KR101579848B1 - Phase Shift Blankmask and Photomask - Google Patents

Abstract

The present invention provides a blank mask ensuring production of a photomask capable of implementing micropatterns which are less than or equal to 32 nm, especially 14 nm or favorably 10 nm. To this end, the blank mask of the present invention comprises: a phase inversion film placed on a transparent substrate, a lighttight film, an etching prevention film, and a hard film, wherein the lighttight film is multi-layered composed of at least two layers with different composition. One of the layers in the lighttight film essentially comprises oxygen (O), and the oxygen-containing lighttight film occupies 50-100% of the whole thickness of the lighttight film. In addition, the phase inversion film has penetration rate of 10-50%.

Description

Phase Inversion Blank Mask and Photomask [

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 capable of realizing a fine pattern of 32 nm or less, particularly, 14 nm or less.

BACKGROUND ART [0002] Today, with the high integration of large-scale integrated circuits, there is a constant demand for miniaturization of circuit patterns. Accordingly, in the case of a blank mask, a conventional binary blank mask and a phase shift blank mask have been developed and commercialized. In recent years, a binary blank mask for a hard mask having a hard film has been developed .

In recent years, a phase inversion blank mask having a hard film in a phase inversion blank mask has been developed in accordance with a high-precision fine pattern implementation of 32 nm or less. The phase inversion blank mask having the hard film essentially has a structure in which a light shielding film, a hard film and a resist film are stacked on a phase reversal film, and a hard film has a structure in which etching selectivity with respect to a lower light shielding film is secured And is generally in the form of a compound containing silicon (Si).

However, since the hard film is formed in the form of a compound containing silicon (Si), the following problems arise. First, since a hard film composed of a compound containing silicon (Si) is provided in contact with the lower portion of the resist film, an electron charge-up (electron) in a hard film during an exposure process using an electron beam charge-up phenomenon occurs. The electron charge-up phenomenon induces a deflection of electrons during exposure, thereby causing a position error of a pattern in a photomask manufacturing process. Accordingly, it is difficult to apply a hard film composed of a compound containing silicon (Si) in an exposure process using a double patterning or a multi-patterning technique in which pattern positions are more strictly managed.

In addition, a hard film composed of a compound containing silicon (Si) causes a problem of adhesion with a resist film. That is, since the hard film made of a compound containing silicon (Si) has a high surface energy, it is difficult to coat the resist film partially, such as peeling of the resist film after the development step following the (Un- . In order to solve the adhesion problem between the resist film and the hard film, a surface treatment process such as HMDS (hexamethyldisilazane) has been carried out. However, an additional surface treatment process such as HMDS can cause defect, Resulting in spotting or scum-forming defects after the developing process.

In addition, when the light shielding film is formed on the phase reversal film without using a hard film and the lower shielding film is etched by using the resist film as an etching mask, formation of a fine pattern of 32 nm or less in thickness This is difficult.

On the other hand, in recent years, studies have been made on a phase inversion blank mask which has a high transmittance without limiting the transmittance of the phase inversion film to about 6%. The phase inversion blank mask having the high transmittance sets the transmittance to about 6% or more so as to increase the destructive interference of the pattern edge portion to make the pattern finer. However, in order to satisfy the optical characteristics such as the transmittance and the phase reversal amount, the phase reversal film needs to have a thickness of about 1000 ANGSTROM or more, which is 1.5 times thicker than the thickness of the general phase reversal film (650 ANGSTROM to 700 ANGSTROM) do. Further, when a large amount of light element is contained in order to increase the transmittance of the phase reversal film, the chemical resistance is deteriorated and defects are generated in pattern formation.

The present invention provides a phase inversion blank mask capable of realizing a fine pattern with a high transmittance phase reversal film of 32 nm or less, particularly 14 nm or less, and a photomask using the same.

The phase inversion blank mask according to the present invention is characterized in that a phase reversal film and a light shielding film are provided on a transparent substrate and the light shielding film is composed of a multilayer film of two or more layers containing at least one of oxygen (O) and nitrogen (N) , At least one of the films essentially contains oxygen (O), and the film essentially containing oxygen (O) accounts for 50% to 100% of the thickness of the entire light shielding film.

In addition, the phase inversion blank mask according to the present invention is characterized in that a phase reversal film and a light shielding film are provided on a transparent substrate, the phase reversal film includes at least silicon (Si) And nitrogen (N), wherein at least one of the films essentially contains oxygen (O), and the film essentially containing oxygen (O) is a multilayer film including at least one of a total thickness To 50% to 100% of the thickness.

The phase reversal film has a transmittance of 10% to 50% with respect to exposure light having a wavelength of 193 nm or 248 nm.

When the phase reversal film has a multilayer film or a continuous film structure, the uppermost part is essentially composed of oxygen (O), and the phase reversal film has a structure of either a single layer or a multilayer film or a continuous film structure of two or more layers.

The phase reversal film and the light shielding film may be formed of silicon (Si), molybdenum (Mo), tantalum (Ta), vanadium (V), cobalt (Co), nickel (Ni), zirconium (Zr), niobium Pd, Zn, Cr, Al, Mn, Cd, Mg, Li, Selenium, Cu, (H), tungsten (W), or one or more of nitrogen (N), oxygen (O), carbon (C), boron (B) Or more.

Wherein the phase reversal film is formed of silicon (Si), a metal silicide, and a silicon (Si) material further containing at least one element selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B) (Si) compounds, and metal suicide compounds.

Wherein the phase reversal film has a composition ratio of silicon (Si) of 40 at% to 90 at% and a light element of 10 at% to 60 at%, and the phase reversal film is a metal silicide or a Compound has a composition ratio of 0.1 at% to 10 at% of metal, 39 at% to 90 at% of silicon (Si), and 0 at% to 60 at% of light element.

The phase reversal film has a thickness of 500 Å to 850 Å, has a phase reversal amount of 170 ° to 190 ° with respect to exposure light having a wavelength of 193 nm or 248 nm, and has a reflectance of 20% to 30%.

The light shielding film may be formed of chromium (Cr) or chromium (Cr) further containing at least one light element among nitrogen (N), oxygen (O), carbon (C), boron (B) Cr) compounds.

