KR20180127190A - Phase Shift Blankmask and Photomask - Google Patents

Abstract

The present invention provides a high-transmittance phase inversion blank mask and a photomask which are made of a silicon (Si) or silicon (Si) compound on a transparent substrate and have a phase reversal film having high transmittance characteristics. The phase inversion blank mask according to the present invention is the phase inversion mask in which the phase inversion film has a high transmittance of 50% or more, and thus it is possible to realize a fine pattern of 32 nm or less, especially 14 nm or less, preferably 10 nm or less, on a semiconductor device, for example, a DRAM, a flash memory, or a logic device.

Description

Phase Inversion Blank Mask and Photomask [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase inversion blank mask and a photomask, and more particularly, to a phase inversion blank mask and a photomask, in which, in order to improve exposure latitude and depth of focus margin at wafer exposure, To a phase inversion blank mask and a photomask having a high transmittance of 50% or more.

Today, high-level semiconductor microprocessing technology is becoming a very important factor to meet the demand for high integration of large-scale integrated circuits and miniaturization of circuit patterns. BACKGROUND ART In the case of a semiconductor integrated circuit, circuit wiring has been miniaturized for low power and high-speed operation, and a contact hole pattern for interlayer connection and a circuit configuration for integration are increasingly required.

The resolution and pattern registration required for a photomask are getting stricter due to the high integration of the fine patterns and the exposure latitude required for manufacturing a complicated multi- And Depth of Focus margin is becoming a key issue in semiconductor device manufacturing.

The above problems are influenced not only by the photomask and semiconductor device manufacturing process, but also by the characteristics of the blank mask, which is a key component material of semiconductor device manufacturing. For example, when a semiconductor device is manufactured using a photomask fabricated using a phase inversion blank mask, the image contrast can be increased to realize a high resolution and an effect of increasing the depth of focus margin.

Recently, a finer and finer semiconductor device device is required, so that a phase reversal film having a high transmittance such as 12%, 18%, 24% and 30% is prepared in comparison with a phase reversal film having a conventional 6% Phase inversion blank masks are being developed. The high transmittance phase inversion mask as described above has an effect of further increasing the exposure tolerance and the depth of focus margin in comparison with the phase inversion mask having the conventional 6% transmittance.

As another phase inversion photomask technology for realizing a high transmittance phase reversal pattern, a phase inversion mask for CPL (Chromless Phase Shift Lithography) which forms a phase inversion pattern by etching a transparent substrate has attracted attention. In detail, the CPL phase reversal mask is formed by forming a light-shielding film and a resist film pattern on a transparent substrate, forming a light-shielding film pattern through an etching process, and etching the light-shielding film pattern to a depth of about 100% A transmittance and a phase inversion amount of 180 degrees are formed and used as a phase inversion section.

However, the phase inversion mask for CPL has limited applicability due to the following problems in the etching process of the transparent substrate for forming the phase inversion pattern.

First, since there is no thin film layer that can distinguish the etching end point for a transparent substrate, there is no difference in detection amount of a specific substance when etching the substrate, so it is difficult to clearly distinguish the etching end point from the CPL phase shift mask . In general, etching endpoint detection of thin films uses the difference in the detection amounts of metal and nitrogen atoms (N), oxygen (O), and carbon (C) present in the thin films. However, End point detection is difficult. Accordingly, the phase inversion unit formed by etching the transparent substrate has problems such as ensuring the reproducibility of the phase amount of the phase inversion unit and difficulty in etching control as the etching proceeds to the transparent substrate depending on the etching time, thereby lowering the resolution.

In addition, since the transparent substrate is formed through a high-temperature heat treatment process and has high hardness, it is difficult to repair the defect caused by etching the transparent substrate. Accordingly, although the CPL mask has excellent properties, it is difficult to mass-produce and use the CPL mask.

The present invention provides a phase inversion blank mask and a photomask to which a phase reversal film having a high transmittance of 50% or more is applied.

The present invention provides a phase inversion blank mask and a photomask capable of reducing the thickness of a resist film and improving the resolution, the critical dimension accuracy, and the linearity.

The present invention provides a phase inversion blank mask and a photomask capable of achieving a fine pattern of 32 nm or less, in particular, 14 nm or less, for various semiconductor elements.

The phase inversion blank mask according to the present invention includes a phase reversal film provided on a transparent substrate and the phase reversal film is etched into the same material as the transparent substrate and includes a material capable of detecting an etching end point in comparison with the transparent substrate .

