JP2003198101A - Method for manufacturing pattern transfer mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a pattern transfer mold capa ble of providing a deep and precise comb type pattern at a low cost and high speed, applicable to a pattern transfer method using a comb type press. <P>SOLUTION: An etch mask thin film 2 is formed on a molding substrate 1, a circuit pattern is formed of a molding resist film 3 on the thin film 2 by photolithography, a circuit pattern is formed on the thin film 2 by wet etching using the resist film 3 as the mask, the substrate 1 is subjected to wet etching using the circuit-carrying thin film 2 as the mask, and then the resist film 3 and the thin film 2 are removed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern transfer method using a concavo-convex press for transferring a circuit pattern formed on a semiconductor device substrate on which a semiconductor element is mounted or a printed circuit board used for driving control of various devices. The present invention relates to a method for manufacturing a pattern transfer mold used when performing the method.

[0002]

2. Description of the Related Art A pattern transfer method using a concavo-convex press is disclosed in US Pat. No. 5,772,905 as one of pattern transfer methods to a semiconductor device substrate or a printed circuit board. This method, by pressing a pattern transfer mold having a concavo-convex pattern formed on the surface of the circuit resist film formed on the circuit substrate, to form a concavo-convex pattern on the circuit resist film, then, This is a method of transferring a convex circuit resist film pattern onto a circuit substrate by etching the circuit resist film. According to this pattern transfer method, finer pattern transfer is possible as compared with the conventional pattern transfer method by the photolithography method, and further, there is a possibility that transfer can be performed at high speed without using an expensive exposure device. Has been attracting attention. The pattern transfer mold required for pattern transfer by the concave-convex press is usually made of a single crystal Si substrate.

FIG. 3 shows a process of manufacturing a conventional pattern transfer mold. Using the single crystal Si substrate 4 as the mold substrate,
A mold resist film 3 is formed on the surface (a), pattern transfer is performed by a photolithography method (b), and then the surface of the single crystal Si substrate 4 is etched to form an uneven pattern (c). The resist film 3 for use is dissolved and removed (d). As the etching method, there are wet etching in which an etching solution suitable for each material is dipped, and dry etching using plasma. Dry etching requires a very expensive dry etching apparatus having a plasma generator and vacuum equipment, and also has the problem that productivity is poor due to the use of vacuum and the procedure is complicated, and the etching rate is slow. Therefore, a long etching time is required to form a deeper uneven pattern. On the other hand, wet etching is cheaper because it is only immersed in the etching solution.
It has the advantage that it is easy and the etching rate is fast.

[0004]

Since a pattern transfer mold made of a single crystal Si substrate is opaque, it is difficult to align each pattern when accurately stacking different patterns such as a transistor. is there. Therefore, quartz glass (SiO ₂ ) is a material that is transparent and has a hardness close to that of single crystal Si. FIG. 4 shows a process of forming a pattern transfer mold using quartz glass as a mold substrate. When a concavo-convex pattern is formed on the surface of the quartz glass substrate 1, the pattern is transferred by a photolithography method, and then wet etching is performed using hydrofluoric acid (HF) which is an etching solution for the quartz glass. However, the mold resist film 3 formed as a mask during photolithography was peeled off (c), and it was difficult to form a precise uneven pattern (d). The reason why the mold resist film 3 is peeled off is that hydrofluoric acid permeates the interface between the quartz glass substrate 1 and the mold resist film 3 because the mold resist film 3 has low adhesion to the quartz glass substrate 1. ing.

Therefore, it is considered to prevent the peeling of the mold resist film 3 by shortening the etching time. However, if the etching time is shortened, the depth of the concavo-convex pattern becomes shallow, and the accuracy of pattern transfer deteriorates. This is because when the depth of the uneven pattern is shallow, the unevenness of the unevenness of the circuit resist film on the substrate after pressing is small and it is difficult to accurately obtain a convex circuit resist film pattern by etching. Is.

Therefore, an object of the present invention is to manufacture a pattern transfer mold capable of obtaining a deep and precise concave / convex pattern at low cost and at high speed by preventing unnecessary peeling of a mold resist film in a pattern transfer method using a concave / convex press. To provide a method.

