JP2008063155A - Method for manufacturing diamond structure and diamond structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a diamond structure, by which relatively deep grooves, holes and perforations can be formed in diamond with a good precision. <P>SOLUTION: A second layer 58 to fifth layer 64 included in a laminated body 54 are formed from a material having resistance to wet-etching to a first layer 56, and the fifth layer 64 is formed from a material having resistance to each dry-etching when dry etching is applied to each of the second layer 58 to fourth layer 62. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a diamond structure and a diamond structure.

Conventionally, a laser is mainly used to cut a diamond or to provide a diamond structure by providing a groove, a hole or a through hole in the diamond. In such a diamond processing method using a laser, (1) graphite powder generated by laser irradiation adheres to the processing surface, (2) the processing surface becomes graphite and becomes conductive, (3) the processing surface has (4) The processed surface is not processed vertically and becomes wedge-shaped and loses the effective use area (that is, a width of about 100 μm from a substrate having a width of about 1 mm and a thickness of about 100 μm). If a plurality of plates are cut out, nine plates can be cut out from this substrate if they can be cut perpendicular to the substrate surface with a cutting margin of about 10 μm, but the substrate surface does not cut perpendicularly to the substrate surface. On the other hand, for example, when cutting at 45 degrees, the cutting margin is about 100 μm, so only 5 plates are cut out.), Or (5) Processing accuracy of 10 μm or less ( In the case of, the actual size relative to the design size is assumed, and the design size is actually adjusted in consideration of the final size, but accuracy is generated due to variations in the reduction ratio (enlargement ratio). This accuracy is improved when the substrate is cut perpendicularly to the surface of the substrate). In order to solve such problems, a method of processing diamond using RIE (Reactive Ion Etching) as described in Non-Patent Document 1, Non-Patent Document 2 and Patent Document 1 below has been studied. Yes. When processing diamond using RIE or the like, a mask is patterned on the diamond, and the diamond is etched using the patterned mask. Thereby, the diamond structure along the shape of the patterned mask is formed. The mask material needs to have etching resistance to an oxygen atmosphere for processing diamond (resistance to a predetermined etching agent, the same applies hereinafter). As the etching resistance of the mask material is larger than that of diamond, deeper etching is possible.
NNEfremow, MWGeis, DCFlanders, GALincoln and NPEconomou: J.Vac.Sci.Technol.B3, p.416, (1985) Yoshiki Nishibayashi, Yutaka Ando, Koji Kobashi, Kiichi Meguro, Takahiro Imai, Takashi Hirao, Kenjiro Oura: New Diamond, Vol.17, No.3, p15 (2001) Japanese Patent Laid-Open No. 2005-135846

  For mask patterning, it is common to use a resist patterned by photolithography or electron beam exposure on the mask. Then, the mask is patterned using either dry etching or wet etching. The dry etching method is very effective because the resist patterning can be accurately transferred. However, the resist etching resistance is limited, and it is difficult to form a thick mask effective in forming deep grooves, holes, and through holes in diamond. A method of increasing the resist thickness to 1 μm or more is also conceivable. In this case, since electron beam drawing becomes difficult, patterning by photolithography is used. However, even if photolithography is used, since the resolution decreases as the resist thickness increases, the etching accuracy also decreases accordingly. On the other hand, in the case of wet etching, although the resist thickness is small, it has etching resistance, so the limitation on the mask thickness as in dry etching is eliminated. However, if wet etching is performed for a long time, the periphery of the portion to be etched is also etched, so that the etching accuracy is lowered. As described above, it is difficult to manufacture a diamond structure in which relatively deep grooves, holes, or through holes are formed with high precision, regardless of whether dry etching or wet etching is used. Accordingly, an object of the present invention is to provide a method for manufacturing a diamond structure in which relatively deep grooves, holes, and through holes can be accurately formed in diamond, and the diamond structure.

  The present invention relates to a method for manufacturing a diamond structure, a laminate forming step of forming a laminate comprising a plurality of layers on a diamond substrate by laminating a plurality of materials on the diamond substrate, and a mask pattern A resist forming step of forming a resist having a mask on the laminate, and the diamond substrate having the mask pattern by wet-etching the laminate using the resist for each layer of the laminate. A mask forming step of forming a mask for use in etching of the substrate, and a diamond substrate processing step of processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask. One of the plurality of layers is formed in the stacked body formation step of the plurality of layers. When there is one or a plurality of layers formed before the formation of the one layer, the mask forming step is made of a material having etching resistance to each wet etching performed for each of the one or more layers. And

  Therefore, when wet etching is performed on each of the plurality of layers constituting the stacked body, the etched layer has etching resistance against the subsequent wet etching, and thus is not easily etched during the subsequent wet etching. Therefore, it is possible to perform etching that can maintain the shape of the mask pattern even for a relatively thick laminate including a plurality of layers.

