JP4509363B2 - Sputtering target, sputtering target manufacturing method, phase shift mask blank manufacturing method, and phase shift mask manufacturing method - Google Patents

Description

【００８２】
【表２】

【００８３】
前記表１および表２から明らかなように、本発明の実施例１〜７と比較例１〜６のスパッタリングターゲットをスパッタリングすることにより成膜された膜の膜厚バラツキおよびパーティクル発生数を比較すると、実施例１〜７のターゲットのスパッタリングにより成膜された膜は比較例１〜６のターゲットでは達成することができなかった低パーティクル化、膜厚均一性を得ることが可能となることがわかる。
【００８４】
実施例１〜７のスパッタリングターゲットを用いて、例えば常法により透明基板上に成膜して薄膜を形成することにより位相シフトマスクブランクを製造した。さらに、この位相シフトマスクブランクの光半透過膜をパターニングすることにより位相シフトマスクを製造した。
【００８５】
製造された位相シフトマスクブランクおよび位相シフトマスクは、パーティクルが少なく、均一な膜厚を有し、良好な特性を有していた。
【００８６】
【発明の効果】
以上詳述したように、本発明によればスパッタリング時において、従来達成することができなかった低パーティクル化、均一膜厚で、さらに耐酸性、高透過率な膜を成膜することが可能で、位相シフトマスクブランクおよび位相シフトマスクにおける光半透過部の薄膜の形成等に極めて有用なスパッタリングターゲットおよびその製造方法を提供することができる。
【００８７】
また、本発明によれば膜中のパーティクルが少なく、均一な膜厚の薄膜を有する位相シフトマスクブランクおよび位相シフトマスクを提供することができる。
【図面の簡単な説明】
【図１】ターゲットの評価サンプル採取位置を示す平面図。
【図２】５ンチウェーハ膜厚サンプル採取位置を示す平面図。
【符号の説明】
１…ターゲット、
２…膜形成されたウェハ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sputtering target containing silicon (Si) as a main component and containing a refractory metal, a manufacturing method thereof, a phase shift mask blank, and a phase shift mask.
[0002]
[Prior art]
As a next-generation photolithography technique, a technique called phase shift lithography has attracted attention. This technology is a method that improves the resolution of photolithography by changing the mask without changing the optical system, and improves the resolution by providing a phase difference between the exposure light that passes through the photomask. is there.
[0003]
As one of the phase shift masks, a halftone phase shift mask has recently been developed. This is because the light semi-transmission part has two functions of a light shielding function that substantially blocks exposure light and a phase shift function that shifts (inverts) the phase of the light, so that the light shielding film pattern and the phase shift film pattern are separately provided. There is a feature that the structure is simple and manufacture is easy.
[0004]
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 (MoSix), specifically oxidized Mo and Si (MoSiO), or oxidized and nitrided Mo and Si (MoSiON).
[0005]
Japanese Patent Application Laid-Open No. 10-73913 discloses that the transmittance of the light semi-transmissive portion of the phase shift mask can be controlled by controlling the oxygen content or the content of oxygen and nitrogen. Further, this publication discloses that the amount of phase shift can be controlled by selecting the thickness of the thin film. Furthermore, it is also disclosed that by using such a material, the light semi-transmissive portion can be configured by a single layer film, and the film forming process can be simplified.
[0006]
However, the MoSiO-based or MoSiON-based film, which is a conventional material, is weak against acids such as sulfuric acid used for cleaning when the degree of oxynitridation is too strong, and the set transmittance and phase difference are not shifted. There was a problem that would occur.
[0007]
In particular, in the design of a mask using KrF excimer laser light, it is necessary to sufficiently perform oxidation and nitridation because it is necessary to reduce the extinction coefficient. For this reason, the phase shift mask made of the above-described material is more likely to cause the above problem.
[0008]
For these reasons, recently, Si-based materials that have both acid resistance and high transmittance and that can make the extinction coefficient relatively small have attracted attention. In order to form this Si-based material on the light semi-transmissive portion of the phase shift mask, a method of reactive sputtering of an Si-based target in an argon + oxygen (nitrogen) atmosphere is employed.