The phase reversal film has a transmittance of 50% or more with respect to the exposure light.

The phase reversal film is made of silicon (Si) or silicon (Si) compound.

The material capable of detecting the etch end point is nitrogen (N).

And a light shielding film provided on the phase reversal film.

The light-shielding film is made of one of chromium (Cr), chromium (Cr) compound, molybdenum chromium (MoCr) or molybdenum chromium (MoCr) compound.

And a hard mask film provided on the sequentially stacked phase reversal film and the light-shielding film.

The hard mask film has the same etching property as the phase reversal film, and is made of a material having the light-shielding film and the etch selectivity.

A resist film provided on the phase reversal film and a charge prevention film provided on the resist film.

The anti-fake film is made of self-doped water-soluble conductive polymer (Self-doped Water Soluble Conducting Polymer).

The present invention uses a phase inversion photomask having a phase reversal film having a high transmittance of 50% or more with respect to an exposure wavelength, thereby exposing not only a high resolution but also a light exposure allowance and a depth of focus margin at wafer exposure for semiconductor device fabrication, The process yield can be improved.

The present invention can reduce the thickness of a resist film by using a hard mask for pattern formation, thereby improving resolution, critical dimension accuracy, and linearity.

The present invention increases the process window in the manufacture of various semiconductor devices such as semiconductor devices, DRAMs, flash memories, and logic devices using a high transmittance phase inversion blank mask. Thereby finally improving the process yield.

1 is a cross-sectional view showing a high transmittance phase inversion blank mask according to the first structure of the present invention
2 is a cross-sectional view showing a high transmittance phase inversion blank mask according to the second structure of the present invention
FIGS. 3A and 3B are cross-sectional views showing a high-transmittance phase inversion blank mask according to the third structure of the present invention
4 is a cross-sectional view illustrating a method of manufacturing a high-transmittance phase-reversal photomask according to a second structure of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings, but it should be understood that the present invention is not limited to these embodiments. For example, And is not intended to limit the scope of the invention. Therefore, it will be understood by those skilled in the art that various modifications and other equivalent embodiments may be made by those skilled in the art. Accordingly, the true scope of protection of the present invention should be determined by the technical matters of the claims.

1 is a cross-sectional view showing a high transmittance phase inversion blank mask according to a first structure of the present invention.

1, a phase inversion blank mask 100 according to the present invention includes a transparent substrate 102, a phase reversal film 104 sequentially formed on the transparent substrate 102, a light blocking film 106, and a resist film 110 ).

The transparent substrate 102 is made of quartz glass, synthetic quartz glass, or fluorine-doped quartz glass. The flatness of the transparent substrate 102 affects the flatness of any one of the thin films formed on the upper side, for example, the phase reversal film 104, the light shielding film 106, and the like, When the flatness of the surface to be formed is defined as the value of Total Indicated Reading (TIR) as the margin is affected, the value is 1,000 nm, preferably 500 nm, more preferably 300 nm Or less.

The material constituting the phase reversal film 104 may be at least one selected from the group consisting of silicon (Si), molybdenum (Mo), tantalum (Ta), vanadium (V), cobalt (Co), nickel (Ni), zirconium Nb, Pd, Zn, Cr, Al, Mn, Cd, Mg, Li, Selenium, (N), oxygen (O), carbon (C), boron (B), hydrogen (H), and the like, or one or more materials selected from the group consisting of copper (Cu), hafnium (Hf), and tungsten H). ≪ / RTI >

In particular, the phase reversal film 104 is preferably formed in the form of a compound containing silicon (Si) for high transmittance. In detail, the phase reversal film 104 is formed of SiN, SiC (SiC), or the like, which contains at least one light element of oxygen (O), nitrogen (N), carbon (Si) compound including at least one selected from SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO and SiBCON.

The phase reversal film 104 has a transmittance of 50% or more, preferably 70% or more, more preferably 90% or more, with respect to the exposure wavelength of 193 nm. The phase reversal film 104 according to the purpose of the present invention is preferably formed in the form of a silicon (Si) compound including oxygen (O) among the silicon (Si) compounds in order to have a high transmittance of 50% or more. The increase of the oxygen (O) content in the silicon (Si) compound decreases the refractive index (n) and the extinction coefficient (k) of the phase reversal film and ultimately increases the transmittance and thickness of the phase reversal film.

