specific position or only through the image information that is not irradiated, the amount of light transmitted through the mask is different from that of a conventional exposure mask through one exposure process , It is not possible to form PR patterns of different thicknesses through halftone exposure or diffraction exposure in the present state.

Therefore, the maskless exposure increases the number of exposing processes per exposure process using an exposure mask, and thus, there is room for improvement in terms of productivity per manufacturing time.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a pattern forming method capable of forming a PR pattern having different thicknesses by exposure with a single exposure, To reduce the number of exposures and the exposure time of the exposure process itself in the maskless exposure process, thereby improving the productivity per unit time.

According to an aspect of the present invention, there is provided a pattern forming method using a maskless exposure apparatus having an exposure head unit including a digital micro-mirror device, A first region where light is not irradiated onto the substrate through the digital micromirror device and a second region where light is irradiated with a first energy density per unit area and a second region where light is irradiated with light having a first energy density per unit area A third region formed with a small second energy density is defined and a data pattern shape applied to the digital micro-mirror device controlling light irradiation to the third region is a data pattern shape having a first width and a first spacing distance And the third region is a pattern of a bar shape, Bar by the pattern information in the form to be applied is characterized by the separation distance of the beam spot is irradiated on the substrate is significantly altered compared to the third region.

At this time, the first width and the first spacing distance are 0.5 to 2 탆.

According to another aspect of the present invention, there is provided a pattern forming method using a maskless exposure apparatus having a digital micro-mirror device, A second region in which light is irradiated with a first energy density per unit area and a third region in which light is formed with a second energy density smaller than the first energy density per unit area, And the data pattern pattern applied to the digital micro-mirror device controlling the light irradiation to the third area is a mosaic pattern in which a rectangular open area and a cloth area are alternately and half-widthed, Wherein the micro-mirror device is a micro-mirror device, The spacing distance of the beam spot irradiated on the plate is largely changed compared to the third region.

At this time, the open region or the cloth region of the rectangular shape is characterized in that one side of each square is 0.5 to 2 탆.

The photoresist layer may include a photoresist layer formed on the substrate and developing the photoresist layer after the photoresist layer is exposed through the maskless exposure apparatus, A photoresist pattern having a first thickness is formed or completely removed in the first region or a third region and a photoresist pattern having a second thickness smaller than the first thickness is formed in the second region .

The maskless exposure apparatus includes a light source, a stage for placing the exposure head unit and the substrate, and the exposure head unit further includes a light source and an exposure optical system, wherein the exposure optical system includes a microlens array, a filter and a projection lens .

The micro-mirror device includes a plurality of memory cells. When the data pattern information is applied to the memory cell, an angle of a microlens included in the micro-mirror device is changed to change a reflection path of incident light And the light source is preferably a semiconductor laser or an ultraviolet lamp.

As described above, the present invention controls the energy density per unit area of light reaching the substrate through the DMD by inputting a bar-type or mosaic-type data pattern having a specific width and a spacing, It is possible to reduce the number of exposures and the exposure time of the maskless exposure process itself in manufacturing the array substrate for a display device, thereby improving the productivity per unit time.

Further, since the thickness of the PR pattern can be finely adjusted by controlling the energy density per unit area of light reaching the substrate through the DMD, it is possible to selectively form different PR patterns of three different thicknesses.

1 is a front view schematically showing a maskless exposure apparatus according to an embodiment of the present invention;
2 is a plan view showing a beam spot array by the maskless exposure apparatus of FIG.
3A to 3D are plan views showing data pattern information applied to a DMD of the maskless exposure apparatus according to the first embodiment of the present invention.
4 is a view showing a form in which a beam spot is irradiated per unit area in a region where a source and drain electrodes are to be formed and a channel region;
FIG. 5 is a graph showing a result of measuring the thickness of a PR pattern remaining after exposure using a DMD by applying data pattern information having a bar pattern shown in FIGS. 3A to 3D as a control signal and performing development. FIG.
6A to 6D are plan views showing data pattern information applied to the DMD of the maskless exposure apparatus according to the second embodiment of the present invention.
FIG. 7 is a graph showing a result of measuring the thickness of a PR pattern remaining after exposure using a DMD by applying data pattern information having a mosaic pattern shown in FIGS. 6A to 6D as a control signal, and performing development.

