JP3875356B2 - Transfer mask substrate and transfer mask manufacturing method using the substrate - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a transfer mask substrate or the like used for manufacturing a transfer mask having a transmission part of the mask as an opening.
[0002]
[Prior art]
[0003]
In recent years, in electron beam lithography in which pattern exposure is performed using an electron beam, a drawing method called partial batch exposure (sometimes called block exposure or cell projection exposure) has been proposed, and the drawing time is short and mass production is possible. Therefore, the next generation LSI technology has emerged rapidly and is in the limelight (Japanese Patent Laid-Open No. 60-81750, etc.).
[0004]
In this partial collective exposure, a transfer mask (stencil mask) in which various openings (through holes) having a pattern shape to be exposed are formed in a Si thin film portion having a thickness of several tens of microns is used. Molding is performed, and predetermined sections (blocks or cells) are partially exposed at once, exposure is repeated while selecting an opening shape, and partial patterns are joined to draw a desired pattern.
[0005]
This drawing method using partial batch exposure is extremely difficult for the drawing time that has been a problem in the direct drawing method (so-called one-stroke writing method) in which the exposure pattern is scanned with a thin beam spot of an electron beam already in practical use. This method has been devised to cope with long and low throughput, and can perform high-speed drawing as compared with the direct drawing method using a variable rectangle.
[0006]
Transfer masks used for such partial batch exposure and the like have been conventionally produced by various methods, but from the viewpoint of workability and strength, a silicon substrate (commercially available silicon wafer or the like) is preferably produced by processing. It is common.
Specifically, for example, as shown in FIG. 2, the back surface of the silicon substrate 31 is etched to form a support frame portion 32 and a thin film portion 33 supported by the support frame portion 32, and an opening is formed in the thin film portion 33. 34 is formed to produce the transfer mask 30. In this case, the back surface processing of the silicon substrate is generally performed by wet etching using an inorganic or organic alkaline aqueous solution, and the opening is generally formed by dry etching because high accuracy is required.
[0007]
In addition, since etching is performed from both the front and back surfaces of the substrate, it is common to use a substrate having an etching stop layer (etching stopper layer) at a predetermined depth of the substrate in consideration of processing stability. As a substrate having such an etching stopper layer, for example, an SOI (Silicon on Insulator) substrate having a structure in which two silicon substrates having different thicknesses are bonded together via a SiO2 layer, oxygen ions are highly applied to a silicon substrate or the like. A SIMOX (separation by implanted oxygen) substrate in which an oxide film is formed by implantation heat treatment at a concentration, a multilayer substrate in which a boron rich layer is formed as an etching stopper layer at a predetermined depth position of a silicon substrate, and the like are known.
[0008]
For the convenience of mounting the above-described transfer mask on an electron beam drawing apparatus for partial batch exposure, the mask size is about 5 mm to 50 mm, and the drawing mask is used in the drawing area of the drawing apparatus used in the manufacturing process of the transfer mask itself. Small compared. Therefore, in recent years, in the manufacturing process of the transfer mask itself, a large-sized substrate is used, and a plurality of transfer masks are patterned on the substrate at once and collectively processed to improve manufacturing efficiency. In this case, in order to separate and transfer each transfer mask from a single substrate, dicing is required.
[0009]
[Problems to be solved by the invention]
However, the conventional transfer mask manufacturing method described above has the following problems.
[0010]
First, it is difficult to shorten TAT (turn around time). TAT means a series of operations such as device pattern design, transfer mask prototyping, LSI chip prototyping, design specification change, and transfer mask fabrication. Although the stencil mask has entered the stage of practical use, the biggest problem is the short TAT. That is, the stencil mask is a so-called hybrid lithography in which a conventional photomask or the like is used for pattern transfer of 0.25 μm or less in the VLSI, and other pattern transfer is performed. If the manufacturing period of the stencil mask is longer than the manufacturing period, the supply of the stencil mask becomes a factor in determining the overall rate. In order to achieve a short TAT, it is indispensable to make the stencil mask manufacturing period equal to the manufacturing period of a photomask or the like.
