KR20220112183A - Mask blanks and photomask - Google Patents

Abstract

The mask blanks of this invention are equipped with a blank mask layer. The blank mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen. In the Mo compound layer, the peaks of the Mo _3d3/2 spectrum and the Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy are separated. The ratio of the peak area of the Mo-Si bonding peak is 73% or more.

Description

MASK BLANKS AND PHOTOMASK

The present invention relates to mask blanks and photomasks.

In order to form a photomask used in the photolithography process in FPD (flat panel display, flat panel display), semiconductor device manufacture, etc., photomask blanks (mask blanks) are used. Mask blanks have a mask layer laminated|stacked on one main surface of transparent substrates, such as a glass substrate.

In manufacture of mask blanks, the film|membrane which is a mask layer which has predetermined optical characteristics, such as a light shielding layer, is formed on a transparent substrate. This mask layer may have a single-layer structure or the structure in which multiple layers were laminated|stacked. A photomask is manufactured by forming a resist pattern on a mask layer, using this resist pattern as a mask, selectively etching the mask layer to remove it, and forming a predetermined mask pattern.

As a mask layer with which a mask blanks or a photomask is equipped, the layer etc. which were comprised from the film|membrane containing a silicon|silicon, and the film|membrane containing silicon and molybdenum, etc. are known (patent document 1).

International Publication No. 2011/125337

By the way, when laser light as exposure light is irradiated with respect to the pattern portion made of the mask layer containing silicon (Si) and molybdenum (Mo) in the exposure step, Mo excited by the laser light A phenomenon called Mo migration, which moves out of this pattern portion, occurs. In addition, the silicon remaining in the pattern portion is oxidized to form silicon oxide, and the silicon oxide increases the line width of the pattern portion, and there is a problem in that the accuracy of the shape of the pattern portion is deteriorated.

This invention was made in view of said situation, and provides the mask blanks and photomask which can suppress the increase in the line|wire width of the mask layer resulting from Mo migration.

In order to solve the said subject, this invention employ|adopts the following structures.

The mask blanks which concern on one aspect of this invention are provided with a blank mask layer. The blank mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen. In the Mo compound layer, the peaks of the Mo _3d3/2 spectrum and the Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy are separated. The ratio of the peak area of the Mo-Si bonding peak is 73% or more.

In the mask blanks which concerns on 1 aspect of this invention, the said Mo compound layer may satisfy|fill following (1) Formula.

{(Si - O/2) × 4/3 + Mo/2 - N}/Si ≥ 0.25 ... (One)

However, each of Mo, Si, O, and N in the formula (1) is a mole fraction (mol%) of molybdenum, silicon, oxygen and nitrogen contained in the Mo compound layer, and the Mo compound layer does not contain oxygen. In this case, O in the formula (1) above is set to 0.

In the mask blanks which concerns on 1 aspect of this invention, the said Mo compound layer may further satisfy|fill following (2) Formula.

Si/Mo ≥ 4.0 … (2)

However, each of Mo and Si in the formula (2) is a mole fraction (mol%) of molybdenum and silicon contained in the Mo compound layer.

In the mask blanks according to one aspect of the present invention, with respect to the composition of molybdenum, silicon, nitrogen, and oxygen contained in the Mo compound layer, the silicon content may be 35 to 50 mol%, and the molybdenum content may be 3 to 10 mol% may be sufficient, the content rate of oxygen may be 0-20 mol%, the content rate of nitrogen may be 35-60 mol%, and 0-1 mol% of carbon may be sufficient.

In the mask blanks which concerns on 1 aspect of this invention, the said Mo compound layer may comprise any 1 type, or 2 or more types of a phase shift layer, a light shielding layer, a reflection prevention layer, an etching stop layer, and a chemical-resistant layer. .

A photomask according to an aspect of the present invention includes a mask layer. The mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen. In the Mo compound layer, the peaks of the Mo _3d3/2 spectrum and the Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy are separated. The ratio of the peak area of the Mo-Si bonding peak is 73% or more.

In the photomask which concerns on 1 aspect of this invention, the said Mo compound layer may satisfy|fill following (3) Formula.

{(Si - O/2) × 4/3 + Mo/2 - N}/Si ≥ 0.25 ... (3)

However, each of Mo, Si, O, and N in the formula (3) is a mole fraction (mol%) of molybdenum, silicon, oxygen and nitrogen contained in the Mo compound layer, and the Mo compound layer does not contain oxygen. In this case, O in the formula (3) above is set to 0.

In the photomask which concerns on one aspect of this invention, the said Mo compound layer may further satisfy|fill following (4) Formula.

Si/Mo ≥ 4.0 … (4)

However, each of Mo and Si in the formula (4) is a mole fraction (mol%) of molybdenum and silicon contained in the Mo compound layer.

In the photomask according to one aspect of the present invention, with respect to the composition of molybdenum, silicon, nitrogen, and oxygen contained in the Mo compound layer, the silicon content may be 35 to 50 mol%, and the molybdenum content may be 3 to 10 mol% may be sufficient, the content rate of oxygen may be 0-20 mol%, the content rate of nitrogen may be 35-60 mol%, and 0-1 mol% of carbon may be sufficient.

In the photomask which concerns on one aspect of this invention, the said Mo compound layer may comprise any 1 type, or 2 or more types of a phase shift layer, a light shielding layer, a reflection prevention layer, an etching stop layer, and a chemical-resistant layer.