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

FIG. 1 is a front view schematically showing a maskless exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view showing a beam spot array by the maskless exposure apparatus of FIG.

As shown in the figure, the maskless exposure apparatus 100 according to the embodiment of the present invention mainly includes at least one exposure head 110 and a stage 150 for moving a substrate 160 to be processed.

In this case, a pattern forming material, that is, a photoresist is coated on the substrate 160 to be processed, and a photoresist layer (not shown) is formed on the uppermost layer. The substrate 160 is placed on the stage 150 In the Y-axis direction defined by the drawing.

An exposure head 110 for exposing a photoresist layer (not shown) is disposed on the substrate 160. Each exposure head 110 includes a light source 115 for providing an exposure beam, a light source 115 (DMD) 120 for modulating an exposure beam provided from the DMD 120 according to an exposure pattern, a modulated exposure beam transmitted from the DMD 120 to a beam spot array and an exposure optical system 130 for transferring the light onto the substrate 160 in the form of a spot array.

The light source 115 may be a semiconductor laser or an ultraviolet lamp.

The DMD 120 includes a memory cell such as an SRAM cell and a plurality of micromirrors (not shown) arranged in a matrix type on the memory cell. For example, the DMD 120 includes a micro mirror (not shown) X 768, and a material having a high reflectance such as aluminum is deposited on the surface of each micromirror (not shown).

Here, the reflectance of the micromirror (not shown) is preferably 90% or more, and the arrangement pitch thereof is preferably substantially the same in the longitudinal direction and the transverse direction. For example, the array pitch may have a width of about 13.7 mu m. Such a micromirror (not shown) is disposed on the memory cell by a support (not shown) such as a hinge.

When a digital signal is applied to the memory cell, the DMD 120 has a micromirror (not shown) supported by the supporting unit (not shown) Lt; / RTI >

Therefore, the inclination of the micromirror (not shown) constituting the DMD 120 is controlled according to the information of the applied exposure pattern, so that the exposure beam incident on the DMD 120 is reflected by each micromirror (not shown) It is reflected in a specific direction according to the inclination.

At this time, the on / off state of each micromirror (not shown) constituting the DMD 120 can be controlled by an external control unit (not shown).

For example, when the micro mirror (not shown) is inclined at + alpha, the exposure beam is reflected by a micromirror (not shown) and is directed to the exposure optical system 130, ) State.

Conversely, when the micromirror (not shown) is inclined at -.alpha., The exposure beam is reflected by a micromirror (not shown) to be directed to a light absorber (not shown), and this state is referred to as an off state.

The exposure beam reflected from the DMD 120 is transmitted to the exposure optical system 130 and is irradiated onto the substrate 160 in the form of a beam spot array. The exposure optical system 130 irradiates the microlens array a micro lens array 133, a special filter 146, and a projection lens 149.

The microlens array 133 is formed by two-dimensionally arranging a plurality of microlenses (not shown) corresponding to the micromirrors (not shown) of the DMD 120. The DMD 120 includes, for example, 1024 (Not shown), corresponding to the number of micro mirrors (not shown), 1024 × 768 are arranged.

These microlenses (not shown) correspond to the arrangement pitch of the micromirrors (not shown) of the DMD 120 as well.

The microlens array 133 separates the exposure beam reflected from the DMD 120 into a plurality of beams to condense the beams.

A plurality of pinholes (not shown) are arranged two-dimensionally on the focal plane of the microlenses (not shown) corresponding to the microlenses (not shown), and the pinholes And functions to uniformize the size of the focused beam spot through a microlens (not shown) or to block noise generated in the optical system.

The projection lens 139 adjusts the resolution of the exposure beams condensed by the microlens array 133 and transmits the adjusted resolution. For example, a plurality of beam spots formed on the focal plane of the microlens array 133 are imaged on the substrate 160, for example, approximately one time.

Here, the exposure head 110 including the DMD 120 and the microlens array 133 is inclined at a predetermined alignment angle with respect to the scan direction of the substrate 160, that is, the Y-axis direction defined by the drawing .

That is, when the arrangement direction Y 'of the beam spot arrays depending on the arrangement angle of the exposure head unit 110 is inclined at a predetermined alignment angle? With respect to the scanning direction (Y-axis direction) The resolution of the maskless exposure apparatus 100 can be increased.