However, the increase in the transmittance of the phase reversal film 104 serves to improve destructive interference at the edge of the pattern during wafer exposure. However, the increase in thickness increases the pattern aspect ratio in manufacturing the photomask, (Collapse) causes. Accordingly, the transmittance and thickness of the phase reversal film can be controlled by suitably controlling the content of oxygen (O) contained in the phase reversal film 104. For example, in order to maintain a pattern aspect ratio of 2 or less and to achieve a high transmittance of 90% or more in manufacturing a high transmittance phase reversal mask for forming a 100 nm dot pattern, the content of oxygen (O) Can be designed. Further, in order to bring the Aspect Ratio to 2 or less in the same 70 nm dot pattern formation, the thin film should have a thickness of 140 nm or less. At this time, in order to control the amount of phase, the content of oxygen (O) may be decreased or the content of nitrogen (N) may be increased to produce a phase reversal film having a transmittance of 70%.

In addition, the content of oxygen (O) and nitrogen (N) contained in the above-mentioned phase reversal film 104 may be appropriately controlled as it is used for etch end point confirmation. For example, when the content of oxygen (O) in the phase inversion 104 is high, it is difficult to confirm the etch point of the transparent substrate 102 underneath. Therefore, it is possible to include an oxygen (O) outer light element such as nitrogen (N), carbon (C) or the like for identifying the etching end point of the phase reversal film 104, It is easy to confirm the etching end point. However, when the content of nitrogen (N) contained in the phase reversal film 104 is high, the transmittance of the phase reversal film 104 with respect to the exposure wavelength decreases. Therefore, in order to easily determine the etch end point, which has a high transmittance of the phase reversal film 106, it is necessary to appropriately control the oxygen (O) content and the content of the light source such as nitrogen (N).

In order to satisfy the above characteristics, the phase reversal film 104 preferably has a composition ratio of silicon (Si) of 10 at% to 40 at% and a content of light elements (total of N, O, C, etc.) of 60 at% to 90 at% desirable. In particular, the content of nitrogen (N) in the light element contained in the phase reversal film 104 is preferably 1 at% to 20 at%, and more preferably 3 at% to 20 at%. When the content of nitrogen (N) is less than 1 at%, it is difficult to confirm the etching end point as compared with the lower transparent substrate 102. When the content of nitrogen is more than 20 at%, it is difficult to secure high transmittance of the phase reversal film 106.

The content of oxygen (O) in the light element contained in the phase reversal film 104 is preferably 50 at% to 90 at%. When the content of oxygen (O) is 50 at% or less, it is difficult to ensure high transmittance of the phase reversal film 106. When the content of oxygen (O) is 90 at% or more, it is difficult to confirm the etching end point in comparison with the transparent substrate 102 at the bottom.

The phase reversal film 104 is formed through a sputtering process and the sputtering process may be performed using a silicon target or a silicon target doped with boron (B) to increase the sputtering electrical conductivity Can be formed. At this time, the resistivity of the silicon target doped with boron (B) is preferably 1.0E-04? 占 ~ m to 1.0E + 01? 占 ㎝ m, more preferably 1.0E-03? Cm to 1.0E-02? 占 ㎝ m Do. If the specific resistance of the target is high, an abnormal discharge phenomenon such as an arc occurs during sputtering, which causes the characteristics and defects of the thin film.

The oxygen (O) contained in the phase reversal film 104 can be removed by sputtering using at least one gas selected from reactive gases such as nitrogen monoxide (NO), nitrogen dioxide (N ₂ O), carbon dioxide (CO ₂ ) .

The silicon (Si) target for forming the phase reversal film 104 can be manufactured by applying a columnar crystal or a single crystal method.

The target preferably controls the content of impurities contained in the target in order to minimize the occurrence of defects in a sputtering process for forming a thin film. To this end, the content of impurities contained in the silicon (Si) target, particularly, the content of carbon (C) and oxygen (O) is preferably 30 ppm or less, more preferably 5.0 ppm or less. The content of impurities such as Al, Cr, Cu, Fe, Mg, Na, and K is preferably 1.0 ppm or less, more preferably 0.05 ppm or less, in addition to the carbon (C) and oxygen (O). In addition, the purity of the target through the control of the impurity is excellent at a defect control rate when the purity is 4N or more, preferably 5N or more.