Since the manufacture of a stencil mask requires formation of a thin film portion and an opening, it is difficult to manufacture a photomask or the like, and there are many manufacturing processes, and the rate of occurrence of defects is high, so it is difficult to shorten the manufacturing period.
[0011]
The present invention has been made in view of the above-described problems, and provides a transfer mask substrate and a transfer mask manufacturing method that can solve the conventional problems described above, can achieve a short TAT, and a short manufacturing time. With the goal.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a transfer mask substrate of the present invention is a transfer mask substrate used for manufacturing a transfer mask in which an opening is formed in a thin film portion supported by a support frame portion, and a predetermined position of the substrate. In this configuration, at least one alignment mark for alignment used for processing is previously provided on the substrate.
[0013]
Further, the transfer mask substrate of the present invention is a transfer mask substrate used for manufacturing a transfer mask in which an opening is formed in a thin film portion supported by a support frame portion, and a back surface recess is previously formed on the back surface of the substrate. In addition, a dry etching stopper layer is provided on the back surface side of the thin film portion.
[0014]
Furthermore, the transfer mask substrate of the present invention is the transfer mask substrate of the present invention,
The back surface recess is filled with one or more materials selected from a resin material, an adhesive, a paste material, and a low melting point metal material,
A configuration in which a flat plate is bonded to the back side of the transfer mask substrate via one or more materials selected from a resin material, an adhesive, a paste material, and a low melting point metal material,
The above flat plate is composed of one or more materials selected from silicon, carbon, metal, and glass,
A configuration in which a dry etching mask layer for forming an opening pattern is provided on the surface of the transfer mask substrate in advance;
A configuration in which a slit for cutting for separating a plurality of transfer masks to be formed on a single substrate is formed on the back side of the transfer mask substrate in advance.
The configuration in which the slit for cutting is filled with one or more materials selected from a resin material, an adhesive material, a paste material, and a low melting point metal material, or
At least one alignment mark for alignment used for processing a predetermined position on the surface of the transfer mask substrate is provided on the substrate in advance.
[0015]
In addition, the transfer mask is manufactured using the transfer mask manufacturing method of the present invention and the transfer mask substrate of the present invention.
[0016]
[Action]
In the present invention, by finishing the processing of the back surface recess (back etching) and the like in advance, the production period of the transfer mask after obtaining the opening pattern design can be easily shortened, and a short TAT can be realized.
In addition, it is possible to avoid the occurrence of defects due to these processes by digesting difficult processes such as forming a thin film portion in advance. When a defect occurs, cost reduction and efficiency improvement can be achieved by not performing opening formation.
Furthermore, since the transfer mask substrate of the present invention is structurally stable, defects such as damage in the transfer mask manufacturing process do not occur, and the transfer mask can be manufactured with a high yield.
[0017]
Hereinafter, the present invention will be described in detail.
[0018]
First, the first invention will be described.
[0019]
The transfer mask substrate of the first invention is characterized in that at least one alignment mark for alignment used for processing a predetermined position of the substrate is previously provided on the substrate.
Thus, by providing the alignment mark on the substrate in advance, the alignment mark forming step can be omitted, and the TAT can be shortened accordingly.
[0020]
Here, the alignment mark for alignment is used as an alignment reference point for performing etching processing or the like on a predetermined position of the substrate when manufacturing the transfer mask by processing the front and back surfaces of the transfer mask substrate. It is what is done. Specifically, for example, the resist layer and the etching mask layer are exposed using an electron beam drawing apparatus and a stepper, and are used for the purpose of strictly determining an exposure position when patterning them.
[0021]
The alignment mark for alignment may be formed on the transfer mask substrate, and the formation position, shape, form, number, etc. thereof are not particularly limited. In the case where a plurality of transfer masks are manufactured collectively on a single substrate, it is preferable that the formation position, shape, form, and number be suitable for the transfer mask.
[0022]
The alignment mark for alignment may be formed directly on the surface of a transfer mask substrate, such as a silicon substrate, by etching (etching), or the front and back surfaces of the substrate for processing the transfer mask substrate. The etching mask layer may be formed by etching, may be formed by deposition on the etching mask layer, or may be formed by laser processing or the like.