In addition, in the following description, {(Si-O/2)x4/3+Mo/2-N}/Si which is the left side of the said (1) formula or said (3) formula, the insufficient nitrogen amount with respect to the amount of Si It is sometimes called the rain of

ADVANTAGE OF THE INVENTION According to this invention, the mask blanks and photomask which can suppress the increase in the line|wire width of the mask layer resulting from Mo migration can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows an example of the mask blanks which concern on embodiment of this invention.
It is a cross-sectional schematic diagram which shows the other example of the mask blanks which concern on embodiment of this invention.
It is a cross-sectional schematic diagram which shows an example of the photomask which concerns on embodiment of this invention.
It is a cross-sectional schematic diagram which shows the other example of the mask blanks which concerns on embodiment of this invention.
5 : is a cross-sectional schematic diagram which shows the other example of the mask blanks which concerns on embodiment of this invention.
It is a cross-sectional schematic diagram which shows the other example of the mask blanks which concern on embodiment of this invention.
7 : is a cross-sectional schematic diagram which shows the other example of the mask blanks which concern on embodiment of this invention.
It is a cross-sectional schematic diagram which shows the other example of the mask blanks which concerns on embodiment of this invention.
It is a schematic diagram which shows the manufacturing apparatus of the mask blanks which concerns on embodiment of this invention.
It is a schematic diagram which shows the manufacturing apparatus of the mask blanks which concerns on embodiment of this invention.
Fig. 11 is a diagram showing photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 after peak separation treatment measured by X-ray photoelectron spectroscopy.

The mask layer of the photomask has a single layer structure or a multilayer structure. In addition, the mask layer may contain a Mo compound layer. In the present specification, the Mo compound layer refers to a layer containing silicon, molybdenum, and nitrogen, and optionally containing oxygen. Mo compound layer is a mask layer. WHEREIN: It is used as a phase shift layer, a light shielding layer, a reflection prevention layer, etc. In the photoresist exposure process, when a laser beam is irradiated to a pattern portion made of a mask layer having a Mo compound layer, so-called Mo migration in which molybdenum moves out of the mask layer may occur. When Mo migration occurs, oxygen or water in the periphery of the mask layer is permeated into the location where the molybdenum is removed. The silicon oxide is oxidized by the permeated oxygen or water to form a silicon oxide, and there is a fear that the formation of the silicon oxide increases the line width of the pattern portion made of the mask layer. In order to solve this problem, the present inventors studied earnestly, and obtained the following knowledge.

In order to adjust the optical properties of the Mo compound layer, the Mo compound layer may contain nitrogen or oxygen. In the mask layer, oxygen and nitrogen are easily bonded to silicon, and nitrogen is also easily bonded to molybdenum. When the amount of nitrogen or oxygen in the Mo compound layer is appropriately adjusted to adjust the optical properties of the Mo compound layer, the bond between silicon and nitrogen, the bond between silicon and oxygen, or the bond between molybdenum and nitrogen increases, while the bond between molybdenum and silicon decreases. there is a case to do The present inventors discovered that the reduction|decrease of the coupling|bonding between molybdenum and silicon in Mo compound layer had become one cause which caused Mo migration, and completed this invention. EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

The mask blanks concerning this embodiment are equipped with the blank mask layer used as the mask layer of a photomask. This blank mask layer contains a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen. In the Mo compound layer, Mo-Si obtained by separating the peaks of the Mo _3d3/2 spectrum and Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy. The ratio of the peak area of the binding peak is 73% or more.

Moreover, the photomask which concerns on this embodiment is provided with a mask layer. The mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen. In the Mo compound layer, Mo-Si obtained by separating the peaks of the Mo _3d3/2 spectrum and Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy. The ratio of the peak area of the binding peak is 73% or more.

In addition, the Mo compound layer in the mask blank which concerns on this embodiment and a photomask may satisfy|fill following (A) Formula. In addition, in the following description, {(Si-O/2)x4/3+Mo/2-N}/Si, which is the left side of the following formula (A), is a case where it is said that the ratio of the amount of insufficient nitrogen with respect to the amount of Si have.

{(Si - O/2) × 4/3 + Mo/2 - N}/Si ≥ 0.25 ... (A)

However, each of Mo, Si, O, and N in the formula (A) is a mole fraction (mol%) of molybdenum, silicon, oxygen and nitrogen contained in the Mo compound layer, and when the Mo compound layer does not contain oxygen, , (A) Let O in the formula be 0.

The photomask according to the present embodiment is a photolithography process using exposure light having a wavelength of 200 nm or less, in particular, exposure light of ArF excimer laser light (wavelength 193 nm) used in photolithography using a phase shift mask. used

In addition, the mask blanks concerning this embodiment are used as a raw material at the time of manufacture of this photomask.

In FIG. 1, an example of the mask blanks which concerns on this embodiment is shown. The mask blanks which concern on this embodiment consist of the glass substrate 11 (transparent substrate), and the blank mask layer 12 formed on the glass substrate 11. As shown in FIG. In addition, the mask blanks which concern on this embodiment are formed on the glass substrate 11, the blank mask layer 12 formed on the glass substrate 11, and the blank mask layer 12, as shown in FIG. It may be comprised by the photoresist layer 13.

In addition, in FIG. 3, an example of the photomask which concerns on this embodiment is shown. The photomask which concerns on this embodiment consists of the glass substrate 11 and the mask layer 12P formed on the glass substrate 11. As shown in FIG. The mask layer 12P is formed by patterning the blank mask layer of the mask blanks to have a predetermined shape.

As the glass substrate 11, a material excellent in transparency and optical isotropy is used, for example, a quartz glass substrate can be used. The size in particular of the glass substrate 11 is not restrict|limited. Depending on the substrate to be exposed using the mask layer 12P (for example, a substrate for FPD such as a semiconductor, an LCD (liquid crystal display), a plasma display, an organic EL (electroluminescence) display, etc.), the glass substrate 11 ) is appropriately selected.

In this embodiment, as the glass substrate 11, the rectangular substrate whose length of one side is about 100 mm, or the rectangular substrate whose length of one side is 250 mm or more is applicable. A substrate having a thickness of 1 mm or less, a substrate having a thickness of several mm, or a substrate having a thickness of 10 mm or more can also be used as the glass substrate 11 .