Wherein the light shielding film has a composition of 30 at% to 70 at% of chromium (Cr), 10 at% to 40 at% of nitrogen (N), 0 to 50 at% of oxygen (O), 0 to 30 at% of carbon (C) Of 0 to 30 at% and hydrogen (H) of 0 to 30 at%.

The light shielding film has a thickness of 300 ANGSTROM to 700 ANGSTROM and has an etching rate of 1.0 ANGSTROM / sec to 4.0 ANGSTROM / sec.

The phase inversion blank mask according to the present invention further includes at least one of an etching stopping film and a hard film provided on the light shielding film.

Wherein the etching stopper film is made of a material having the same etching property as that of the phase reversal film and the hard film has an etching property different from that of the phase reversal film and the etching stopper film and is made of a material having the same etching property as the light- do.

The hard film may be chromium (Cr) or chromium (Cr) further containing at least one light element of nitrogen (N), oxygen (O), carbon (C), boron (B) Cr) compounds.

The etch stop layer has a thickness of 20 ANGSTROM to 150 ANGSTROM.

The hard film has a thickness of 20 ANGSTROM to 100 ANGSTROM and has an etching rate of 0.4 ANGSTROM / sec or more.

A phase inversion photomask can be manufactured using the phase inversion blank mask according to the present invention.

The present invention can form a finer pattern by forming the phase reversal film to have a transmittance of 6% or more.

In addition, the present invention uses a chromium (Cr) hard film and an etch stopper film having a different light-shielding film and etching property at the lower part thereof to solve the adhesion problem between the hard film and the resist film, It is possible to prevent spot or scum-like defects from occurring due to no additional process being performed, and to solve the electronic charge-up phenomenon that has occurred in the hard film including silicon (Si) can do.

Accordingly, the present invention can form a blank mask capable of producing a photomask capable of realizing a fine pattern of 32 nm or less, particularly 14 nm or less, and preferably 10 nm or less.

1 is a cross-sectional view showing a phase inversion blank mask according to a first embodiment of the present invention;
2 is a cross-sectional view showing a phase inversion blank mask according to a second embodiment of the present invention;
3 is a sectional view showing a phase inversion blank mask according to a third embodiment of the present invention;
4 is a cross-sectional view showing a phase inversion blank mask according to a fourth embodiment 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.

FIG. 1 is a cross-sectional view showing a phase inversion blank mask according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a phase inversion blank mask according to a second embodiment of the present invention.

1 and 2, 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 shielding film 106, And a resist film 112.

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 thin film formed on the upper side, for example, the phase reversal film 104, the light shielding film 106, etc., Is defined as a value of TIR (Total Indicated Reading), the value is controlled to be 100 nm or less, preferably 50 nm or less, in the region of 142 mm < 2 >.

The phase reversal film 104 may be formed of a material such as silicon (Si), molybdenum (Mo), tantalum (Ta), vanadium (V), cobalt (Co), nickel (Ni), zirconium (Zr), niobium ), Zinc (Zn), chromium (Cr), aluminum (Al), manganese (Mn), cadmium (Cd), magnesium (Mg), lithium (Li), selenium Or at least one of nitrogen (N), oxygen (O), carbon (C), boron (B), and hydrogen (H) Lt; / RTI > material.

The phase reversal film 104 may be formed of a material such as silicon (Si) or silicon (Si) such as SiN, SiC, SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO, Si) compound. MoSiN, MoSiN, MoSiCON, MoSiB, MoSiBN, MoSiBC, MoSiBO, MoSiBCN, MoSiBCO, MoSiBNO, MoSiBNO, MoSiN, MoSiN, MoSiC, MoSiO, MoSiCN, MoSiCO, (MoSi) compound, such as MoSiBCON, for example.

The phase reversal film 104 is formed by adjusting the composition ratio of at least one of silicon (Si) and the light element contained therein so as to satisfy the required transmittance and phase inversion amount. Specifically, when the phase reversal film 104 is made of a silicon compound, the phase reversal film 104 has a composition ratio of silicon (Si) of 40 at% to 90 at% and a light element of 10 at% to 60 at% Preferably, the composition ratio of silicon (Si) is 50 at% to 85 at% and the light element is 15 at% to 50 at%. In the case where the phase reversal film 104 is made of a metal silicide or a compound thereof, the phase reversal film 104 preferably has a metal content of 0.1 at% to 10 at%, a silicon (Si) content of 39 at% to 90 at% % To 60 at%, and preferably has a composition ratio of 0.1 at% to 5 at% of metal, 49 at% to 80 at% of silicon (Si), and 15 at% to 50 at% of light element.

The phase reversal film 104 may be formed as a single layer or a multilayer structure of two or more layers, or may be formed in the form of a single film having the same composition ratio or a continuous film having a continuously varying composition ratio. In the case where the phase reversal film 104 has a multilayer film or a continuous film structure, the uppermost part essentially contains oxygen (O) in an amount of 1 at% to 20 at% to improve the chemical resistance and antinodality of the phase reversal film 104 .

In the case where the phase reversal film 104 is formed through a sputtering process and the phase reversal film 104 is made of a metal silicide or a compound thereof, the target may be formed using a metal and a separately formed target of silicon (Si) As shown in FIG. At this time, the metal silicide target has a composition ratio of metal: Si = 1 at% to 10 at%: 90 at% to 99 at%, and preferably a composition ratio of Mo: Si = 1 at% to 6 at%: 94 at% . When the target contains boron (B), the target has a composition ratio of metal: Si: B = 1 at% to 10 at%: 80 at% to 98 at%: 1 at% to 10 at%. If the metal content of the phase reversal film 104 is more than 10 at%, it is difficult to secure a transmittance of about 30% for exposure light having a wavelength of 193 nm or 248 nm due to its metallic property, so that the metal content of the target is 10 at% .

The phase reversal film 104 has a thickness of 500 to 850 ANGSTROM and preferably has a thickness of 550 ANGSTROM to 650 ANGSTROM and has a phase reversal amount of 170 DEG to 190 DEG relative to exposure light of 193 nm or 248 nm wavelength, And has a surface reflectance of 30% to 30%.

