JP2002173765A - Sputtering target - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering target which enables the stable deposition of a film having reduced particles and a uniform film thickness. SOLUTION: The sputtering target consists of 70 to 97 wt.% silicon, and the balance substantially high melting point metallic silicide. Its metallic structure at least has a silicon phase and a high melting point metallic silicide phase consisting of the above silicon and the above high melting point metal. In the sputtered surface, the half-value width of the peak in the Si (111) plane obtained by an X-ray diffraction method (XRD) is <=0.5 deg, and also, the half-value width of the peak in the high melting point metallic silicide (101) plane is <=0.5 deg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering target containing silicon (Si) as a main component and a refractory metal, a method for manufacturing the same, a phase shift mask blank, and a phase shift mask.

[0002]

2. Description of the Related Art As a next-generation photolithography technique, a technique called phase shift lithography has attracted attention. This technique improves the resolution of photolithography by changing the mask without changing the optical system.It improves the resolution by giving a phase difference between the exposure light transmitted through the photomask. is there.

As one of the phase shift masks, a halftone type phase shift mask has recently been developed. This is because the light semi-transmissive portion has two functions of a light blocking function of substantially blocking exposure light and a phase shifting function of shifting (inverting) the phase of light, so that the light blocking film pattern and the phase shift film pattern are separated. There is no need to form the structure, and the structure is simple and easy to manufacture.

Conventionally, the light semi-transmissive portion of the phase shift mask is formed of a thin film made of a material mainly composed of metal such as molybdenum, silicon, and oxygen. The material is molybdenum silicide (MoSi
x), specifically oxidized Mo and Si (MoSi
O) or oxidized and nitrided Mo and Si (M
oSiON).

[0005] Japanese Patent Application Laid-Open No. 10-73913 discloses that the transmittance of a light transmissive portion of a phase shift mask can be controlled by controlling the oxygen content or the oxygen and nitrogen contents. I have. This publication also discloses that the amount of phase shift can be controlled by selecting the thickness of the thin film. Furthermore, it is disclosed that by using such a material, a light semi-transmissive portion can be formed with a single-layer film, and a film-forming process can be simplified.

However, the conventional material MoSi
If the degree of oxynitridation is too strong, the O-based or MoSiON-based film is susceptible to acids such as sulfuric acid used for cleaning and the like, and there is a problem that the set transmittance and the phase difference are shifted. .

In particular, in the design of a mask using KrF excimer laser light, it is necessary to sufficiently perform oxidation and nitridation because of the need to reduce the extinction coefficient. Therefore, a phase shift mask made of the above-mentioned material is more likely to cause the above problem.

For these reasons, Si-based materials having acid resistance and high transmittance and capable of reducing the extinction coefficient relatively easily have recently attracted attention. This S
In order to form the i-type material on the light translucent portion of the phase shift mask, a method of reactively sputtering a Si-type target in an atmosphere of argon + oxygen (nitrogen) is adopted.

[0009]

However, the aforementioned S
In the film formation of the i-based material, as the degree of oxidation and nitridation in the sputtering atmosphere is increased, oxides and nitrides are deposited on the target surface, and the discharge becomes unstable. For this reason, the transmittance and the uniformity of the film thickness are reduced, and particles due to abnormal discharge frequently occur. The target (molded body) used here is generally manufactured by a powder sintering method. However, when a film is formed by using a conventional low-density target, abnormal discharge is likely to occur in pores and the like, and particles are generated. Likely to happen. Further, since Si is a main component, conductivity becomes a problem. That is, unless sufficient conductivity is given to the target, discharge becomes unstable in DC sputtering,
It becomes difficult to form a high quality film.

An object of the present invention is to provide a Si-based sputtering target capable of stably forming a film having a reduced number of particles and a uniform film thickness, and a method of manufacturing the same.

According to the present invention, there are few particles in a film,
An object of the present invention is to provide a phase shift mask blank and a phase shift mask each having a thin film having a uniform thickness.