[0009]
[Problems to be solved by the invention]
However, in the film formation of the Si-based material, as the degree of oxidation and nitridation in the sputtering atmosphere increases, oxides and nitrides are deposited on the target surface, and the discharge becomes unstable. For this reason, the uniformity of transmittance and film thickness is reduced, and particles due to abnormal discharge frequently occur. In addition, the target (molded body) used here is generally manufactured by a powder sintering method. However, when a film is formed using a conventional low-density target, abnormal discharge is likely to occur in the pores and the particles are also generated. Likely to happen. Furthermore, since Si is the main component, conductivity becomes a problem. That is, unless sufficient conductivity is imparted to the target, the discharge becomes unstable in DC sputtering, and it becomes difficult to form a high-quality film.
[0010]
The present invention intends to provide a Si-based sputtering target capable of stably forming a film having a low particle size and a uniform film thickness, and a method for producing the same.
[0011]
The present invention is intended to provide a phase shift mask blank and a phase shift mask having a thin film with a uniform film thickness with few particles in the film.
[0012]
[Means for Solving the Problems]
The sputtering target according to the present invention is a sputtering target in which silicon is 70 to 97% by weight and the balance is substantially made of refractory metal silicide,
The metal structure has at least a silicon phase and a refractory metal silicide phase composed of the silicon and the refractory metal, and
As for the sputtering surface, the half width of the peak of the Si (111) surface obtained by X-ray diffraction (XRD) is 0.5 deg or less, and the half width of the peak of the refractory metal silicide (101) surface is 0.5 deg. It is characterized by the following.
[0013]
Such a sputtering target of the present invention can form a stable film while suppressing generation of particles, and can form a film having acid resistance and high transmittance.
[0014]
  In the sputtering target manufacturing method according to the present invention, silicon is 70 to 97% by weight, the balance is substantially made of a refractory metal silicide, and the metal structure is made of at least a silicon phase, the silicon and the refractory metal. A method for producing a sputtering target having a refractory metal silicide phase,
  Mixing a high-purity silicon powder having a maximum particle size of 32 μm or less and a refractory metal powder having a maximum particle size of 20 μm or less;
  The mixed powder is filled into a mold and 10^-2-10^-3A process of forming a refractory metal silicide by reacting the silicon with a refractory metal by heating to 1000 ° C. to 1300 ° C. under a press pressure of 0.1 to 3 MPa in a vacuum of Pa;
  10^-2-10^-3In vacuum of Pa or 5.32 × 10^Four~ 6.65 × 10^FourSintering and densifying at 1350 ° C. to 1450 ° C. under a press pressure of 24.5 to 39.2 MPa in a Pa inert gas atmosphere;
  In the cooling step after the sintering, the temperature is 1200 ° C. to 1300 ° C. without pressure.3-6 hoursHolding and removing residual stress, and cooling
It is characterized by comprising.
[0015]
According to such a method of the present invention, it is possible to produce a sputtering target capable of forming a stable film that suppresses generation of particles and that can form a film having acid resistance and high transmittance. Can do.
[0016]
  Phase shift mask blank according to the present inventionManufacturing methodThe sputtering target of the present inventionSputtering to form a translucent film on a transparent substrateIt is characterized by this.
  In the method for producing a phase shift mask according to the present invention, a sputtering target of the present invention is sputtered to form a light semitransmissive film on a transparent substrate to produce a phase shift mask blank, and then the light semitransmissive film is patterned. It is characterized by this.
[0017]
Such a phase shift mask blank and a phase shift mask of the present invention have a thin film with a uniform film thickness with few particles in the film.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The sputtering target according to the present invention will be described in detail below.
[0019]
The sputtering target of the present invention is a sputtering target having 70 to 97% by weight of silicon and the balance being substantially made of a refractory metal silicide, wherein the metal structure includes at least a silicon phase, the silicon and the refractory metal. And has a refractory metal silicide phase. The sputtering surface of this target has a half-width of the peak of the Si (111) surface obtained by X-ray diffraction (XRD) of 0.5 deg or less and a half-width of the peak of the refractory metal silicide (101) surface. 0.5 deg or less.
[0020]
When the silicon content in the target is less than 70% by weight, the required performance (acid resistance, high transmittance) as a light semi-transmissive portion of the phase shift mask of the film formed by sputtering this target is lowered. There is a fear. On the other hand, if the silicon content exceeds 97% by weight, the conductivity of the target is lowered, and the film formation characteristics may be deteriorated. A more preferable silicon content in the target is 75 to 90% by weight, and a more preferable silicon content is 80 to 85% by weight.