[0007]

According to a method of manufacturing a pattern transfer mold according to claim 1 of the present invention, a pattern transfer mold having an uneven shape is pressed on a circuit resist film formed on a substrate. After that, in the method of manufacturing a pattern transfer mold used when pattern transfer is performed by etching the circuit resist film, after forming a thin film for an etching mask on the substrate surface of the pattern transfer mold, the mold resist film is formed. Then, after forming the pattern of the mold resist film by the photolithography method, a similar pattern is formed in the etching mask thin film by the etching method using the mold resist film as a mask, and the etching mask thin film on which the pattern is formed. Wet etching of the mold substrate using the mask as a mask, and then the mold resist film and etch And removing the thin film Gumasuku.

According to the present invention, the thin film for the etching mask is formed on the surface of the mold substrate, and the resist film for the mold is further formed thereon to form the concavo-convex pattern. Therefore, during wet etching of the mold substrate, The etching liquid does not soak between the mold substrate and the mold resist, and excessive etching of the mold substrate due to peeling of the mold resist film can be prevented.

According to a second aspect of the present invention, in the method of manufacturing a pattern transfer mold, the pattern transfer mold is made of glass containing quartz. Characterize.

According to the present invention, since the pattern transfer mold is made of glass containing quartz, the pattern transfer mold is transparent, and the alignment when pressing on the substrate can be easily and highly accurately performed.

In the method for manufacturing a pattern transfer mold according to claim 3 of the present invention, the thin film for an etching mask is made of chromium, aluminum, copper, silicon, or, based on the invention of claim 1 or 2. It is a compound of silicon.

These materials have high adhesiveness with quartz glass and a resist for molds, can easily form a thin film for an etching mask by a method such as vacuum deposition, sputtering and CVD, and a wet etching solution can be selected. It's easy.

In the method for manufacturing a pattern transfer mold according to claim 4 of the present invention, the film thickness of the etching mask thin film is 0.1, based on the invention described in claims 1 to 3.
It is characterized by being μm.

In the invention described in any one of claims 1 to 3, the thin film for the etching mask does not need to be thick, and about 0.1 μm is sufficient.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
Description will be given with reference to the drawings. FIG. 1 shows a manufacturing process of a pattern transfer mold in the present embodiment. As the mold substrate, a quartz glass substrate 1 having a 20 mm square and a thickness of 1 mm is used. Chromium (Cr) was vapor-deposited to a thickness of 0.1 μm on the surface of the quartz glass substrate 1 by a vacuum vapor deposition method to form an etching mask thin film 2 (a). The etching mask thin film 2 is not limited to chromium, but in order to obtain etching selectivity with respect to the quartz glass substrate 1 and the mold resist film 3,
Any material may be used as long as it has an etching solution different from those of these materials, and it is preferable that the material has high adhesion to the quartz glass substrate 1. For example, aluminum (Al), copper (C
u), silicon (Si), or a compound of silicon (for example, a silicon nitride film (Si ₃ N ₄ )) and the like.
Further, the method for forming the etching mask thin film 2 may be a method such as a sputtering method or a CVD method other than the vacuum vapor deposition method.

Next, pattern transfer is performed by photolithography (b). A photosensitive mold resist film 3 is applied to the surface of the etching mask thin film 2, and ultraviolet rays are irradiated through a photomask on which a circuit pattern is drawn.
The mold resist film 3 in the portion irradiated with ultraviolet rays is deteriorated or cured. In this way, after the mold resist film 3 has etching selectivity, the mold resist film 3 is dissolved and removed with a developing solution, and the circuit pattern is transferred.
In the present embodiment, the negative resist film 3 is formed of a negative photoresist (OMR-83; Tokyo Ohka Kogyo Co., Ltd.).
However, a general-purpose photoresist can also be applied.

After the pattern is transferred to the mold resist film 3 by the photolithography method, the etching mask thin film 2 is etched (c). In the present embodiment, since the etching mask thin film 2 is chromium, a diammonium cerium nitrate aqueous solution was used as an etching solution, and the exposed etching mask thin film 2 was removed by immersion for 60 seconds. The etching method for the etching mask thin film 2 may be a dry etching method depending on the material, but the wet etching method is preferable as in the present embodiment from the viewpoints of being inexpensive, easy, and having a high etching rate.