The phase reversal film 104 has a structure of a single layer having a uniform composition, a single layer continuous film in which the composition or composition ratio continuously changes, and a multilayer film in which one or more films having different compositions or composition ratios are stacked one or more layers.

The phase reversal film 104 has a thickness of 1,000 Å to 2,000 Å and preferably has a thickness of 1,100 Å to 1,800 Å and has a thickness of 170 ° to 240 °, preferably 180 ° to 230 °, , More preferably from 190 DEG to 220 DEG. In addition, the phase reversal film 104 has a reflectance of 20% or less at all wavelengths of 190 nm to 1,000 nm.

It is preferable that the phase reversal film 104 is heat-treated at a temperature of 100 ° C to 1,000 ° C in order to release stress caused by thin film formation. The heat treatment may be performed using a vacuum rapid thermal process, a furnace, or a hot plate. Further, the heat treatment process may be performed in a gas atmosphere containing oxygen (O) or nitrogen (N) to improve thin film surface characteristics, for example, resistance to chemicals used in cleaning.

When the thin film stress is defined as TIR (Total Indicated Reading), the phase reversal film 104 has a TIR change rate of 300 nm or less, preferably 200 nm or less before / after the film formation.

The light shielding film 106 may be formed on the phase reversal film 104 in various forms such as a single layer, a continuous film, a multilayer film of two or more layers including a first light shielding layer and a second light shielding layer, Is formed of a material having an etch selectivity of 10 or more in dry etching.

The light shielding film 106 may be formed of a material selected from the group consisting of molybdenum (Mo), tantalum (Ta), nickel (Ni), zirconium (Zr), niobium (Nb), palladium (Pd), zinc (Zn) (Al), Mn (Mn), Cd, Mg, Li, Se, hafnium (Hf), and tungsten Or one or more light elements of nitrogen (N), oxygen (O), and carbon (C) in the material. In particular, the light shielding film 106 is preferably made of a metal compound containing chromium (Cr). When the light shielding film 106 is formed of a chromium compound, chromium (Cr) is 30 at% to 70 at%, nitrogen (N) is 10 at% to 40 at%, oxygen O is 0 to 50 at% ) Is 0 to 30 at%.

The light shielding film 106 may be formed of a compound including chromium (Cr) and molybdenum (Mo), and may contain molybdenum (Mo) to increase the etch rate and extinction coefficient The light shielding film 106 can be made thinner. At this time, the compound has a molybdenum (Mo) content of 2 at% to 30 at%, a Cr content of 30 at% to 60 at%, a nitrogen content of 10 at% to 40 at%, an oxygen content of 0 to 50 at% And a molybdenum chromium (MoCr) compound having a composition ratio of carbon (C) of 0 to 30 at%.

The light shielding film 106 has a thickness of 500 ANGSTROM to 1,000 ANGSTROM, preferably 500 ANGSTROM to 800 ANGSTROM.

The anti-reflection film may be formed of a material having the same etching property as that of the light blocking film 106, or may be formed of a material having an etching selectivity ratio And the like.

The thin film on which the phase reversal film 104 and the light shielding film 106 are laminated has an optical density of 2.5 to 3.5 with respect to the exposure light of 193 nm wavelength and preferably has an optical density of 2.7 to 3.2, % To 40%, preferably 20% to 35%.

The light-shielding film 106 may be selectively heat-treated, and the heat-treatment temperature may be equal to or lower than the heat-treatment temperature of the lower phase reversal film 104.

2 is a cross-sectional view showing a high transmittance phase inversion blank mask according to a second structure of the present invention.

2, a high transmittance phase shift blank mask 200 according to the present invention includes a transparent substrate 202, a phase reversal film 204 sequentially provided on the transparent substrate 202, a light shielding film 206, A mask 208 film, and a resist film 210. Here, the transparent substrate 202, the phase reversal film 204, and the light shield film 206 are the same as those described in the first structure of the present invention described above.

The hard mask film 208 is formed on the light shielding film 206 to serve as an etching mask when the light shielding film 206 is patterned so that the hard mask film 208 has an etching selectivity to the lower light shielding film 206 Etch Selectivity) is preferably 10 or more.

The hard mask film 208 is preferably made of a material having the same etching property as that of the phase reversal film 204 in order to simplify the photomask manufacturing process. Type hard mask film 208 are removed together.