Moreover, you may reduce the flatness of the glass substrate 11 by grinding|polishing the surface of the glass substrate 11. As shown in FIG. The flatness of the glass substrate 11 can be 5 micrometers or less, for example. Thereby, the depth of focus of the mask becomes deep, and it becomes possible to greatly contribute to fine and high-precision pattern formation. Moreover, it is preferable that flatness is a small value, such as a value of 0.5 micrometer or less, for example.

The blank mask layer 12 and the mask layer 12P according to the present embodiment may have a Mo compound layer containing molybdenum, silicon, and nitrogen, or may have a Mo compound layer containing molybdenum, silicon and nitrogen and oxygen. do. That is, the blank mask layer 12 and the mask layer 12P concerning this embodiment may have Mo compound layer which consists of MoSiN or MoSiON, when it shows in the form which enumerates constituent elements. The Mo compound layer according to the present embodiment contains molybdenum, silicon, and nitrogen as basic components, and may further contain oxygen or carbon. The content of nitrogen, oxygen, and carbon contained in the blank mask layer 12 and the mask layer 12P is set within a desired range for the optical properties, etching rate, etc. of the blank mask layer 12 and the mask layer 12P. For this, it is set appropriately.

Mo compound layer according to this embodiment isolates the peaks of the Mo _3d3/2 spectrum and Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy. It is a layer in which the ratio of the peak area of the Mo-Si bonding peak obtained by doing this is 73% or more. Mo _3d3/2 spectrum and Mo _3d5/2 spectrum are spectra observed by splitting Mo _3d spectrum into two. The ratio of the peak area of the Mo-Si bonding peak to the peak area of the photoelectron spectrum of Mo _3d represents the ratio of the content of Mo bonded to Si among the contents of Mo contained in the Mo compound layer. By setting the Mo-Si bonding ratio to be 73% or more, Mo migration is suppressed and the increase in the line width of the mask layer can be suppressed. Mo-Si bonding ratio of Mo becomes like this. Preferably it is made into 75 % or more. Although it is not necessary to specifically limit the upper limit of the ratio of Mo-Si couple|bonded, it is good also considering the upper limit as 95 % or less, for example.

The mechanism (action) by which Mo migration becomes difficult to occur as the Mo-Si bond increases is estimated as follows from the results of experiments conducted by the inventors. Si in the Mo compound layer is easily bonded to O or N to form an oxide or nitride. In addition, Mo is easily bonded to excess N that has not been bonded to Si to form a nitride. And Mo contained in Mo nitride is easy to migrate because a chemical bond is weaker than Mo bonded to Si. It is estimated that the Mo couple|bonded with N decreases relatively as Mo couple|bonded with Si increases. For this reason, it is thought that Mo migration becomes difficult to occur, so that Mo-Si bonding increases. However, the mechanism demonstrated here is speculation to the last, and another unknown mechanism may be involved in suppression of Mo migration. In any case, it has been experimentally confirmed by the present inventors that Mo migration becomes more difficult as the Mo-Si bond increases.

The position of the Mo compound layer measured by X-ray photoelectron spectroscopy may be on the surface of the Mo compound layer, or the position of t/2 when the thickness of the Mo compound layer is t. In addition, the number in particular of the measurement location of X-ray photoelectron spectroscopy is not restrict|limited. For example, you may obtain the value which performed the measurement by X-ray photoelectron spectroscopy in 10 measurement locations, and averaged the some obtained measurement result.

In order to measure the peak area of the photoelectron spectrum of Mo _{3d3/2 and} the photoelectron spectrum of Mo 3d5/2, by narrow scan analysis using AlKα as an X-ray source, measurement is performed at a binding energy of around 220 to 240 eV. . The photoelectron spectrum in which the peak top appears around 227 eV is specified as the photoelectron spectrum of Mo _3d5/2 . The photoelectron spectrum in which the peak top appears around 230 eV is specified as the photoelectron spectrum of Mo _3d3/2 . And each peak area of these two photoelectron spectra is measured. Further, the total area of the two peak areas is calculated. At this time, the background intensity is subtracted from the peak area.

In addition, Mo-Si bonding peaks are specified by performing a peak separation process with respect to the photoelectron spectra of Mo _3d3/2 and Mo _3d5/2 . The method of the peak separation process is not specifically limited. For example, you may use the software for peak separation built in the X-ray photoelectron spectroscopy apparatus. A peak in which a peak top appears in the vicinity of 226 to 227 eV by peak separation is specified as a Mo-Si bonding peak in the photoelectron spectrum of Mo _3d5/2 . A peak at which a peak top appears in the vicinity of 229 to 231 eV is specified as a Mo-Si bonding peak in the photoelectron spectrum of Mo _3d3/2 . Then, the peak area of each Mo-Si bonding peak is measured. Further, the total area of the two peak areas is calculated. At this time, the background intensity is subtracted from the peak area. Then, the ratio (%) of the peak area (total area) of the Mo-Si bonding peak to the peak area (total area) of the photoelectron spectrum of Mo _3d3/2 and Mo _3d5/2 may be obtained.

Moreover, it is preferable at the point which can suppress Mo migration further that the Mo compound layer which concerns on this embodiment satisfy|fills said (A) Formula. (A) By satisfying Formula, Mo migration becomes more difficult to generate|occur|produce, and the increase of the line|wire width of the mask layer 12P in a photomask can be prevented reliably. 0.30 or more may be sufficient as ratio of the insufficient nitrogen amount with respect to the Si amount, and 0.35 or more may be sufficient as it. In addition, the upper limit in particular of the left side (ratio of the amount of deficiency nitrogen with respect to the amount of Si) of said (A) formula is not restrict|limited. For example, ratio of the amount of insufficient nitrogen to the amount of Si may be 1.00 or less, 0.70 or less, or 0.60 or less.

Moreover, it is preferable that Si/Mo which is a molar ratio of molybdenum and silicon in a Mo compound layer is 4.0 or more. By setting Si/Mo to 4.0 or more, exposure light having a wavelength of 200 nm or less, particularly, exposure light of ArF excimer laser light (wavelength 193 nm) used in photolithography using a phase shift mask is used in a photolithography process. It can be used preferably.