The phase reversal film 104 has a transmittance of 10% to 50% with respect to exposure light having a wavelength of 193 nm or 248 nm. If the transmittance of the phase reversal film 104 is lower than 10%, the intensity of exposure light for destructive interference during exposure to the resist film applied to the wafer is reduced and the phase reversal effect is insignificant, , Damage to the resist film applied to the wafer is given to increase the loss of the resist film.

The phase reversal film 104 can be selectively heat-treated at 100 ° C to 500 ° C to adjust chemical resistance and flatness.

The light shielding film 106 is provided in the form of a single layer or a multilayer on the phase reversal film 104 and is formed of a material having an etching selectivity ratio of 10 or more with the phase reversal film 104.

The light shielding film 106 may be formed of tantalum (Ta), nickel (Ni), zirconium (Zr), niobium (Nb), palladium (Pd), zinc (Zn), tin (Sn), chromium (Cr) At least one of Mn, Mn, Cd, Mg, Li, Se, Hf, W, and Si, Or one or more light element materials selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B) and hydrogen (H).

The light shielding film 106 may be formed of, for example, chromium (Cr) or a chromium (Cr) compound including chromium (Cr) such as CrN, CrC, CrO, CrCN, CrON, CrCO, desirable. When the light shielding film 106 is formed of a chromium (Cr) compound, the light shielding film 106 is formed of 30 at% to 70 at% of chromium (Cr), 10 at% to 40 at% of nitrogen (N) To 50 at%, carbon (C) is 0 to 30 at%, boron (B) is 0 to 30 at%, and hydrogen (H) is 0 to 30 at%.

The light shielding film 106 may be composed of a multilayer film of two or more layers, wherein the multilayer film includes a film for controlling the etching rate and a film for adjusting the optical density (OD).

2, the light shielding film 106 is composed of a first light shielding layer 114 and a second light shielding layer 116 made of chromium (Cr) compound including a light element in chromium (Cr).

The first light-shielding layer 114 is formed on the phase reversal film 104 and serves to shorten the time of the etching process of the entire light shielding film 106 by increasing the etching rate.

The first light-shielding layer 114 has a thickness of 300 ANGSTROM to 550 ANGSTROM and has a thickness corresponding to 50% to 95% of the total thickness of the light shielding film 106, preferably 70% to 90% .

The first light-shielding layer 114 essentially contains oxygen (O), thereby increasing the etching rate. The first light-shielding layer 114 has an oxygen (O) content of 10 at% to 50 at%, preferably an oxygen (O) content of 10 at% to 20 at% The effect of shortening the entire etching time can be obtained.

The second light blocking layer 116 is formed on the first light blocking layer 114 to control the optical density. When the optical density is adjusted only by the first light-shielding layer 114, the thickness of the light-shielding film 106 is increased to match the optical characteristics required for the light-shielding film 106. Therefore, 106 to compensate for the optical density required.

The second light-shielding layer 116 has a thickness of 20 ANGSTROM to 150 ANGSTROM, preferably 30 ANGSTROM to 100 ANGSTROM.

The second light-shielding layer 116 is formed of a chromium (Cr) compound with or without oxygen (O).

When the second light-shielding layer 116 includes oxygen (O), the thickness of the film may be thicker than the case where oxygen (O) is not included in order to secure a certain light shielding property. However, The same effect can be obtained in the thinning of the resist film thickness. At this time, the second light-shielding layer 116 has an oxygen (O) content of 1 at% to 20 at%, and preferably an oxygen (O) content of 1 at% to 15 at%. When the content of oxygen (O) in the second light-shielding layer 116 exceeds 20 at%, the resistance to the fluorine (F) etching gas used for etching the phase reversal film 104 is weakened, The second light-shielding layer 116 is damaged at the time of etching and the optical density is lowered.

When the second light-shielding layer 116 does not contain oxygen (O), the second light-shielding layer 116 has a chromium (Cr) content of 30 at% to 70 at%, preferably 40 at% to 50 at% Chromium (Cr) content.

The light shielding film 106 has a thickness of 300 ANGSTROM to 700 ANGSTROM and preferably has a thickness of 350 ANGSTROM to 550 ANGSTROM and has an average etching rate of 2.0 ANGSTROM to 4.0 ANGSTROM / sec.

The optical density of the portion where 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 wavelength of 193 nm or 248 nm and preferably has an optical density of 2.7 to 3.2 . The surface reflectance of the portion where the phase reversal film 104 and the light shielding film 106 are laminated is 20% to 40%, preferably 25% 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-reversing film 104.

A chemically amplified resist (CAR) is used as the resist film 114, and the resist film 114 has a thickness of 400 ANGSTROM to 1500 ANGSTROM, preferably 400 ANGSTROM to 1200 ANGSTROM.

FIG. 3 is a cross-sectional view showing a phase inversion blank mask according to a third embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a phase inversion blank mask according to the fourth embodiment of the present invention.

3 and 4, a phase inversion blank mask 200 according to the present invention includes a transparent substrate 202, a phase reversal film 204 sequentially formed on the transparent substrate 202, a light shielding film 206, An etching stopper film 208, a hard film 210, and a resist film 212. Here, the phase reversal film 204, the light shielding film 206, and the resist film 212 have the same optical, chemical, and physical characteristics as those of the first and second embodiments described above.

The etch stop film 208 is provided on the light shielding film 206 and protects the light shielding film 206 positioned below when the pattern of the hard film 210 is formed or when the hard film 210 is removed And serves as an etching mask in the pattern formation of the light shielding film 206. [ The etching stopper film 208 is formed of a material having an etching selectivity ratio of 10 or more with the hard film 210 and the light shielding film 206. In addition, The etching stopper film 208 may be formed of the same material as the phase reversal film 204 when the etching stopper film 208 is removed during the pattern formation of the reversing film 204.

