TWI431409B - Half tone mask having multi half permeation part and manufacturing method of the same - Google Patents

Description

Half-tone mask with multiple semi-transmissive portions and manufacturing method thereof

The present invention claims priority to the Korean Patent No. 10-2009-0044350 filed on May 21, 2009, and the Korean Patent No. 10-2009-0098717 filed on Oct. 16, 2009, which is incorporated herein by reference. The manner of this is incorporated herein by reference.

The invention relates to a half-tone mask, wherein the semi-transparent region is formed by using a slit type or a stacked semi-transmissive portion or a combination thereof, wherein the pattern density of the fine pattern can be adjusted to improve the transmittance adjustment. effectiveness.

As shown in FIG. 1 , the conventional photomask for patterning via the lithography process includes a transparent substrate 1 , and a transmission part 3 is formed on the transparent substrate 1 to completely transmit light, and a light blocking portion 2 can completely block the light, and the half of the light transmitting portion 4 has a semi-adjusting film layer capable of transmitting part of the light.

Conventional reticle can only be used for a lithography process cycle consisting of exposure-development-etching, since conventional reticle can only perform one layer of pattern.

More specifically, TFT (thin film transistor) and CF (color filter) are deposited/coated with many layers, and individual deposited/coated layers are patterned by lithography process. . At this point, if it is possible to even reduce a lithography process, it will be a great economic effect. However, traditional reticle is not economical It is because it is designed to be used only for one layer of pattern. In addition, several tones must be performed to construct a multiple semi-transmissive portion, thereby creating process delays and delivery issues.

At the same time, as shown in FIG. 2, a different type of photomask, called a Gray Tone Mask, includes a light transmissive portion 13 formed on a transparent substrate 11 for completely transmitting light, and a light barrier. Layer 12 serves to completely block light and a slit pattern 14 that is transmitted by reducing the amount of light that is illuminated.

However, due to limitations in implementing the slit pattern, the gray scale mask has its limit in adjusting the amount of transmitted light because the gray scale mask uses a diffraction pattern of a fine pattern to adjust the amount of light. .

A further disadvantage of the gray scale reticle is that if the size of the gray scale reticle is larger than the predetermined one, the patterning of the same condition cannot be performed. A further disadvantage of the gray scale mask is that, for the slit type, exposure to the semi-transmissive portion is difficult to control because the gray scale mask employs diffracted light.

In order to avoid the above problems, an object of the present invention is to provide a half-tone mask in which a translucent region is formed by using a slit type or a stacked semi-transmissive portion or a combination thereof, wherein the pattern density of the fine pattern is adjusted to Improve the efficiency of light transmittance adjustment.

Another object is to provide a multiple half-tone mask in which a semi-transmissive material is filled in a discrete space of a slit-type semi-transmissive portion to construct a controllable three or more different ones. The structure of light transmittance.

In an aspect of the invention, a half-tone mask is provided with at least one or more semi-transmissive portions, which can be adjusted to form a pattern of a semi-transmissive portion and a fine pattern. Density to adjust the light transmittance.

In some embodiments, the semi-transmissive portion in the half-tone mask may have a structure for forming a fine pattern on the semi-transmissive film layer, and a fine pattern is formed on the light-shielding layer and a half-transparent film layer is formed. The structure thereon, or a combination thereof.

In some embodiments, the semi-transmissive film layer may employ a semi-transmissive material having a light transmittance ranging from 4 to 75%.

In several embodiments, the line width of the fine pattern can be adjusted in the range of 0.1 μm to 1.3 μm.

In some embodiments, the semi-transmissive material may be a material having one of chromium, bismuth, molybdenum, niobium, titanium, aluminum as a main element or a combination of at least two or more elements, or at least added One of Cox, Ox, Nx to the main element material or the material of the combination material.

In another aspect of the present invention, there is provided a method of fabricating a halftone reticle having a plurality of semi-transmissive portions, wherein the halftone reticle includes a fine pattern to adjust optical transmittance, and wherein the fine pattern is The pattern density is adjusted, and the optical transmittance is adjusted in the range of 0.1 μm to 1.3 μm by adjusting the line width of the fine pattern.