At this time, the exposure beam focused on the focal plane of the microlens array 133 has a circular or elliptic shape.

The beam spot array is referred to as a beam spot array as shown in FIG. 2, in which such an exposure beam is imaged on the substrate 160 via the special filter 136 and the projection lens 139, And a plurality of beam spots 180 arranged in a matrix form.

That is, the DMD 120 forms a beam spot array of a plurality of beam spots 180 on the substrate 160. At this time, each beam spot 32 of the beam spot array corresponds to a micromirror (not shown) of the DMD 120 and a microlens (not shown) of the microlens array 133. Therefore, the DMD 120, the microlens array 133, and the beam spot array all have substantially the same alignment direction Y '.

In the present embodiment, when the DMD 120 is composed of a micromirror (not shown) having M columns and N rows, the beam spot array is also a microlens of M columns × N rows ). At this time, the beam spots 180 are arranged at the same pitch in the horizontal and vertical directions.

For example, the array pitch of the beam spots 180 may be between 2 and 2.5 μm, and the beam spot 180 may have a roundness with a Gaussian distribution of about 2.5 μm full width at half maximum (FWHM).

The stage 150 or the exposure head unit 110 is rotated so that the alignment direction Y 'of the beam spot array forms a predetermined alignment angle? With respect to the scan direction Y of the substrate 160, A scan line is formed along an area where the beam spot 180 is imaged on the substrate 160 while the substrate 160 moves along the scan direction Y. [

Accordingly, if the scan direction Y and the alignment direction Y 'are arranged at a predetermined alignment angle?, The pitch of the beam spot 180 is maintained, but the distance between neighboring scan lines is reduced. Accordingly, the resolution of the maskless exposure apparatus 100 is increased.

Here, in the embodiment of the present invention, the DMD 120 and the microlens array 133 are arranged at 1024 × 768 and the magnification of the projection lens 139 is 1 ×. However, the present invention is not limited thereto, The arrangement of the DMD 120 and the microlens array 133 and the magnification of the projection lens 139 are determined by a desired beam spot size, a minimum feature size of the pattern to be exposed, 110), it is possible to derive an optimum magnification combination.

However, the maskless exposure apparatus 100 also has a resolution capability, and the beam spot 180 has a diameter (w1) of usually 4 to 5 mu m, which is limited depending on the characteristics of the maskless exposure apparatus. There are some resolutions that have already been determined and therefore can not change the beam spot 180 size.

Although the stage 150 on which the substrate 160 is mounted moves with respect to the exposure head 110 in the embodiment of the present invention, the stage 150 is fixed and the exposure head 110 may move. Further, both the stage 150 and the exposure head portion 110 may move.

In addition, the present invention is not limited to this, and a plurality of exposure head units 110 may be disposed on the substrate 160 in the scanning direction Y (Y) of the stage 150, So that the processing time can be shortened.

Thus, the maskless exposure apparatus 100 emits an exposure beam from the light source 115, and exposes the exposure beam emitted from the light source 115 in the DMD 120 to an exposure beam having at least two or more successive overlapping patterns .

The special filter 146 and the projection lens 139 are condensed in the microlens array 133 by separating the exposure beam reflected by the DMD 120 into a plurality of exposure beams from the microlens array 133, (Not shown) on the substrate 160 by adjusting the resolution of the exposed exposure beams and allowing them to be exposed in a desired form.

Hereinafter, a method of forming a PR pattern having different thicknesses through a maskless exposure apparatus having such a configuration will be described.

On the other hand, in the manufacture of an array substrate for a flat panel display device, for example, an array substrate for a liquid crystal display device, exposure is generally performed using four different exposure masks in total when using an exposure mask.

Originally, a 5-mask process was mainly used, but a diffraction exposure or a halftone exposure mask having different light transmission amounts was developed, so that the formation of the semiconductor layer, the source electrode and the drain electrode requiring two exposure masks was performed in one mask process It has become common to manufacture an array substrate through a total of four mask processes.

An exposure mask capable of halftone or diffraction exposure can control the amount of light passing through the exposure mask to form PR patterns of different heights by varying the amount of light reaching the photoresist layer on the substrate during exposure.