Accordingly, the hard mask film 208 can be formed of, for example, SiN containing at least one of oxygen (O), nitrogen (N), and carbon (C) (Si) compounds such as SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO, SiBCON, molybdenum silicide (MoSi) or MoSiN, MoSiC, MoSiO, MoSiCN, And a molybdenum silicide (MoSi) compound including MoSiCO, MoSiNO, and MoSiCON.

The hard mask film 208 has a thickness of 20 ANGSTROM to 200 ANGSTROM and preferably has a thickness of 50 ANGSTROM to 150 ANGSTROM. The hard mask film 208 has an etching rate of 10 angstroms / sec or less.

The resist film 210 formed on the hard mask film 208 may be a positive resist or a negative chemically amplified resist. The resist film 210 has a thickness of 400 ANGSTROM to 1,500 ANGSTROM, preferably 600 ANGSTROM to 1,200 ANGSTROM.

Although not shown, HMDS can be selectively formed between the resist film 210 and the underlying thin film to improve the adhesion between the resist film 210 and the underlying thin film.

3 (a) and 3 (b) are cross-sectional views showing a high-transmittance phase inversion blank mask according to the third structure of the present invention.

3 (a) and 3 (b), a high-transmittance phase reversal blank mask 300 according to the present invention is a high-transmittance phase reversal blank mask 300, which is provided on the resist films 110 and 210 of the above- And a Charge Dissipation layer 312 (CDL). Here, the transparent substrates 102 and 202, the phase reversal films 104 and 204, the light shield films 106 and 206, and the hard mask film 208 are the same as those described in the first and second structures of the present invention Do.

The charge-blocking films 112 and 212 may be selectively formed on the resist film and may be formed of a self-doped water-soluble conductive polymer having a property of being dissolved in DI water. can do. This prevents the charge-up phenomenon of electrons during exposure and prevents thermal deformation of the resist films 110 and 210 due to the charge-up phenomenon.

The charge blocking films 112 and 212 have a thickness of 5 nm to 60 nm, preferably 5 nm to 30 nm.

As described above, the present invention uses a phase reversal photomask having a phase reversal film having a high transmittance of 50% or more with respect to the exposure wavelength, and therefore, not only high resolution but also exposure tolerance and depth of focus The margin can be widened, and finally, the process yield can be improved.

In addition, the present invention can reduce the thickness of a resist film by using a hard mask for pattern formation, thereby improving the resolution, critical dimension accuracy, and linearity. have.

In addition, the present invention provides a process window for manufacturing various semiconductor devices such as a semiconductor device, a DRAM, a flash memory, and a logic device using a high transmittance phase inversion blank mask. Can be increased to finally improve the process yield.

Hereinafter, a phase inversion blank mask according to an embodiment of the present invention will be described in detail.

(Example)

Example  1: Blank mask and Photomask  The manufacturing method (transmittance: about 70% PSM )

This embodiment will be described with reference to FIG. 4 to explain a method of manufacturing a high-transmittance phase inversion blank mask and a photomask according to the second structure of the present invention.

4A, a phase reversal film 204, a light shielding film 206, a hard mask 208 film, and a resist film 210 are sequentially formed on a transparent substrate 202.

The transparent substrate 202 has a concave shape and has a value of -82 nm when the flatness is defined as TIR (Total Indicated Reading).

The phase reversal film 204 is formed on a DC magnetron sputtering apparatus of a single row structure having a purity of 6N and a silicon (Si) target doped with boron (B) Was injected with Ar: N ₂ : NO = 5 sccm: 5 sccm: 5.3 sccm and a process power of 1.0 kW was applied to form a SiON film having a thickness of 125 nm.

The transmittance and the phase amount of the phase reversal film 204 were measured using a n & k analyzer 3700RT apparatus. As a result, the transmittance center value was 68% and the phase amount center value was 205 ° for a wavelength of 193 nm. As a result, it was + 80nm in convex form. The compositional ratio of the phase reversal film 204 was analyzed by using an AES instrument, and as a result, silicon (Si): nitrogen (N): oxygen (O) = 16.3 at%: 15.6 at%: 68.1 at%.

Thereafter, the phase reversal film 204 was subjected to a heat treatment for improving the flatness at a temperature of 500 ° C for 40 minutes using a vacuum rapid thermal processing apparatus. As a result of measurement of the stress of the phase reversal film 204, +30 nm in the convex form was exhibited, and the stress change amount (Delta Stress) of the total phase reversal film 204 was +121 nm, and stress relaxation was confirmed through the heat treatment process I could.