Then, the quartz glass substrate 1 is wet-etched (d). BHF (buffered hydrofluoric acid) was used as an etching solution and immersed for 60 minutes.
The circuit pattern width of the present embodiment is about 1 mm, an immersion depth of about 6 μm was obtained by immersion for 60 minutes, and the mold resist film 3 was not peeled off. This is because the adhesion between the etching mask thin film 2 made of chromium and the quartz glass substrate 1 is high, and the etching mask thin film 2 is
This is because BHF does not soak into the interface between the quartz glass substrate 1 and the quartz glass substrate 1. As described above, if the circuit pattern width is about 1 mm, the etching depth is about 0.5 μm in 5 minutes, and the etching depth can be adjusted by adjusting the immersion time. Also, by adjusting the immersion time according to the width of the circuit pattern, it is possible to perform appropriate etching. Further, at the time of etching, in order to prevent the back surface side of the quartz glass substrate 1 from being etched, it is desirable to attach a protective mask such as a protective resin tape to the back surface side.

Next, the mold resist film 3 is immersed in a developing solution (resist stripping solution) to remove the mold resist film 3 (e). The mold resist film 3 may be removed by immersing in a developing solution or by ashing.

Further, the etching mask thin film 2 is removed by etching. Since chromium is used in the present embodiment, a diammonium cerium nitrate aqueous solution is used as the etching solution. In this way, the pattern transfer mold 10 is manufactured. Here, the etching mask thin film 2 can be used as a concavo-convex pattern without being peeled off, but when the pattern transfer is performed by a concavo-convex press, the etching mask thin film 2 easily adheres to the circuit resist film 5. Therefore, it may cause peeling of the circuit resist film 5, and it is preferable to peel off the etching mask thin film 2.

Using the pattern transfer mold 10 thus produced, pattern transfer was performed by a concave-convex press. The pattern transfer process is shown in FIG. A circuit resist film 5 having a film thickness of 7 μm is formed on the surface of the Si substrate 4 and fixed to the positioning stage 6 (a). Pattern transfer mold 1
By attaching 0 to the controller 7 and moving the positioning stage 6 while observing with the microscope 8,
The pattern is aligned (b). At this time, since the pattern transfer mold 10 is made of quartz glass, for example, only the peripheral portion of the pattern transfer mold 10 is held by the controller 7 and the pattern transfer mold 10 is held from the back surface (upper side in the figure) side. If the position of the Si substrate 4 is observed by the microscope 8, the position of the microscope 8 can be accurately adjusted. In the present embodiment,
The pattern could be transferred with the positioning accuracy within 0.5 μm, which is the operation accuracy of the positioning stage 6. After that, the controller 7 is lowered and the pattern transfer mold 1
0 is a predetermined pressure and the circuit resist film 5 on the Si substrate 4
To press (c). As a result, a convex pattern having a height of 6 μm was formed on the circuit resist film 5 (d). afterwards,
The circuit resist film 5 was irradiated with ultraviolet rays and etched to form a convex pattern having a height of 5 μm on the Si substrate 4 (e).

As a comparative example, a pattern transfer mold was manufactured by a conventional method. The pattern transfer mold of the comparative example was manufactured under the same conditions as the pattern transfer mold 10 according to the present embodiment, except that the etching mask thin film 2 made of chromium was not formed. However, when the quartz glass was etched using BHF (buffered hydrofluoric acid), the mold resist film 3 was peeled off by immersion for 5 minutes, and the etching depth was about 0.5 μm. After that, when pattern transfer was performed by a concavo-convex press under the same conditions as in the present embodiment, the height of the convex pattern immediately after pressing was only about 0.5 μm. Variation and the Si substrate 4
Also, since the ratio of the surface processing accuracy of the circuit resist film 5 to the height (0.5 μm) of the convex pattern was large, it was impossible to accurately perform the convex pattern formation by subsequent ultraviolet irradiation and etching. . On the other hand, according to the pattern transfer mold 10 of the present embodiment, since the height of the convex pattern is 5 μm, the influence of such variations is small.