The reason for deriving said (A) formula is as follows. In the following description, each of Mo, Si, O, and N is a mole fraction (mol%) of molybdenum, silicon, oxygen, and nitrogen contained in the Mo compound layer.

When the mask layer contains the Mo compound layer containing silicon, molybdenum, nitrogen, and oxygen, silicon in the Mo compound layer bonds with oxygen in the Mo compound layer to easily form SiO ₂ . Moreover, the excess silicon which did not couple|bond with oxygen in Mo compound layer couple|bonds with nitrogen _in Mo compound layer, _and Si3N4 is easy to form. Then, the amount of nitrogen required in order to nitride the whole amount of silicon in Mo compound layer becomes (Si-O/2)x4/3.

In addition, when molybdenum in the Mo compound layer is nitrided, Mo ₂ N is easily formed. Then, the amount of nitrogen required for nitriding the whole amount of molybdenum in Mo compound layer is represented by Mo/2.

And when the amount of nitrogen required for nitriding the whole amount of silicon and molybdenum in Mo compound layer is N ^* , it will be N ^* =(Si-O/2)*4/3+Mo/2.

Here, the amount obtained by subtracting the amount of nitrogen actually contained in the mask layer from N ^* , that is, {(Si - O/2) × 4/3 + Mo/2 - N} is the total amount of silicon and molybdenum The amount of nitrogen (N ^* ) required to nitrate is insufficient. The Mo compound layer with a large deficiency amount means that the amount of oxidized or nitrided silicon and molybdenum is small, and the amount of the bonding between silicon and silicon and the bonding between silicon and molybdenum is large. Therefore, in addition to the increase in the peak area ratio of the Mo-Si bonding peak, the ratio of the shortage amount of nitrogen to the amount of silicon in the Mo compound layer (= {(Si - O/2) × 4/3 + Mo/2 - N}) As it becomes higher, it becomes possible to more effectively suppress an increase in the line width of the mask layer of the photomask.

Moreover, in the Mo compound layer which concerns on this embodiment, in order to set predetermined|prescribed optical characteristic, an etching rate, etc. within a desired range, you may set content of the structural element of a Mo compound layer as follows. That is, when the total amount of molybdenum (Mo), silicon (Si), nitrogen (N), oxygen (O), and carbon (C) as constituent elements of the Mo compound layer is 100 mol%, the Si content is 35 to The composition of the Mo compound layer is such that the content of 50 mol%, the content of Mo is 3 to 10 mol%, the content of O is 0 to 20 mol%, the content of N is 35 to 60 mol%, and the content of C is 0 to 1 mol%. The content of the element may be set.

The composition (mol fraction) of the element contained in the Mo compound layer can be measured by wide scan measurement of X-ray photoelectron spectroscopy. Then, by substituting the mole fraction of each element obtained by the measurement of X-ray photoelectron spectroscopy into the formula (A), it can be determined whether or not the formula (A) is satisfied. Moreover, Si/Mo can also be calculated|required from the mole fraction of molybdenum and silicon calculated|required by the measurement.

The blank mask layer 12 and the mask layer 12P according to the present embodiment may be a single mask layer made of a Mo compound layer, or a mask layer made of a multilayer body in which a Mo compound layer and other layers are laminated.

When the blank mask layer 12 and the mask layer 12P are single-layered mask layers which consist of Mo compound layer, it is preferable that the blank mask layer 12 and the mask layer 12P function as a phase shift layer. The thickness of the mask layer in this case may be, for example, about 50 to 70 nm.

In addition, when the blank mask layer 12 and the mask layer 12P consist of a multilayer body containing a Mo compound layer, the Mo compound layer is any one of a phase shift layer, a light shielding layer, an antireflection layer, an etching stop layer, a chemical resistant layer, etc. It is preferred to function as a species or two or more species. The thickness of the Mo compound layer in this case may be, for example, about 60 to 80 nm.

That is, in general, when the blank mask layer 12 and the mask layer 12P are formed of a multilayer body, as a function given to each layer constituting the blank mask layer 12 and the mask layer 12P, the phase shift is Function, light blocking function to block exposure light, antireflection function to prevent reflection of exposure light, adhesion function to increase adhesion with photoresist during photomask formation, etching stop function for photomask formation, etching solution for photomask formation A chemical-resistant function against the back, and a low-reflectance function that suppresses the reflectance of exposure light, and the like. In order to implement|achieve these functions, a mask layer is equipped with the 1 type(s), or 2 or more types of layers chosen from a phase shift layer, a light shielding layer, a reflection prevention layer, an adhesion layer, an etching stop layer, a chemical-resistant layer, a low reflectance layer, etc. The Mo compound layer which concerns on this embodiment may comprise any of these phase shift layer, a light shielding layer, a reflection prevention layer, an adhesion layer, an etching stop layer, a chemical-resistant layer, and a low reflectance layer.

Hereinafter, the structure of the blank mask layer 12 and the mask layer 12P is demonstrated taking mask blanks as an example.

When the blank mask layer 12 is comprised by a multilayer body, as shown in FIG. 4, the blank mask layer 12 is the phase shift layer 12a and the light shielding layer 12b of Cr system from the glass substrate 11. You may have the structure laminated|stacked in this order. In this case, let the phase shift layer 12a be Mo compound layer which concerns on this embodiment.

In addition, the Cr-based light-shielding layer 12b in the example shown in FIG. 4 contains, for example, Cr (chromium) and O (oxygen) as main components, and also C (carbon) and N (nitrogen). contains More specifically, as a constituent material of the light-shielding layer 12b, one material selected from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonitride, and chromium oxycarbonitride, or two or more types of materials can be selected. When two or more types of materials are selected, the light-shielding layer 12b has a structure in which these two or more types of materials are laminated. In addition, the light-shielding layer 12b may have a different composition in the thickness direction of the light-shielding layer 12b. For example, the light-shielding layer 12b may be configured to have a concentration gradient in the film thickness direction of the light-shielding layer 12b with respect to the nitrogen concentration or oxygen concentration.

