JPH09219351A - Mask structure, method and apparatus for exposure using the structure, and manufacture of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent local strain, thermal expansion, the deterioration in profile irregularity, and the appearance of positional distortion at the time of bonding by combining the main bonding for fixing a holding frame which holds a supporting film and a reinforcing body which reinforces the holding frame and an auxiliary dynamic support. SOLUTION: An X-ray permeable supporting film 2 is deposited by CVD on an Si substrate which will become a holding frame 1. Then, for an auxiliary dynamic support 7, plated electrodes are formed on the Si substrate and SiC- made auxiliary-bodies 4 and then resist patterns are formed to make Au-plated projections 7a, 7b. In order to conduct a one-point bonding which will become a main bonding 6 by anode junction, glass including Na+ is sputtered in an area of 3mmϕ on each of the reinforcing bodies 4 and is deposited on the Si substrate using a mask and then is heat-treated to bond the Si substrate and the reinforcing bodies 4. At the same time, the projections 7a and 7b are pushed against each other to be bonded. By this method, the local strain, thermal expansion, the deterioration in profile irregularity, and the appearance of positional distortion can be prevented at the time of bonding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask structure, an exposure method and an exposure apparatus using the same, and a device manufacturing method using the mask structure.

[0002]

2. Description of the Related Art In recent years, with the increase in density and speed of semiconductor integrated circuits, the pattern line width of integrated circuits has been reduced, and semiconductor manufacturing methods are required to have higher performance. For this reason, as a printing apparatus, the exposure wavelength is set in the X-ray range (2 to 15).
A stepper using light of 0 Å has been developed.

An X-ray mask structure used in this X-ray exposure apparatus usually has a structure as shown in FIG. An X-ray absorber 3, a support film 2 for supporting the absorber 3, a holding frame 1 for holding the support film 2, and a reinforcing body 4 for reinforcing the holding frame 1 are used for bonding the holding frame and the reinforcing body. It was adhered on the entire surface or at a plurality of points by using the adhesive 5 or anodic bonding.

[0004]

However, due to the difference in the coefficient of thermal expansion after adhesion and other changes over time, the X-ray mask suffers from positional distortion and deterioration of surface accuracy, which results in a high position of the X-ray absorber. Since it is difficult to ensure accuracy, one-point bonding as shown in FIG. 13 has been proposed. However, it is difficult to secure the adhesive strength with one-point bonding, and it has become necessary to increase the area of one point in order to secure the strength. When the area of one-point adhesion was increased, a large force was applied at the time of adhering the reinforcing body and the holding frame, and local distortion occurred. Further, in the one-point bonding, a large vibration is generated on the mask during the vibration of the machine or the step & repeat in the exposure device. Furthermore, when an unexpected force, rather than a steady force, acts, the probability of breakage etc. was very high.

It is an object of the present invention to provide a novel mask structure which solves the above-mentioned problems of the prior art, an exposure method using the same, an exposure apparatus and a device manufacturing method.

[0006]

The above object is achieved by the following means.

That is, the present invention relates to a mask structure having a radiation absorber, a support film for supporting the absorber, a holding frame for holding the support film, and a reinforcing body for reinforcing the holding frame,
A main object of the present invention is to propose a mask structure characterized by combining a main bonding for fixing the holding frame and the reinforcing body and an auxiliary dynamic support, wherein the auxiliary dynamic support is the holding frame and the The reinforcement is firmly supported in the direction perpendicular to the joint surface and dynamically supported in the horizontal direction, the main adhesive is one-point adhesive, and the area of the one-point adhesive of the main adhesive is 5 mmφ or less, either main bonding of the holding frame and the reinforcing body is directly bonded, anodic bonding, bonding with an inorganic adhesive, bonding with eutectic or diffusion of metal, or bonding with an organic adhesive. The auxiliary support of the holding frame and the reinforcing body is made of a metal having a low elastic coefficient, an elastic hinge spring, a structure of a clasp, or micromechanics, and the mask structure. Is for X-ray exposure.

The present invention also uses the mask structure described above,
The present invention proposes an exposure method characterized by transferring a pattern to a transfer target by exposure.

Further, the present invention uses the mask structure described above,
An exposure apparatus, which is provided with a mechanism for transferring a pattern to a transfer target by exposure, and the mask structure is used to transfer the pattern onto a processed substrate by exposure, and the processed and formed pattern is manufactured. The present invention proposes a device manufacturing method characterized by the above, and a device manufactured by the above method.

[0010]

Next, the present invention will be described in detail with reference to preferred embodiments.