[0021]
The metal structure of the target in the present invention has at least a silicon phase and a refractory metal silicide phase composed of the silicon and the refractory metal. This is more stable when the refractory metal is present as a silicide than when the refractory metal is present alone, so that sputtering can be performed stably. Although all the refractory metals are preferably silicided, they may partially exist alone.
[0022]
Examples of the refractory metal include at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). Can be used.
[0023]
The surface state when performing X-ray diffraction of the sputtered surface of the target was obtained by roughly polishing the sputtered surface of the target for 3 minutes each in the order of grindstone particle number # 120 → # 320 → # 500 → # 800 → # 1000. Puff polishing is performed for 3 minutes with a polishing liquid containing 0.3 μm alumina particles, followed by polishing for 6 hours with a paste containing 0.3 μm diamond.
[0024]
Here, the half width of the crystal plane of the present invention is a value measured by the following method.
[0025]
That is, as shown in FIG. 1, for example, test pieces (samples) each having a length of 15 mm and a width of 15 mm are collected from five evaluation sample collection positions (center, top, bottom, right, left) of a disk-shaped target 1. . The crystal planes of these five test pieces are respectively measured by X-ray diffraction, and the average value is taken as the crystal plane of the present invention. For the crystal plane, the half width is calculated from the peak obtained by X-ray diffraction. Each value is an average of 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.
[0026]
<Conditions>
X-ray: Cu, kα-1, 50 kV, 100 mA, vertical goniometer,
Divergence slit: 1deg,
Scattering slit: 1 deg
Light emitting slit: 0.15 mm,
Scanning mode: continuous,
Scan speed: 1 ° / min,
Scan step: 0.01 °
Scanning axis: 2θ / θ,
Measurement angle: 38 ° to 42 °.
[0027]
For peak editing, the half-value width calculated as a result of the next editing for the peak on the (101) plane measured under the above conditions is the value used in this proposal.
[0028]
The smoothing method is weighted average.
[0029]
The background removal method is a straight line that touches both ends.
[0030]
The kα2 removal method is the intensity ratio (kα2 / kα1 = 0.5).
[0031]
When 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 refractory silicide (101) plane exceeds 0.5 deg, non-uniform strain is generated in the target crystal. It becomes difficult to effectively suppress the generation of particles during sputtering. More preferably, the half width of the Si (111) plane and the half width of the peak of the refractory silicide (101) plane are each 0.3 deg or less, more preferably 0.1 deg or less.
[0032]
The maximum particle diameter of the refractory metal silicide is desirably 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less. A sputtering target containing a refractory metal silicide having such a grain size regulation can suppress abnormal discharge during sputtering, more effectively suppress the generation of particles, and make the film thickness uniform. become.
[0033]
The target preferably has a relative density of 90% or more. A sputtering target having such a density can suppress abnormal discharge during sputtering, suppress generation of particles, and make the film thickness uniform. The relative density of the target is more preferably 95% or more, and still more preferably 98% or more.
[0034]
The target further allows 0.1 ppm to 0.5 wt% of at least one element selected from the group consisting of boron, phosphorus, antimony and arsenic. In the sputtering target having such a configuration, conductivity is further imparted to a target having an insulating silicon as a main phase by containing the element, and thus stable DC sputtering is possible.
[0035]
The target is further allowed to be added in an amount of 0.5 to 3.0 wt% with respect to the Si by silicon carbide (SiC). Since the sputtering target having such a structure is further provided with conductivity by containing the SiC, stable DC sputtering is possible.
[0036]
Next, an example of the manufacturing method of the sputtering target which concerns on this invention is demonstrated in detail.
[0037]
(First step)
First, a refractory metal powder having a maximum particle size of 20 μm or less is added to a high-purity silicon powder having a maximum particle size of 32 μm or less, and selected from the group of boron, phosphorus, antimony and arsenic having an average particle size of about 10 μm as necessary. At least one element powder and / or silicon carbide powder having an average particle size of about 10 μm is added and mixed.
[0038]
If high-purity silicon powder containing coarse particles exceeding the maximum particle size of 32 μm is used, it becomes difficult to increase the density at the time of molding, and it causes non-uniform structure due to aggregation and the like. It becomes difficult to perform the film. The maximum grain size of the silicon powder is preferably 20 μm or less, more preferably 10 μm or less.