In addition, as shown in FIG. 5, as for the blank mask layer 12, the phase shift layer 12c, the etching stopper layer 12d, and the light shielding layer 12e of Cr system from the glass substrate 11 are this order. You may have a laminated structure. In this case, let one or both of the phase shift layer 12c and the etching stopper layer 12d be Mo compound layer which concerns on this embodiment.

As the phase shift layer 12c in the example shown in FIG. 5, the layer containing Cr as a main component other than Mo compound layer may be sufficient. Specifically, the phase shift layer 12c is formed by a single layer of chromium and one selected from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonitride, and chromium oxycarbonitride. configuration can be done. Moreover, the phase shift layer 12c can also be comprised by laminating|stacking 2 or more types chosen from these materials.

The etching stopper layer 12d in the example shown in FIG. 5 may be a metal silicide compound layer containing nitrogen other than Mo compound layer. For example, a layer containing at least one metal selected from Ni, Co, Fe, Ti, Al, Nb, Mo, W, and Hf, a layer containing an alloy formed of these metals and Si, a molybdenum silicide compound layer, The etching stopper layer 12d may be formed of a MoSi _X (X ≥ 2) film (eg, MoSi ₂ film, MoSi ₃ film, MoSi ₄ film, etc.).

The Cr-based light shielding layer 12e in the example shown in Fig. 5 contains, for example, Cr (chromium) and O (oxygen) as main components, and further contains C (carbon) and N (nitrogen). layer can be employed for the light-shielding layer 12e. More specifically, as the light-shielding layer 12e, one material selected from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonitride, and chromium oxycarbonitride, or two or more types of materials can be selected. have. When two or more types of materials are selected, the light-shielding layer 12e has a layer constituted by laminating these two or more types of materials. In addition, the light-shielding layer 12e may have a different composition in the thickness direction of the light-shielding layer 12e. For example, the light-shielding layer 12e may be configured to have a concentration gradient in the film thickness direction of the light-shielding layer 12e with respect to the nitrogen concentration or oxygen concentration.

In addition, as shown in FIG. 6, the blank mask layer 12 may have the structure by which the phase shift layer 12f of Cr system and the reflection prevention layer 12g were laminated|stacked in this order from the glass substrate 11. In addition, as shown in FIG. 7, the blank mask layer 12 may have the structure in which the phase shift layer 12f of Cr system, the reflection prevention layer 12g, and the adhesion layer 12h of Cr system were laminated|stacked. . In this case, the antireflection layer 12g is a Mo compound layer according to the present embodiment.

It is preferable that phase shift layer 12f of Cr system in the example shown to FIG. 6 and FIG. 7 is comprised by the layer which contains Cr as a main component, and C (carbon), O (oxygen), and N It is preferable that it is comprised by the layer containing (nitrogen). Specifically, the phase shift layer 12f can be comprised with chromium single-piece|unit and one chosen from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonization nitride, and chromium oxycarbonitride. Moreover, the phase shift layer 12f can also be comprised by laminating|stacking 2 or more types chosen from these materials.

In addition, it is preferable that the Cr-type adhesive layer 12h in the example shown in FIG. 7 is comprised by the layer containing Cr (chromium) and O (oxygen) as main components, and C (carbon) and It is preferable that it is comprised by the layer containing N (nitrogen). Specifically, as the adhesion layer 12h, one selected from chromium oxide, chromium nitride, chromium carbide, chromium oxynitride, chromium carbonitride, and chromium oxycarbonitride, or two or more types may be laminated. have. In addition, the adhesive layer 12h may have a different composition in the thickness direction of the adhesive layer 12h.

Moreover, as shown in FIG. 8, as the blank mask layer 12, the phase shift layer 12i, the low reflectance layer 12j, and the chemical-resistance layer 12k were laminated|stacked in this order from the glass substrate 11. may have In this case, let at least 1 or 2 or more of the phase shift layer 12i, the low reflectance layer 12j, and the chemical-resistant layer 12k be Mo compound layer which concerns on this embodiment.

The silicide layer containing nitrogen other than Mo compound layer may be sufficient as the phase shift layer 12i and the chemical-resistant layer 12k in the example shown in FIG. For example, a layer containing a metal such as Ta, Ti, W, Mo, Zr, a layer containing an alloy formed of these metals and silicon, a MoSi _X (X ≥ 2) film (eg, MoSi ₂ film; In _MoSi3 film|membrane, _MoSi4 film|membrane, etc.), the phase shift layer 12i and the chemical-resistance layer 12k can also be comprised.

In addition, as the low-reflectance layer 12j in the example shown in FIG. 8, similarly to said phase shift layer and chemical-resistance layer, other than Mo compound layer, the silicide layer containing nitrogen can also be employ|adopted, and oxygen is contained. layer may be employed.

In FIGS. 4-8, although mask blanks were mentioned as an example and demonstrated, you may apply the structure of the blank mask layer 12 shown in FIGS. 4-8 to the mask layer 12P of a photomask.

Next, the manufacturing method of the mask blanks which concerns on this embodiment is demonstrated.

The manufacturing method of the mask blanks which concerns on this embodiment is a method of forming the blank mask layer 12 into a film on the glass substrate 11. As shown in FIG. When forming the blank mask layer 12, a blank mask by laminating|stacking the 1 type(s) or 2 or more types of layers chosen from a phase shift layer, a light shielding layer, a reflection prevention layer, an adhesion layer, an etching stop layer, a chemical-resistant layer, a low reflectance layer, etc. You may form a layer. At this time, it is good also considering 1 type, or 2 or more types of a phase shift layer, a light shielding layer, a reflection prevention layer, an adhesion layer, an etching stop layer, a chemical-resistant layer, and a low reflectance layer as Mo compound layer which concerns on this embodiment.

