This application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2018-0078657, filed on Jul. 6, 2018 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
Exemplary embodiments of the inventive concept relate to a pattern width correction system and a method of manufacturing a semiconductor device using the same.
Generally, a method of forming a pattern on a substrate contained in a liquid crystal display (LCD), a plasma display panel (PDP), a flat panel display (FPD), an organic light-emitting diode (OLED) panel, or the like includes applying a pattern material onto the substrate, and selectively exposing the pattern material using a photomask to selectively remove a specific pattern material part having a changed chemical property or the remaining parts other than the specific pattern material pattern, thus forming the pattern.
However, as the size of substrates is gradually increased and the precision of patterns is also gradually increased, a maskless exposure apparatus capable of forming a desired pattern on a substrate without using a photomask has been developed recently. The maskless exposure apparatus forms a pattern by transferring light beams onto the substrate with pattern information formed as electric signals by means of an electronic device. A representative example of the electronic device is a digital micromirror device (DMD). In a DMD, a pattern is exposed on an exposure surface with only needed light by a plurality of micromirrors transmitting, at a desired angle, light incident at the desired angle and transmitting, at other angles, light incident at the other angles.
According to an exemplary embodiment of the inventive concept, a pattern width correction system includes a pattern width measurement unit configured to measure a width of a first pattern formed at a first distance, where the first pattern is formed by irradiating first light modulated using first pattern data, a first error data calculator configured to generate first error data on the basis of the measured width of the first pattern, a regression analyzer configured to perform regression analysis on the first error data to generate a first relational expression between X-Y coordinates of the first pattern and a width error of the first pattern, a second error data calculator configured to generate second error data in a manipulation area having a second distance by using the first relational expression, and a pattern data correction unit configured to generate second pattern data by correcting the first pattern data on the basis of the second error data.
According to an exemplary embodiment of the inventive concept, a pattern width correction system includes a pattern forming unit configured to form a first pattern on a substrate using first pattern data, a pattern width measurement unit configured to measure a width of the first pattern, and a pattern width correction unit configured to generate first error data of the measured width of the first pattern, generate a first relational expression of a location of the substrate and a width error of the first pattern using the first error data, calculate the width error of the first pattern at a first location of the substrate by substituting the first location into the first relational expression, and generate second pattern data obtained by correcting the first pattern data at the first location using the width error of the first pattern at the first location.
According to an exemplary embodiment of the inventive concept, a method of manufacturing a semiconductor apparatus includes forming a first pattern on a first substrate using first pattern data, generating second pattern data obtained by correcting the first pattern data using the first pattern, and forming a second pattern on a second substrate using the second pattern data. The generating of the second pattern data includes measuring a width of the first pattern, generating first error data of the measured width of the first pattern, generating a first relational expression between a location of the first substrate and a width error of the first pattern using the first error data, calculating the width error of the first pattern at a first location of the first substrate by substituting the first location into the first relational expression, and generating the second pattern data using the width error of the first pattern at the first location.
The above and other aspects and features of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.
Exemplary embodiments of the inventive concept provide a pattern width correction system for making a critical dimension (CD) uniform over an entire substrate.
Exemplary embodiments of the inventive concept also provide a method of manufacturing a semiconductor apparatus having a uniform CD on the whole.
Exemplary embodiments of the inventive concept will be described more fully hereinafter with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout this application.
Referring to
The pattern forming unit 110 may form a pattern designed using pattern data. For example, the pattern forming unit 110 may form a first pattern using first pattern data and may form a second pattern using second pattern data. The second pattern data may be obtained by correcting the first pattern data. A detailed description thereof will be provided below.
The pattern forming unit 110 according to an exemplary embodiment of the inventive concept may include a maskless exposure device, which will be described below with reference to
The controller 113 may provide pattern data to the OMD 111. The pattern data may be data associated with turning the OMD 111 on/off. The DMD included in the OMD 111 may be tilted according to the pattern data. For example, the DMD included in the OMD 111 may be set to a first angle according to the pattern data to irradiate desired light to the substrate SUB. As another example, the DMD included in the OMD 111 may be set to a second angle according to the pattern data to prevent undesired light from being irradiated to the substrate SUB.