[0012]

The sputtering target according to the present invention is a sputtering target comprising 70 to 97% by weight of silicon and the balance substantially consisting of a high-melting-point metal silicide. Phase, having a high melting point metal silicide phase composed of the silicon and the high melting point metal, and the sputtering surface,
Si (111) determined by X-ray diffraction (XRD)
The half-value width of the peak on the surface is 0.5 deg or less, and the half-value width of the peak on the refractory metal silicide (101) surface is 0.5 deg.
deg or less.

The sputtering target of the present invention can form a stable film while suppressing the generation of particles, and can form a film having an acid resistance and a high transmittance.

The method of manufacturing a sputtering target according to the present invention is characterized in that silicon is 70 to 97% by weight, and the balance is substantially composed of a high melting point metal silicide, and the metal structure is at least a silicon phase, and the silicon and the high melting point A method for producing a sputtering target having a high melting point metal silicide phase composed of a metal, wherein the maximum particle size is 32 μm
A step of mixing the following high-purity silicon powder and a high-melting-point metal powder having a maximum particle size of 20 μm or less; filling the mixed powder into a molding die; and placing the mixed powder in a vacuum of 10 ⁻² to 10 ⁻³ Pa. ~
Heating at a pressure of 3 MPa to 1000 ° C. to 1300 ° C. to react the silicon with the refractory metal to form a refractory metal silicide; 10 ⁻² to 10 ⁻³ Pa
In vacuum or 5.32 × 10 ^{4 to} 6.65 × 10 ⁴
A step of sintering at 1350 ° C. to 1450 ° C. under a press pressure of 24.5 to 39.2 MPa in a Pa inert gas atmosphere to densify; After removing the residual stress while maintaining the temperature at 〜1300 ° C., and then cooling.

According to the method of the present invention, a sputtering target capable of forming a film having an acid resistance and a high transmittance as well as being capable of forming a stable film while suppressing generation of particles is provided. Can be manufactured.

A phase shift mask blank and a phase shift mask according to the present invention are characterized in that at least a part thereof has a thin film formed by using the sputtering target of the present invention.

Such a phase shift mask blank and a phase shift mask of the present invention have a small thickness of particles in the film and have a uniform thickness.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a sputtering target according to the present invention will be described in detail.

The sputtering target of the present invention is a sputtering target comprising 70 to 97% by weight of silicon and the balance substantially consisting of a high melting point metal silicide, wherein the metal structure is at least a silicon phase, the silicon and the silicon It has a refractory metal silicide phase composed of a refractory metal. On the sputter surface of this target, the half width of the peak of the Si (111) plane obtained by X-ray diffraction (XRD) is 0.5 deg or less, and the half width of the peak of the high melting point metal silicide (101) plane is not more than 0.5 deg. It is 0.5 deg or less.

When the silicon content in the target is less than 70% by weight, the required performance (acid resistance, high transmittance) as a light semi-transmitting portion of a phase shift mask of a film formed by sputtering this target. May decrease. On the other hand, if the silicon content exceeds 97% by weight, the conductivity of the target may be reduced, and the film forming characteristics may be degraded. More preferably, the silicon content in the target is 75 to 90% by weight, and further preferably, the silicon content is 80 to 85% by weight.

In the present invention, the metal structure of the target is
At least a silicon phase and a refractory metal silicide phase composed of the silicon and the refractory metal are provided. This is more stable when the refractory metal is present in the form of silicide than when the refractory metal is present alone, and the sputtering can be performed stably. It is preferable that all of the refractory metals are silicided, but some of them may exist alone.

The refractory metal is, for example, at least one selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). The above metals can be used.

The surface condition of the target when performing X-ray diffraction on the sputtered surface is as follows: the sputtered surface of the target has a grindstone particle number of # 120 → # 320 → # 500 → # 800 → # 1.
After performing rough polishing for 3 minutes each in the order of 000, puff polishing is performed for 3 minutes with a polishing liquid containing 0.3 μm alumina particles, and polishing is further performed for 6 hours with a paste containing 0.3 μm diamond.

Here, the half width of the crystal plane of the present invention indicates a value measured by the following method.