[0023]
The formation position of the alignment mark is not particularly limited, but normally, avoiding the thin film portion (corresponding to the opening formation area), a plurality of transfer masks are collectively placed on a transfer mask other than the thin film portion or on a single substrate. In this case, it is preferable to form the transfer mask in a region other than the formation region of each transfer mask.
In this case, the alignment mark is formed at a position where the positional relationship between the thin film portion forming region and the back surface recessed portion forming region becomes clear in terms of arrangement design (layout). The position is, for example, the intersection of the peripheral portion of the substrate or the transfer mask portion that is adjacent on all sides.
The alignment mark can be formed on both the front and back surfaces of the substrate because both surfaces can be normally aligned by a mirror, and may be formed on both the front and back surfaces. Usually, it forms in the surface side (opening pattern formation surface) of a board | substrate.
[0024]
Next, the second invention will be described.
[0025]
The transfer mask substrate of the second invention is characterized in that a back surface recess (window portion) is formed in advance on the back surface of the substrate, and a dry etching stopper layer is provided on the back surface side of the thin film portion.
[0026]
Thus, by forming the back surface concave portion in advance (processing the back surface concave portion in advance), the production period of the transfer mask itself can be shortened. In addition, by shortening the production period of the transfer mask itself, a series of operations (TAT: turn-off) from device pattern design, transfer mask trial production, LSI chip trial production, design specification change, and transfer mask production The time spent on around time) can be greatly shortened. Furthermore, in the back surface recess processing step, a delicate thin film portion is formed which is very weak in strength, so that there are many occurrences of defects such as breakage due to the back surface recess processing step, regardless of the opening processing step. By performing the processing of the back surface concave portion in advance, it is possible to avoid the occurrence of defects due to the processing step of the back surface concave portion.
[0027]
Furthermore, in the second invention, since the dry etching stopper layer is provided on the back side of the thin film portion, the transfer mask manufacturing process can be stabilized. That is, the etching control is facilitated by the dry etching stopper layer in the opening processing step and the back surface recess processing step. In addition, it serves to protect the opening in the step of removing the filling material for the back surface recess described later.
[0028]
The dry etching stopper layer may be formed in advance in the middle layer portion of the substrate (such as an SOI substrate or a SIMOX substrate), or may be formed later on the back surface side of the thin film portion after the processing of the back surface recess. When it is formed later, a dry etching stopper layer may be used with a filling material for a back surface recess described later. As a dry etching stopper layer, for example, SiO₂, SOG, SiN and the like.
[0029]
Examples of the etching solution on the back surface of the substrate include an alkaline aqueous solution such as KOH and NaOH, an alkaline aqueous solution containing alcohol and the like, and an alkaline solution such as organic alkali in the case of a silicon substrate.
It is more preferable that the etching temperature is appropriately selected according to the material and the like.
Examples of the etching method include a dipping method.
[0030]
As a wet etching mask layer for protecting parts other than the part to be etched (for example, the substrate front side or the support frame part on the back side of the substrate) during the back side processing, SiO2, SiC, Si3N4, sialon (Si and Al Composite layers), inorganic layers such as SiON can be used. In addition, the wet etching mask layer includes a single metal such as tungsten, zirconium, nickel, chromium, and titanium, an alloy containing one or more of these metals, or at least one of these metals or alloys and oxygen, nitrogen, and carbon. A metal compound containing any of the above elements can also be used.
As a method for forming an inorganic wet etching mask layer such as a SiO2 layer, a sputtering method, a vapor deposition method, a thermal oxidation method, a CVD method, a method using SOG (spin-on-glass), photosensitive glass, photosensitive SOG, or the like. And the like. Examples of the method for forming the metal-based wet etching mask layer include thin film forming methods such as sputtering, vapor deposition, and CVD.
[0031]
In the transfer mask substrate of the second invention, the back surface recess (window portion) is preferably filled with a resin material, an adhesive material, a paste material, or a low melting point metal material.