[0039]
When the refractory metal powder having a maximum particle size exceeding 20 μm is used, it is difficult to increase the density during molding, the particle size of the refractory metal silicide is increased, and the dispersibility may be lowered. . The maximum particle size of the refractory metal silicide is preferably 15 μm or less, more preferably 10 μm or less. The average particle size of the refractory metal powder is preferably 5 to 10 μm. When the average particle size of the refractory metal powder is less than 5 μm, gas components are adsorbed on the refractory metal, and as a result, the residual gas components may increase in the sintered body. If the average particle diameter of the refractory metal powder exceeds 10 μm, silicide grains may become coarse during the silicide synthesis reaction.
[0040]
When an element powder such as boron added as necessary, or a silicon carbide powder having an average particle diameter of more than 10 μm is used, it is difficult to increase the density at the time of molding. There is a risk of non-uniformity. The preferred average particle size of these powders is 8 μm or less, more preferably 6 μm or less.
[0041]
The mixing is preferably performed for 24 hours or more. When mixing for a shorter time, 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 lowered, resulting in a non-uniform structure.
[0042]
(Second step)
The mixed powder is filled in a mold and 10^-2-10^-3Heating is performed at 1000 to 1300 ° C. under a press pressure of 0.1 to 3 MPa in a vacuum of Pa. At this time, the silicon powder in the mixed powder reacts with the refractory metal powder to synthesize a refractory metal silicide. Next, 10^-2-10^-3In vacuum of Pa or 5.32 × 10^Four~ 6.65 × 10^FourBy sintering to 1350 ° C. to 1450 ° C. under a press pressure of 24.5 to 39.2 MPa in an inert gas atmosphere of Pa, the molded product containing the refractory metal silicide is sintered and densified. .
[0043]
That is, the synthesis of the refractory metal silicide is held at a low pressure at a temperature of 1000 ° C. to 1300 ° C., and then subjected to pressure sintering immediately below the melting point of Si as the main phase, thereby densifying (relative density is 90% or more) can be obtained.
[0044]
(Third step)
The sintered body is held at a temperature of 1200 ° C. to 1300 ° C. without pressure in the cooling step after sintering to remove residual stress, and then cooled.
[0045]
Cooling at a stretch from the state immediately below the melting point after the sintering step causes a large difference in thermal expansion due to temperature, and a residual stress is generated inside the sintered body, so that the sintered body is likely to crack and the product yield is reduced. There is a risk of lowering.
[0046]
For this reason, the main component is silicon (containing 70 to 97% by weight) by adopting a method of once holding at a temperature of 1200 ° C. to 1300 ° C. in a non-pressurized state after densification and cooling. The sputtering surface contains a trace amount of refractory metal silicide, and the sputtering surface has a half-width of the peak of the Si (111) surface determined by X-ray diffraction (XRD) of 0.5 deg or less, and the refractory metal silicide (101) surface. It becomes possible to manufacture a sputtering target in which the half width of the peak is 0.5 deg or less. Moreover, cracks are less likely to occur in the sintered body, and the product yield can be improved. Furthermore, the directivity of the sputtered particles is improved due to the decrease in residual stress, and the generation of particles can be reduced.
[0047]
If the temperature at the time of holding is less than 1200 ° C., it is insufficient to effectively remove the residual stress, and it becomes difficult to obtain the half width intended in the present invention. On the other hand, if the temperature during the heat treatment exceeds 1300 ° C., cracks are likely to occur in the sintered body during subsequent cooling. Preferable temperature is 1230-1260 degreeC.
[0048]
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 becomes difficult to obtain the half width intended in the present invention. On the other hand, if the holding time is too long, the silicon and silicon grains may be coarsened. A more preferable holding time is 3 to 5 hours, and further preferably 4 to 5 hours.
[0049]
The manufactured sputtering target can form a stable film while suppressing the generation of particles, and can obtain a uniform film thickness, and can form a film with acid resistance and high transmittance equal to or higher than the conventional one. I can make a film.
[0050]
In this invention, a phase shift mask blank and a phase shift mask can be manufactured by forming a thin film on a transparent substrate, for example by a conventional method, using the said sputtering target. Specifically, for example, a phase shift mask blank is manufactured by forming a thin film on a transparent substrate to form a light semi-transmissive film, and further, a phase shift mask is manufactured by patterning the light semi-transmissive film. .
[0051]
The manufactured phase shift mask blank and phase shift mask have good characteristics because they have few particles and a uniform film thickness.
[0052]
【Example】
Hereinafter, preferred embodiments of the present invention will be described in detail.