The light shielding film 206 is formed by injecting a process gas of Ar: N ₂ : CH ₄ = 5 sccm: 12 sccm: 0.8 sccm into a DC magnetron sputtering system of a single-wafer structure equipped with a chromium (Cr) target, To form a lower layer film made of a CrCN film having a thickness of 43 nm. Then, a process gas of Ar: N ₂ : NO = 3 sccm: 10 sccm: 5.7 sccm was injected and a process power of 0.62 kW was applied to form an upper layer film made of a CrON film having a thickness of 16 nm, .

Optical density and reflectance of the light-shielding film 206 were measured with respect to the light-shielding film 206. As a result, the optical density of the light-shielding film 206 was 3.10 with respect to the exposure light of 193 nm wavelength and the reflectivity was 29.6% It was confirmed that there was no problem described below.

The hard mask film 208 was formed by injecting a process gas of Ar: N ₂ : NO = 7 sccm: 7 sccm: 5 sccm into a DC magnetron sputtering system of a single-wafer structure equipped with a silicon (Si) target, To form a SiON film having a thickness of 10 nm.

Then, after the HMDS process was performed on the hard mask film 208, a negative chemical amplification type resist was formed to have a thickness of 100 nm by using a spin coating facility to finally complete the manufacture of the phase inversion blank mask.

The thus prepared blank mask was subjected to an exposure process, followed by PEB (Post Exposure Bake) for 100 minutes and 10 minutes, and then developed to form a resist film pattern 210a.

Thereafter, the hard mask film pattern 208a is formed by dry-etching the resist film pattern 210a on the hard mask film under the etching mask based on the flourine gas. At this time, the etching end time point of the hard mask film was measured using an EPD (End Point Detection) system, and it was 17 seconds.

Referring to FIG. 4B, after the resist film pattern is removed, a light shielding film pattern 206a is formed by etching the lower light shielding film with the hard mask film pattern 208a using an etching mask. On the other hand, the light-shielding film may be etched using the resist film and the hard mask film as an etching mask.

Referring to FIG. 4C, the lower phase reversal film is dry-etched based on a fluorine gas using the hard mask film pattern 208a and the light-shielding film pattern 206a as an etching mask to form a phase reversal film pattern 204a .

As a result of analyzing the etching end point using the EPD system, the phase reversal film pattern 204a can discriminate the etching end point by using a nitrogen (N) peak in comparison with the lower transparent substrate 202 . Here, the hard mask film pattern 208a was completely removed at the time of etching for forming the phase reversal film pattern 204a.

4D and 4E, after the secondary resist film pattern 214a is formed on the transparent substrate 202 on which the phase reversal film pattern 204a is formed, The light shielding film pattern 206a of the main area was removed to finally complete the phase reversal photomask manufacturing.

The pure transmittance and the phase amount of the phase reversal film pattern were measured using the MPM-193 equipment for the phase inversion photomask prepared as described above. As a result, the transmittance was 72.3% at a wavelength of 193 nm, and the phase amount was 215 °. Also, the pattern profile was observed with TEM and showed 86 °.

Example  2: blank mask and Photomask  Manufacturing method (transmittance about 100% PSM )

In this embodiment, a phase inversion photomask having a high transmittance of the phase reversal film pattern was manufactured in comparison with the first embodiment.

First, a sputtering target and an apparatus were prepared in the same manner as in Example 1, and then a process gas of Ar: N ₂ : NO = 5 sccm: 5 sccm: 7.1 sccm was introduced and a process power of 1.0 kW was applied. Film.

The transmittance and phase of the formed phase reversal film 104 were measured using an n & k analyzer 3700RT instrument. As a result, the transmittance was 87% and the phase amount was 204 DEG at a wavelength of 193 nm. The compositional ratio of the phase reversal film thus prepared was analyzed using AES equipment, and as a result, the silicon (Si): nitrogen (N): oxygen (O) = 21.2 at%: 4.0 at%: 74.8 at%.

The transparent transmittance and the phase amount of the phase reversal film pattern were measured sequentially using MPM-193 after lamination of a light-shielding film, a hard mask and a resist in the same manner as in Example 1 through a photomask process. As a result, Of 97.2% and the phase amount of 213 °.