9 : is a schematic diagram which shows the manufacturing apparatus of the mask blanks which concerns on this embodiment. 10 : is a schematic diagram which shows the manufacturing apparatus of the mask blanks which concerns on this embodiment. The mask blanks which concern on this embodiment are manufactured by the manufacturing apparatus shown in FIG. 9 or FIG.

Manufacturing apparatus S10 shown in FIG. 9 is a single-wafer type sputtering apparatus. Manufacturing apparatus S10 has a load/unload chamber S11 and the film-forming chamber (vacuum processing chamber) S12 connected to the load/unload chamber S11 via the sealing part S13.

In the load/unload chamber S11, a conveying device S11a and an exhaust device S11b are provided. Conveying apparatus S11a conveys the glass substrate 11 carried in from the outside of manufacturing apparatus S10 to film-forming chamber S12. In addition, conveying apparatus S11a conveys the glass substrate 11 to the outside of film-forming chamber S12. The exhaust device S11b is constituted by a rotary pump or the like that roughly evacuates the inside of the load/unload chamber S11.

In the film forming chamber S12, a substrate holding device S12a, a cathode electrode (backing plate) S12c having a target S12b as a device for supplying a film forming material, and a backing plate S12c are provided. A power supply S12d for applying a sputtering voltage of negative potential, a gas introduction device S12e for introducing gas into the film formation chamber S12, and a high vacuum such as a turbo molecular pump for exhausting the interior of the film formation chamber S12 to a high vacuum An exhaust device S12f is provided.

Substrate holding apparatus S12a hold|maintains the glass substrate 11 so that the glass substrate 11 conveyed by conveyance apparatus S11a may oppose target S12b during film-forming. Substrate holding apparatus S12a can carry in the glass substrate 11 from the load/unload chamber S11 to the film-forming chamber S12, The glass substrate 11 can be loaded/unloaded from the film-forming chamber S12. It is possible to take it out in (S11).

The target S12b is made of a material having a composition necessary for forming a film on the glass substrate 11 . For example, as a target in the case of forming a Mo compound layer, you may use combining the target containing molybdenum and the target containing silicon, and may use the single target containing molybdenum and silicon. Further, for example, in order to form a Cr-based film, a target containing chromium may be used. These targets may be exchanged for each layer to be formed into a film.

In manufacturing apparatus S10 shown in FIG. 9, sputtering film-forming is performed in film-forming chamber S12 with respect to the glass substrate 11 carried in from load/unload chamber S11. Then, from the load/unload chamber S11, the glass substrate 11 in which film-forming was complete|finished is carried out to the outside of manufacturing apparatus S10.

In a film-forming process, sputtering gas and reactive gas are supplied from gas introduction apparatus S12e to film-forming chamber S12, and a sputtering voltage is applied to backing plate (negative electrode) S12c from an external power supply. Further, a predetermined magnetic field may be formed on the target S12b by a magnetron magnetic circuit. The ions of the sputtering gas excited by the plasma in the film formation chamber S12 collide with the target S12b of the cathode electrode S12c, and the particles of the film formation material are ejected from the target S12b. Then, after the protruding particles and the reactive gas are combined, a predetermined film is formed on the surface of the glass substrate 11 by adhering to the glass substrate 11 .

At this time, when forming the Mo compound layer according to the present embodiment, that is, the Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen, satisfying the above formula (A), as a target (S12b) , a target containing molybdenum and a target containing silicon are used in combination, or a single target containing molybdenum and silicon is used. Then, the gas introduction device S12e controls the partial pressures of the nitrogen gas and the oxygen-containing gas by changing each of the flow rate of the nitrogen gas and the flow rate of the oxygen-containing gas to set the gas composition within a set range. The gas having the composition set in this way is supplied into the film formation chamber S12 from the gas introduction device S12e.

Here, examples of the oxygen-containing gas include CO ₂ (carbon dioxide), O ₂ (oxygen), N ₂ O (dinitrogen monoxide), and NO (nitrogen monoxide).

Next, manufacturing apparatus S20 shown in FIG. 10 is a single-wafer sputtering apparatus. The manufacturing apparatus S20 includes a rod chamber S21, a film formation chamber (vacuum processing chamber) S22 connected to the rod chamber S21 via a sealing portion S23, and a sealing portion ( It has the unloading chamber S25 connected via S24.

In the load chamber S21, a conveying apparatus S21a which conveys the glass substrate 11 carried in from the outside of the manufacturing apparatus S20 to the inside to the film-forming chamber S22, and rough vacuum inside the load chamber S21 An exhaust device S21b such as a rotary pump that exhausts the gas is provided.

In the film formation chamber S22, a negative potential sputtering voltage is applied to a substrate holding apparatus S22a, a cathode electrode (backing plate) S22c having a target S22b as an apparatus for supplying a film formation material, and a backing plate S22c. A power supply S22d for applying , a gas introduction device S22e for introducing gas into the film formation chamber S22, and a high vacuum exhaust system S22f such as a turbo molecular pump for high vacuum exhaustion of the interior of the film formation chamber S22 (S22f) ) is provided.

Substrate holding apparatus S22a hold|maintains the glass substrate 11 so that the glass substrate 11 conveyed by conveyance apparatus S21a may oppose target S22b during film-forming. The substrate holding apparatus S22a can carry in the glass substrate 11 from the load chamber S21 to the film formation chamber S22, and transfers the glass substrate 11 from the film formation chamber S22 to the unload chamber S25. It is possible to take out

The target S22b is made of a material having a composition necessary for forming a film on the glass substrate 11 . As in the case of the apparatus shown in Fig. 9, as a target for forming the Mo compound layer, a target containing molybdenum and a target containing silicon may be used in combination, or a single target containing molybdenum and silicon may be used. do. Further, for example, in order to form a Cr-based film, a target containing chromium may be used. These targets may be exchanged for each layer to be formed into a film.