That is, the exposure mask is largely composed of a light transmission region, a blocking region, and a semi-transmission region, and the semi-transmission region transmits only 20 to 80% of light passing through the transmission region.

Accordingly, when the exposure is performed using the exposure mask having the above-described transmission region, blocking region and transflective region, the photoresist layer on the substrate is irradiated with almost 100% of light corresponding to the transmission region, Light corresponding to the blocking region is not irradiated and a light amount of 20 to 80% corresponding to the semi-transmission region is irradiated. Thus, when the exposed photoresist layer is developed, the light of the photoresist forming the photoresist layer A photoresist pattern of a first thickness is formed or completely removed at a portion corresponding to the blocking region or the transmissive region, and a portion of the photoresist pattern corresponding to a second thickness A PR pattern is formed.

Meanwhile, the maskless exposure apparatus for pattern formation used in the embodiment of the present invention does not have an exposure mask for adjusting the amount of light transmitted, and thus a PR pattern having different thickness can not be formed in the present state. Therefore, in order to manufacture an array substrate using a maskless exposure apparatus, a total of five exposure steps must be performed.

The present invention proposes a method of forming a PR pattern having different thicknesses by using a maskless exposure apparatus having such a structural feature, so that the exposure process is repeated four times using a maskless exposure apparatus to complete an array substrate .

1 and 2, in the maskless exposure apparatus 100, the light irradiated to the photoresist layer (not shown) selectively on the substrate 160 through the DMD 120 has a spot shape, The beam spot 180 having a half width of 2 to 2.5 占 퐉 in the present technology.

At this time, since the energy spot of the beam spot 180 has a Gaussian distribution, a difference in energy density occurs between the apex and the periphery of the beam spot 180.

Therefore, in the maskless exposure apparatus 100, the spacing d1 between the beam spots 180 is formed to be very narrow, about 0.5 μm to 2 μm, for the region to be irradiated with light on the substrate 160, And the spots 180 are superimposed on each other.

In the pattern formation method using the maskless exposure apparatus 100 according to the embodiment of the present invention, the data pattern information to be applied to the DMD 120 is appropriately adjusted, and finally, light selectively reflected through the DMD 120 reaches And the energy density per unit area in the region where the energy density is different is different.

3A to 3D are plan views showing data pattern information to be applied to the DMD of the maskless exposure apparatus according to the first embodiment of the present invention, and are diagrams of data pattern information corresponding to a portion where the thin film transistor of the array substrate is formed to be.

In the array substrate for a flat panel display, a plurality of pixel regions are defined. In each pixel region, a thin film transistor is provided as a switching element for controlling a signal voltage applied to a pixel electrode included in each pixel region.

When the thin film transistor includes a semiconductor layer using amorphous silicon, the thin film transistor may include a semiconductor layer composed of a gate electrode, a gate insulating film, an ohmic contact layer made of impurity amorphous silicon and spaced apart from the active layer of amorphous silicon, And a source electrode and a drain electrode which are spaced apart from and in contact with the ohmic contact layer, respectively.

In order to form a thin film transistor having such a stacked structure, two mask processes are carried out in the case of the four mask process, and a PR pattern having a first thickness corresponding to the region A1 where the source and drain electrodes are formed is formed, A PR pattern having a second thickness that is thinner than the first thickness is formed corresponding to the spacing region between the source electrode and the drain electrode (hereinafter referred to as a channel region A2), thereby forming a semiconductor layer having the above- And source and drain electrodes spaced apart therefrom can be formed.

Therefore, the pattern formation method using the maskless exposure apparatus 100 according to the first embodiment of the present invention can be applied to the maskless exposure apparatus 100 in order to form PR patterns having different thicknesses using the maskless exposure apparatus 100, As shown in FIG. 3D, the bar pattern 220 having a planar shape corresponding to the channel region A2 and having the same planar shape as that of the channel region A2 is spaced at a constant interval bpd, And the data pattern information is applied to the DMD 120.

For example, when the channel region A2 has a U-shape, the channel region A2 has a width of about 4 to 6 mu m. In the channel region A2, Pattern data in the form of a bar pattern 220 having a first width bpw and a predetermined spacing bpd as the planar shape of the DMD 120 The exposure amount of the substantially exposed light in the channel region A2 is changed to form a PR pattern having a thinner thickness than the region A1 where the source and drain electrodes are formed.