[0053]
Example 1
High-purity Si powder sieved to a maximum particle size of 32 μm or less was mixed with 5 wt% of Mo powder having a maximum particle size of 15 μm (average particle size of 10 μm) and mixed for 48 hours in a ball mill substituted with high-purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1150 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1380 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 3 hours. Thereafter, in the cooling step, the mixture was heated and held at 1200 ° C. for 1 hour to remove residual stress, and cooled to prepare a dense sintered body.
[0054]
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.
[0055]
(Example 2)
High-purity Ar gas is blended into high-purity Si powder that has been screened to a maximum particle size of 32 μm or less, Ta powder with a maximum particle size of 15 μm (average particle size of 10 μm), and 1 wt% of SiC powder for imparting conductivity. For 48 hours. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1250 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1400 ° C. and sintering was performed under conditions of a pressure of 34.3 MPa for 3 hours. Thereafter, in the cooling step, the resin was heated and held at 1300 ° C. for 1.5 hours to remove the residual stress, and cooled to prepare a dense sintered body.
[0056]
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 as in Example 1.
[0057]
(Example 3)
The high-purity Si powder sieved to a maximum particle size of 32 μm or less was mixed with 10 wt% of W powder having a maximum particle size of 12 μm (average particle size of 10 μm) and mixed for 48 hours in a ball mill substituted with high-purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1200 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1390 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 5 hours. Thereafter, in the cooling process, the residual stress was removed by heating and holding at 1300 ° C. for 1 hour, and a dense sintered body was produced by cooling.
[0058]
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 as in Example 1.
[0059]
Example 4
10 wt% of Ti powder with a maximum particle size of 15 μm (average particle size of 10 μm) and 0.3 wt% of boron (B) powder with an average particle size of 5 μm are blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less, It mixed for 48 hours with the ball mill substituted by the high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1200 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1350 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 4 hours. Thereafter, in the cooling step, the mixture was heated and held at 1200 ° C. for 2 hours to remove residual stress, and cooled to produce a dense sintered body.
[0060]
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 as in Example 1.
[0061]
(Example 5)
16 wt% of Cr powder having a maximum particle size of 14 μm (average particle size of 10 μm) was mixed with high-purity Si powder sieved to a maximum particle size of 32 μm or less, and mixed for 48 hours in a ball mill substituted with high-purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1100 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1330 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 4 hours. Thereafter, in the cooling step, the resultant was heated and held at 1250 ° C. for 2 hours to remove residual stress, and cooled to prepare a dense sintered body.
[0062]
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 as in Example 1.
[0063]
(Example 6)
A high-purity Si powder sieved to a maximum particle size of 32 μm or less is mixed with 5 wt% of Nb powder with a maximum particle size of 15 μm (average particle size of 10 μm) and 0.05 wt% of phosphorus (P) powder with an average particle size of 7 μm, It mixed for 48 hours with the ball mill substituted by the high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1200 ° C. for 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1350 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 3 hours. Thereafter, in the cooling step, the mixture was heated and held at 1200 ° C. for 1 hour to remove residual stress, and cooled to prepare a dense sintered body.
[0064]
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 as in Example 1.
[0065]
(Example 7)
High-purity Ar gas is blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less, W powder with a maximum particle size of 15 μm (average particle size 10 μm), and 1 wt% of SiC powder for imparting conductivity. For 48 hours. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1150 ° C. for 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1350 ° C., and sintering was performed under conditions of a pressure of 34.3 MPa for 4 hours. Thereafter, in the cooling step, the mixture was heated and held at 1200 ° C. for 2 hours to remove residual stress, and cooled to produce a dense sintered body.
[0066]
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 as in Example 1.
[0067]
(Comparative Example 1)
High purity Si powder sieved to a maximum particle size of 32 μm or less was mixed with 10 wt% of Mo powder having a maximum particle size of 15 μm (average particle size of 10 μm) and mixed for 48 hours in a ball mill substituted with high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 700 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1380 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 3 hours. Then, after heating and holding at 800 ° C. for 1 hour in the cooling step, a dense sintered body was produced by cooling.
[0068]
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 as in Example 1.