  Further, the present invention is a method for producing a diamond structure, wherein a laminated body forming step of forming a laminated body composed of a plurality of layers on the diamond substrate by laminating a plurality of materials on the diamond substrate; A resist forming step of forming a resist having a mask pattern on the stacked body, and dry-etching the stacked body using the resist for each layer constituting the stacked body, thereby having the mask pattern and A mask forming step of forming a mask for use in etching the diamond substrate, and a diamond substrate processing step of processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask. And the last layer formed in the stacked body formation step among the plurality of layers. Consists of a material having an etching resistance to the dry etching performed in the mask formation process for each of one or more layers other than the layer formed on the last of the plurality of layers, characterized in that.

  Therefore, when dry etching is performed on each of the plurality of layers constituting the stacked body, even if the resist formed in the resist formation process disappears by dry etching, the layer that was first dry-etched is not subjected to subsequent dry etching. And function as a resist. Therefore, it is possible to perform etching that can maintain the shape of the mask pattern even for a relatively thick laminate including a plurality of layers.

  Further, the present invention is a method for producing a diamond structure, wherein a laminated body forming step of forming a laminated body composed of a plurality of layers on the diamond substrate by laminating a plurality of materials on the diamond substrate; A resist forming step of forming a resist having a mask pattern on the laminate, and performing wet etching and dry etching of the laminate using the resist for each layer constituting the laminate, thereby providing the mask pattern. A mask forming step for forming a mask for use in etching the diamond substrate, and a diamond substrate processing step for processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask. And one of the plurality of layers is formed of the laminate. When the stacked body includes another layer that is formed before the formation of the one layer in the forming step and is wet-etched in the mask forming step, the plurality of layers are made of a material having etching resistance to the wet etching. Among the plurality of layers, the last layer formed in the stacked body forming step is other than the last formed layer and includes other layers that are dry-etched in the mask forming step It is characterized by comprising a material having etching resistance against the dry etching.

  Therefore, when wet etching and dry etching are performed on each of a plurality of layers constituting the laminated body, the etched layer has resistance to subsequent wet etching, so that it is difficult to be etched at the time of subsequent wet etching, and resist formation is performed. Even if the resist formed in the process disappears by dry etching, the layer dry-etched first functions as a resist for the subsequent dry etching. Therefore, it is possible to perform etching that can maintain the shape of the mask pattern even for a relatively thick laminate including a plurality of layers.

  Further, the present invention is a diamond structure comprising a diamond substrate including a groove or hole having a depth of 30 micrometers or more and 300 micrometers or less, wherein the width of the groove or the hole is 1/100 or more of the depth 1 The height difference of the unevenness representing the roughness of the side surface of the groove or the hole is 1/1000 or more and 1/10 or less of the depth.

  Further, the present invention is a diamond structure comprising a diamond substrate having a thickness of 30 micrometers or more and 3000 micrometers or less, wherein the unevenness representing the roughness of the side surface of the diamond substrate has a difference in thickness of the diamond substrate. It is characterized by being 1/1000 or more and 1/10 or less.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a diamond structure which can form a comparatively deep groove | channel, a hole, and a through-hole in a diamond with sufficient precision, and a diamond structure can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, if possible, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  First, a method for manufacturing a diamond structure when a mask pattern for a diamond substrate is formed using wet etching will be described. First, the concept of this manufacturing method using wet etching will be described. A diamond substrate is prepared (preparation process). Next, by laminating a plurality of materials on the diamond substrate, a laminate composed of a plurality of layers is formed on the diamond substrate (laminated body forming step). Next, a resist having a mask pattern is formed on the stacked body (resist forming step). Next, the layered product is wet etched using a resist for each layer constituting the layered product to form a mask having a mask pattern and used for etching the diamond substrate (mask forming step). Next, the diamond substrate is etched into a diamond structure by using a mask (diamond substrate processing step). If one or more layers of the plurality of layers are formed before the formation of the one layer in the stacked body formation step, the one or more layers are formed in the mask formation step. It consists of a material which has etching resistance with respect to each wet etching performed every time.