Comparative Example  : Board Angular shape  Phase Inversion Blank Mask Manufacturing

In this comparative example, a substrate-type square-shaped phase inversion blank mask and a photomask were prepared in order to compare with Example 1.

The substrate type hexagonal blank mask, first, the process gas on the chromium (Cr) in the single wafer type structure equipped with a target DC magnetron sputtering machine on a transparent substrate _{Ar: N 2: CH 4 =} 5 sccm: 5 sccm: 0.8sccm And a process power of 1.4 kW was applied to form a lower layer film made of a CrCN film having a thickness of 43 nm. Then, a process gas of Ar: N ₂ : NO = 3 sccm: 10 sccm: 5.7 sccm was injected and a process power of 0.62 kW was applied to form an upper layer film of a CrON film having a thickness of 16 nm to form a two-layer structure .

The optical density and the reflectance of the light-shielding film were measured. As a result, the light-shielding film exhibited an optical density of 3.05 and a reflectance of 31.2% for the exposure light of 193 nm wavelength.

Then, a negative chemical amplification type resist was formed on the hard mask film to a thickness of 170 nm using a spin coating apparatus, and finally, the phase inversion blank mask was completed.

After the resist film pattern was formed, a light shielding film was formed by etching the lower light shielding film with the resist film pattern using an etching mask. Subsequently, after removing the resist film, the exposed part of the transparent substrate at the bottom was etched using a light shielding film pattern using an etching mask based on a florine (F) gas.

At this time, etching of the transparent substrate was performed by designating the etching time, and the thickness of the etched transparent substrate was 200 nm and the phase amount was 220 °.

The uniformity of the phase inverting portion of the phase inverting photomask according to Example 1 and the phase inverting portion of the substrate type square-phase inverting photomask manufactured as in the comparative example were measured and the results are shown in Table 1 below.

Point # 1 Point # 2 Point # 3 Point # 4 Point # 5 Range
(Max-Min) Transmittance
@ 193 nm Example 1 72.3% 72.9% 73.2% 72.2% 71.8% 1.4% Comparative Example 99.8% 100% 99.2% 100% 99.3% 0.8% Phase quantity
@ 193 nm Example 1 215.2 [deg.] 215.3 DEG 216.2 DEG 215.0 DEG 215.2 [deg.] 1.2 ° Comparative Example 219 [deg.] 220 ° 225 ° 217 [deg.] 22 ° 8 °

Referring to Table 1, in the case of the transmittance of Example 1 and the comparative example, each range difference is small. In the case of the amount of phase, however, Example 1 has a phase amount range of 1.2 degrees, And it was confirmed that the substrate type square-phase inversion photomask is difficult to use.

The reproducibility evaluation process for fabricating five phase inversion photomasks according to Example 1 and Comparative Example with respect to the transmittance and the phase amount as described above was performed and the center value thereof was measured. The results are shown in Table 2 below.

Point # 1 Point # 2 Point # 3 Point # 4 Point # 5 Lot-to-lot
(Max-Min) Transmittance
@ 193 nm Example 1 72.5% 72.2% 72.7% 73.2% 73.6% 0.014% Comparative Example 99% 98% 99% 99% 99% 0.01% Phase quantity
@ 193 nm Example 1 215 ° 214 DEG 215 ° 216 ° 215 ° 2 ° Comparative Example 220 ° 216 ° 224 ° 226 ° 213 ° 13 °

Referring to Table 2, although the center values of transmittances of the respective plates were similar to each other in Example 1 and Comparative Example, there was no significant difference, but the amount of phase was 2 ° in Example 1, And it is confirmed that phase amount control is relatively difficult.

While the present invention has been described with reference to the preferred embodiments, the technical scope of the present invention is not limited to the range described in the above embodiments. It will be readily apparent to those skilled in the art that various changes and modifications can be made to the embodiments described above. It is apparent from the description of the claims that the form of such modification or improvement can be included in the technical scope of the present invention.