The etch stop layer 208 is formed of a material such as silicon (Si), molybdenum (Mo), tantalum (Ta), vanadium (V), cobalt (Co), nickel (Ni), zirconium (Zr), niobium (Pd), Zn, Cr, Al, Mn, Cd, Mg, Li, Selenium, Cu, (N), oxygen (O), carbon (C), boron (B), hydrogen (H) in the material, or one or more materials selected from the group consisting of hydrogen (Hf) and tungsten Or more.

The etch stop layer 208 may be formed of a material such as silicon (Si) or silicon (Si) such as SiN, SiC, SiO, SiCN, SiCO, SiNO, SiCON, SiB, SiBN, SiBC, SiBO, SiBCN, SiBCO, SiBNO, Si) compound. The etching stopper film 208 may be formed of a material such as molybdenum silicide (MoSi) or MoSiN, MoSiC, MoSiO, MoSiCN, MoSiCO, MoSiNO, MoSiCON, MoSiB, MoSiBN, MoSiBC, MoSiBO, MoSiBCN, MoSiBCO, MoSiBNO, (MoSi) compound, such as MoSiBCON, for example.

In the case where the etching stopper film 208 is made of a silicon compound, the etching stopper film 208 has a composition ratio of silicon (Si) of 40 at% to 90 at% and a light element of 10 at% to 60 at% , Silicon (Si) of 50 at% to 85 at%, and light element of 15 at% to 50 at%. In the case where the etching stopper film 208 is formed of a metal silicide or a compound thereof, the etching stopper film 208 may be formed to have a metal content of 0.1 at% to 10 at%, a silicon (Si) content of 39 at% to 85 at% % To 60 at%, and preferably has a composition ratio of 0.1 at% to 5 at% of metal, 50 at% to 80 at% of silicon (Si), and 15 at% to 50 at% of light element.

The etch stop layer 208 has a thickness of 20 ANGSTROM to 150 ANGSTROM, preferably 30 ANGSTROM to 100 ANGSTROM.

The hard film 210 is provided on the etch stop layer 208 to serve as an etch mask for the etch stop layer 208 so that the etch stop layer 208 is formed of a material having an etch selectivity of 10 or more do. The hard film 210 is formed of a material having the same etching property as that of the light shielding film 206 when the light shielding film 206 is removed in patterning for simplification of the etching process.

The hard film 210 may be formed of at least one of Ta, Ni, Zr, Nb, Pd, Zn, Sn, Cr, At least one of Mn, Mn, Cd, Mg, Li, Se, Hf, W, and Si, Or one or more light element materials selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B) and hydrogen (H).

The hard film 210 may be formed of, for example, chromium (Cr) or a chromium (Cr) compound containing chromium (Cr), such as CrN, CrC, CrO, CrCN, CrNO, CrCO, desirable. The hard film 210 is formed of a compound such as CrSn, CrSnN, CrSnC, CrSnO, CrSnCN, CrSnNO, CrSnCO, CrSnCON which further contains tin (Sn) in the chromium (Cr) desirable.

The hard film 210 has an etching rate of 0.4 Å / sec or more, and preferably an etching rate of 1.0 Å / sec or more because the resist film 212 is easily thinned as the etching rate is higher.

The hard film 210 has a thickness of 20 ANGSTROM to 100 ANGSTROM, preferably 30 ANGSTROM to 60 ANGSTROM. In the case where the hard film 210 has a thickness of 20 angstroms or less, it is difficult to perform the role as an etch mask. When the hard film 210 has a thickness of 100 angstroms or more, it is difficult to reduce the thickness of the resist film 212.

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

(Example)

Phase Inverted membrane  Characterization of constituent materials

The phase reversal film of the phase inversion blank mask according to the embodiment of the present invention was composed of silicon (Si), silicon (Si) compound and molybdenum silicide (MoSi) compound to evaluate the transmittance and phase inversion amount according to the thickness.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 target Si SiB MoSi MoSi MoSi MoSi Target composition ratio
(at%) 100 Si: B
= 99: 1 Mo: Si
= 2: 98 Mo: Si
= 5: 95 Mo: Si
= 10: 90 Mo: Si
= 10: 90 Gas (sccm)
Ar: N ₂ 7: 3.5 7: 7.5 7: 8.2 7: 8.5 7: 9 7: 20 Transmittance (%)
(@ 193 nm) 30.1 25 20.5 13.2 6.2 10.1 Phase inversion amount (°)
(@ 193 nm) 182 182 183 182 182 181 thickness
(A) 565 572 584 602 650 900

Referring to Table 1, it was confirmed that the silicon phase reversal films of Examples 1 to 4 exhibited a transmittance of 13.2% to 30.1%, so that there is no problem in forming a phase reversal film having a high transmittance.

However, the phase reversal films using the molybdenum silicide (MoSi) target (Mo: Si = 10: 90) of Comparative Examples 1 to 2 exhibited a transmittance of 6.2% when the conditions of the thickness and the phase reversal amount were satisfied, The transmittance (10% to 50%) of the phase reversal film required for the invention was not satisfied. When the content of nitrogen (N) was increased to satisfy the conditions of the transmittance and the phase inversion amount, a thickness of 900 ANGSTROM was required. (500 Å to 850 Å) due to the presence of the film.

Chemical resistance evaluation of phase reversal film

The chemical resistance of SC-1 and SPM solutions was evaluated by fabricating a phase reversal film according to an embodiment of the present invention as a single layer and a multilayer structure of two or more layers. The phase reversal film was formed using a molybdenum silicide (MoSi) target (composition ratio Mo: Si = 2 at%: 98 at%), and the substrate except for the phase reversal film and the heat treatment were all applied in the same manner.

Example 5 was formed as a molybdenum nitride silicide (MoSiN) film by implanting Ar: N ₂ = 7 sccm: 8.5 sccm as a process gas for 550 seconds at a process power of 0.7 kW. Thereafter, heat treatment was performed at 350 ° C for 30 minutes using a rapid thermal process (RTP) apparatus.

The transmittance and phase inversion of the phase reversal film were measured using an n & k analyzer 3700RT instrument. As a result, a transmittance of 18.2% and a phase reversal amount of 183 ° were exhibited. In addition, the thickness of the phase reversal film was measured using an X-ray reflectometer (XRR), and the thickness of the upper layer was 584 ANGSTROM.