That is, as shown in FIG. 1, for example, a test piece (sample) having a length of 15 mm and a width of 15 mm from five evaluation sample collection positions (center, top, bottom, right, left) of a disk-shaped target 1, for example. Collect. The crystal planes of these five test pieces were measured by X-ray diffraction, and the average value was taken as the crystal plane of the present invention. For the crystal plane, a half width is calculated from a peak obtained by X-ray diffraction. Each value is the average of the values measured at least 10 times at each location. As the X-ray diffractometer, an X-ray diffractometer (XRD) manufactured by Rigaku Corporation is used, and the X-ray diffraction conditions are shown below.

<Conditions> X-ray: Cu, kα-1, 50 kV, 100 mA, vertical goniometer, divergence slit: 1 deg, scattering slit: 1 deg, emission slit: 0.15 mm, scanning mode: continuous, scan speed: 1 ° / Min, scan step: 0.01 °, scan axis: 2θ / θ, measurement angle: 38 ° to 42 °.

In the peak editing, the half-width calculated as a result of performing the following editing for the peak of the (101) plane measured under the above conditions is used as the value used in the present proposal.

The smoothing method is weighted average.

The background removal method uses straight lines tangent to both ends.

The kα2 removal method is based on the intensity ratio (kα2 / kα).
1 = 0.5).

If the half-width of the peak of the Si (111) plane by XRD exceeds 0.5 deg and the half-width of the peak of the high melting point silicide (101) plane exceeds 0.5 deg, undesired in the target crystal. It is difficult to effectively suppress the generation of particles during sputtering due to the presence of uniform distortion. More preferably, the half width of the Si (111) plane and the half width of the peak of the high melting point silicide (101) plane are 0.3 deg or less, and further preferably 0.1 deg or less.

The maximum particle size of the refractory metal silicide is as follows:
It is desirable that the thickness be 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. The sputtering target containing the refractory metal silicide having such a particle size regulation suppresses abnormal discharge during sputtering, and can more effectively suppress the generation of particles.
It is possible to make the film thickness uniform.

The target preferably has a relative density of 90% or more. A sputtering target having such a density suppresses abnormal discharge during sputtering,
The generation of particles can be suppressed, and the film thickness can be made uniform. More preferably, the relative density of the target is 95% or more, more preferably 98% or more.

The target further comprises boron, phosphorus,
At least one element selected from the group consisting of antimony and arsenic is allowed to be contained in an amount of 0.1 ppm to 0.5% by weight. In the sputtering target having such a configuration, since the target containing insulative silicon as a main phase is further provided with conductivity by containing the element, stable DC sputtering can be performed.

The target further comprises silicon carbide (S
iC) allows 0.5 to 3.0 wt% to be added to the Si. Since the sputtering target having such a configuration is further provided with conductivity by containing the SiC, stable DC sputtering can be performed.

Next, an example of a method for manufacturing a sputtering target according to the present invention will be described in detail.

(First Step) First, a high melting point metal powder having a maximum particle diameter of 20 μm or less is added to a high-purity silicon powder having a maximum particle diameter of 32 μm or less, and if necessary, an average particle diameter of about 10 μm.
At least one element powder selected from the group consisting of boron, phosphorus, antimony and arsenic and / or silicon carbide powder having an average particle size of about 10 μm are added and mixed.

When a high-purity silicon powder containing coarse particles exceeding the maximum particle size of 32 μm is used, it becomes difficult not only to increase the density during molding, but also to cause a non-uniform structure due to agglomeration and the like. It is difficult to form a stable film. The maximum particle size of the silicon powder is preferably 20 μm or less, more preferably 10 μm or less.

When a high melting point metal powder having a maximum particle size of more than 20 μm is used, it is difficult to increase the density during molding, and the particle size of the high melting point metal silicide increases, and its dispersibility also decreases. There is a fear. The maximum particle size of the high melting point metal silicide is preferably 15 μm or less, more preferably 10 μm or less. The average particle size of the high melting point metal powder is preferably 5 to 10 μm. If the average particle size of the high melting point metal powder is less than 5 μm, the gas component is adsorbed on the high melting point metal, and as a result, the residual gas component may increase in the sintered body. If the average particle size of the high melting point metal powder exceeds 10 μm, silicide particles may become coarse during the silicide synthesis reaction.