In this way, by embedding the embedding material in the back surface recess, structural damage is prevented during the process performed after processing the back surface recess, and vacuum chucking and dry etching methods in the resist processing step on the substrate surface side, etc. Therefore, it is possible to prevent bending (warping) of the thin film portion due to a pressure difference generated between the front and back surfaces of the substrate when the opening pattern is formed in the thin film portion. In addition, it is possible to prevent the heat insulation of the concave portion on the back surface of the substrate and to improve the thermal conductivity, and to form a straight and clean opening in the silicon thin film portion, thereby making it possible to produce a transfer mask with high practicality.
[0032]
The embedding material is less susceptible to stress on the thin film part (small shrinkage rate and linear expansion coefficient, etc.), easy to fill (fill) and remove, and has excellent thermal conductivity and conductive removability (cleanability). A material having characteristics such as excellent properties is preferable. Examples of such materials include resin materials such as acrylic resin and vinyl resin, photo-curing type and room temperature curing type adhesives, paste materials such as thermoplastic paste and silver paste, and low melting point metal materials such as solder. Can be mentioned. As a material having good thermal conductivity, a metal selected from Sn, In, Zn, Sb, Pb, Bi, Ag, or a low melting point metal such as an alloy containing these metals, or a polymer material having good thermal conductivity, etc. Is mentioned.
These embedding materials can be degassed by baking or the like in order to prevent gas generation during electron beam exposure. In addition, a metal filler or the like can be added to the embedding material in order to impart thermal conductivity or conductivity.
As the characteristics of the embedded filling material, it is necessary that no gas is generated in a vacuum (under reduced pressure) and that no gas is generated in the same manner at a temperature increase of about 200 ° C. If the gas is generated, it may adversely affect the formation of the opening pattern (resist formation, dry etching) and may cause contamination of the apparatus, thereby reducing the processing stability.
[0033]
As a filling method, a method of filling (embedding) a resin material or an adhesive into a substrate back surface recess, a method of pouring a low melting point metal into a substrate back surface recess in a molten state, and filling a substrate back surface recess with a low melting point metal, an organic metal state ( In a colloid or gel state), it is poured into the recesses on the back surface of the substrate and heat filled to fill, or a material in which ultrafine metal particles are dispersed (such as silver paste) is poured into the recesses on the back surface of the substrate to be debindered and filled. The method etc. are mentioned.
In addition, it is preferable to embed the embedding material in a back surface recess that is flush with the back surface of the substrate.
The method for removing the embedded low melting point metal is not particularly limited, but can be easily removed using a solution that does not corrode the silicon substrate, such as hot concentrated sulfuric acid or an alkaline aqueous solution.
[0034]
In the transfer mask substrate of the second invention, a flat plate may be bonded to the back side of the transfer mask substrate via one or more materials selected from a resin material, a paste material, and an adhesive material.
This is because even if the embedded material is embedded in the recess on the back surface, irregularities are likely to occur on the surface of the embedded material due to shrinkage, tension, etc., and exposure and dry etching are performed for processing the thin film portion by this unevenness. In order to avoid such a situation, the substrate is inclined on the holder (stage, chuck) of these apparatuses or cannot be fixed by suction due to a gap in the back plane of the substrate. Further, by sticking a flat plate to the back side of the transfer mask substrate and fixing the transfer mask substrate on the flat plate, it is possible to more completely prevent damages and the like that occur during subsequent processes and during handling.
[0035]
The same material as the embedding material described above can be used for bonding the flat plates. In this case, the embedding material and the flat plate bonding agent may be the same material or may be different materials. The flat plate bonding agent may have a laminated structure made of the same or different materials.
[0036]
The flat plate preferably has excellent thermal conductivity, flatness, processing accuracy, and excellent removability when the flat plate is removed by dissolution. Examples of such a flat plate material include one or more materials selected from silicon, carbon, metal, and glass.
[0037]
In the transfer mask substrates of the first and second inventions, a dry etching mask layer for forming an opening pattern in advance may be provided on the surface of the transfer mask substrate.