In the unloading chamber S25, the conveying apparatus S25a which conveys the glass substrate 11 carried in from the film-forming chamber S22 to the outside of the manufacturing apparatus S20, and rough evacuation of the inside of the unloading chamber S25 An exhaust device S25b such as a rotary pump is provided.

In manufacturing apparatus S20 shown in FIG. 10, after sputtering film-forming in film-forming chamber S22 with respect to the glass substrate 11 carried in from load chamber S21, film-forming is complete|finished from unloading chamber S25. The used glass substrate 11 is carried out to the outside of the film formation chamber S22.

In a film-forming process, sputtering gas and reactive gas are supplied from gas introduction apparatus S22e to film-forming chamber S22, and a sputtering voltage is applied to backing plate (negative electrode) S22c from an external power supply. Further, a predetermined magnetic field may be formed on the target S22b by a magnetron magnetic circuit. Ions of the sputtering gas excited by the plasma in the film formation chamber S22 collide with the target S22b of the cathode electrode S22c to eject the particles of the film formation material. Then, after the protruding particles and the reactive gas are combined, a predetermined film is formed on the surface of the glass substrate 11 by adhering to the glass substrate 11 .

At this time, when forming the Mo compound layer according to the present embodiment, that is, the Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen, satisfying the above formula (A), as a target (S22b) , a target containing molybdenum and a target containing silicon are used in combination, or a single target containing molybdenum and silicon is used. Then, the gas introduction device S22e controls the partial pressures of the nitrogen gas and the oxygen-containing gas by changing each of the flow rate of the nitrogen gas and the flow rate of the oxygen-containing gas to set the composition of the gas within a set range. The gas having the composition set in this way is supplied into the film formation chamber S22 from the gas introduction device S22e.

Here, examples of the oxygen-containing gas include CO ₂ (carbon dioxide), O ₂ (oxygen), N ₂ O (dinitrogen monoxide), and NO (nitrogen monoxide).

Next, the manufacturing method of the photomask which concerns on this embodiment is demonstrated.

As a resist pattern formation process, as shown in FIG. 2, the photoresist layer 13 is formed on the outermost surface of mask blanks. Alternatively, a mask blank in which the photoresist layer 13 is formed on the outermost surface in advance may be prepared.

Then, the photoresist layer 13 is exposed and developed to form a resist pattern. The resist pattern functions as a mask used for etching the blank mask layer 12 .

Then, the blank mask layer 12 is dry-etched through this resist pattern using a dry etching apparatus, and the blank mask layer 12 is patterned to have a predetermined shape. Of the blank mask layer 12 according to the present embodiment, the gas used for etching the Mo compound layer is at least one selected from perfluorocarbons typified by carbon tetrafluorocarbon and hydrofluorocarbons typified by trifluoromethane. It is preferable to use a gas containing a fluorocarbon gas of

As described above, a photomask having the patterned mask layer 12P is obtained as shown in FIG. 3 .

The mask blanks and photomasks according to the embodiment of the present invention include a Mo compound layer in which the ratio of the peak area of the Mo-Si bonding peak to the peak area of the photoelectron spectrum of Mo _3d3/2 and Mo _3d5/2 is 73% or more. have For this reason, even when exposure light is irradiated to a photomask in a photolithography process, increase in the line|wire width of the pattern part by Mo migration can be suppressed. In particular, according to the mask blanks and photomasks according to the present embodiment, exposure light having a wavelength of 200 nm or less, in particular, exposure light of ArF excimer laser light (wavelength 193 nm) used in photolithography using a phase shift mask It can be applied to a photomask used in a photolithography process using

(Example)

Hereinafter, the present invention will be described in more detail by way of Examples.

A large glass substrate was prepared. This large-sized glass substrate is made of synthetic quartz (QZ). A large sized glass substrate has a thickness of 10 mm and has a size of 850 mm × 1200 mm. A Mo compound layer (blank mask layer) was formed on a large glass substrate using a large sized in-line sputtering apparatus. Specifically, the MoSi _X targets whose values of X are 5.4, 7.4, and 9.4 were prepared. At least one of Ar gas, N ₂ gas, CO ₂ gas, or O ₂ gas was used as the sputtering gas. A plurality of Mo compound layers having a film species a to g were formed. In Table 1, the film-forming conditions for forming into a film the Mo compound layer of film-type a-g are shown.

The ratio of the peak area of the Mo-Si bonding peak in the Mo compound layer was calculated|required. Specifically, samples were obtained by cutting out each of the substrates having the Mo compound layer of the film species a to g to a size of 10 × 20 mm. This sample was introduced into an X-ray photoelectron spectroscopy apparatus (Quantera manufactured by ULVAC-PHI, Inc.), the surface of the Mo compound layer was subjected to narrow scan analysis, and the measurement was performed at a binding energy of around 220 to 240 eV. The photoelectron spectrum in which the peak top appears around 227 eV was identified as the photoelectron spectrum of Mo _3d5/2 . The photoelectron spectrum in which the peak top appears around 230 eV was specified as the photoelectron spectrum of Mo _3d3/2 . And the total area of the peak area of these two photoelectron spectra was computed (measured) using the data processing program with which the X-ray photoelectron spectroscopy apparatus was equipped. At this time, the background intensity was subtracted from the peak area.

Then, the peak separation process was performed with respect to the photoelectron spectra of Mo _3d3/2 and Mo _3d5/2 . For the peak separation processing, a data processing program included in the X-ray photoelectron spectrometer was used. A peak in which a peak top appears in the vicinity of 226 to 227 eV by peak separation was identified as the Mo-Si bonding peak in the photoelectron spectrum of Mo _3d5/2 . A peak at which a peak top appears in the vicinity of 229 to 231 eV was identified as the Mo-Si bonding peak in the photoelectron spectrum of Mo _3d3/2 . And the peak area of each Mo-Si bonding peak was measured. Further, the total area of the two peak areas was calculated. At this time, the background intensity was subtracted from the peak area. And the ratio (%) of the peak area of Mo-Si bonding peak with respect to the peak area of the photoelectron spectrum of Mo _3d3/2 and Mo _3d5/2 was calculated|required. A result is shown in Table 1. In addition, in FIG. 11, an example of the photoelectron spectrum of Mo _{3d3 /2} and Mo 3d5/2 after a peak separation process is shown.