The above-mentioned elemental powder such as boron and silicon carbide powder which are added as required have an average particle size of 10 μm.
If a coarser material is used, it is not only difficult to increase the density at the time of molding, but also there is a possibility that the structure may become uneven due to agglomeration or the like. The preferred average particle size of these powders is 8
μm or less, more preferably 6 μm or less.

The mixing is preferably performed for 24 hours or more. If the mixing is performed for a shorter time than this, the dispersibility of the additive element powder such as boron and the silicon carbide powder as well as the refractory metal to be added may be reduced, resulting in a non-uniform structure.

(Second Step) The mixed powder is filled in a mold, and heated to 1000 ° C. to 1300 ° C. under a pressure of 0.1 to ³ MPa in a vacuum of 10 ⁻² to 10 ⁻³ Pa. At this time, the silicon powder and the high melting point metal powder in the mixed powder react with each other to synthesize a high melting point metal silicide. Subsequently, in a vacuum of 10 ^-2 to 10 ^-3 Pa, or 5.32
In an inert gas atmosphere of × 10 ^{4 to} 6.65 × 10 ⁴ Pa, under a press pressure of 24.5 to 39.2 MPa, 135
By sintering at 0 ° C. to 1450 ° C., the molded article containing the refractory metal silicide is sintered and densified.

That is, the synthesis of the refractory metal silicide is maintained at a low pressure at a temperature of 1000 ° C. to 1300 ° C., and thereafter, pressure sintering is performed immediately below the melting point of the main phase of Si, whereby densification ( It is possible to obtain a sintered body having a relative density of 90% or more.

(Third Step) In the cooling step after sintering, the sintered body is held without pressure at a temperature of 1200 ° C. to 1300 ° C. to remove residual stress, and then cooled.

When cooling is performed at once from a state immediately below the melting point after the sintering step, the difference in thermal expansion due to temperature is large,
Residual stress is generated inside the sintered body, so that the sintered body is easily cracked, which may lower the product yield.

For this reason, by adopting a method in which after densification, the system is once held at a temperature of 1200 ° C. to 1300 ° C. in a non-pressurized state and cooled, the main component is silicon (containing 70 to 97% by weight). ) Contains a trace amount of high-melting metal silicide, and the half-width of the peak of the Si (111) plane determined by X-ray diffraction (XRD) is 0.
5 deg or less and high melting point metal silicide (101)
It is possible to manufacture a sputtering target in which the half width of the surface peak is 0.5 deg or less. Also,
Cracks are less likely to occur in the sintered body, and the product yield can be improved. Further, the directivity of the sputtered particles is improved by the reduction of the residual stress, and the generation of particles can be reduced.

If the temperature during the holding is lower than 1200 ° C., it becomes insufficient to effectively remove the residual stress.
It becomes difficult to obtain the half width intended in the present invention. On the other hand, if the temperature at the time of the heat treatment exceeds 1300 ° C., cracks tend to be formed in the sintered body during the subsequent cooling. The preferred temperature is 1300-1260C.

The holding time is preferably 3 to 6 hours. If the holding time is too short, the residual stress is not sufficiently removed, and it is difficult to obtain the half width intended in the present invention. On the other hand, if the holding time is too long, silicon and silicon grains may be coarsened. A more preferred holding time is 3 to 5 hours, and further preferably 4 to 5 hours.

The manufactured sputtering target is:
A stable film can be formed while suppressing generation of particles, a uniform film thickness can be obtained, and a film having acid resistance and high transmittance equal to or higher than the conventional film can be formed.

In the present invention, a phase shift mask blank and a phase shift mask can be manufactured by forming a thin film on a transparent substrate by, for example, a conventional method using the sputtering target. Specifically, for example, by manufacturing a phase shift mask blank by forming a thin film on a transparent substrate to form a light translucent film,
Further, a phase shift mask is manufactured by patterning the light translucent film.

