Patent Publication Number: US-9885953-B2

Title: Method of manufacturing a mask

Description:
CROSS REFERENCE TO RELATED APPLCIATIONS 
     This is a divisional application based on pending application Ser. No. 13/440,112, filed Apr. 5, 2012, the entire contents of which is hereby incorporated by reference. 
     Korean Patent Application No. 10-2011-0030993, filed on Apr. 5, 2011, in the Korean Intellectual Property Office, and entitled: “Method of Manufacturing A Mask And Apparatus for Performing the Same,” is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     Example embodiments relate to a method of manufacturing a mask and an apparatus for performing the same. More particularly, example embodiments relate to a method of manufacturing a mask that may be used for forming a semiconductor pattern, and an apparatus for performing the method. 
     2. Description of the Related Art 
     Generally, a pattern may be formed by a process for forming a layer on a semiconductor substrate, a process for transcribing a mask pattern of a mask into the layer, etc. 
     The mask pattern may be formed by transcribing a design pattern into a polymer layer on a mask substrate. A template having the design pattern may press the polymer layer to engrave the design pattern on the polymer layer, thereby forming the mask pattern. 
     SUMMARY 
     According to an embodiment, there is provided a method of manufacturing a mask, the method including dividing an upper surface of a template having a design pattern into a plurality of regions, the template being arranged over a polymer layer on a mask substrate, correcting a distorted region among the regions, pressing the polymer layer with the template to form a mask pattern corresponding to the design pattern on the polymer layer, and curing the mask pattern. 
     The correcting of the distorted region may include deforming the distorted region using a piezo actuator. The deforming of the distorted region may include moving the distorted region in two horizontal axes substantially perpendicular to each other using the piezo actuator. The deforming of the distorted region may further include moving the distorted region in a vertical axis using the piezo actuator. 
     The curing of the mask pattern may include irradiating an ultraviolet light to the mask pattern. The irradiating of the ultraviolet light may include irradiating the ultraviolet light to a side surface of the mask pattern. 
     According to an embodiment, there is provided an apparatus for manufacturing a mask, the apparatus including a template having a design pattern, a correcting unit that divides an upper surface of the template into a plurality of regions, the correcting unit being connected to each of the regions to selectively correct a distorted region among the regions, a pressing unit that presses a polymer layer with the template to form a mask pattern corresponding to the design pattern on the polymer layer, and a curing unit that cures the mask pattern. 
     The correcting unit may include a plurality of piezo actuators. Each of the piezo actuators may be connected to one of the regions of the upper surface of the template. The piezo actuators may be moveable along two horizontal axes substantially perpendicular to each other. The piezo actuators may be moveable along a vertical axis. 
     The curing unit may be arranged at side of the mask pattern. The curing unit may include an ultraviolet light-irradiating member that irradiates an ultraviolet light to a side surface of the mask pattern. 
     According to an embodiment, there is provided a method of correcting a template used to manufacture a mask, the method including arranging a template over a polymer layer on a mask substrate, the template having a design pattern and including an upper surface with a plurality of regions, and correcting one or more distorted regions among the plurality of regions of the template using a correcting unit that does not substantially affect non-distorted regions among the plurality of regions of the template. 
     The correcting unit may include a plurality of piezo actuators, each being connected to one region of the plurality of regions. The correcting of the one or more distorted regions may include activating only ones of the plurality of piezo actuators corresponding to the one or more distorted regions. 
     The correcting of the one or more distorted regions may include activating the ones of the plurality of piezo actuators corresponding to the one or more distorted regions to independently move the one or more distorted regions horizontally or vertically. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features will become apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which: 
         FIG. 1  illustrates a cross-sectional view relating to an apparatus for manufacturing a mask in accordance with some example embodiments; 
         FIG. 2  illustrates a plan view relating to the apparatus in  FIG. 1 ; and 
         FIGS. 3 to 5  illustrate cross-sectional views relating to a method of manufacturing the mask using the apparatus in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
     It will be understood that spatially relative terms, such as “lower,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented in an “upper” disposition relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Hereinafter, example embodiments will be explained in detail with reference to the accompanying drawings. 
     Apparatus for Manufacturing a Mask 
       FIG. 1  is a cross-sectional view illustrating an apparatus for manufacturing a mask in accordance with some example embodiments, and  FIG. 2  is a plan view illustrating the apparatus in  FIG. 1 . 
     Referring to  FIG. 1 , an apparatus  100  for manufacturing a mask in accordance with this example embodiment may include a template  110 , a correcting unit  120 , a pressing unit  130  and curing unit  140 . 
     The template  110  may be arranged over a mask substrate S. In example embodiments, a polymer layer P may be formed on an upper surface of the mask substrate S. The template  110  may have a design pattern  112 . The design pattern  112  may be formed on a lower surface of the template  110 . Thus, the design pattern  112  may be oriented toward the polymer layer P. 