In another aspect of the present invention, a half-modular photomask includes a light transmissive portion, a light blocking portion and a half light transmitting portion formed on a transparent substrate, wherein the semi-transmissive portion includes a The slit is filled with a plurality of semi-transmissive portions of a half-tone material.

In some embodiments, the semi-transmissive portion includes at least one or more multiple half-tone portions, wherein the semi-transmissive portion further includes at least one single half-tone portion formed by a layer of a light transmissive material or only a slit Slit half-tone section.

In some embodiments, the multiple half-tone portion may include a slit-type photoresist wall having a predetermined discrete pitch, wherein a half of the light-transmissive material layer is formed at a discrete pitch between the slit-type light-blocking wall and the light blocking portion. .

In several embodiments, a layer of semi-transmissive material can be formed over the slit-type barrier wall and the light-blocking portion.

In some embodiments, the semi-transmissive material layer may be a bonding material having molybdenum, niobium, tantalum, tungsten, aluminum, chromium, niobium, zirconium, vanadium, nickel, niobium, cobalt, titanium as a main element, and combined At least two or more main element materials or main elements, or at least one of Cox, Ox, Nx, or a material of a main element material or a combination material, wherein x is a natural number.

A halftone mask having the above structure according to the present invention can be manufactured by the following fabrication method.

In still another aspect of the present invention, a method for fabricating a half-tone mask is provided, characterized in that a photoresist is coated on a transparent substrate on which a light blocking layer is stacked (first step); by exposure and development Photoresist patterning (second step); forming a slit type light blocking wall and a light transmitting portion via the etching light blocking layer (third step); and stacking half of the light transmissive material layer in the slit type light blocking wall And a multiple halftone is formed (fourth step).

In some embodiments, the fourth step is characterized by: stacking a half of the light transmissive material layer a1 on an upper surface of the light blocking layer; patterning a2 by coating the photoresist on the semi-transmissive material layer; The semi-transmissive material layer a3 filled in a light transmitting portion or a slit type light blocking wall is selectively removed through the pattern portion.

In some embodiments, the photoresist removal step after etching of the light blocking layer or semi-transmissive material layer may further comprise a subsequent third step and fourth step.

An advantage of the present invention is that the pattern density of the fine pattern can be adjusted to enhance the transmittance of the halftone mask formed by using a slit semi-transmissive portion, a stacked semi-transmissive portion or a combination thereof. effectiveness.

Another advantage is that the light transmittance of the semi-transmissive region can be accurately controlled by the adjustment of the pattern density without relying on separate manufacturing processes.

Still another advantage is that a multiple half-tone mask can be filled with a semi-transmissive material in discrete intervals of the slit-type semi-transmissive portion to construct a three- or more mutually different light transmission. The structure of the rate.

A further advantage is that a high quality multiple half-tone mask can be provided by the diffraction phenomenon in the slit and the light transmittance controlled by the half of the light transmissive material layer to greatly improve the design freedom and the defect. The light transmittance corrects the degree of freedom to help improve process yield, shorten process cycle, and improve product quality after exposure.

The architecture and operation of the present invention will be described in detail with reference to the accompanying drawings.

(First Embodiment)

The gist of the present invention is to provide a halftone mask formed by arranging a semi-transmissive region in a fine pattern, and it is possible to adjust the precise optical transmittance by adjusting the pattern density of the fine pattern.

Please refer to Figure 3, which illustrates the basic principle of adjusting the transmittance of a half-tone mask.

The halftone mask includes a half light transmissive layer 210 formed on a substrate 200, and a light blocking layer 220 completely blocks light. The semi-transmissive layer 210 can be implemented by forming a fine pattern on a light-blocking layer or forming a light-blocking layer on a half of the light-transmissive film layer. The semi-transmissive layer shown shows two semi-transmissive regions A, B in which the optical transmittance can be adjusted.