[0069]
(Comparative Example 2)
The high-purity Si powder sieved to a maximum particle size of 32 μm or less is mixed with 20 wt% of W powder having a maximum particle size of 15 μm (average particle size of 10 μm) and 0.07 wt% of phosphorus (P) powder having an average particle size of 7 μm. It mixed for 48 hours with the ball mill substituted by the high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 800 ° C. for 1.5 hours at a pressure of 1.5 MPa, the temperature was raised to 1380 ° C., and sintering was performed under conditions of a pressure of 34.13 MPa and 5 hours. Then, the sintered compact was produced by cooling, without heat-processing in a cooling process.
[0070]
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 as in Example 1.
[0071]
(Comparative Example 3)
High purity Si powder sieved to a maximum particle size of 32 μm or less was mixed with 5 wt% of Ti powder having a maximum particle size of 12 μm (average particle size of 10 μm), and mixed for 48 hours in a ball mill substituted with high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 600 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1350 ° C., and sintering was performed under conditions of a pressure of 39.12 MPa and 4 hours. Thereafter, in the cooling step, the mixture was heated and held at 1000 ° C. for 1 hour and cooled to prepare a dense sintered body.
[0072]
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 as in Example 1.
[0073]
(Comparative Example 4)
High purity Si powder sieved to a maximum particle size of 32 μm or less is mixed with 12 wt% of Nb powder having a maximum particle size of 14 μm (average particle size of 10 μm) and 0.1 wt% of antimony (Sb) powder having an average particle size of 10 μm, It mixed for 48 hours with the ball mill substituted by the high purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at a pressure of 1.5 MPa for 600 ° C. for 1.5 hours, the temperature was raised to 1350 ° C. and sintering was performed under conditions of a pressure of 34.3 MPa for 3 hours. Then, the sintered compact was produced by cooling, without heat-processing in a cooling process.
[0074]
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 as in Example 1.
[0075]
(Comparative Example 5)
High-purity Ar gas is blended with high-purity Si powder sieved to a maximum particle size of 32 μm or less, 10 wt% of Cr powder with a maximum particle diameter of 12 μm (average particle diameter of 10 μm), and 1 wt% of SiC powder for imparting conductivity. For 48 hours. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1000 ° C. for 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1330 ° C. and sintering was performed under conditions of a pressure of 29.4 MPa and 3 hours. Thereafter, a dense sintered body was produced by cooling without heat treatment in the cooling step.
[0076]
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 as in Example 1.
[0077]
(Comparative Example 6)
5 wt% of W powder having a maximum particle size of 15 μm (average particle size of 10 μm) was mixed with high-purity Si powder sieved to a maximum particle size of 32 μm or less, and mixed for 48 hours in a ball mill substituted with high-purity Ar gas. Subsequently, the mixed powder was filled into a graphite mold. This mold was placed in a hot press machine and the degree of vacuum was 5 × 10^-3In the following vacuum, after holding at 1100 ° C. × 1 hour at a pressure of 1.5 MPa, the temperature was raised to 1350 ° C., and sintering was performed under conditions of a pressure of 29.4 MPa and 4 hours. Thereafter, in the cooling step, the mixture was heated and held at 600 ° C. for 1 hour and cooled to prepare a dense sintered body.
[0078]
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 as in Example 1.
[0079]
A sample having a length of 15 mm and a width of 15 mm was taken out from the evaluation sample collection positions (center, top, bottom, left, right) shown in FIG. 1 for the targets of Examples 1 to 7 and Comparative Examples 1 to 6, and relative density measurement was performed. Then, the half width of the structure observation, Si (111) plane, and refractory metal silicide (101) plane was investigated. Specifically, the Archimedes method by the paraline impregnation method was measured for the relative density, and the maximum particle size of the silicide phase was measured for the structure. Further, with respect to the half width, an X-ray diffraction apparatus in which the sputtering surface of the target is polished under the above-mentioned conditions so that the surface roughness is Rmax of 0.1 μm, and the Cu-kα ray is used for the above-described X-ray source. The profile was taken and measured by (trade name, RAD-B, manufactured by Rigaku Instruments Co., Ltd.). These results are shown in the following Table 1 (Examples 1 to 7) and the following Table 2 (Comparative Examples 1 to 6).
