Abstract:
A method of arranging mask patterns, which includes a first mask has a first mask pattern, a second mask has a second mask pattern. The distance between the first mask boundary and the first mask pattern boundary is different form the distance between the second mask boundary and the second mask pattern boundary.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a method of arranging mask patterns, more particularly, to a method of arranging several mask patterns have different corresponding positions with lenses to lessen the lens mura of the panel.  
         [0003]     2. Description of the Prior Art  
         [0004]     In an exposure process, a light source of a scan exposure apparatus produces exposure light, like i-line, KrF, ArF, etc. The light passes through a mask and a projection lens to project on a photoresist of a semiconductor wafer or a glass substrate. The circuit pattern on the mask is transferred to the planned section of the substrate (called “a scan”) to be a hard mask of the etching or the ion implanting. Then, the plate stage or the mask stage of the scan exposure apparatus moves toward the next position and repeats the same exposure, and the pattern of the mask is transferred to the photo-resist of the whole substrate step by step.  
         [0005]     Recently, the size of LCD and PDP monitors have become bigger and bigger, and the size of the mask have become bigger, too. Therefore, the lenses of the recent exposure apparatus are combined by a plurality of lenses. The pattern of the mask is transferred to the glass substrate in the ratio of 1:1. However, every lens has a slight difference, lenses have overlapping sections, or the projection lenses have a precision bias after a long period of use.  
         [0006]     Please refer to  FIG. 1 .  FIG. 1  is schematic diagram of a corresponding position of a mask pattern and a lens of an exposure apparatus according to the prior art. The five masks in  FIG. 1  are the exposure masks in the general TFT LCD manufacture process. The five masks are individually the gate electrode (GE) mask I, the semiconductor (SE) mask II, the source/drain (SD) mask III, the contact hole(CH) mask IV, and the pixel electrode (PE) mask V. Each of them has a corresponding mask pattern  102 ,  104 ,  106 ,  108 , and  110  on the center of the masks I, II, III, IV, and V. All of the five masks I, II, III, IV, V have the width of L, and the mask patterns  102 ,  104 ,  106 ,  108 ,  110  have the width of I respectively.  
         [0007]     Please note that, lenses of the exposure apparatus usually have n lenses, and the lens and the adjacent lens intercross and have a lens overlapping section. Hence,  FIG. 1  illustrates the masks I, II, III, IV and V in the exposure apparatus, the corresponding position of each lens overlapping section  112 ,  114 ,  116 ,  118  and  120 , the mask patterns  102 ,  104 ,  106 ,  108  and  110 , and the masks I, II, III, IV and V. The distances of the mask patterns  102 ,  104 ,  106 ,  108  and  110  with the lens overlapping sections  112 ,  114 ,  116 ,  118  and  120  are z. The distance of the boundary of the masks I, II, III, IV and V with the boundary of the mask patterns  102 ,  104 ,  106 ,  108  and  110  are A for clear illustration in the prior art. But, the distance of the boundary of the mask and the boundary of the mask pattern isn&#39;t a fixed width in real manufacture.  
         [0008]     Please refer to  FIG. 2 .  FIG. 2  is a schematic diagram of photoresist patterns after exposure of the mask patterns of  FIG. 1 .  FIG. 2  continues the condition of  FIG. 1 . Photoresist layers I′, II′, III′, IV′, and V′ are the schematic diagrams of the masks I, II, III, IV and V exposure on the glass panel. That means following the process of the scanning exposure apparatus, one section of the glass panel will be exposed by the masks I, II, III, IV and V in sequence. Therefore, in  FIG. 2 , the photoresist layers I′, II′, III′, IV′, V′ and the photoresist patterns  202 ,  204 ,  206 ,  208 ,  210  individually show the diagrams of the masks I, II, III, IV, V and the mask patterns  102 ,  104 ,  106 ,  108 ,  110  exposed on the glass panel.  
         [0009]     As an example of the ratio 1:1, after completing many PEPs (photo-etching-processes), the width of the photoresist layers I′, II′, III′, IV′, V′ are L, and the width of the photoresist patterns  202 ,  204 ,  206 ,  208 ,  210  are I. The distances of the boundaries of photoresist layer I′, II′, III′, IV′, V′ and the boundaries of photoresist patterns  202 ,  204 ,  206 ,  208 ,  210  are A as the distance of the boundaries of the masks I, II, III, IV, V and the boundaries of the boundaries of the mask patterns  102 ,  104 ,  106 ,  108 ,  110 . The distances of the photoresist patterns  202 ,  204 ,  206 ,  208 ,  210  with the lens sections  212 ,  214 ,  216 ,  218 ,  220  are z as the distance of the mask patterns  102 ,  104 ,  106 ,  108 ,  110  with the lens overlapping sections  112  ,  114 ,  116 ,  118 ,  120 . Finally, every lens section  212 ,  214 ,  216 ,  218 ,  220  is in the same position of the photoresist layer I′, II′, III′, IV′, V′.  