The controller 113 may provide a stage control signal to the stage 112. The stage 112 may be moved in an X direction or a Y direction according to the stage control signal. The stage control signal may be synchronized with, for example, the pattern data. In other words, the controller 113 may provide the pattern data to the OMD 111 and may also adjust the movement of the stage 112 to form a desired pattern at a desired position on the substrate SUB.
The light source 114 may provide first light to the OMD 111 through the reflection mirror 115. In other words, the light source 114 may input incident light to the reflection mirror 115 and may reflect the first light to the OMD 111 in response to the incident light. In response to the first light provided to the OMD 111, the second light may be provided to the substrate SUB according to the pattern data provided by the controller 113.
The elements of the pattern forming unit 110 are not limited to those described above. The above-described elements may be omitted, and other elements may be added.
Referring to
Referring to
Referring to
Referring to
According to an exemplary embodiment of the inventive concept, the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 are shown as separate elements, but the inventive concept is not limited thereto. In exemplary embodiments of the inventive concept, the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 are classified by functional differences for convenience of description and may physically be the same element. For example, the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 may be physically implemented as an analog circuit, a digital circuit such as a logical gate, an integrated circuit, a microprocessor, a microcontroller, a memory circuit, a passive electronic component, an active electronic component, an optical component, and/or a hardwired circuit.
According to an exemplary embodiment of the inventive concept, the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 may be driven by firmware or software.
According to an exemplary embodiment of the inventive concept, a circuit for implementing the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 may be implemented on, for example, a substrate support such as a printed circuit board (PCB) or one or more semiconductor chips. As another example, the circuit for implementing the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 may be implemented by a dedicated hardware device or a processor (e.g., one or more programmed microprocessors and associated circuits), or may be implemented by a combination of a dedicated hardware device that performs some functions of the first error calculator 131, the regression analyzer 132, the second error calculator 133, and the pattern data correction unit 134 and a processor that performs the remaining functions of the blocks.
The first error calculator 131 may generate first error data from the measured pattern width. According to an exemplary embodiment of the inventive concept, the first error data may include measured X-Y coordinates of the pattern (or X-Y coordinates of the substrate) and a measured error of the pattern width.
The regression analyzer 132 may perform regression analysis on the first error data generated by the first error calculator 131 to derive a first relational expression between the X-Y coordinates of the pattern (or the X-Y coordinates of the substrate) and the error of the pattern width.
The second error calculator 133 may generate second error data using the first relational expression generated by the regression analyzer 132. The second error data may include X-Y coordinates corresponding to a first location on the substrate (or the pattern) and a result value obtained by substituting the X-Y coordinates corresponding to the first location into the first relational expression.
The pattern data correction unit 134 may correct the first pattern data on the basis of the second error data generated by the second error calculator 133. For convenience of description, the corrected first pattern data is referred to as the second pattern data. The second pattern data may be provided to the pattern forming unit 110. The following detailed description will be made with reference to
Referring to
Referring to
According to an exemplary embodiment of the inventive concept, when a pattern width is corrected, the pattern width may be isotropically corrected such that a degree of pattern correction in the X direction is isotropic with respect to a direction of pattern correction in the Y direction, or may be anisotropically corrected such that a degree of pattern correction in the X direction is anisotropic with respect to a degree of pattern correction in the Y direction. The former and latter may be referred to as isotropic error correction and anisotropic error correction, respectively.
The first pattern P1 may include X direction widths Wx1 and Wx2 and Y direction widths Wy1 and Wy2. According to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the isotropic error correction, a width of the first pattern may be defined according to Equation 1 below:
=¼(Wx1+Wx2+wy1+wy2) [Equation 1]
On the other hand, according to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the anisotropic error correction, an X component
W
x
According to an exemplary embodiment of the inventive concept, the first error calculator 131 may generate first error data on the basis of X-Y coordinates on the substrate SUB and the measured width of the first pattern P1 (S530). As described above, the first error data may include the X-Y coordinates of the first pattern P1 on the substrate and a width error of the first pattern P1.