First, the support film is sufficiently transparent to X-rays, and
Since it is necessary to stand by itself, the range of 1-10 μm
It is preferable that the thickness is within the enclosure, for example, Si, S
iO _Two , SiN, SiC, SiCN, BN, AlN, etc.
Inorganic film, radiation resistant organic film such as polyimide, etc.
Alternatively, it is made of a known material such as a composite film. next,
As an X-ray absorber, it absorbs X-rays sufficiently and can be processed.
It is necessary to have good properties, but the range of 0.2-1.0 μm
It is preferable that the thickness is within the enclosure, for example, Au,
For heavy metals such as W, Ta, and Pt, as well as these compounds
It is composed. Also, a holding frame for holding the support film
Is composed of a silicon wafer or the like. further,
Protective film of radiation absorber, conductive film, reflection of alignment light
It may be an X-ray mask structure provided with a protective film or the like.

The holding frame is provided with a reinforcing member for reinforcing the holding frame, and the reinforcing member is made of glass such as Pyrex glass or quartz glass, Si or ceramics. Among them, Young's modulus is 50 GPa or more, and linear expansion coefficient is 1 × 10 ^-5 K ^-1
The following are preferred.

[0013] These reinforcements are subjected to processing required for transportation or chucking, and at the same time, processing related to joining may be performed. When the main joining is carried out by one-point bonding, and when the frame itself is directly joined with the holding frame, one bonding point may be processed. Usually, the area of one point is controlled by forming an adhesive or forming glass or metal by vapor deposition or the like. The area is 5 mmφ or less,
It is preferable that the area is 0.01 mmφ or more and the area is as small as possible.

The Si substrate to be the holding frame is etched with an alkali or the like to form an X-ray transmission window, but the bonding with the reinforcing body may be performed after or before the window is formed. Further, it may be before or after the formation of the radiation absorber. However, if the adhesive layer is not resistant to the chemicals used for etching or forming the absorber, a protective film or the like is required. In addition, when the characteristics of the bonding change due to heat applied during etching or formation of the absorber, the bonding is performed later.

The main bonding is direct bonding capable of obtaining strong bonding by one-point bonding, anodic bonding, bonding by eutectic or diffusion of Au, Al, Cu, etc., bonding by an inorganic adhesive, strong organic bonding Agent bonding is used.

Here, the direct bonding is a method of directly bonding Si, which is the holding frame, and the reinforcing body by heat, and a thermal oxide film of Si may be interposed. Usually, it heats at 400-1200 degreeC.

Further, the anodic bonding is carried out on the reinforcing member 4 by 0.01 to 5
Na ⁺ , Li ⁺ , k ⁺ , Pb ²⁺ , M so that mmφ
Glass (borosilicate glass, alumina silicate glass) or the like containing mobile ions such as g ²⁺ , Ca ²⁺ , Al ³⁺ is sputtered, mask vapor deposition is performed, and several V to 3 KV between substrate 1 and
Adhesion may be performed at room temperature to 500 ° C. As the inorganic adhesive, active metals such as Ti and Zr and Cu, Ni, Ag,
Examples include active metal methods using an alloy such as Sn as an insert material, and examples of organic adhesives include epoxy-based, acrylic-based, and silicon-based adhesives.

As the auxiliary dynamic support, it is preferable that the support is rigidly supported in the direction perpendicular to the joint surface between the holding frame and the reinforcing member and dynamically supported in the horizontal direction. The strength of the vertical direction is strengthened without strictly fixing the positional relationship between the holding frame and the reinforcing body in the horizontal direction. The positional relationship between the holding frame and the reinforcing body is determined by the main bonding, and the deformation caused by the difference in the coefficient of thermal expansion and other changes with time is in the same state as the one-point joining,
It is possible to reduce or eliminate deterioration such as surface accuracy. Further, it is possible to prevent the vibration of the machine and the vibration of the mask during the step & repeat in the exposure apparatus. Furthermore, it is possible to prevent damage and the like against sudden force.

As a supplementary dynamic support, a metal having a low elastic coefficient is used for fusion, or a structure having a structure called an elastic hinge spring is attached, and a very small clasp is used for micromechanics or the like. May be manufactured in. As a metal having a low elastic coefficient, Au, Ag, Cu, Al, Pb, Z
n, Ti, Bs and their compounds and mixtures,
The elastic modulus is preferably about 1 × 10 ¹⁰ Pa or more and 15 × 10 ¹⁰ Pa or less. If the elastic modulus is 1 × 10 ¹⁰ Pa or less, it will not be reinforced, and if it is 15 × 10 ¹⁰ Pa or more, it will not be dynamic support. The size of the above-mentioned clasp is 10 μm to several m in width.
Those having a size of about m are preferably used.