This is because TAT can be shortened by performing all possible processes in advance before the opening pattern is formed. In other words, compared to the case where these steps are performed after obtaining the opening pattern design, a transfer mask can be produced simply by forming an opening pattern and removing unnecessary layers, etc. As a result, TAT can be shortened.
From the same viewpoint, a resist layer may be provided in advance on the dry etching mask layer as necessary.
[0038]
Examples of dry etching mask layers include inorganic layers such as silicon oxide (SiO2), SiC, Si3N4, sialon (a composite mixture of Si and Al), SiON, metals such as titanium, chromium, tungsten, zirconium, nickel, and these metals. Or a metal layer such as a metal compound of these metals or alloys with oxygen, nitrogen, carbon, or the like, or an organic layer such as a resist or a photosensitive film. As a method for forming an inorganic dry etching mask layer such as a SiO2 layer, a method using sputtering, vapor deposition, thermal oxidation, CVD, SOG (spin-on-glass), photosensitive glass, photosensitive SOG, or the like. And the like. Examples of the method for forming the metal-based dry etching mask layer include thin film forming methods such as sputtering, vapor deposition, and CVD.
[0039]
In the transfer mask substrates of the first and second inventions, if necessary, the transfer masks formed in multiple arrays on a single substrate are separated in advance on the back side and / or the front side of the transfer mask substrate. It is preferable to form a slit for cutting.
This is because, when it is necessary to form slits for cutting to separate the transfer masks formed in a plurality on a single substrate, this step is completed in advance to shorten TAT. Because.
[0040]
The slit for cutting is preferably formed on the back side of the transfer mask substrate. This is because a slit for cutting can be formed simultaneously with the processing of the recess on the back surface, and the cutting can be performed easily and stably. That is, since groove processing for separating each transfer mask from only one direction is performed, there is no problem of misalignment that occurs when groove processing is performed from both the front and back surfaces. In addition, a structurally weak portion caused by a positional shift is not formed in the entire transfer mask. Furthermore, a transfer mask having a highly accurate outer diameter and outer peripheral side wall can be manufactured by a simple process.
[0041]
The shape of the slit for cutting is not particularly limited, but by making it a V-shaped groove having a shallow depth, breakage or the like in the process after forming the slit can be avoided.
[0042]
In the present invention, the step of forming the slit for cutting on the back surface of the substrate by wet etching and the step of forming the recess on the back surface of the transfer mask by wet etching to form the support frame portion and the thin film portion are the same etching solution. Can be done at the same time. Thereby, the increase in a manufacturing process can be avoided. Although these processes can be performed separately, a wet etching mask layer is formed on the back surface of the substrate, and when this is patterned, a pattern for processing slits for cutting and recesses on the back surface is simultaneously formed, Manufacturing efficiency is better when simultaneous processing is performed with the same etching solution.
[0043]
In order to prevent the transfer mask from being dispersed or damaged when the transfer mask is divided by the slit for cutting formed on the back side of the transfer mask substrate, a constraining film may be provided on the front side of the transfer mask substrate. it can. Examples of the material for such a constraining film include a resin containing at least one resin selected from fluorine-based, ethylene-based, propylene-based, butadiene-based, silicon-based, and styrene-based materials, rubber obtained by solidifying these resins, and photosensitive material. Examples thereof include an inorganic resin or an inorganic film forming material (for example, SOG, SiN). Removal of the constraining film can be easily performed with an organic solvent or the like.
[0044]
In the present invention, cutting can be performed with the embedding material embedded in the back surface recess. Further, in the present invention, damage to the transfer mask can be avoided by back surface embedding or flat plate fixing, so that a mechanical cutting / separation method using a dicing saw or a laser beam can be used without forming a slit for cutting.
[0045]
Next, the manufacturing method of the transfer mask of this invention is demonstrated.
In the transfer mask manufacturing method of the present invention, the transfer mask is manufactured using the transfer mask substrate of the present invention described above.
[0046]
In order to pattern the dry etching mask layer in the above-described transfer mask substrate of the present invention into the same shape as the desired opening shape, for example, a resist is applied on the etching mask layer, and a resist pattern is formed by exposure and development. The etching mask layer may be etched using this resist pattern as a mask. The resist process can be omitted by applying photosensitive glass on a silicon substrate and using the photosensitive glass as it is as an etching mask material.