According to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the isotropic error correction, a width error ei of the first pattern P1 may be defined according to Equation 3 below:
e
i
=
i=¼(Wx1+Wx2+Wy1+Wy2)−ti [Equation 3]
where ti is a target width of the first pattern P1.
According to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the anisotropic error correction, width error ex and ey of the first pattern P1 may be defined according to Equation 4 below:
e
x=
e
y=
where tx is a target width of the first pattern P1 in the X direction, and ty is a target width of the first pattern P1 in the Y direction.
Referring to
In exemplary embodiments of the inventive concept, the first relational expression 810 may be a third-order polynomial. According to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the isotropic error correction, the first relational expression 810 may be represented according to Equation 5 below:
e
i
=a
1
+a
2
x+a
3
y+a
4
x
2
+a
5
xy+a
6
y
2
+a
7
x
3
+a
8
x
2
y+a
9
x
2
+a
9
xy
2
+a
10
y
3 [Equation 5]
In exemplary embodiments of the inventive concept, when it is assumed that the number of pieces of the first error data generated by the first error calculator 131 is N (here, N>10), Equation 5 may be expressed as the matrix of Equation 6 below:
Here, the coefficient ak of Equation 6 may be approximated using an inverse matrix of the matrix M as shown in Equation 7 below. The inverse matrix M+ of the matrix M may be found using a pseudo inverse matrix as shown in Equation 8 below or using singular value decomposition (SVD) as shown in Equation 9 below.
M
+=(MTM)−1MT [Equation 8]
M
+
=VΣ
+
U
T. [Equation 9]
According to an exemplary embodiment of the inventive concept, when the pattern width correction method uses the anisotropic error correction, the first relational expression 810 may be represented according to Equation 10 below:
e
x
=b
1
+b
2
x+b
3
y+c
4
x
2
+b
5
xy+b
6
y
2
+b
7
x
3
+b
8
x
2
y+b
9
xy
2
+b
10
y
3,
e
y
=c
1
+c
2
x+c
3
y+c
4
x
2
+c
5
xy+c
6
y
2
+c
7
x
3
+c
8
x
2
y+c
9
xy
2
+c
10
y
3. [Equation 10]
Here, the coefficients bk and ck of Equation 10 may be found through approximation using the methods shown in
Equations 5 to 10 assume that the first relational expression 810 is a third-order polynomial. However, this is merely an exemplary illustration, and the inventive concept is not limited thereto. For example, the first relational expression 810 may not be a polynomial, and the regression analyzer 132 may perform regression analysis on the first error data using a neural network to generate the first relational expression 810.
Referring to
In exemplary embodiments of the inventive concept, the substrate SUB may be divided into manipulation areas MAs having a second distance D2. Here, the second distance D2 may be smaller than the first distance D1. According to an exemplary embodiment of the inventive concept, the correction of the pattern width may be performed in units of the manipulation area (MA). Second error data em for each manipulation MA may be represented according to Equation 11 below:
e
m
=f(center point coordinate of mth MA). [Equation 11]
For example, when it is assumed that the coordinates of the center point of a first manipulation area MA1 is (0.5, 0.5), the second error data of the first manipulation area MA1 may be e1=f(0.5, 0.5).
Referring to
In exemplary embodiments of the inventive concept, the pattern data correction unit 134 may convert the generated first vector data into first bitmap data (S570). The pattern data correction unit 134 may generate the second pattern data using the first bitmap data (S580). The second pattern data may refer to the corrected first pattern data.
In exemplary embodiments of the inventive concept, the pattern data correction unit 134 forms a second pattern using the corrected first pattern data, e.g., the second data pattern, and measures the width of the second pattern. The correction process ends when the width of the second pattern is smaller than a desired allowable range. Operations S510 to S580 for the correction are performed when the width of the second pattern is greater than or equal to the desired allowable range (S590).
Referring to
Referring to
Since operations S1410 to 1450 of
Referring to
Referring to
While the inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the inventive concept as set forth by the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2018-0078657 | Jul 2018 | KR | national |