In Example 6, a molybdenum nitride silicide (MoSiN) film was formed by implanting Ar: N ₂ = 7 sccm: 20 sccm as a process gas for 900 seconds at a process power of 0.7 kW. Thereafter, a process gas of Ar: N ₂ : NO = 7 sccm: 7 sccm: 7 sccm was successively injected for a period of 80 seconds at a process power of 0.7 kW to form a high-transmittance film having a two-layer structure composed of molybdenum silicide oxide (MoSiON) Thereby forming a phase reversal film.

The transmittance, phase reversal amount and thickness of the two-layer structure phase reversal film were measured using the same equipment as in Example 1, and as a result, the transmittance was 20.1% and the phase reversal amount was 184 °. The thickness of the phase reversal film was 540 Å in the upper layer and 50 Å in the lower layer.

In Example 7, a molybdenum nitride silicide (MoSiN) film was formed by implanting Ar: N ₂ = 7 sccm: 25 sccm as a process gas for 400 seconds at a process power of 0.7 kW. Subsequently, a molybdenum nitride silicide (MoSiN) film was formed by continuously injecting Ar: N ₂ = 7 sccm: 15 sccm as a process gas for 800 seconds at a process power of 0.7 kW. Then, a process gas was injected at a rate of 5 sccm: 10 sccm of Ar: NO = 5 sccm and film formation was performed at a process power of 0.7 kW for 80 seconds to form a high-transmittance phase reversal film having a three-layer structure composed of molybdenum silicide (MoSiO).

As a result, the transmittance, the phase reversal amount, and the thickness were measured. As a result, a transmittance of 19.1% and a phase reversal amount of 185 were shown. The thickness of the phase reversal film was 150 ANGSTROM for one layer, 390 ANGSTROM for two layers, Lt; / RTI > thickness.

The chemical resistance of the prepared phase reversal film was evaluated for SC-1 and SPM.

The SC-1 evaluation was carried out by using a solution of NH ₄ OH, H ₂ O ₂ and H ₂ O mixed in a volume ratio of NH ₄ OH: H ₂ O ₂ : H ₂ O = 1: 1: 5, The cleaning process was carried out three times at 45 캜 for 20 minutes, and the changes in phase amount and transmittance before and after the cleaning process were measured.

The SPM evaluation uses a solution of H ₂ SO ₄ and H ₂ O ₂ mixed with H ₂ SO ₄ : H ₂ O ₂ = 9: 1 at a temperature of about 90 ° C. for 10 minutes, , And the changes in phase amount and transmittance before and after the cleaning process were measured.

Example 5 Example 6 Example 7 rescue Single layer structure Two-layer structure 3-layer structure Surface layer material MoSiN MoSiON MoSiO SC-1
Transmittance change
(@ 193 nm) 0.3% 0.1% 0.8% Phase amount change
(@ 193 nm) 2.5 DEG 1.0 0.6 ° SPM
Transmittance change
(@ 193 nm) 0.15% 0.08% 0.06% Phase amount change
(@ 193 nm) 1.5 ° 0.7 ° 0.5 °

Referring to Table 2, Example 5 shows a change in the amount of phase of 2.5 ° and a transmittance change of 0.3% in the 193 nm exposure light at SC-1, The amount of phase change and the transmittance change of 0.1% were shown. In Example 7, the phase amount change of 0.6 ° and the transmittance change of 0.8% in the exposure light of 193 nm were shown.

In the case of the SPM evaluation, Example 5 exhibited a phase amount change of 1.5 ° and a transmittance change of 0.15% at 193 nm exposure light, Example 6 shows a phase amount change of 0.7 ° at 193 nm exposure light and 0.08% And Example 7 showed a change in the amount of phase of 0.5 ° and a change in transmittance of 0.06% in the 193 nm exposure light.

As a result of the chemical resistance evaluation of Examples 5 to 7, the transmittance change and the phase amount change in a good range were shown. As a result of comparing the chemical resistance evaluations of Examples 5 to 7, it was found that as the oxygen content of the surface layer increased, . ≪ / RTI >

Etching Evaluation for Shading Film

When the light shielding film of the phase inversion blank mask according to the embodiment of the present invention is etched into an etching gas containing fluorine (F) based gas, the thickness and optical density change of the light shielding film depend on the constituent material of the light shielding film topmost layer Respectively.

The light shielding film was formed using a chromium (Cr) target, and a first light shielding layer commonly used was injected with 5 sccm of Ar: N ₂ : NO = 5 sccm: 10 sccm as a process gas, A CrO layer was formed to a thickness of 300 angstroms.

In Example 8, a second light-shielding layer made of chromium nitride (CrN) was formed on the first light-shielding layer by injecting Ar: N ₂ = 3 sccm: 5 sccm as a process gas and applying a process power of 0.8 kW. In Example 9, Ar: N ₂ : NO = 5 sccm: 10 sccm: 2 sccm was injected as a process gas, and a process power of 0.8 kW was applied to form a second light-shielding layer made of chromium oxynitride (CrON) .

The prepared light shielding film was etched into an etching gas containing a fluorine (F) gas to form a pattern, and then the thickness and optical density of the remaining light shielding film were measured.

matter Shading Film Thickness Shading film optical density Etching After etching Variation Etching After etching Variation The first light- CrON 300 Å 1.30 Example 8 The second light- CrN 302 Å 298 4 Å 2.25 2.24 0.01 Example 9 The second light- CrON 300 Å 293 Å 7 Å 2.05 2.02 0.03

Referring to Table 3, the second light-shielding layer (CrN) of the upper layer without oxygen in Example 8 showed a thickness change of 4 angstroms, and the second light-shielding layer (CrON) containing less oxygen in Example 9 7 Å.

The change in the thickness of the second light-shielding layer influences the light-shielding function, which is a basic function of the light-shielding film. Thus, in Example 8, the optical density change was 0.01, and in Example 9, the optical density was 0.03 .

The chromium oxynitride (CrON) film containing a small amount of oxygen has a relatively poorer change in the thickness and the optical density than the chromium nitride (CrN) film. However, the second light-shielding layer, which is the uppermost layer of the light- There is no problem to apply.