In addition, the composition of the structural element of Mo compound layer was measured by the wide scan analysis of X-ray photoelectron spectroscopy. Table 2 shows the mole fraction of each element determined by the measurement of X-ray photoelectron spectroscopy. In Table 2, Si/Mo which is ratio of the mole fraction of molybdenum and a silicon, and the calculation result of the left side of the said Formula (A) are shown together.

Next, a patterned photoresist layer is formed on the plurality of Mo compound layers obtained under the film formation conditions shown in Table 1, and wet etching is performed using the photoresist layer as a mask, whereby the Mo compound layer is patterned to have a line width of 100 nm. did. The Mo compound layer patterned in this way was used as a mask layer. Mo migration was induced by irradiating an ArF excimer laser beam (wavelength 193 nm) to the Mo compound layer after patterning. Then, the amount of change in the line width of the Mo compound layer after irradiation with ArF excimer laser light (wavelength 193 nm) was measured. The results are shown in Table 1.

As shown in Table 1, it turns out that the increase amount of the line|wire width of Mo compound layer (mask layer) becomes small, so that the ratio of the peak area of a Mo-Si bonding peak becomes large. In order to make the amount of increase in the line width of the Mo compound layer (mask layer) 4 nm or less, it has been found that the ratio of the peak area of the Mo-Si bonding peak is 73% or more, preferably 75% or more.

Moreover, as shown in Table 2, like the film type b, when quantity of Mo is least and Formula (A) is small, pattern thickness generate|occur|produces strongly. That is, the amount of increase in the line width increases. On the other hand, even if a large amount of Mo was contained like the film type d, when the formula (A) was large, the pattern thickness hardly occurred. That is, the line width hardly increases. In the last species a and b, the Mo content is the same, but the nitrogen content in the last species a is smaller than that of the last species b. For this reason, it is estimated that the quantity of Mo nitridation decreased, and as a result, the quantity of Mo migration decreased and the increase amount of line|wire width became small.

[Table 1]

[Table 2]

11: glass substrate
12: blank mask layer
12P: mask layer

Claims (10)

A mask blanks having a blank mask layer, comprising:
The blank mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen,
In the Mo compound layer, the peaks of the Mo _3d3/2 spectrum and the Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy are separated. The mask blanks whose ratio of the peak area of Mo-Si bonding peak is 73 % or more. According to claim 1,
Mask blanks in which the said Mo compound layer satisfy|fills following (1) Formula.
{(Si - O/2) × 4/3 + Mo/2 - N}/Si ≥ 0.25 ... (One)
However, each of Mo, Si, O, and N in the formula (1) is a mole fraction (mol%) of molybdenum, silicon, oxygen and nitrogen contained in the Mo compound layer, and the Mo compound layer does not contain oxygen. In this case, O in the formula (1) above is set to 0. 3. The method of claim 1 or 2,
Mask blanks in which the said Mo compound layer further satisfy|fills following (2) Formula.
Si/Mo ≥ 4.0 … (2)
However, each of Mo and Si in the formula (2) is a mole fraction (mol%) of molybdenum and silicon contained in the Mo compound layer. 3. The method of claim 1 or 2,
Regarding the composition of molybdenum, silicon, nitrogen, and oxygen contained in the Mo compound layer,
The silicon content is 35 to 50 mol%,
The content of molybdenum is 3 to 10 mol%,
Oxygen content is 0 to 20 mol%,
The nitrogen content is 35 to 60 mol%,
The mask blanks whose carbon content is 0 to 1 mol%. 3. The method of claim 1 or 2,
Mask blanks in which the said Mo compound layer comprises any 1 type, or 2 or more types of a phase shift layer, a light shielding layer, a reflection prevention layer, an etching stop layer, and a chemical-resistant layer. A photomask having a mask layer, comprising:
The mask layer includes a Mo compound layer containing molybdenum, silicon, and nitrogen, and optionally containing oxygen,
In the Mo compound layer, the peaks of the Mo _3d3/2 spectrum and the Mo _3d5/2 spectrum with respect to the peak areas of the photoelectron spectra of Mo _{3d3 /2} and Mo 3d5/2 measured by X-ray photoelectron spectroscopy are separated. The photomask of which the ratio of the peak area of a Mo-Si bonding peak is 73 % or more. 7. The method of claim 6,
The said Mo compound layer, the photomask which satisfy|fills following (3) Formula.
{(Si - O/2) × 4/3 + Mo/2 - N}/Si ≥ 0.25 ... (3)
However, each of Mo, Si, O, and N in the formula (3) is a mole fraction (mol%) of molybdenum, silicon, oxygen and nitrogen contained in the Mo compound layer, and the Mo compound layer does not contain oxygen. In this case, O in the formula (3) above is set to 0. 8. The method of claim 6 or 7,
The said Mo compound layer further satisfy|fills following (4) Formula, The photomask.
Si/Mo ≥ 4.0 … (4)
However, each of Mo and Si in the formula (4) is a mole fraction (mol%) of molybdenum and silicon contained in the Mo compound layer. 8. The method of claim 6 or 7,
Regarding the composition of molybdenum, silicon, nitrogen, and oxygen contained in the Mo compound layer,
The silicon content is 35 to 50 mol%,
The content of molybdenum is 3 to 10 mol%,
Oxygen content is 0 to 20 mol%,
The nitrogen content is 35 to 60 mol%,
A photomask having a carbon content of 0 to 1 mol%. 8. The method of claim 6 or 7,
The photomask in which the said Mo compound layer comprises any 1 type, or 2 or more types of a phase shift layer, a light shielding layer, a reflection prevention layer, an etching stop layer, and a chemical-resistant layer.

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