Referring to FIG. 4, the semi-transmissive area A is shown in an enlarged manner, and has a fine pattern of a predetermined line width X1, X2, X3, ..., Xn on one of the barrier layers or a half of the light-transmissive layer 210 on a substrate. The pitches S1, S2, S3, ..., Sn are formed. In the case of performing exposure through a half-tone mask, a photo-sensitive material (PR) changes its shape due to a change in optical transmittance after development, as shown. In particular, the adjustment of the width of the fine pattern is an important factor in the adjustment of the light transmittance. The fine pattern density is a ratio of a fine pattern per unit area, and is derived from the sum of a plurality of line widths X1, X2, X3, ... Xn according to a ratio of the entire unit area ratio in the figure. A numerical value in which the pattern density is inversely proportional to the optical transmittance.

Figure 5 is a flow diagram of a process for making an embodiment of the present invention.

First, in order to form a structured halftone mask as shown in FIG. 3, the substrate 200 is filmed with a light blocking layer 220 P1 on which a photoresist 230 P2 is applied. Then, a conventional halftone mask having a fine pattern is completed by including an exposure process P3, a development/etching P4, and a removal/cleaning process P5.

In particular, the preferred fine pattern formed in the present invention has a line width which can be varied in the range of 0.1 μm to 1.3 μm. More preferably, the formation has a fine pattern The semi-transmissive region is coated with a half of the light transmissive film layer 240. The semi-transmissive film layer 240 may be a chromium oxide film, and the semi-transmissive material may be a material having one of chromium, bismuth, molybdenum, niobium, titanium, aluminum as a main element or mixed with at least two or more elements. The combination material, or at least one of Cox, Ox, Nx, is added to the main element material or the material of the combination material.

More specifically, the composition of a stacked semi-transmissive region can be any composition that only needs to transmit light in a particular portion of the band. For example, the stacked semi-transmissive regions may be comprised of a group comprising Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , Si _x O _y , Si _x O _y N _z , Si _x CO _y , Si _x CO _y N _z , Mo _x Si _y , Mo _x O _y , Mo _x O _y N _z , Mo _x CO _y , Mo _x O _y N _z , Mo _x Si _y O _z , Mo _x Si _y O _z N Mo _x Si _y CO _z N, Mo _x Si _y CO _z , Ta _x O _y , Ta _x O _y N _z , Ta _x CO _y , Ta _x O _y N _z , Al _x O _y , Al _x CO _y , Al _x O a composition of any one of _y N _z , Al _x CO _y N _z , Ti _x O _y , Ti _x O _y N _z , Ti _x CO _y , or a combination thereof, wherein the suffixes x, y, and z are natural numbers and are defined The number of atoms of individual elements.

Immediately, the upper surface of the semi-transmissive film layer 240 may be coated with a photoresist 250 again, patterned, exposed, developed, etched Q1 to Q3, and the photoresist Q4 removed to form the half-tone mask C of the present invention.

Referring now to Figure 6, the features of the halftone reticle obtained by light transmittance adjustment will be described in accordance with the process of Figure 5 in accordance with the present invention.

Figure 6 plots a graph in which the semi-transmissive film layer coated on the fine pattern has a light transmittance of 50%, and the light-blocking material forming the light-blocking layer is chromium Cr, wherein the density of each pattern is transparent. See the chart for light rate changes. As shown in the chart, it can be noted that when the pattern density increases in the normal ratio, the optical transmittance is Reduced.

In order to adjust the pattern density, the line width of the fine pattern is varied or adjusted in the range of 0.1 μm to 1.3 μm, wherein a line width difference of 0.1 μm has a value change of 14% optical transmittance. The summary of the change in the transmittance value is shown in Fig. 7.

The present invention can easily change the light transmittance by changing the value of the line width of the fine pattern as described above, and not only can the numerical line width change be obtained, but also the manufacturing process can be greatly reduced. The present invention also has an advantage of reducing the defect rate, thereby increasing the production yield.