Further, the thickness loss of the first and second light-shielding layers is not so much as to cause a problem in the light-shielding function of the light-shielding film, and the configurations of the eighth and ninth embodiments are applicable to an actual light-shielding film.

Optical density evaluation for light shielding film

The optical density of the phase reversal film in the phase inversion blank mask according to the embodiment of the present invention was evaluated according to the transmittance and the structure of the light shielding film. In Examples 10 to 12, the first light-shielding film was formed under the same process conditions, and the optical density was controlled by changing the thicknesses of the first light-shielding film and the second light-shielding film.

The first light-shielding layer was injected with Ar: N ₂ : NO = 5 sccm: 10 sccm: 5 sccm as a process gas, and a process power of 1.0 kW was applied to form a chromium oxynitride (CrON) film having a thickness of 480 Å to 485 Å.

In Example 10, a chromium oxynitride (CrON) layer was formed to a thickness of 480 Å on a phase reversal film having a transmittance of 20%, and then Ar: N ₂ : NO = 5 sccm: 10 sccm: 2 sccm was injected as a process gas, KW was added to form a second light-shielding layer composed of chromium oxynitride (CrON) of 80 ANGSTROM.

In Example 11, a chromium oxynitride (CrON) layer was formed to a thickness of 485 angstroms on a phase reversal film having a transmittance of 25%, Ar: N ₂ = 3 sccm: 5 sccm was injected as a process gas, Was added to form a second light-shielding layer composed of chromium nitride (CrN) of 90 angstroms.

In Example 12, a chromium oxynitride (CrON) layer was formed to a thickness of 485 angstroms on a phase reversal film having a transmittance of 30%, and Ar: N ₂ = 3 sccm: 5 sccm was injected as a process gas. To form a second light-shielding layer composed of chromium nitride (CrN) of 100 ANGSTROM.

In Comparative Example 3, Ar: N ₂ = 3 sccm: 5 sccm was injected as a process gas onto a phase reversal film having a transmittance of 20%, and a process power of 0.8 kW was applied to form a light-shielding layer composed of chromium nitride (CrN) Then, Ar: N ₂ : NO = 5 sccm: 10 sccm: 2 sccm was injected as a process gas, and a process power of 0.8 kW was applied to form an antireflective layer composed of CrO 3 of 120 Å.

The optical density, the average etching rate and the residual film thickness of the resist film after pattern formation were measured for Examples 10 to 12 and Comparative Example 3 in which the phase reversal film and the light shielding film were stacked.

Example 10 Example 11 Example 12 Comparative Example 3 Phase reversal film Transmittance 20% 25% 30% 20% The first light- Constituent material CrON CrON CrON CrN Film thickness 480 485 485 410 Å The second light shielding film Constituent material CrON CrN CrN CrON Film thickness 80 Å 90 Å 100 Å 120 Å Optical density (@ 193 nm) 2.8 2.6 2.7 3.0 Average etching rate 2.3 A / sec 2.1 A / sec 2.0 A / sec 1.36 A / sec Resist film Film thickness 100 nm 100 nm 100 nm 100 nm Residue after etching 35 nm 27 nm 25 nm 0

Referring to Table 4, both of Examples 10 to 12 and Comparative Example 3 exhibited optical density values of 2.6 to 3.0, and both showed good values when used as a photomask after pattern formation.

However, in the case of the average etching rate, it was found that the etching rates in Examples 10 to 12 were in the range of 2.0 Å / sec to 2.3 Å / sec, which is higher than 1.36 Å / sec in Comparative Example 3, The residual film thickness of the resist film due to the formation is also the same as that of the resist film of Comparative Example 3, but the resist film of 25 nm to 35 nm remains in Examples 10 to 12 and the resist film can be made thin.

Production of Phase Inversion Blank Mask According to the Present Invention I

For the fabrication of the phase inversion blank mask according to the present invention, the substrate has a size of 6 inches x 6 inches x 0.25 inches, a birefringence of 2 nm / 6.3 mm, a flatness (TIR: Total Indicated Reading) was controlled to 2,560 Å.

A phase reversal film having a high transmittance was formed on the glass substrate using a DC magnetron reactive sputtering apparatus. The phase reversal film was doped with a molybdenum silicide (MoSi) target (composition ratio Mo: Si = 2 at%: 98 at%) as a process gas and Ar: N ₂ = 7 sccm: 8.5 sccm, The film was formed for about 550 seconds and formed into a molybdenum nitride suicide (MoSiN) film. Thereafter, heat treatment was performed at 350 ° C for 30 minutes using a rapid thermal process (RTP) apparatus.

The transmittance and phase inversion of the phase reversal film were measured using an n & k analyzer 3700RT instrument. As a result, a transmittance of 18.2% and a phase reversal amount of 183 ° were exhibited. In addition, the thickness of the phase reversal film was measured using an X-ray reflectometer (XRR), resulting in a thickness of 58.4 nm. The composition ratio of the phase reversal film was analyzed by using Auger Electron Spectroscopy (AES). As a result, it was found that molybdenum (Mo) was 2.1 at%, silicon (Si) was 70.1 at%, nitrogen 27.8%, respectively. In addition, the flatness of the phase reversal film was measured using an Ultra-Flat equipment to compare the flatness change amount due to the phase reversal film formation. As a result, the flatness of the phase reversal film was 3,120 Å. The flatness (2,560 Å) , It can be indirectly confirmed that the pattern alignment degree and the DoF margin are superior in the subsequent photomask and wafer wafer printing process.