[0080]
In addition, the targets of Examples 1 to 7 and Comparative Examples 1 to 6 thus obtained were 2 × 10 using a sputtering apparatus (trade name of ULVAC; SH-550).^-3Sputtering was performed under the conditions of torr and argon gas pressure, and a film having a thickness of approximately 2000 angstroms was deposited on a 5-inch wafer. A sample is cut out from the evaluation sample collection position (center, top, bottom, left, right) of the wafer 2 shown in FIG. 2, and the film thickness is measured using a film thickness meter (trade name manufactured by TENCOR; alpha-Step200). Then, the variation in film thickness was calculated by [(maximum value−minimum value) / (maximum value + minimum value)]. Moreover, the number of particles; piece / wafer (p / wafer) was measured by a particle counter (trade name: WM-3). These results are shown in the following Table 1 (Examples 1 to 7) and the following Table 2 (Comparative Examples 1 to 6).
[0081]
[Table 1]

[0082]
[Table 2]

[0083]
As is apparent from Table 1 and Table 2, when film thickness variations and the number of generated particles of the films formed by sputtering the sputtering targets of Examples 1 to 7 and Comparative Examples 1 to 6 of the present invention are compared. It can be seen that the films formed by sputtering the targets of Examples 1 to 7 can achieve low particle size and film thickness uniformity that cannot be achieved by the targets of Comparative Examples 1 to 6. .
[0084]
Using the sputtering targets of Examples 1 to 7, a phase shift mask blank was manufactured by forming a thin film by forming a film on a transparent substrate by a conventional method, for example. Further, a phase shift mask was manufactured by patterning the light semi-transmissive film of this phase shift mask blank.
[0085]
The manufactured phase shift mask blank and phase shift mask had few particles, a uniform film thickness, and good characteristics.
[0086]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to form a film with low particle size, uniform film thickness, acid resistance, and high transmittance that could not be achieved at the time of sputtering. Further, it is possible to provide a sputtering target that is extremely useful for forming a thin film of a light translucent portion in a phase shift mask blank and a phase shift mask, and a method for manufacturing the same.
[0087]
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 with a uniform film thickness with few particles in the film.
[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 5-inch wafer film thickness sample collection position.
[Explanation of symbols]
1 ... Target,
2 ... A film-formed wafer.

Claims (10)

A sputtering target comprising 70 to 97% by weight of silicon and the balance being substantially made of refractory metal silicide,
The metal structure has at least a silicon phase and a refractory metal silicide phase composed of the silicon and the refractory metal, and the sputtering surface has a peak of the Si (111) surface obtained by X-ray diffraction (XRD). The sputtering target is characterized in that the half width of the refractory metal silicide (101) plane is 0.5 deg or less.   The refractory metal is at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). The sputtering target according to claim 1.   The sputtering target according to claim 1 or 2, wherein the maximum particle size of the refractory metal silicide phase is 20 µm or less.   The sputtering target according to any one of claims 1 to 3, wherein a relative density is 90% or more.   5. The sputtering target 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.   Furthermore, 0.5-3 wt% of silicon carbide (SiC) is added, The sputtering target in any one of the Claims 1 thru | or 4 characterized by the above-mentioned. Production of sputtering target having 70 to 97% by weight of silicon, the balance being substantially made of refractory metal silicide, and having a metal structure having at least a silicon phase and a refractory metal silicide phase comprising silicon and the refractory metal. A method,
Mixing a high-purity silicon powder having a maximum particle size of 32 μm or less and a refractory metal powder having a maximum particle size of 20 μm or less;
The mixed powder is filled into a molding die, heated in a vacuum of 10 ⁻² to 10 ⁻³ Pa under a press pressure of 0.1 to ³ MPa to 1000 ° C. to 1300 ° C., and the silicon and the refractory metal are mixed. Reacting to form a refractory metal silicide;
1350 ° C. to 1450 ° C. under a press pressure of 24.5 to 39.2 MPa in a vacuum of 10 ⁻² to 10 ⁻³ Pa or in an inert gas atmosphere of 5.32 × 10 ^{4 to} 6.65 × 10 ⁴ Pa. Sintering and densifying with,
A method of manufacturing a sputtering target, comprising: a step of cooling after sintering after holding residual pressure at 1200 ° C. to 1300 ° C. for 3 to 6 hours without removing pressure and then cooling. .   The refractory metal is at least one metal selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), and niobium (Nb). The manufacturing method of the sputtering target of Claim 7 characterized by the above-mentioned. A method for producing a phase shift mask blank , comprising sputtering the sputtering target according to claim 1 to form a light semi-transmissive film on a transparent substrate . A phase shift mask blank is formed by sputtering the sputtering target according to claim 1 to form a light semitransmissive film on a transparent substrate, and then patterning the light semitransmissive film. Shift mask manufacturing method.

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