Further, the exposure method and exposure apparatus of the present invention are characterized in that the pattern is transferred to the transfer target by exposing the transfer target through the mask of the present invention as described above. The device of the present invention is a device manufactured by exposing the processed substrate through the above-mentioned mask structure to transfer the pattern onto the processed substrate, and processing and forming the pattern. .

The exposure method and exposure apparatus of the present invention may be conventionally known methods except that the above-described mask structure of the present invention is used. Further, the device of the present invention is a device manufactured by a conventionally known method except that the mask structure of the present invention is used.

[0022]

The present invention will be described in more detail by way of examples with reference to the drawings.

Example 1 FIG. 1 is a sectional view of an X-ray mask structure of the present invention.

On the Si substrate which finally becomes the holding frame 1 as shown in FIG. 1, the SiC 2.
A film having a thickness of 0 μm was formed by CVD.

Next, in order to carry out auxiliary dynamic support 7, as shown in FIG. 2, a plating electrode 8 is formed on the reinforcement 4 made of Si substrate and SiC, and a resist pattern 9 is formed.
7a and 7b made of Au were formed by plating. FIG.
In order to form the resist pattern as described in 1), the pattern may be formed by two exposures, but the pattern may be formed by one exposure by overexposing the negative resist. In particular, when a novolac-based resist is exposed at a short wavelength such as KrF, absorption on the surface is large and a resist pattern as shown in FIG. 2 is formed. Further, when an amine is applied to the surface of a chemically amplified positive resist and exposed to light, a pattern having a shape called T-top is obtained, and the shape is similar.

Further, since the one-point bonding which is the main bonding 6 is performed by anodic bonding, a glass containing mobile ions such as Na ⁺ (Corning, # 7740-Pyrex) is provided on the reinforcing body 4 made of SiC so as to have an area of 3 mmφ. Glass)
Is sputtered and mask vapor deposition is performed. 2 between the Si substrate
00V350 degreeC was applied and it adhered. 7a and 7b at the same time
Are bonded by pressing.

Au is a metal having a small elastic coefficient, and due to its shape, it is not strictly fixed in the horizontal direction.

The Si substrate was etched with 30 wt% KOH to form a holding frame 1 having an X-ray transmitting portion. An etching protection film may be formed on the Pyrex glass.

Subsequently, after forming the plated electrode, the resist is EB
Form a desired pattern with a drawing device and add 0.4μ of Au.
A film was formed, the resist and the plating electrode were peeled off, and the radiation absorber pattern 3 was formed.

In this example, Au prepared by plating was used.
Although the auxiliary dynamic support was performed using, it may be formed by vapor deposition or other material having a small elastic coefficient may be used.

By carrying out the main bonding and the bonding of the holding frame and the reinforcing body by the auxiliary dynamic support as described above, the surface due to the thermal expansion and other changes over time can be obtained without causing local distortion during bonding. Since it is possible to stably obtain a strong bond without deterioration of accuracy and position distortion,
An X-ray mask structure having strong vibration resistance and a high degree of positional accuracy could be manufactured stably with a good yield.

Example 2 The same method as in Example 1 was used, but as auxiliary dynamic support, solid support was provided in the direction perpendicular to the joint surface between the holding frame and the reinforcing member, and horizontal support was provided. Has increased the length of the auxiliary adhesive 7 in the vertical direction in order to enhance the dynamic supporting effect.
Therefore, a groove is formed in the reinforcing body 4 as shown in FIG.

By bonding the holding frame 1 and the reinforcing body 4 by the main bonding 6 and the auxiliary dynamic support 7 as described above,
As in Example 1, the X-ray mask structure having a high degree of positional accuracy could be stably manufactured with a good yield.

Example 3 The same method as in Example 1 was used, but as the auxiliary dynamic support, two types of materials were used to form a part of the dynamic support of the auxiliary adhesion due to the difference in etching rate. did. In this embodiment, Ti and Al are stacked and etched by dry etching using Cl ₂ gas. Wet etching may be used.

The shape of the auxiliary dynamic support is shown in FIG.
The shape may be the same as that in FIG. 3 or may be the shape in which the number of layers is increased as in FIG.

Also in this embodiment, similarly to the first embodiment, the X-ray mask structure having a high degree of positional accuracy can be stably manufactured with a good yield.

Example 4 In Example 1, the main adhesion was carried out by a metal eutectic of Au-Si. Also in this embodiment, as in the case of the first embodiment, the X-ray mask structure having a high degree of positional accuracy can be stably manufactured with high yield.