3A, the width bpw of the bar pattern is 0.5 mu m, the thickness of the bar pattern is 1 mu m in Fig. 3B, 1.5 mu m in Fig. 3C, and 2 mu m in Fig. 3D.

In the figure, the data pattern information applied to the DMD 120 corresponds to the portion A1 where the source and drain electrodes are to be formed, so that a control signal is applied that a pattern has been formed on the whole real portion, The beam spot having a predetermined size is reflected by a micro mirror (not shown) in the DMD 120 and overlapped with the beam spot having the same spacing at the same interval.

However, depending on the data pattern 200 for the channel region A2, the region in which the bar pattern 220 is formed and the region in which the bar pattern 220 is not formed are formed alternately in close proximity to the data pattern, The operation of turning on / off the movement of the micro mirror (not shown) in the DMD 120 may not be continuous and may be on / off off interval of the beam spot is changed in a very short period of time, which substantially changes the spacing distance of the beam spot, whereby the beam spot irradiated to the region A1 where the source and drain electrodes are formed is spaced apart from the beam spot The spacing of the beam spots relative to the spacing changes, so that the overlapping areas between the beam spots are rarely generated or the overlapped areas are significantly reduced. That is, the spacing between the beam spots is widened in the channel region A2 with respect to the region A1 where the source and drain electrodes are to be formed.

In this case, referring to FIG. 4 (a view showing a form in which the beam spot is irradiated per unit area in the region where the source and drain electrodes are to be formed and the channel region), the region A1 in which the source and drain electrodes are to be formed is substantially The beam spot is normally overlapped and formed so that 100 beam spots 180 per unit area are irradiated and irradiated, and a plurality of bar patterns (220 in FIGS. 3A to 3D) are provided for the channel part A2 The spacing distance between the beam spots 180 is changed by the data pattern information so that the width bpw and the spacing bpd of the bar patterns 220 in FIGS. The beam spot 180 per unit area is smaller than the area A1 where the source and drain electrodes are to be formed. As a result, the energy density of light irradiated on the unit area of the PR layer as a whole is reduced.

In this case, when the development process is performed on the PR layer on the substrate after the exposure is completed, the beam spot 180 normally has the first spacing distance d1 due to the difference in the amount of light (energy density) A PR pattern of a first thickness is formed for the source and drain electrode formation regions A1 to be overlapped with each other, a PR layer is removed for the region where the beam spot 180 is not irradiated, and a plurality of The beam spot (220 in FIGS. 3A to 3D) is irradiated with the irradiated channel region A2 having a second spacing distance d2 greater than the first spacing distance d1, ), A PR pattern having a second thickness that is thinner than the first thickness is formed.

In the embodiment, the PR layer is a negative type in which a portion irradiated with light reacts with the irradiated light to remain at the time of development. However, in the case of the positive type in which the light-irradiated portion of the PR layer is removed during development As described above, when the pattern data information in which a plurality of bar patterns are arranged at a predetermined interval in the channel region is applied to the DMD, the same progress can be obtained.

In this case, the beam spot is not irradiated to the region A1 where the source and drain electrodes are formed, and the beam spot is normally overlapped and irradiated with the first spacing corresponding to the portion where the PR layer is to be removed. Regions are spaced apart from each other with a second spacing interval larger than the first spacing interval and are substantially not overlapped with each other, so that a PR pattern having a first thickness and a thickness different from each other after development can be formed.

3A, when the width (bpw) of the bar pattern 220 in the data pattern corresponding to the channel region A2 is 0.5 mu m, The width bpw of the bar pattern 220 is gradually increased to 1 占 퐉, 1.5 占 퐉 and 2 占 퐉 and the spacing bpd thereof is progressively widened gradually as shown in Figs. 3c and 3d, (D2 in FIG. 4) is adjusted when the bar pattern 220 is gradually reduced to a smaller number than the first plurality, and the DMD (120 in FIG. 1) It can be seen that the thickness of the PR pattern is thinner when the width bpw of the bar pattern 220 is small.