[0047]
Regarding the opening processing on the substrate surface side, it is preferable to process the opening pattern portion with high accuracy by dry etching in consideration of the processing accuracy of the opening, but a method of forming the opening pattern portion by electric discharge processing (Japanese Patent Laid-Open No. 5-217876). ) Etc. can also be used.
[0048]
The etching gas used for dry etching is not particularly limited. For example, examples of the etching gas for the dry etching mask layer (SiO2 etc.) include fluorocarbon gases (CF4, C2F6, CHF3 etc.). HBr gas, Cl2 / O2 mixed gas, SiCl4 / N2 mixed gas, and the like.
[0049]
The unnecessary layer that has finished its role is removed at an appropriate stage in the manufacturing process.
[0050]
In the method of the present invention, a metal layer can be formed on the surface of the transfer mask produced above.
This is because the transfer mask made of silicon alone has a silicon thin film portion in which an opening is formed as it is, which has poor durability against an electron beam. Therefore, tantalum (Ta), tungsten (W), molybdenum ( This is because a metal layer such as Mo), gold (Au), platinum (Pt), silver (Ag), iridium (Ir) palladium (Pd) is formed to improve the durability of the mask during electron beam irradiation. In addition, these metals are good conductors and are excellent in electronic conductivity and thermal conductivity, and thus contribute to the effect of preventing beam displacement due to charging (charge-up) and the effect of preventing thermal distortion of the mask due to heat generation. Furthermore, since these metals have excellent shielding properties against electron beams and act as energy absorbers, it is possible to make the silicon thin film portion thin, thus improving the opening accuracy and affecting the electron beams by the opening sidewalls. Can be reduced.
Examples of the metal layer forming method include thin film forming methods such as sputtering, vacuum evaporation, ion beam evaporation, CVD, ion plating, electrodeposition, and plating.
[0051]
Furthermore, in the method of the present invention, a metal layer is first formed on the above-described transfer mask substrate of the present invention, and the metal layer and the silicon thin film portion can be continuously dry-etched to form an opening. .
In this way, when the metal layer and the silicon thin film portion are continuously dry-etched to form the opening, the opening including the metal layer can be formed in a single process and in a short time by the continuous dry etching. An accurate opening can be easily formed. In addition, a metal layer can be formed at a time on a plurality of transfer masks.
Examples of the dry etching gas for the metal conductive layer include fluorocarbon-based gas (SF6 / O2 mixed gas, SF6 / Cl2 mixed gas, CF4 / O2 mixed gas, CBrF3 gas, etc.). Further, the metal conductive layer and the silicon substrate can be continuously etched with the same etching gas using SF6 gas or the like.
[0052]
As the substrate material, Si, Mo, Al, Au, Cu, etc. can be used. However, from the viewpoint of chemical resistance, processing conditions, dimensional accuracy, etc., silicon substrate, SOI substrate, oxygen ions are high in silicon substrate, etc. It is preferable to use a SIMOX (separation by implanted oxygen) substrate or the like in which an oxide film is formed by implantation heat treatment at a concentration. When a silicon substrate doped with phosphorus or boron is used, the electron conductivity of the silicon substrate can be improved.
[0053]
【Example】
Hereinafter, the present invention will be described in more detail based on examples.
[0054]
Example 1
Fabrication of transfer mask substrate
FIG. 1 is a partial cross-sectional view showing an example of a procedure for producing a transfer mask substrate of the present invention.
[0055]
As shown in FIG. 1, an SOI substrate 10 (FIG. 1A) having a multilayer structure of Si (20 .mu.m) 1 / SiO2 (2 .mu.m) 2 / Si (500 .mu.m) 3) is used. ), A 1 μm thick SiO 2 layer 4 was formed by CVD, and then alignment marks 5 were formed by etching at two predetermined positions on the surface side SiO 2 layer (FIG. 1B). The SiO2 layer on the back side of the substrate was formed at the same time as the formation of the SiO2 layer on the front side of the substrate in order to prevent the generation of scratches during the process.