Embodiment 5 FIGS. 5 and 6 are sectional views of a mask structure of the present invention.

A W of 0.7 μm, which is an X-ray absorber, is formed by a sputtering apparatus, and then a desired pattern is formed by EB drawing, and W is etched by using SF ₆ gas to obtain a radiation absorber 3. , Etching Si substrate with KOH,
The holding frame 1 was formed.

As the main adhesive 6, an epoxy type two-liquid mixed type adhesive was used.

The auxiliary dynamic support 7 is shown in FIG.
An elastic hinge spring made of Al as shown in FIG. This time, a spring separately machined was bonded at the same time as the main bonding as shown in FIG. 5 (c). You may form a groove | channel in the reinforcement body 4 like FIG.

In the present embodiment, the absorber was formed before the etching of Si. However, stress does not change at the etching temperature, and a complicated process is performed while maintaining a high degree of positional accuracy of the X-ray absorber. Could be avoided.

Embodiment 6 FIG. 7 is a part of a sectional view of a mask structure of the present invention.

Auxiliary dynamic support was carried out by using a fine clasp as shown in FIGS. 7 (b) and 7 (c). S to be the holding frame 1
The clasps formed on both the i substrate and the reinforcing body 4 are generally formed by a method called micromechanics. One of the manufacturing methods is shown in FIG.

First, as shown in FIG. 8A, the sacrificial layer 1
0 was made with a resist or the like. Any material can be used as long as it has a wet etching ratio with respect to the material that will eventually become the clasp.

Next, a material 7 (c) 'to be a clasp as shown in FIG. 8 (b) was formed. This 7 (c) 'is shown in FIG.
Patterning was performed as in (c) to obtain 7 (c).

Finally, the sacrificial layer 10 is removed to form a fine clasp. This clasp was fitted to provide additional dynamic support.

The reinforcing body 4 is made of Si, and the portion for main bonding is formed during processing of the reinforcing body. The holding frame 1 and the reinforcing body 4 are directly joined by heating at 800 ° C. for 3 hours.

By preliminarily processing the bonded portion, the mask manufacturing process is simplified.

2 μm of SiN to be the supporting film 2 is formed on the Si substrate.
A film is formed by mCVD, and the Si substrate is etched using an ethylenediamine-pyrocatechol solution to form an X-ray transmission window. A Ta film to be an X-ray absorber having a thickness of 0.8 μm was formed by a sputtering apparatus, and then a desired pattern was formed by EB drawing, and Ta was etched using CBrF ₃ gas to obtain a radiation absorber 3.

The material used as the clasp is SiO here.
_{Although 2} is used, a metal such as W may be used.

Embodiment 7 Next, an embodiment of an exposure apparatus for manufacturing microdevices (semiconductor devices, thin film magnetic heads, micromachines, etc.) using the mask described in Embodiments 1 to 6 will be described. FIG. 9 is a view showing the arrangement of the X-ray exposure apparatus according to this embodiment. In the figure, S
The sheet beam-shaped synchrotron radiation B emitted from the R radiation source A is expanded by the convex mirror C in a direction perpendicular to the plane of the radiation beam. The emitted light reflected and expanded by the convex mirror C is adjusted by the shutter D so that the exposure amount in the irradiation area becomes uniform, and the emitted light that has passed through the shutter D is guided to the X-ray mask E. The X-ray mask E is manufactured by the method described in any of the embodiments described above. The exposure pattern formed on the X-ray mask E is exposed and transferred onto the wafer F by a step & repeat method, a scanning method, or the like.

Example 8 Next, an example of a method of manufacturing a semiconductor device using the above-described X-ray mask structure will be described. FIG. 10 is a flowchart showing a manufacturing flow of semiconductor devices (semiconductor chips such as IC and LSI, liquid crystal panels, CCDs, thin film magnetic heads, microsyringes, etc.). In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask manufacturing), the X-ray mask structure having the designed circuit pattern is manufactured by using the method of Examples 1 to 6. On the other hand, in step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by the X-ray lithography technique using the X-ray mask structure and the wafer prepared above. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer manufactured in step 4, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), etc. including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 11 shows a detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. Step 1
In 4 (ion implantation), ions are implanted into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the X-ray exposure method described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of the present invention, it is possible to manufacture a highly integrated semiconductor device which has been difficult to manufacture in the past.

Further, in a device produced by X-ray exposure using these X-ray mask structures, a pattern faithful to the device design drawing can be produced, and therefore, a high-level feature utilizing the characteristics of X-ray lithography can be obtained. It can be integrated and has good device characteristics.