The manufactured phase shift mask blank and phase shift mask have good characteristics because they have few particles and a uniform film thickness.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail.

Example 1 5 wt% of Mo powder having a maximum particle size of 15 μm (average particle size: 10 μm) was blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less to obtain a high-purity Ar powder.
The mixture was mixed for 48 hours in a ball mill replaced with gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
0 ^-3 During the following vacuum, at a pressure 1.5 MPa 115
After holding at 0 ° C. × 1 hour, the temperature was raised to 1380 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 3 hours. Thereafter, in a cooling step, the residual stress was removed by heating at 1200 ° C. for 1 hour, and a dense sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding to produce a target having a diameter of 127 mm and a thickness of 6 mm.

Example 2 10 wt% of Ta powder having a maximum particle size of 15 μm (average particle size of 10 μm) and 1 wt% of SiC powder for imparting conductivity were added to high-purity Si powder sieved to a maximum particle size of 32 μm or less. % And mixed for 48 hours in a ball mill replaced with high-purity Ar gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press apparatus, and was placed in a vacuum of 5 × 10 ⁻³ or less at a pressure of 1.5 MPa and 1250 ° C. × 1.
After holding for 1 hour, the temperature was raised to 1400 ° C., and the pressure was 34.3.
The sintering was performed at 3 MPa for 3 hours. After that, in a cooling step, a residual sintered body was removed by heating at 1300 ° C. for 1.5 hours, and a dense sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding, and had a diameter of 127 mm and a thickness of 6 m similar to those in Example 1.
m targets were produced.

Example 3 10 wt% of a W powder having a maximum particle size of 12 μm (average particle size of 10 μm) was blended with a high-purity Si powder sieved to a maximum particle size of 32 μm or less to obtain a high-purity Ar powder.
The mixture was mixed for 48 hours in a ball mill replaced with gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In a vacuum of 0 ^-3 or less, 120 at a pressure of 1.5 MPa.
After maintaining at 0 ° C. × 1 hour, the temperature was raised to 1390 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 5 hours. Thereafter, in a cooling step, the residual stress was removed by heating at 1300 ° C. for 1 hour, and a dense sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding, and had a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Example 4 10 wt% of a Ti powder having a maximum particle size of 15 μm (average particle size of 10 μm) was added to a high-purity Si powder sieved to a maximum particle size of 32 μm or less, and an average particle size of 5 μm.
0.3% by weight of boron (B) powder of high purity Ar
The mixture was mixed for 48 hours in a ball mill replaced with gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In a vacuum of 0 ^-3 or less, 120 at a pressure of 1.5 MPa.
After maintaining at 0 ° C. × 1 hour, the temperature was raised to 1350 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 4 hours. Thereafter, in a cooling step, the residual stress was removed by heating at 1200 ° C. for 2 hours, followed by cooling to produce a dense sintered body.

The obtained sintered body is subjected to predetermined machining and grinding, and has a diameter of 127 mm and a thickness of 6 m similar to that of Example 1.
m targets were produced.

Example 5 16 wt% of a Cr powder having a maximum particle size of 14 μm (average particle size: 10 μm) was blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less to obtain a high-purity A powder.
The mixture was mixed for 48 hours in a ball mill replaced with r gas. Subsequently, this mixed powder was filled in a molding die made of graphite.
This molding die is set in a hot press machine, and the degree of vacuum is 5 ×
In a vacuum of 10 ⁻³ or less, 11 at a pressure of 1.5 MPa.
After holding at 00 ° C. × 1 hour, the temperature was raised to 1330 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 4 hours. After that, in a cooling step, a residual sintered body was removed by heating at 1250 ° C. for 2 hours, and a dense sintered body was produced by cooling.

The obtained sintered body is subjected to predetermined machining and grinding, and has a diameter of 127 mm and a thickness of 6 m similar to that of Example 1.
m targets were produced.