         [0010]     Please refer to  FIG. 3 .  FIG. 3  is schematic diagram of transfer patterns of  FIG. 2  after exposure. As  FIG. 3  shows, glass panel  302  has a plurality of transfer patterns  304 . Each transfer pattern  304  is exposed by the above-mentioned five masks in the same section of the glass panel  302 . That is why every lens overlapping section  212 ,  214 ,  216 ,  218 ,  220  in  FIG. 2  is in the same position of the photoresist layers I′, II′, III′, IV′, V′ and the photoresist patterns  202 ,  204 ,  206 ,  208 ,  210 . And, each transfer pattern  304  on the glass panel  302  has an obvious lens mura  306 .  
         [0011]     As mentioned above, because of the precision bias after a long period of use, the lenses overlapping sections of the prior art exposure apparatus become the uniformity of the exposure light from each lens. So, in the prior art, after many mask exposures, the many PEP is complete, and the monitor has various critical dimensions (CD) and overlays in a few sections of the panel. The monitor has lens mura. The quality of the product drops, and the yield of manufacture decreases. Therefore, to solve the lens mura problem is an important issue.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention relates to a method of arranging mask patterns, more particularly, to a method of arranging several mask patterns have different corresponding positions with lenses to lessen the lens mura of the panel, to solve the above-mentioned problem.  
         [0013]     The embodiment of the present invention relates to a method of arranging the mask pattern. The method comprising providing a first mask having a first mask pattern and a second mask having a second mask pattern, the distance between the first mask pattern and the first mask being different from the distance between the second mask pattern and the second mask.  
         [0014]     The other embodiment of the present invention relates to a method of mending a lens mura, the being applied in an exposure apparatus has a plurality of lenses, the method at least comprising providing a first mask pattern and a second mask pattern, and positioning the lenses to have different corresponding positions with the first mask pattern and the second mask pattern during an exposure process.  
         [0015]     In the present invention, five mask patterns of the five masks have different distances with the lenses of the exposure apparatus in the TFT LCE exposure processes, so the distance of the photoresist patterns and the lenses are different, which amends the lens mura of the glass panel to solve the prior art problem.  
         [0016]     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is schematic diagram of a corresponding position of a mask pattern and a lens of an exposure apparatus according to the prior art.  
         [0018]      FIG. 2  is a schematic diagram of photoresist patterns after exposure of the mask patterns of  FIG. 1 .  
         [0019]      FIG. 3  is schematic diagram of transfer patterns of  FIG. 2  after exposure.  
         [0020]      FIG. 4  is schematic diagram of the corresponding position of the mask pattern and the lenses of the exposure apparatus according to the present invention.  
         [0021]      FIG. 5  is a diagram of the photoresist pattern after the mask pattern of  FIG. 4  exposure process.  
         [0022]      FIG. 6  is a schematic diagram of a transfer pattern after the mask patterns of  FIG. 5  exposed.  
     
    
     DETAILED DESCRIPTION  
       [0023]     Please refer to  FIG. 4 .  FIG. 4  is schematic diagram of the corresponding position of the mask pattern and the lenses of the exposure apparatus according to the present invention. For convenience, the preferred embodiment of the present invention uses five masks for five different PEP processes to illustrate the method of arranging the mask patterns for TFT LCD exposure process. These five masks have the same size, they individually are a gate electrode (GE) mask VI, a semiconductor (SE) mask VlI, a source/drain (SD) mask VIII, a contact hole(CH) mask IX, a pixel electrode (PE) mask X. The sequence of these five masks is masks VI, VII, VIII, IX, X in TFT LCD manufacture. The scan exposure apparatus is able to transfer a predetermined pattern into the glass panel (not shown) and produce the corresponding photoresist pattern (not shown).  
         [0024]     As  FIG. 4  shows, the width of the masks VI, VII, VIII, IX, X is L, the width of the mask patterns is I. Otherwise,  FIG. 4  illustrates the corresponding position of the lens overlapping section  412  with the mask pattern  402  and mask VI, when the mask VI processes exposure in an exposure apparatus. In the same way, this embodiment is illustrated by many lenses and the lens and the adjacent lens overlap each other. Therefore, each mask VI, VII, VIII, IX and X in  FIG. 4  has many lens overlapping sections  412 .  