[0056]
Next, after an Si3N4 layer (not shown) is formed on the entire surface of the SOI substrate by CVD, predetermined patterning is performed on the Si3N4 layer and the SiO2 layer at predetermined positions on the back side of the substrate positioned with the alignment mark 5 on the front side Using the patterned Si3N4 layer as a mask, backside recesses 6 and slits 7 for cutting were formed at predetermined positions on the backside of the substrate by wet etching using KOH (FIG. 1 (c)). In addition, in order to obtain a several transfer mask simultaneously, the back surface recessed part 6 and the slit 7 for cutting were formed in multiple numbers according to it.
[0057]
Subsequently, the substrate obtained above is washed and dried, and then the back surface recess 6 and the slit 7 for cutting are filled with Ag-based low-temperature curable paste as the embedding material 8 so as not to enter air bubbles, and dried at room temperature. After that, a curing treatment was performed at a maximum of 200 ° C. (FIG. 1D).
[0058]
Finally, a quartz substrate 11 was bonded to the back side of the substrate obtained above via a photocurable adhesive 9 (FIG. 1 (e)). At this time, a mercury lamp was used for curing the photocurable adhesive 9, and baking was performed in a vacuum of 200 ° C. as a degassing process.
Through the above steps, a partially processed transfer mask substrate 20 was obtained.
[0059]
Production of transfer mask
A resist layer was formed on the upper surface side of the transfer mask substrate obtained above, and this was patterned by an electron beam exposure method and a dry etching method.
[0060]
Next, using the patterned resist layer as a mask, the dry etching mask layer 4 (SiO2 layer) is patterned by the dry etching method to remove the resist, and then transferred by the dry etching method using the patterned dry etching mask layer as a mask. An opening pattern was formed in the thin film portion of the mask substrate.
[0061]
Subsequently, after removing the unnecessary SiO 2 layer, the filling material, and the quartz substrate, metal layers were formed on both surfaces of the transfer mask substrate.
[0062]
Finally, the transfer mask was obtained by dividing into each transfer mask using the cutting slit as a base point.
[0063]
Since the transfer mask substrate of the present invention is structurally stable, no defects such as breakage occurred in the transfer mask manufacturing process. In addition, the stability of the entire transfer mask manufacturing process was significantly improved.
[0064]
Further, by using the transfer mask substrate of the present invention as described above, the transfer mask production period after obtaining the opening pattern design can be easily shortened. In particular, it took about 3 weeks to obtain a transfer mask by performing all the steps after obtaining an opening pattern design. However, by using the transfer mask substrate of the present invention, it takes about 3 days. The transfer mask could be manufactured in time, and TAT was shortened.
[0065]
Furthermore, since a plurality of transfer masks having different opening pattern designs can be manufactured at once, TAT can be further shortened.
[0066]
Example 2
A transfer mask was obtained in the same manner as in Example 1 except that no slit for cutting was formed and one transfer mask was formed from the transfer mask substrate.
[0067]
Example 3
A transfer mask was formed in the same manner as in Example 1 except that the SOI substrate was not used, a back surface recess was formed on the back surface of the silicon substrate, and then SOG was applied to the back surface side of the thin film portion to form a dry etching stopper layer. Obtained.
In this case, since bare silicon is used, the manufacturing cost is lower than when an SOI substrate is used.
[0068]
Example 4
A transfer mask was produced in the same manner as in Examples 1 to 3 except that a metal layer was formed on the substrate surface in Examples 1 to 3 and the opening including the metal layer was formed by continuous dry etching. did.
The obtained transfer mask had a highly accurate opening compared with the case where the metal layer was coated after the opening was formed.
[0069]
Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the above embodiments.
[0070]
For example, the embedding material and the adhesive material may be the same material and may be continuously integrated.
Moreover, the material and formation method of the etching mask layer are not particularly limited, and the etching mask layers on the front surface side and the back surface side may be formed separately.
Furthermore, after forming the thin film portion from the surface side, an alignment mark may be formed on the surface side where the position is specified.