In the present embodiment, the material of the substrate to be concave-convex pressed is Si, but the present invention is not limited to this, and
It can also be applied to pattern transfer to a glass substrate, a ceramic substrate, a PMMA resin substrate, or the like.

[0024]

As described above, according to the present invention, when the pattern transfer mold used in the pattern transfer by the concave-convex press is prepared, the etching mask thin film is formed on the surface of the mold substrate and the mold is formed on the surface of the etching mask thin film. After forming the resist film for mold, the pattern of the resist film for mold is formed by the photolithography method and the wet etching method, and then the same pattern as the resist film for mold is formed on the thin film for the etching mask using the resist film for mold as a mask. The wet etching of the mold substrate is performed using the etching mask thin film on which the pattern is formed as a mask, and thereafter,
The mold resist film and the etching mask thin film are removed by a wet etching method. As a result, even during wet etching of the mold substrate, it is possible to prevent the mold substrate from being excessively etched at the interface with the mold resist film and being etched to a portion that does not need to be etched as in the conventional case. It this is,
This is because the etching mask thin film has high adhesion to the mold substrate, so that the etching liquid does not soak into the interface between the mold substrate and the etching mask thin film. As a result, it is possible to sufficiently secure the immersion time for wet etching of the mold substrate, and it is possible to obtain a deep and precise uneven pattern. Further, since the wet etching method can be used, the pattern transfer mold can be manufactured at a lower cost and higher speed than the conventional dry etching method. Furthermore, by making the pattern transfer mold with glass mixed with quartz, in the pattern transfer method by the concave-convex press suitable for mass production, compared with the pattern transfer method of the circuit resist by the conventional photolithography method,
Positioning can be performed easily and accurately.

[0025]

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a pattern transfer mold according to the present embodiment.

FIG. 2 is a diagram showing a process of pattern transfer in the present embodiment.

FIG. 3 is a diagram showing a process of manufacturing a conventional pattern transfer mold using single crystal Si.

FIG. 4 is a diagram showing a manufacturing process of a conventional pattern transfer mold using quartz glass.

[Explanation of symbols] 1 Quartz glass substrate 2 Thin film for etching mask 3 type resist film 4 Si substrate 5 Circuit resist film 6 Positioning stage 7 controller 8 microscope 10 Pattern transfer mold (this embodiment)

Continued front page    (72) Inventor Hideki Matsumura             93, 43, Minami, 43, Kanazawa, Ishikawa Prefecture (72) Inventor Kenichiro Kida             3 Bomaru-cho, Matsuto City, Ishikawa Prefecture (72) Inventor Taruya             128-8 Awazakicho, Kanazawa, Ishikawa Prefecture F-term (reference) 2H096 AA30 BA01 CA05 EA02 GA02                       HA17 JA04 LA01                 2H097 FA09 FA10 LA01 LA16 LA20                 5E339 AB05 CE12 CE18 CG04                 5E343 AA02 AA22 CC61 ER11 GG11                 5F046 AA25 AA28

Claims (4)

[Claims] 1. A pattern transfer for use when pattern transfer is performed by pressing a pattern transfer mold having an uneven shape on a circuit resist film formed on a substrate and then etching the circuit resist film. In the mold manufacturing method, after forming a thin film for an etching mask on the surface of a pattern transfer mold substrate, a mold resist film is formed, and the pattern of the mold resist film is formed by a photolithography method. A similar pattern is formed in the etching mask thin film by an etching method using the film as a mask, and the mold substrate is wet-etched using the etching mask thin film on which the pattern is formed as a mask, and then the mold resist film and etching are performed. Manufacture of a pattern transfer mold characterized by removing a mask thin film Law. 2. The pattern transfer mold is made of glass mixed with quartz.
A method for producing the pattern transfer mold described. 3. The method for manufacturing a pattern transfer mold according to claim 1, wherein the etching mask thin film is a compound of chromium, aluminum, copper, silicon, or silicon. 4. The film thickness of the etching mask thin film is:
The pattern transfer mold according to claim 1, wherein the pattern transfer mold has a thickness of 0.1 μm.