         [0025]     In the embodiment of the present invention, the distance between the boundary of the mask VI and the boundary of the mask pattern  402  is B (the reference boundary is left line). The parallel distance between the boundary of the mask pattern  402  and the lens overlapping section  412  is m. The parallel distance between the boundary of the mask VII and the boundary of the mask pattern  404  is C (the reference boundary is left line). C is less or greater than B. The parallel distance between the boundary of the mask pattern  404  and the boundary of the lens overlapping section  412  is n, n being greater or less than m. In the same way, the mask patterns  406 ,  408 ,  410  on the masks VIII, IX, X have parallel distances D, E, F individually. And, the parallel distances between the mask patterns  406 ,  408 ,  410  and the lens overlapping sections  412  are o, p, q. Otherwise, for convenience, as  FIG. 4  shows, a dotted line contrast mask pattern  414  is drawn on each of masks VII, VIII, IX, X. It presents a reference mask pattern having a B parallel distance with the boundary of the mask (the same with the distance relation between the mask VI and the mask pattern  402 ). The contrast mask pattern  414  of the embodiment clearly shows the mask patterns  402 ,  406 ,  408 ,  410  position movement.  
         [0026]     Please note that each lens in the recent exposure apparatus has the same size. The distance and the position of each lens are fixed values. So, when the same size masks are put on the exposure apparatus, each mask has a fixed position with the lenses. But, in the present invention, each mask pattern has different distance with each mask, which causes each mask to have a different distance with the lenses in the exposure apparatus. Especially, each mask pattern has a different distance with the lens overlapping section.  
         [0027]     Please refer to  FIG. 5 .  FIG. 5  is a diagram of the photoresist pattern after the mask pattern of  FIG. 4  exposure process.  FIG. 5  continues the conditions of  FIG. 4 . The mask VI, VII, VIII, IX, X expose and transfer to the glass panel on the photoresist layers VI′, VII′, VIII′, IX′, X′ in  FIG. 5 . That means one position of the glass panel will be exposed by every PEP and the mask VI, VII, VIII, IX, X sequencing. As  FIG. 5  shows, photoresist layers VI′, VII′, VIII′, IX′, X′ are presented individually and the mask patterns  402 ,  404 ,  406 ,  408 ,  410  on the mask VI, VII, VIII, IX, X expose singly on the glass panel. This situation does not reflect the real situation, in which the next exposure will cover the last photoresist pattern.  
         [0028]     Please refer to  FIG. 5 , the parallel distance between the mask pattern  502  and the lens overlapping section  512  is m. And the parallel distance between the mask pattern  504 ,  506 ,  508 ,  510  and the lens overlapping section  514 ,  516 ,  518 ,  520  individually are n, o, p, q. That is caused by the parallel distance between the mask pattern  402 ,  404 ,  406 ,  408 ,  410  and the lens overlapping section  412  are m, n, o, p, q in  FIG. 4 . Therefore, the final mask pattern has no lens mura after five exposure. Because the parallel distance between every mask pattern and the lens overlapping section is different, each lens mura is formed in different position of the photoresist layer and the lens mura is blurred. LCD of the present invention has no lens mura.  
         [0029]     Please refer to  FIG. 6 .  FIG. 6  is a schematic diagram of a transfer pattern after the mask patterns of  FIG. 5  exposed. As  FIG. 6  shows, the glass panel  602  has a plurality of transfer pattern  604 . Each of transfer patterns  604  in the same section of the glass panel  302  is made by the above-mentioned five masks exposure. Therefore, each lens overlapping section  512 ,  514 ,  516 ,  518 ,  520  fall on the different position of the photoresist layers VI′, VII′, VIII′, IX′, X and the photoresist patterns  502 ,  504 ,  506 ,  508 ,  510 . Finally, the transfer pattern  604  on the glass panel  602  will not have lens mura.  
         [0030]     Please note that, the present invention can choose to change the corresponding position of the mask pattern  406  and the mask VIII in  FIG. 4m ask. The key process of the exposure process of TFT LCD manufacture is the mask VIII for the source/drain process in  FIG. 4 . Every TFT channel length is a fixed value that can maintain stable and uniform TFT electrical performance. So, in the present invention, the distances between the mask pattern  402 ,  404 ,  408 , 410  of the mask VI, VII, IX,X and the lens overlapping section  412  can be the same. But the mask VIII must be different. And, forming a gate is an important process in the TFT manufacture, so the distances of the mask patterns  402 ,  406 , the lens overlapping section  412 , and the mask VI, VIII are different. And the others can be the same.  
         [0031]     Comparing to the prior art, because these five mask patterns of the five masks have different distances with the lenses of the exposure apparatus in the present invention, the distance of the photoresist patterns and the lenses are different, that amends the varied critical dimension (CD) and varied overlay of the fixed position (corresponds the lens overlapping section) on the glass panel, and blurs the lens mura. The present invention improves the problem of the prior art, in which the lens overlapping sections fall in the same position of the glass panel, and the lens mura is produced, the yield decreases, and the products quality decreases.  
         [0032]     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.