100, 200: phase inversion blank mask
102: transparent substrate
104: phase reversal film
106: a light-shielding film
108: hard mask film
110: resist film

Claims (26)

A phase inversion blank mask comprising a phase reversal film provided on a transparent substrate,
Wherein the phase reversal film is etched into the same material as the transparent substrate and comprises a material capable of etching end point detection relative to the transparent substrate.
The method according to claim 1,
Wherein the phase reversal film has a transmittance of 50% or more with respect to the exposure light.
The method according to claim 1,
Wherein the phase reversal film is made of a material selected from the group consisting of SiN, SiC, SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO, (Si) compound of one of SiBCON and SiBCON.
The method of claim 3,
Wherein the phase reversal film is made of a silicon (Si) compound and has a composition ratio of silicon (Si) of 10 at% to 40 at% and a light element of 60 at% to 90 at%.
The method according to claim 1,
Wherein the etch endpoint detectable material is nitrogen (N).
6. The method of claim 5,
Wherein when the phase reversal film contains nitrogen (N), the nitrogen (N) has a content of 1 at% to 20 at%.
The method according to claim 1,
Wherein when the phase reversal film contains oxygen (O), the content of oxygen (O) is 50 at% to 90 at%.
The method of claim 3,
Wherein the phase reversal film is formed using a silicon (Si) target or a doping silicon (Si) target doped with boron (B), and the resistivity of the target is in the range of 1.0E-04? Cm to 1.0E + Lt; RTI ID = 0.0 > cm. ≪ / RTI >
The method according to claim 1,
Wherein the phase reversal film has a structure of a single layer having a uniform composition, a single layer continuous film in which the composition or composition ratio continuously changes, and a multi-layer film in which one or more films having different compositions or composition ratios are stacked one or more layers. Mask.
The method according to claim 1,
Wherein the phase reversal film has a thickness of 1,000 ANGSTROM to 2,000 ANGSTROM.
The method according to claim 1,
Wherein the phase reversal film has a phase amount of 170 占 to 240 占 with respect to exposure light having a wavelength of 193nm.
The method according to claim 1,
Further comprising a light shielding film provided on the phase reversal film.
13. The method of claim 12,
Wherein the light-shielding film comprises 30 at% to 70 at% of chromium (Cr) or chromium (Cr), 10 at% to 40 at% of nitrogen (N), 0 to 50 at% of oxygen (O) (Cr) compound, molybdenum chromium (MoCr) or molybdenum (Mo) is contained in an amount of 2 at% to 30 at%, chromium (Cr) in 30 at% to 60 at%, nitrogen (N) (MoCr) compound having a composition ratio of oxygen (O) of 0 to 50 at%, carbon (C) of 0 to 30 at%, and a molybdenum chromium (MoCr) compound having a composition ratio of 0 to 30 at%.
13. The method of claim 12,
Wherein the light-shielding film has a thickness of 500 ANGSTROM to 1,000 ANGSTROM.
13. The method of claim 12,
Further comprising an antireflection film provided on the light-shielding film, wherein the antireflection film is formed of a material having the same etching property as that of the light-shielding film, or is formed of a material having an etch selectivity.
13. The method of claim 12,
Wherein the structure in which the light shielding film or the phase reversal film and the light shielding film are laminated has an optical density of 2.5 to 3.5 with respect to the exposure light.
13. The method of claim 12,
Wherein the portion where the phase reversal film and the light shielding film are laminated has a surface reflectance of 10% to 40%.
13. The method of claim 12,
And a hard mask film provided on the sequentially stacked phase reversal film and the light-shielding film.
19. The method of claim 18,
Wherein the hard mask film is made of a material having the same etch characteristics as the phase reversal film and having the light-shielding film and the etch selectivity ratio.
19. The method of claim 18,
The hard mask film may be formed of silicon (Si) or a silicon (Si) compound including SiN, SiC, SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO, SiBCON, (MoSi) or a molybdenum silicide (MoSi) compound including MoSiN, MoSiC, MoSiO, MoSiCN, MoSiCO, MoSiNO, and MoSiCON.
19. The method of claim 18,
Wherein the hard mask film has an etching rate of 10 angstroms / sec or less.
19. The method of claim 18,
Wherein the hard mask film has a thickness of 20 ANGSTROM to 200 ANGSTROM.
The method according to claim 1,
Further comprising a resist film provided on the phase reversal film and a charge prevention film provided on the resist film.
24. The method of claim 23,
Wherein the anti-charging film is made of self-doped water-soluble conductive polymer (Self-doped Water Soluble Conducting Polymer).
The method of claim 23, wherein
Wherein the charge blocking film has a thickness of 5 nm to 60 nm.
A phase inversion photomask produced using the phase inversion blank mask of any one of claims 1 to 25.

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