(Second exemplary embodiment)

SUMMARY OF THE INVENTION The gist of the present invention is to provide a reticle structure having a plurality of half-tone modulating portions filled with a semi-transmissive material in discrete intervals of the slit-type semi-transmissive portion.

8 and 9 are flowcharts and process diagrams of a manufacturing process of a half-tone mask according to another embodiment of the present invention.

One embodiment of a reticle structure implemented via a manufacturing method will now be described in detail with reference to the flowchart of the present invention.

Referring to Figures 8 and 9, a mask manufacturing method is characterized in that a photoresist is coated on a transparent substrate on which a light blocking layer is stacked (first step); photoresist patterning is performed by exposure and development (second step) Forming a slit type light blocking wall and a light transmitting portion via the etching light blocking layer (third step); and forming a multiple halftone portion by stacking a half of the light transmissive material layer in the slit type light blocking wall (Fourth step).

More specifically, in the first step S1, the manufacturing method may include forming a blank mask in which a transparent substrate 110 is covered with a light blocking layer 120. The material forming the light blocking layer may be any material capable of blocking light, but most suitably, a combination of either Cr and Cr _x O _y or both, wherein x and y are natural numbers, according to combinations of elements And change.

Next, in the second step (S2), the photoresist 130 is applied, then exposed, developed, and patterned into a predetermined pattern. A light blocking layer 120 is etched through a patterned pattern 131 to form a half light transmitting portion 123 formed by a light transmitting portion 122 and a slit light blocking wall 121.

Thereafter, half of the light transmissive material 141 may be filled in the slit type barrier wall 121 to form a multiple halftone portion H (S41).

That is, the multiple half-tone portion H according to the present invention has a structure in which a slit-type light-blocking wall is filled with a semi-transmissive material.

The semi-translucent material may preferably be a material having molybdenum, niobium, tantalum, tungsten, aluminum, chromium, lanthanum, zirconium, vanadium, nickel, niobium, cobalt, titanium as one of main elements, or may be a combination. The material is mixed with at least two or more elements, or at least one of Cox, Ox, Nx, or a single primary element material or a combination material. It may be from a group including Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , Si _x O _y , Si _x O _y N _z , Si _x CO _y , Si _x CO _y N _z , Mo _x Si _y , Mo _x O _y , Mo _x O _y N _z , Mo _x CO _y , MO _x O _y N _z , Mo _x Si _y O _z , Mo _x Si _y O _z N Mo _x Si _y CO _z N, Mo _x Si _y CO _z , Ta _x O _y , Ta _x O _y N _z , Ta _x CO _y , Ta _x O _y N _z , Al _x O _y , Al _x CO _y , Al _x O _y N _z , Al _x CO A composition of any one of _y N _z , Ti _x O _y , Ti _x O _y N _z , Ti _x CO _y , or a combination thereof, wherein the suffixes x, y, and z are natural numbers and define the number of atoms of the individual elements.

Hereinafter, the content of the fourth step (S4) will be explained, including multiple The halftone portion H forms a process of forming three or more semi-transmissive portions.

More specifically, although the method of forming the multiple half-tone portion can be variably utilized by the process of filling the semi-transmissive material in the slit-type photoresist wall 121 in the third step S3, this embodiment will introduce a single use. The process and the use of photoresist to implement a process of multiple semi-transmissive portions having individual different transmittances.

First, an upper surface of one of the light blocking layers formed in the third step (S3) is coated with a half of the light transmissive material layer 140 (S41), and a photoresist 150 is applied to an upper portion of the semi-transmissive material layer 140. On the surface.

Selective patterning is performed on a region having a varying light transmittance (S43), and selective etching is performed on the semi-transmissive material layer through the patterned pattern. The photoresist is removed and a light-transmissive portion W is formed on a region where the transparent substrate is exposed to complete one of the slit-type half-adjusting portion Z and the half-tone material film formed by only the slit-type light-blocking wall. A single half adjustment portion Y, and a multiple half-tone portion mask formed by the slit type barrier wall and the semi-transmissive material (S44).