Example 6 5 wt% of Nb powder having a maximum particle size of 15 μm (average particle size of 10 μm) and phosphorus (P) powder having an average particle size of 7 μm were added to high-purity Si powder sieved to a maximum particle size of 32 μm or less. Was mixed in a ball mill replaced with high-purity Ar gas for 48 hours. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In a vacuum of 0 ^-3 or less, 120 at a pressure of 1.5 MPa.
After holding at 0 ° C. × 1 hour, the temperature was raised to 1350 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 3 hours. Thereafter, in a cooling step, the residual stress was removed by heating at 1200 ° C. for 1 hour, and a dense sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding, and had a diameter of 127 mm and a thickness of 6 m similar to those in Example 1.
m targets were produced.

Example 7 10 wt% of W powder having a maximum particle size of 15 μm (average particle size of 10 μm) and 1 wt% of SiC powder for imparting conductivity were added to high-purity Si powder sieved to a maximum particle size of 32 μm or less. % And mixed for 48 hours in a ball mill replaced with high-purity Ar gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press apparatus, and kept in a vacuum at a degree of vacuum of 5 × 10 ⁻³ or less at a pressure of 1.5 MPa at 1150 ° C. × 1 hour, and then heated to 1350 ° C. and a pressure of 34.3 M.
Sintering was performed under the conditions of Pa and 4 hours. Thereafter, in a cooling step, the residual stress was removed by heating at 1200 ° C. for 2 hours, followed by cooling to produce a dense sintered body.

The obtained sintered body was subjected to predetermined machining and grinding to obtain a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 1 10 wt% of Mo powder having a maximum particle size of 15 μm (average particle size of 10 μm) was blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less.
The mixture was mixed for 48 hours in a ball mill replaced with r gas. Subsequently, this mixed powder was filled in a molding die made of graphite.
This molding die is set in a hot press machine, and the degree of vacuum is 5 ×
In a vacuum of 10 ⁻³ or less, 70 at a pressure of 1.5 MPa.
After holding at 0 ° C. × 1 hour, the temperature was raised to 1380 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 3 hours. Then, after heating and holding at 800 ° C. for 1 hour in a cooling step, a dense sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding, to obtain a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 2 20 wt% of W powder having a maximum particle size of 15 μm (average particle size of 10 μm) and phosphorus (P) powder having an average particle size of 7 μm were added to high-purity Si powder sieved to a maximum particle size of 32 μm or less. Was mixed in a ball mill replaced with high-purity Ar gas for 48 hours. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In 0 ^-3 time in a vacuum, 800 pressure 1.5MPa
After the temperature was maintained at 1 ° C. × 1.5 hours, the temperature was increased to 1380 ° C., and sintering was performed under the conditions of a pressure of 34.13 MPa and 5 hours. Thereafter, the sintered body was produced by cooling without performing a heat treatment in a cooling step.

The obtained sintered body was subjected to predetermined machining and grinding, and had a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 3 5 wt% of a Ti powder having a maximum particle size of 12 μm (average particle size of 10 μm) was blended with a high-purity Si powder sieved to a maximum particle size of 32 μm or less to obtain a high-purity Ar.
The mixture was mixed for 48 hours in a ball mill replaced with gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In 0 ^-3 time in a vacuum, 600 pressure 1.5MPa
℃ × 1 hour, then raised to 1350 ℃, pressure 3
Sintering was performed under the conditions of 9.12 MPa and 4 hours. Then, in a cooling process, it is heated and held at 1000 ° C. for 1 hour,
By cooling, a dense sintered body was produced.

The obtained sintered body was subjected to predetermined machining and grinding to obtain a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 4 Nb powder having a maximum particle size of 14 μm (average particle size of 10 μm) was added to a high-purity Si powder sieved to a maximum particle size of 32 μm or less at 12 wt% and an average particle size of 10 μm.
0.1 wt% of antimony (Sb) powder was mixed and mixed for 48 hours in a ball mill replaced with high-purity Ar gas.
Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press apparatus, and kept in a vacuum at a degree of vacuum of 5 × 10 ⁻³ or less at a pressure of 1.5 MPa at 600 ° C. for 1.5 hours. The sintering was performed at 3 MPa for 3 hours. After that, without heat treatment in the cooling process,
A sintered body was produced by cooling.