When the width bpw of the bar pattern 220 is larger than 2 μm and the spacing distance bpd between the bar patterns 220 is larger than 2 μm and the width bpw of the bar pattern 220 is larger than 2 μm, A beam spot having a Gaussian distribution having a half width of 2 to 2.5 占 퐉 is irradiated when the spacing distance bpd between the bar patterns 220 and 220 is smaller than 0.5 占 퐉. Experimental results show that PR patterns with different thicknesses are not well formed because the spacing and overlapping are not properly adjusted.

When the width bpw of the bar pattern 220 itself or the spacing bpd between the bar patterns 220 is larger than 2 탆, a region where a normal pattern is formed or a region where a pattern should not be formed is recognized The beam spot is superimposed with the first spacing distance (d1 in Fig. 4) as in the region A1 in which the source and drain electrodes are to be formed, or the beam spot is not irradiated at all.

And the width bpw of the bar pattern 220 itself or the spacing distance bpd between the bar patterns 220 is less than 0.5 μm, it is smaller than the minimum resolution of the pattern required for reading information through the data pattern It can be seen that the normal on / off of the DMD (120 in FIG. 1) is not transmitted due to the ON / OFF control of the DMD (120 in FIG. 1) there was.

Accordingly, in the case of performing exposure using the maskless exposure apparatus according to the first embodiment of the present invention, in order to form a PR pattern having different thicknesses by the progress of one exposure process, It is experimentally found that it is desirable to input data pattern information such that a plurality of bar patterns 220 having a width (bpw in FIG. 3A) and a spacing (bpd in FIG.

FIG. 5 is a graph showing a result of measuring the thickness (halftome Avg) of a PR pattern remaining after performing exposure using a DMD by applying data pattern information having a bar pattern shown in FIGS. 3A to 3D as a control signal, Fig. At this time, black, red, blue, and green are shown in FIGS. 3A, 3B, 3C, and 3d, respectively.

As shown in the figure, when the scan speed of the maskless exposure apparatus is constant, the thickness of the final PR pattern varies depending on the width, number, and spacing of the bar pattern.

Accordingly, in the data pattern information serving as a control signal applied to the DND, the width and spacing of the bar pattern are suitably adjusted in the range of 0.5 to 2 mu m, and the number of the bar patterns is appropriately adjusted, And a PR pattern having a thickness difference of three or more different from each other can be formed.

FIGS. 6A to 6D are plan views showing data pattern information applied to the maskless exposure apparatus according to the second embodiment of the present invention, and are diagrams of data pattern information corresponding to portions where thin film transistors are formed on an array substrate. 6A is data pattern information in which a mosaic pattern 320 is formed such that an open area 320a and a close area 320b are repeated in a square shape of 0.5 mu m and FIG. 6C shows data pattern information in which a mosaic pattern 320 is formed such that an open area 320a and a closure area 320b are repeated in a square shape. FIG. 6C shows data pattern information in which an open area 320a and a cloth area 320b, 6D shows data pattern information on which the mosaic pattern 320 is formed so that the open region 320a and the closure region 320b repeat in a square shape of 2 mu m along the center of the channel. And is the formed data pattern information.

6A to 6D show that the mosaic pattern 320 is formed in the channel region A2.

1, the data pattern information is written in the form of a mosaic pattern 320 in which the open area 320a and the cloth area 320b are alternately arranged in a square or rectangular shape and repeatedly alternated. The same result as in the first embodiment in which the bar pattern is formed can also be obtained in the case of being applied to the DMD (120 in FIG. 1).

FIG. 7 shows a result of measuring the thickness (HT THK AVG) of the PR pattern remaining after the exposure using the DMD by applying the data pattern information having the mosaic pattern shown in FIGS. 6A to 6D as a control signal, Fig. 6A, 6B, 6C and 6D, black, red, blue and green, respectively.

As shown in the figure, when the scanning speed of the exposure apparatus is constant, the thickness of the final PR pattern varies depending on the number of mosaic patterns.

Accordingly, by appropriately setting the number of the mosaic patterns 320 alternating with the open area 320a and the cloth area 320b in the data pattern information serving as a control signal applied to the DND, It can be seen that a PR pattern having three or more different thicknesses can be formed.