FIG. 10 is a schematic structural view of an important part of a multiple half-tone mask according to another embodiment of the present invention.

As shown in FIG. 10, the halftone mask according to the present invention can be completed by forming a light transmitting portion W on an exposed transparent substrate 110 and forming a structure having three or The above part and each of the plurality of differently controllable light transmittances, wherein one of the slit type halftone portion Z and the half tone material film layer 143 formed by only one slit type barrier wall is formed. Part Y, and a multiple half-tone portion X formed by the slit-type photoresist wall and the half-transmissive material.

That is, as shown in FIG. 10, if the light transmitting portion W has 100% transmittance, the slit halftone portion Z, the single half adjustment portion Y, and the multiple half adjustment portion X have mutually different light transmittances, respectively. And the illumination light can have different wavelength bands according to the exposure. Although not limited, in general, the illumination light has a wavelength range between 300 nm and 440 nm.

Any material that can be partially transmitted by the irradiation light can be used as the semi-transmissive portion, and although there is no limitation on the amount of light transmission, preferably 10% to 99% of the illumination light can be controlled.

It will be apparent that the halftones of the different structures described above may include at least one or more multiple halftones and may be modified to different numbers and structural designs.

According to the reticle structure of the present embodiment, the light-blocking layer 120, which is itself capable of completely blocking light, can be used, and according to the manufacturing process of the present embodiment, the light-blocking layer 120 has a half-transmissive material layer 144 thereon. In addition, the slit type photoresist wall 121 may have a half of the light transmissive material layer 142 thereon. This is because the present embodiment includes a stacking process for filling the semi-transmissive material layer in discrete pitches of the slit-type photoresist walls.

In particular, the multiple half-tone portion X is formed by a structure in which a slit-type light-blocking wall is inserted into a single half-tone portion to form a composite semi-transmissive portion having different light transmittances, thereby eliminating the single half. The adjustment portion and the slit halftone portion can also add a region for adjusting the light transmittance, so that the degree of freedom in design and the degree of freedom in correcting the transmittance for defects can be greatly improved, which improves the process yield and shortens the process. Process time and improved product quality after exposure.

The present invention is applicable to the industry in that the pattern density of the fine pattern is adjusted to enhance the shape of a slit-type semi-transmissive portion, a stacked semi-transmissive portion, or a combination thereof. Transmittance adjustment efficiency in a half-tone mask.

Another industry application is that the light transmittance of the semi-transmissive region can be accurately controlled by the adjustment of the pattern density without relying on separate manufacturing processes.

Another industry application is that a multiple half-tone mask is filled with a semi-transparent material in a discrete pitch of the slit-type semi-transmissive portion to construct a three- or more mutually different light transmission. The structure of the rate.

The application in the industry is to provide a high-quality multi-half-type reticle by controlling the transmittance through the diffraction phenomenon in the slit, and to greatly improve the design freedom and the defect through the half-transmissive material layer. The transmittance correction degree of freedom helps to improve process yield, shorten process cycle and improve product quality after exposure.