The obtained sintered body was subjected to predetermined machining and grinding, to obtain a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 5 10 wt% of a Cr powder having a maximum particle size of 12 μm (average particle size of 10 μm) and 1 wt% of a SiC powder for imparting conductivity were added to a high-purity Si powder sieved to a maximum particle size of 32 μm or less. % And mixed for 48 hours in a ball mill replaced with high-purity Ar gas. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and in a vacuum at a degree of vacuum of 5 × 10 ⁻³ or less, a pressure of 1.5 MPa and a temperature of 1000 ° C. × 1.
After holding for a time, the temperature was raised to 1330 ° C. and the pressure was 29.4.
The sintering was performed at 3 MPa for 3 hours. After that, a dense sintered body was produced by cooling without performing a heat treatment in a cooling step.

The obtained sintered body was subjected to predetermined machining and grinding, and had a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

Comparative Example 6 A high-purity Si powder sieved to a maximum particle size of 32 μm or less was mixed with 5 wt% of a W powder having a maximum particle size of 15 μm (average particle size of 10 μm), and the ball mill was replaced with high-purity Ar gas. For 48 hours. Subsequently, this mixed powder was filled in a molding die made of graphite. This molding die was set in a hot press machine, and the degree of vacuum was 5 × 1.
In 0 ^-3 time in a vacuum, 110 pressure 1.5MPa
After maintaining at 0 ° C. × 1 hour, the temperature was raised to 1350 ° C., and sintering was performed under the conditions of a pressure of 29.4 MPa and 4 hours. Thereafter, in a cooling step, the mixture was heated and held at 600 ° C. for 1 hour, and cooled to produce a dense sintered body.

The obtained sintered body was subjected to predetermined machining and grinding to obtain a diameter of 127 mm and a thickness of 6 m as in Example 1.
m targets were produced.

The targets of Examples 1 to 7 and Comparative Examples 1 to 6 were 15 m in length from the above-described evaluation sample collection positions (center, top, bottom, left, right) shown in FIG.
m, take out sample of 15mm width, measure relative density,
The structure was observed, and the half widths of the Si (111) plane and the refractory metal silicide (101) plane were investigated. Specifically, for relative density, Archimedes method by Paralyne impregnation method,
Regarding the structure, the maximum particle size of the silicide phase was measured. Regarding the half-value width, the sputtered surface of the target was polished under the above-mentioned conditions to reduce the surface roughness to 0.1 μm in Rmax.
m, and the X-ray source described above for this sputtered surface was Cu
A profile was measured with an X-ray diffractometer (trade name: RAD-B, manufactured by Rigaku Corp.) using -kα ray and measured. The results are shown in Table 1 below (Examples 1 to 7) and Table 2 below (Comparative Examples 1 to 6).

Further, the obtained targets of Examples 1 to 7 and Comparative Examples 1 to 6 were used in a sputtering apparatus (ULVAC).
2 × 10 ^-3 torr using SH-550)
Sputtering under argon gas pressure conditions of
A film approximately 2000 angstroms thick was deposited on a 5 inch wafer. A sample is cut out from an evaluation sample collection position (center, top, bottom, left, right) of the wafer 2 shown in FIG.
The measurement was performed using NCOR (trade name: alpha-Step 200), and the variation in film thickness was calculated by [(maximum value−minimum value) / (maximum value + minimum value)]. The number of particles; piece / wafer (p / wafer) was measured by a particle counter (trade name: WM-3). These results are shown in Table 1 below (Examples 1 to 7) and Table 2 below.
The results are shown in (Comparative Examples 1 to 6).

[0081]

[Table 1]

[0082]

[Table 2]

As is clear from Tables 1 and 2,
When comparing the film thickness variation and the number of generated particles of the films formed by sputtering the sputtering targets of Examples 1 to 7 of the present invention and Comparative Examples 1 to 6, it was found that the sputtering of the targets of Examples 1 to 7 was successful. It can be seen that the formed film can be reduced in particles and uniform in film thickness, which cannot be achieved by the targets of Comparative Examples 1 to 6.