[0071]
The transfer mask of the present invention can be used as an electron beam exposure mask, an ion beam exposure mask, an X-ray exposure mask, and the like.
[0072]
【The invention's effect】
As described above, according to the transfer mask substrate and the transfer mask manufacturing method of the present invention, the transfer mask manufacturing period after obtaining the opening pattern design can be easily shortened, and a short TAT can be realized.
[0073]
In addition, the process stability is high, and the manufacturing cost can be reduced with a high yield.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view illustrating an example of a manufacturing procedure of a transfer mask substrate of the present invention.
FIG. 2 is a cross-sectional view for explaining a transfer mask.
[Explanation of symbols]
1 Si
2 SiO2 layer
3 Si
4 SiO2 layer
5 Alignment mark
6 Back recess
7 Slit for cutting
8 Embedding material
9 Adhesive
10 SOI substrate
11 Quartz substrate
20 Transfer mask substrate
30 Transfer mask
31 Silicon substrate
32 Support frame
33 Thin film part
34 Opening pattern

Claims (13)

A transfer mask substrate used for manufacturing a transfer mask in which an opening is formed in a thin film portion supported by a support frame portion,
Having at least one alignment mark on the substrate for alignment used for processing the opening pattern at a predetermined position of the substrate;
On the back side of the substrate, a back surface recess is formed in advance at a position positioned with the alignment mark ,
On the back side of the substrate, a slit for cutting is formed for separating each transfer mask formed on a single substrate, and the slit for cutting is on the back side of the substrate, and A transfer mask substrate provided at a position facing an alignment mark .   The transfer mask substrate according to claim 1, further comprising a dry etching stopper layer on a back surface side of the thin film portion.   The transfer mask substrate according to claim 1, wherein the back surface recess is filled with one or more materials selected from a resin material, an adhesive material, a paste material, and a low melting point metal material.   A flat plate is bonded to the back side of the transfer mask substrate according to any one of claims 1 to 3 through one or more materials selected from a resin material, an adhesive material, a paste material, and a low melting point metal material. The transfer mask substrate according to any one of claims 1 to 3.   5. The transfer mask substrate according to claim 4, wherein the flat plate is made of one or more materials selected from silicon, carbon, metal, and glass.   6. The transfer according to any one of claims 1 to 5, wherein a dry etching mask layer for forming an opening pattern is provided in advance on the surface of the transfer mask substrate according to any one of claims 1 to 5. Mask substrate.   The transfer mask substrate according to claim 6, wherein the alignment mark is provided on the dry etching mask layer. 2. The transfer mask substrate according to claim 1, wherein the cutting slit is filled with one or more materials selected from a resin material, an adhesive material, a paste material, and a low melting point metal material. In the method of manufacturing a transfer mask having an opening pattern based on a desired device pattern in the thin film portion supported by the support frame portion,
Forming an alignment mark for alignment used for processing a predetermined position of the substrate;
Forming a back surface recess at a position positioned with the alignment mark on the back surface side of the substrate, and forming a structure in which the thin film is supported on the support frame;
Before the opening pattern processing step, a slit for cutting to be separated into a plurality of transfer masks is formed on the back side of the substrate at a position facing the alignment mark on the back side of the substrate. And a process of
Then, based on a desired device pattern, a step of processing an opening pattern at a position positioned with the alignment mark,
A method for producing a transfer mask, comprising: The method for manufacturing a transfer mask according to claim 9 , further comprising a dry etching stopper layer on a back surface side of the thin film portion. Before processing steps of the opening pattern, the back surface recess, a resin material, adhesive, paste material, according to claim 9 or 10, characterized in that filling with one or more materials selected from among the low melting point metal material The manufacturing method of the transfer mask as described in 2. The method for manufacturing a transfer mask according to any one of claims 9 to 12 , wherein a dry etching mask layer for forming an opening pattern is provided on the surface of the transfer mask substrate in advance. 13. The method of manufacturing a transfer mask according to claim 12 , wherein the alignment mark is provided on the dry etching mask layer.

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