In the case of the second embodiment as well, when the length of each square of the mosaic pattern is smaller than 0.5 μm or larger than 2 μm, on / off control of the DMD 120 is not properly performed, It can not be formed.

The data pattern according to the first and second embodiments of the present invention is applied as a control signal to perform exposure using a maskless exposure apparatus on a PR layer formed on a substrate, The first and second PR patterns are formed and patterned to form a source / drain pattern by using the first and second PR patterns to pattern the metal layer located under the first and second PR patterns, A second PR pattern having a low thickness is removed from the PR pattern to expose the center of the source / drain pattern, and etching is performed to remove the source / drain pattern and the ohmic contact layer located under the source / drain pattern, And a source electrode and a drain electrode spaced apart from each other above the ohmic contact layer are formed. Thus, a single exposure process is performed. It may be possible to form a semiconductor layer and source and drain electrodes.

At this time, a gate electrode is formed through one exposure process before forming the semiconductor layer and the source and drain electrodes, and a protection with a drain contact hole exposing the drain electrode by performing one exposure process on the source and drain electrodes And finally forming a pixel electrode over the protective layer in contact with the drain electrode through the drain contact hole.

Therefore, by applying the data pattern according to the first and second embodiments of the present invention as a control signal, the array substrate can be completed through the four exposure processes using the maskless exposure apparatus.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

200: Data pattern information
220: bar pattern
A1: region where source and drain electrodes are to be formed
A2: Channel area
bpw: width of the bar pattern
bpd: spacing of the bar pattern

Claims (9)

A pattern forming method using a maskless exposure apparatus having an exposure head portion including a digital micro-mirror device,
A first region where light is not irradiated onto the substrate through the digital micromirror device, a second region where light is irradiated with a first energy density per unit area, and a second region where light is irradiated with a second energy A third region formed with a density is defined,
Wherein a data pattern pattern to be applied to the digital micro-mirror device controlling light irradiation to the second area is formed so as to have a first width and a first spacing distance,
Wherein a data pattern shape to be applied to the digital micro-mirror device controlling light irradiation to the third region has a first width and a second spacing interval larger than the first spacing interval, bar shape,

The method comprising the steps of: providing a photoresist layer on the substrate, and developing the photoresist layer after the photoresist layer is exposed through the maskless exposure apparatus,
A photoresist pattern having a first thickness is formed in the second region after the photoresist layer is developed and a photoresist pattern having a second thickness smaller than the first thickness is formed in the third region Lt; / RTI >
The method according to claim 1,
Wherein the second width and the second spacing distance are 0.5 to 2 占 퐉.
A pattern forming method using a maskless exposure apparatus having a digital micro-mirror device,
A first region where light is not irradiated onto the substrate through the digital micromirror device, a second region where light is irradiated with a first energy density per unit area, and a second region where light is irradiated with a second energy A third region formed with a density is defined,
The data pattern pattern applied to the digital micro-mirror device controlling light irradiation to the third area is a mosaic pattern in which a rectangular open area and a cloth area are alternately and half-
Wherein the third region is largely changed in spacing distance between beam spots irradiated onto the substrate due to mosaic pattern information applied to the digital micro mirror device,
The method comprising the steps of: providing a photoresist layer on the substrate, and developing the photoresist layer after the photoresist layer is exposed through the maskless exposure apparatus,
A photoresist pattern having a first thickness is formed or completely removed in the first region or a second region after the photoresist layer is developed, and a photoresist pattern having a second thickness smaller than the first thickness is formed in the third region, Wherein a resist pattern is formed.
The method of claim 3,
Wherein the rectangular open region or the cloth region is 0.5 to 2 占 퐉 for each side.
delete The method according to claim 1 or 3,
Wherein the maskless exposure apparatus includes an exposure head portion including a light source and the digital micromirror device, and a stage for seating the substrate.
The method according to claim 6,
Wherein the exposure head portion further comprises a light source and an exposure optical system, wherein the exposure optical system further comprises a microlens array, a filter, and a projection lens.
8. The method of claim 7,
The micromirror device includes a plurality of memory cells. When the data pattern information is applied to the memory cell, the angle of the microlenses provided in the micromirror device is changed to change the reflection path of the incident light. Pattern formation method.
The method according to claim 6,
Wherein the light source is a semiconductor laser or an ultraviolet lamp.

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