Using the sputtering targets of Examples 1 to 7, for example, a phase shift mask blank was manufactured by forming a thin film on a transparent substrate by a conventional method. Further, a phase shift mask was manufactured by patterning the light semi-transmissive film of the phase shift mask blank.

The manufactured phase shift mask blank and phase shift mask had few particles, had a uniform film thickness, and had good characteristics.

[0086]

As described in detail above, according to the present invention, during sputtering, a film having a low particle size, a uniform film thickness, an acid resistance, and a high transmittance, which could not be achieved conventionally, is formed. It is possible to provide a sputtering target which is extremely useful for forming a thin film of a light transmissive portion in a phase shift mask blank and a phase shift mask, and a method for manufacturing the same.

Further, according to the present invention, it is possible to provide a phase shift mask blank and a phase shift mask having a thin film having a small thickness and a uniform thickness.

[Brief description of the drawings]

FIG. 1 is a plan view showing an evaluation sample collection position of a target.

FIG. 2 is a plan view showing a sampling position of a 5-inch wafer film thickness sample.

[Explanation of symbols]

 1. Target: 2. Film-formed wafer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Yamanobe 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba Yokohama Office (72) Inventor Takashi Ishigami 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa (72) Inventor Koichi Watanabe 8th place, Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside of Toshiba Yokohama Works (72) Yoichiro Yabe 8th, Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Electronics Engineering (72) Inventor Yukinobu Suzuki 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Toshiba Yokohama Office (reference) 2H095 BB03 BB25 4K029 BA35 CA05 DC05 DC09

Claims (10)

[Claims] 1. A sputtering target comprising 70 to 97% by weight of silicon and a balance substantially consisting of a high-melting-point metal silicide, wherein the metallographic structure comprises at least a silicon phase, said silicon and said high-melting-point metal. It has a refractory metal silicide phase, and the sputter surface has a half-width of 0.5 d of the peak of the Si (111) surface determined by X-ray diffraction (XRD).
a sputtering target having a peak width on the refractory metal silicide (101) surface of 0.5 deg or less and 0.5 deg or less. 2. The refractory metal is molybdenum (M
o), at least one metal selected from the group consisting of tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). The sputtering target according to the above. 3. The sputtering target according to claim 1, wherein the maximum particle size of the refractory metal silicide phase is 20 μm or less. 4. The sputtering target according to claim 1, wherein the relative density is 90% or more. 5. The method according to claim 1, further comprising 0.1 ppm to 0.5 wt% of at least one element selected from the group consisting of boron, phosphorus, antimony and arsenic. Sputtering target. 6. Silicon carbide (SiC) is added in an amount of 0.5 to
The sputtering target according to any one of claims 1 to 4, wherein 3 wt% is added. 7. Silicon is 70 to 97% by weight, and the balance is substantially composed of a high melting point metal silicide. The metal structure is at least a silicon phase and a high melting point metal silicide phase composed of the silicon and the high melting point metal. Mixing a high-purity silicon powder having a maximum particle size of 32 μm or less and a high melting point metal powder having a maximum particle size of 20 μm or less; filling the mixed powder into a molding die; ^-2 to 10 ^-3 Pa
Under a pressure of 0.1 to 3 MPa in a vacuum of 1000
Heating the silicon to the high melting point metal to form a high melting point metal silicide by heating the silicon to the high melting point metal, in a vacuum of 10 ⁻² to 10 ⁻³ Pa, or 5.32 × 10 3
^{4 to} 6.65 × 10 ⁴ Pa in an inert gas atmosphere, 24.5
1350 ° C. to 145 under a press pressure of ３９39.2 MPa
Sintering at 0 ° C. to densify, and cooling at 1200 ° C. to 1
Removing the residual stress while maintaining the temperature at 300 ° C., and then cooling the sputtering target. 8. The high melting point metal is molybdenum (M
8. At least one metal selected from the group consisting of o), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). A method for producing the sputtering target according to the above. 9. A phase shift mask blank having a thin film formed at least in part by using the sputtering target according to claim 1. 10. A phase shift mask having a thin film formed at least in part by using the sputtering target according to claim 1.