1‧‧‧Transparent substrate

2‧‧‧Light barrier

3‧‧‧Transmission Department

4‧‧‧ semi-transmission department

11‧‧‧Transparent substrate

12‧‧‧Light barrier

13‧‧‧Transmission Department

14‧‧‧Slit pattern

110‧‧‧Transparent substrate

120‧‧‧Light barrier

121‧‧‧Slit type barrier wall

122‧‧‧Transmission Department

123‧‧‧ semi-transmission department

130‧‧‧Light resistance

131‧‧‧ Graphical patterns

140‧‧‧Translucent material layer

141‧‧‧Translucent material

142‧‧‧ semi-transparent material layer

143‧‧‧ halftone material film

144‧‧‧ semi-transparent material layer

150‧‧‧Light resistance

200‧‧‧Substrate

210‧‧‧ semi-transparent layer

220‧‧‧Light barrier

230‧‧‧Light resistance

240‧‧‧ semi-transparent film

250‧‧‧Light resistance

A‧‧‧ semi-transparent area

B‧‧‧ semi-transparent area

C‧‧‧ half-tone mask

PR‧‧‧Photosensitive materials

S1‧‧‧ spacing

S2‧‧‧ spacing

S3‧‧‧ spacing

Sn‧‧‧ spacing

X1‧‧‧ line width

X2‧‧‧ line width

X3‧‧‧ line width

X4‧‧‧ line width

Xn‧‧‧ line width

H‧‧‧Multiple halftones

W‧‧‧Transmission Department

X‧‧‧Multiple halftones

Y‧‧‧ single half adjustment

Z‧‧‧Slit half-tone

1 and 2 are schematic views of a halftone reticle and a gray scale reticle according to the prior art.

3 and 4 are schematic views illustrating the principle of optical transmittance adjustment in accordance with a fine pattern.

Figure 5 is a flow diagram of a process for making an embodiment of the present invention.

6 and 7 are numerical values of transmittance change of the pattern density adjustment of the halftone mask produced according to the process of Fig. 5.

8 and 9 are flowcharts and process diagrams of a manufacturing process of a half-tone mask according to another embodiment of the present invention.

FIG. 10 is a schematic structural view of an important part of a multiple half-tone mask according to another embodiment of the present invention.

110‧‧‧Transparent substrate

120‧‧‧Light barrier

121‧‧‧Slit type barrier wall

140‧‧‧Translucent material layer

141‧‧‧Translucent material

142‧‧‧ semi-transparent material layer

143‧‧‧ halftone material film

W‧‧‧Transmission Department

X‧‧‧Multiple halftones

Y‧‧‧ single half adjustment

Z‧‧‧Slit half-tone

Claims (11)

A half-tone mask comprising: a substrate; a barrier region on a first portion of the substrate, the barrier region comprising a barrier material; a light transmissive region on a second portion of the substrate; and a half The light transmissive region is located on at least a third portion and a fourth portion of the substrate, wherein the semi-transmissive region comprises a plurality of slit walls spaced apart from each other, and the slits of the third portion The arrangement density of the wall is different from the arrangement density of the slit walls of the fourth part. The halftone reticle of claim 1, wherein the slit walls are formed of the barrier material and/or a first semi-transmissive material. The halftone reticle of claim 1, wherein the first semi-transmissive material has a light transmittance in a range of 4% to 75%. The halftone reticle of claim 1, wherein the slit walls have a line width in the range of 0.1 μm to 1.3 μm. The semi-transmissive reticle of claim 3, wherein the first semi-transmissive material comprises one of chromium, bismuth, molybdenum, niobium, titanium, aluminum as one of main elements or mixed with at least two Or combining one of two or more elements, or adding at least one of Cox, Ox, Nx to the main element material or one of the materials of the combination. The half-tone mask of claim 1, wherein the semi-transparent area is further included And comprising: a second semi-transparent material between the slit walls and at least the slit walls of the third portion and the fourth portion. The halftone reticle of claim 6, wherein the height of the second semi-permeable material is greater than the height of the slit walls. The halftone reticle of claim 6, wherein the height of the second semi-permeable material is less than the height of the slit walls. The semi-tone reticle of any one of claims 6 to 8, wherein the second semi-permeable material comprises a main element selected from the group consisting of chromium, bismuth, molybdenum, niobium, titanium, aluminum or a combination of materials at least. The above two or more elements, or at least one of Cox, Ox, and Nx is added to the main element material or the combination material. A method of fabricating a halftone mask includes: forming a barrier layer on a substrate; applying a photoresist to the barrier layer; patterning the photoresist to form at least a first slit wall and at least a second slit wall; and forming the first slit wall, the second slit wall and a light transmissive area by etching the barrier layer, wherein the first slit walls are arranged The density is different from the arrangement density of the second slit walls. The method of claim 10, further comprising: forming a semi-transparent material on at least one of the first slit wall and the second slit walls and the first slit type Wall and the second slit type Between the slit walls of one of the walls.