[0057]

As described above, the one-point bonding by the main bonding is performed in the smallest possible area, the holding frame and the reinforcing body are fixed, and the strength is reinforced by the auxiliary dynamic support.
Vibration resistance, because no local strain is generated during bonding, surface degradation or positional distortion due to thermal expansion or other changes over time does not occur, and a strong bond can be stably obtained. It is possible to stably manufacture a mask structure having high accuracy and high positional accuracy with a good yield.

Furthermore, the exposure method and exposure apparatus using the mask structure of the present invention can provide an exposure method and exposure apparatus with high yield and high accuracy.

Further, a high performance device can be provided by transferring a pattern onto a processed substrate by the mask structure of the present invention, and processing and forming the pattern.

[Brief description of drawings]

1A is a sectional view showing an embodiment of a mask structure of the present invention, and FIG. 1B is a partially enlarged sectional view of FIG. 1A.

FIG. 2 is a cross-sectional view of a resist pattern applied to a reinforcing body.

FIG. 3 is a sectional view showing another embodiment of the mask structure of the present invention.

FIG. 4 (a) is a cross-sectional view showing another embodiment of the mask structure of the present invention, and FIG. 4 (b) is a cross-sectional view showing one example of a state of auxiliary dynamic support. is there.

5 (a) is a sectional view showing another embodiment of the mask structure of the present invention, and FIG. 5 (b) is another example of the auxiliary dynamic support used in the present invention. Sectional view shown in FIG.
FIG. 6 is a partial cross-sectional view of another embodiment of the mask structure of the present invention.

FIG. 6 is a sectional view showing another embodiment of the mask structure of the present invention.

7 (a) is a sectional view showing another embodiment of the mask structure of the present invention, FIG. 7 (b) is a sectional view showing another example of auxiliary dynamic support, and FIG. c) is a sectional view showing an example of auxiliary dynamic support.

8 (a) to 8 (d) are cross-sectional views showing a manufacturing process of auxiliary dynamic support.

FIG. 9 is a schematic view showing an example of an exposure apparatus of the present invention.

FIG. 10 is a manufacturing flow chart of a device manufactured by an exposure apparatus using the mask structure of the present invention.

FIG. 11 is a detailed flow chart of a wafer process in a manufacturing flow of a device manufactured by an exposure apparatus using the mask structure of the present invention.

FIG. 12 is a cross-sectional view of a conventional mask structure.

FIG. 13 is a cross-sectional view of another conventional mask structure.

[Explanation of symbols]

 1 Holding Frame 2 Supporting Film 3 Radiation Absorber 4 Reinforcement 5 Adhesive 6 Main Adhesion 7 Auxiliary Dynamic Support 8 Plating Electrode 9 Resist 10 Sacrificial Layer A SB Radiation Source B Synchrotron Radiation C Convex Mirror D Shutter EX Line mask F wafer

Claims (11)

[Claims] 1. A mask structure having a radiation absorber, a support film for supporting the absorber, a holding frame for holding the support film, and a reinforcing body for reinforcing the holding frame, wherein the holding frame and the reinforcing body are provided. A mask structure, characterized in that it combines a main adhesive for fixing the surface and an auxiliary dynamic support. 2. The auxiliary dynamic support according to claim 1, wherein the auxiliary dynamic support is rigidly supported in a direction perpendicular to a joint surface between the holding frame and the reinforcing body and dynamically supported in a horizontal direction. Mask structure. 3. The mask structure according to claim 1, wherein the main bonding is one-point bonding. 4. The area of one-point adhesion of the main adhesion is 5 mmφ
The mask structure according to claim 1, wherein: 5. The main bonding between the holding frame and the reinforcing member is either direct bonding, anodic bonding, bonding with an inorganic adhesive, bonding with eutectic or diffusion of metal, or bonding with an organic adhesive. The mask structure according to claim 1, wherein the mask structure is provided. 6. The auxiliary support of the holding frame and the reinforcing body is one using a metal having a low elastic coefficient, an elastic hinge spring, a structure of a clasp, or micromechanics. Mask structure. 7. The mask structure according to claim 1, wherein the mask structure is for X-ray exposure. 8. An exposure method using the mask structure to transfer a pattern to an object to be transferred by exposure. 9. An exposure apparatus comprising a mechanism for transferring a pattern onto a transfer target by exposure using the mask structure. 10. A method of manufacturing a device, which comprises using the mask structure to transfer a pattern onto a processed substrate by exposure, processing and forming the pattern, and manufacturing the device. 11. A device manufactured by the method of claim 10.