A light shielding film composed of a first light shielding layer and a second light shielding layer was formed on the phase reversal film. The light-shielding film formation, we used all the chromium (Cr) target, the first light-shielding layer is _{Ar: N 2: NO = 5sccm} : 10sccm: injecting process gas into 5sccm, and by forming for 368 seconds with a power step of 1.0㎾ (CrON) film. The second light shielding layer was formed of a chromium nitride (CrN) film by injecting a process gas with Ar: N ₂ = 3 sccm: 5 sccm and forming the film with a process power of 0.8 kW for 60 seconds. The thicknesses of the first light-shielding layer and the second light-shielding layer were measured in the same manner as the phase reversal film described above. As a result, the thicknesses of the first light-shielding layer and the second light-shielding layer were 48 nm and 5 nm, respectively. As a result of analyzing the compositional ratios of the first light-shielding layer and the second light-shielding layer, it was found that the first light-shielding layer had a composition ratio of 48 at% of chromium (Cr), 30 at% of nitrogen (N) The second light-shielding layer showed a composition ratio of 58 at% of chromium (Cr) and 42 at% of nitrogen (N). The optical density of the film having the phase reversal film and the light shielding film deposited thereon was measured. As a result, the value was 2.95 in the 193 nm exposure light and the reflectance was 33%.

An etch stop film was formed on the light shielding film. The etching stopper film was implanted with a molybdenum silicide (MoSi) target (composition ratio Mo: Si = 2 at%: 98 at%) as a process gas and Ar: N ₂ : NO = 3 sccm: 3 sccm: 5 sccm as a process gas, (MoSiON) film having a thickness of 20 ANGSTROM by using the process power. As a result of analyzing the composition ratio of the etching stopper film, the etching stopper film had a composition ratio of molybdenum (Mo) of 1.5 at%, silicon (Si) of 60.3 at%, oxygen (O) of 12.5 at% and nitrogen of 25.7 at% Respectively.

A hard film was formed on the etch stop film. The hard film was formed into a chromium (Cr) film having a thickness of 40 angstroms by using a chromium (Cr) target, injecting a process gas at 8 sccm of Ar at a process power of 0.6 kW for 22 seconds.

A chemically amplified resist was formed on the hard film to a thickness of 100 nm by a spin coating method to complete a blank mask according to the present invention.

Preparation of Phase Inversion Blank Mask According to the Present Invention II

With reference to Production I of the phase inversion blank mask described above, a phase inversion blank mask was manufactured with different compositions of the second light-shielding layer. The physical, chemical and optical properties of the substrate and the metal films except for the second light-shielding layer were all formed identically.

A chromium (Cr) target was used for the formation of the second light-shielding layer, Ar: N ₂ : NO = 5 sccm: 10 sccm: 2 sccm was injected as the process gas, the process power was 0.8 kW, Thereby forming a chromium nitride (CrON) film.

The thickness of the film was measured using an X-ray (X-ray) reflectometer (XRR) apparatus after the film formation. As a result, the thickness of the second light-shielding layer was 7.5 nm. The composition ratio of Cr (Cr) was 54at%, oxygen (O) was 7at% and nitrogen (N) was 39at%. The optical density of the film including the phase reversal film and the light shielding film was measured and found to be 2.92 in the 193 nm exposure light and 31% reflectance.

According to the present invention, Photo  Manufacture of masks

The above-described phase inversion blank mask was subjected to an exposure process using an electron beam and subjected to a post exposure bake process at a temperature of 190 DEG C for 10 minutes using a hot plate, and then the resist film was developed Thereby forming a resist film pattern.

Thereafter, the lower hard film is etched with an etching gas containing a chlorine (Cl) gas to form a chromium (Cr) hard film pattern by using the resist pattern as an etching mask. After removing the resist film, The etching stopper film containing silicon (Si) at the bottom was etched with an etching gas containing fluorine (F) based gas as an etching mask to form an etching stopper film pattern.

Then, the light shielding film pattern was formed by etching the lower shielding film with an etching gas containing a chlorine (Cl) gas using an etching mask film pattern as an etching mask. At this time, since the hard film pattern has the same etch characteristics as the etch stop layer, the hard film pattern is removed in the process of forming the etch stop layer pattern.

Subsequently, the lower phase reversal film was etched with an etching gas containing fluorine (F) based gas using the light-shielding film pattern as an etching mask to form a phase reversal film pattern. At this time, the etching stopper film pattern is removed in the process of forming the phase inversion film pattern as the etching characteristics are the same as that of the phase inversion film.

Thereafter, a resist film pattern is formed on the resultant product including the phase reversal film pattern, and the light shielding film pattern of the blind region where the main pattern is not formed is removed to complete the phase reversal photomask manufacturing according to the present invention Respectively.

Etch barrier  An undeformed phase inversion blank mask and Photo  Mask manufacturing

For comparison with Manufacturing I of the phase inversion blank mask according to the present invention, unlike the present invention, except for the etching stopper film, a molybdenum silicide (MoSi) compound containing silicon (Si) And a resist film was formed thereon to prepare a phase inversion blank mask according to a comparative example. The transparent substrate, the phase reversal film, and the light shielding film constituting the phase inversion blank mask of the comparative example are the same as the embodiment of the present invention.

In the hard film according to the comparative example, a molybdenum silicide (MoSi) target (composition ratio Mo: Si = 2 at%: 98 at%) was used in order to have a light-shielding film made of a lower chromium (Cr) , And Ar: N ₂ : NO = 3 sccm: 5 sccm: 5 sccm as a process gas, and formed into a silicon oxynitride molybdenum silicide (MoSiON) film having a thickness of 40 angstroms using a process power of 0.6 kW.

Thereafter, a chemically amplified resist was formed to a thickness of 1,000 Å on the hard film to complete the production of a phase inversion blank mask according to a comparative example.

However, the phase inversion blank mask according to the comparative example has a problem that the resist film is not partially coated (Un-coating) on the hard film made of the oxynitride molybdenum silicide (MoSiON) film at each corner of the transparent substrate . Accordingly, after the HMDS process is further performed on the hard film, a resist film is coated on the hard film to solve the above problem.

A phase inversion photomask was fabricated by performing the etching process using the same etching material and method as in the present invention using the phase inversion blank mask.

First, the resist film is exposed and developed to form a resist film pattern. Using the resist pattern as an etching mask, a hard film made of a molybdenum disilicide (MoSiON) film of oxynitride is filled with a fluorine (F) Lt; / RTI > to form a hard film pattern. However, due to strong adhesion due to HMDS provided on the hard film during the formation of the hard film pattern, a scum is present in the resist pattern with a thickness of about 2 A to 50 A, so that the etching time of the hard film is long, Also, by-products due to scumming of the resist pattern are formed as defects.