     The correcting unit  120  may be arranged on an upper surface of the template  110 . As shown in  FIG. 2 , the correcting unit  120  may divide the upper surface of the template  110  into a plurality of regions R. The correcting unit  120  may be individually connected to each of the regions R to correct a shape of a region R having a distorted pattern. 
     In example embodiments, the correcting unit  120  may include a plurality of piezo actuators. The piezo actuators  120  may be connected to the regions R, respectively. Thus, the number of the regions R may be substantially the same as the number of the piezo actuators  120 . 
     The piezo actuators  120  may directly apply a voltage to the region R having the distorted pattern to correct the distorted pattern. In example embodiments, the piezo actuators  120  may move the region R having the distorted pattern along two horizontal axes substantially perpendicular to each other, i.e., along an X-axis and a Y-axis. Further, the piezo actuators  120  may move the region R having the distorted pattern along a vertical axis, i.e., along a Z-axis. Therefore, the piezo actuators  120  may control a critical dimension and an overlay as well as the shape of the design pattern in the region R. 
     The pressing unit  130  may be connected to an upper surface of the correcting unit  120 . The pressing unit  130  may lower the template  110  toward the polymer layer P. Thus, the template  110  may press the polymer layer P to engrave the design pattern  112  of the template  110  on the polymer layer P. A pattern on the polymer layer P may correspond to a mask pattern. After forming the mask pattern, the pressing unit  130  may raise the correcting unit  120  and the template  110  from the polymer layer P. 
     The curing unit  140  may cure the mask pattern. In example embodiments, the curing unit  140  may include an ultraviolet light-irradiating member that irradiates an ultraviolet light to a side surface of the mask substrate S. Because the correcting unit  120  may be arranged over the template  110 , it may not be feasible to irradiate the ultraviolet light to the upper surface of the template  110 . Thus, the curing unit  140  may be arranged at a side of the mask substrate S. 
     Method of Manufacturing a Mask 
       FIGS. 3 to 5  are cross-sectional views illustrating a method of manufacturing the mask using the apparatus in  FIG. 1 . 
     Referring to  FIG. 3 , the template  110  and the correcting unit  120  may initially be raised by the pressing unit  130 . Thus, the template  110  and the correcting unit  120  may be spaced apart from the upper surface of the mask substrate S. 
     As shown in  FIG. 2 , the correcting unit  120  may divide the upper surface of the template  110  into the regions R. When the design pattern of the template  110  is distorted, a corresponding piezo actuator  120  connected to a region R having a distorted pattern may be operated to correct a shape of the distorted region R. Particularly, the piezo actuator  120  may selectively move the distorted region R along the X-axis, the Y-axis and the Z-axis to correct the distorted region R. 
     In example embodiments, an indirect correction of the shape of the distorted region R that affects other regions may be avoided. Only the piezo actuator  120  connected to the distorted region R may be operated to correct the shape of only the distorted region R. Thus, during the correcting of the shape of the distorted region R, deformation of other regions R having normal patterns may be avoided. 
     Referring to  FIG. 4 , after correcting the shape of the template  110 , the pressing unit  130  may lower the template  110  and the correcting unit  120 . Thus, the design pattern  112  of the template  110  may press the polymer layer P. 
     Referring to  FIG. 5 , the pressing unit  130  may raise the template  110  and the correcting unit  120  after the pressing of the polymer layer P. A mask pattern MP corresponding to the design pattern  112  may be formed on the polymer layer P. 
     The curing unit  140  may irradiate the ultraviolet light to the mask pattern MP to cure the mask pattern MP. 
     By way of summation and review, in a process of manufacturing a mask by transcribing a design pattern of a mask from a template into a layer, it is desirable to provide a design pattern having the desired pattern. Accuracy of the design pattern may be determined in accordance with flatness and distortion of the template. When the template has a non-flat portion and/or a partially distorted portion, the design pattern may not be accurately transcribed into the polymer layer. 
     Therefore, in order to correct the flatness and the distortion of the template, it is desirable to perform a process for correcting a shape of the template. For example, the shape of the template may be corrected using a piezo actuator connected to a side surface of the template. 
     However, the piezo actuator connected to the side surface of the template may not correct a desired portion of the template. For example, when the distorted portion is formed at a central portion of the template, the piezo actuator may move a normal edge portion of the template as well as the central portion of the template. Thus, the normal edge portion of the template may become distorted. 
     The example embodiments disclosed herein advance the art by dividing the upper surface of the template into regions such that only a region having a distorted portion among the regions is directly corrected. Thus, only the distorted portion may be accurately corrected. Thereafter, the design pattern may be engraved on the polymer layer, so that the mask may have a desired mask pattern. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.