No HMDS process HMDS process progress Resist film scum Not occurring 2 Å to 50 Å Defects due to scum 1ea to 2ea 10ea to 20ea

Referring to Table 4, the scum of the resist film according to the HMDS process and the defects in the dry etching process by the scum were analyzed. As a result, according to the HMDS treatment, the scum of the resist film was present in a thickness of 2 ANGSTROM to 50 ANGSTROM, which indicates that the defect in the dry etching process of the hard film was increased by about 5 to 6 times there was.

Phase inversion blank mask Sheet resistance  analysis

To analyze the charge-up phenomenon for the phase inversion blank mask of Preparation I and II of the phase inversion blank mask according to the present invention, the sheet resistance was measured using a 4-point probe , And the sheet resistance was measured with respect to the phase inversion blank mask of the phase inversion blank mask not provided with the above-mentioned etch stop film under the same conditions and compared and analyzed.

Preparation I and II of the phase inversion blank mask according to the present invention are represented by Examples 13 and 14, and the phase inversion blank mask without the etching stopper film is represented by Comparative Example 4. [

Phase Inversion Blank Mask Example 13 Example 14 Comparative Example 4 Sheet resistance (Ω / □) 520 550 3,025

Referring to Table 5, the sheet resistance of the thin film constituting the phase inversion blank mask according to Example 13, Example 14, and Comparative Example 4, that is, the phase inversion blank mask formed up to the hard film was measured. As a result, 13 shows 520 Ω / □, Example 14 shows 550 Ω / □, whereas Comparative Example 4 shows 3,025 Ω / □, and Comparative Example 4 has a high sheet resistance of about 15 times or more as compared with Examples 13 and 14 - up phenomenon was found to occur severely.

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 apparent to those skilled in the art that various changes or 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 according to the present invention
102, 202: transparent substrate
104, 204: phase reversal film
106, 206: Shading film
208: etch stop film
210: Hard film
112, and 212:
114, 214: first light-shielding layer
116, 216: a second light-shielding layer

Claims (16)

A phase inversion blank mask provided with a phase reversal film and a light shielding film on a transparent substrate,
Wherein the light shielding film is made of a multilayer film of two or more layers including at least one of oxygen (O) and nitrogen (N), at least one of the films essentially including oxygen (O)
The film essentially containing oxygen (O) occupies 50% to 95% of the total thickness of the light shielding film,
Wherein the light shielding film has an etching rate of 1.0 A / sec to 4.0 A / sec. The method according to claim 1,
The phase reversal film may have a structure of a single layer, a multilayer film of two or more layers, or a continuous film structure,
Wherein when the phase reversal film has a multilayer film or a continuous film structure, the uppermost part essentially comprises oxygen (O). The method according to claim 1,
Wherein the phase reversal film has a transmittance of 10% to 50% with respect to exposure light having a wavelength of 193 nm or 248 nm. The method according to claim 1,
The phase reversal film may be formed of at least one selected from the group consisting of silicon (Si), molybdenum (Mo), tantalum (Ta), vanadium (V), cobalt (Co), nickel (Ni), zirconium (Zr), niobium (Nb), palladium (Zn), Cr, Al, Mn, Cd, Mg, Li, Selenium, Cu, Hafnium, (N), oxygen (O), carbon (C), boron (B) and hydrogen (H) in the material Wherein the phase shift mask is formed on the substrate. The method according to claim 1,
Wherein the phase reversal film is formed of silicon (Si), a metal silicide, and a silicon (Si) material further containing at least one element selected from the group consisting of nitrogen (N), oxygen (O), carbon (C), boron (B) (Si) compounds, a metal suicide, and a metal suicide compound. 6. The method of claim 5,
In the case where the phase reversal film is made of a silicon compound, the phase reversal film has a composition ratio of silicon (Si) of 40 at% to 90 at% and a light element of 10 at% to 60 at%
Wherein when the phase reversal film is made of a metal silicide or a compound thereof, it has a composition ratio of 0.1 to 10 at% of metal, 39 to 90 at% of silicon (Si) and 0 to 60 at% of light element Reverse Blank Mask. The method according to claim 1,
Wherein the phase reversal film has a thickness of 500 Å to 850 Å and has a phase reversal amount of 170 ° to 190 ° with respect to exposure light having a wavelength of 193 nm or 248 nm and a reflectance of 20% to 30% Blank mask. The method according to claim 1,
Wherein the light shielding film is made of a chromium compound having a composition ratio of 30 at% to 70 at% of chromium (Cr), 10 at% to 40 at% of nitrogen (N), and 0 to 50 at% of oxygen (O) Phase inversion blank mask. 9. The method of claim 8,
Wherein the light shielding film further comprises at least one of carbon (C), boron (B), and hydrogen (H), wherein the light shielding film comprises 0 to 30 at% of carbon (C), 0 to 30 at% of boron (B) ) Has a composition ratio of 0 to 30 at%. The method according to claim 1,
Wherein the light shielding film has a thickness of 300 ANGSTROM to 700 ANGSTROM. The method according to claim 1,
Wherein at least one of an etching stopper film and a hard film is further formed on the light shielding film. 12. The method of claim 11,
The etching stopper film is made of a material having the same etching property as the phase inversion film,
Wherein the hard film is made of a material having an etching property different from that of the phase reversal film and the etching stopper film and having the same etching property as that of the light shielding film. 12. The method of claim 11,
The hard film may be chromium (Cr) or chromium (Cr) further containing at least one light element of nitrogen (N), oxygen (O), carbon (C), boron (B) Cr) < / RTI > compounds. 12. The method of claim 11,
Wherein the etch stop layer has a thickness of 20 ANGSTROM to 150 ANGSTROM. 12. The method of claim 11,
Wherein the hard film has a thickness of 20 ANGSTROM to 100 ANGSTROM and has an etching rate of 0.4 ANGSTROM / sec or more. A phase inversion photomask produced using the phase inversion blank mask of any one of claims 1 to 15.

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