  This will be specifically described below. First, the diamond substrate 2 is prepared (preparation process). After the preparation step, a laminate 4 is formed on the diamond substrate 2 as shown in FIG. The stacked body 4 includes a first layer 6 and a second layer 8. The first layer 6 is formed on the diamond substrate 2, and the second layer 8 is formed on the first layer 6. The material of the first layer 6 can be Ti (titanium), and the material of the second layer 8 can be Mo (molybdenum) (laminated body forming step). After the laminated body forming step, a pattern (a dot pattern with a width of about 1 to 3 μm or a line pattern with a width of about 1 to 3 μm, the same applies hereinafter) is formed on the resist using photolithography (resist formation). Process). Here, the dot pattern means a simple shape (triangle, quadrangle, circle, or the like), but assumes a circular pattern. Further, not only one pattern but also a plurality of patterns may be arranged.

After the resist formation step, the second layer 8 made of Mo is wet-etched using aqua regia, which is the first etchant, using the resist 10 as a mask. In this case, the first layer 6 made of Ti has etching resistance against aqua regia. The first layer 6 becomes a second mask region 12 having a pattern substantially identical to the pattern of the resist 10 by this wet etching. Then, after the etching of the second layer 8 is completed, the first layer 6 made of Ti is wet-etched using BHF (buffered hydrofluoric acid) which is a second etching agent. In this case, the second layer 8 made of Mo has etching resistance to BHF. The second layer 8 becomes the first mask region 14 having a pattern substantially the same as the pattern of the second mask region 12 (pattern of the resist 10) by this wet etching. As described above, when the etching on the first layer 6 and the second layer 8 is completed, a mask 16 patterned with high accuracy and substantially the same shape as the pattern of the resist 10 is formed (see FIG. 1B). The mask 16 has a second mask region 12 and a first mask region 14. The first mask region 14 is formed on the diamond substrate 2, and the second mask region 12 is formed on the first mask region 14. ing. Since the first layer 6 is difficult to be etched while the second layer 8 is being etched, the width L2 of the end of the cross section of the mask 16 (the width of the end of the cross section of the second mask region 12) The width of each end of the cross section of the mask region 14 is the same as the width L1 of the cross section of the resist 10 (mask forming process). After the mask formation step, the diamond substrate 2 is etched using the mask 16 using a RIE apparatus in a plasma of CF ₄ / O ₂ = 1% (diamond substrate processing step).

  Here, with reference to FIG. 2, the reason why a highly accurate mask pattern is difficult in the case of a single layer will be described. As shown in FIG. 2A, a laminated body 18 made of one material (hereinafter referred to as a laminated body) is formed on the diamond substrate 2, and the laminated body 18 is formed on the laminated body 18. In the case where the stacked body 18 is wet-etched after the resist 10 is formed, the etching progresses greatly in the direction indicated by the symbol A in FIG. 2B as the thickness of the stacked body 18 increases. Therefore, the width L3 of the end portion of the cross section of the mask 20 formed by this etching is smaller than the width L2 of the mask 16 than the width L1 of the pattern of the resist 10 (width L3 <width L2). Therefore, when the single-layer laminate 18 made of one kind of material is used, high-precision patterning that is possible in the case of the mask 16 made of a plurality of layers becomes difficult.

The materials of the first layer 6 and the second layer 8 are not limited to Mo and Ti as long as they have different etching resistances. For example, the material of the first layer 6 and the second layer 8 may be the material shown in FIG. The material of the first layer 6 shown in FIG. 3A is Ti, SiO ₂ or W (tungsten), and the material of the second layer 8 is Mo or Au.

If the laminate is composed of three or more layers, patterning with higher accuracy becomes possible. In this case, the material of each layer constituting this laminate has different etching resistances. FIG. 1C shows a state in which a laminate 22 composed of three layers is formed on the diamond substrate 2. The three layers constituting the stacked body 22 are a first layer 24, a second layer 26, and a third layer 28. As shown in FIG. 3 (B), it can be a material of the first layer 24 and a-Si, the material of the second layer 26 and Ti or SiO _2, the material of the third layer 28 and Mo or Au . The first etchant for the third layer 28 is aqua regia, the second etchant for the second layer 26 is BHF, and the third etchant for the first layer 24 is KOH (potassium hydroxide). As shown in FIG. 1D, the laminate 22 becomes a mask 30 after wet etching on the laminate 22. The mask 30 has a first mask region 32, a second mask region 34, and a third mask region 36. The first mask region 32 is formed on the diamond substrate 2, the second mask region 34 is formed on the first mask region 32, and the third mask region 36 is formed on the second mask region 34. ing. The third layer 28 is difficult to be etched while the second layer 26 is being etched, and the second layer 26 is difficult to be etched while the first layer 24 is being etched. The width L4 (the width of the end portion of the cross section of the third mask region 36 is the same as the width of each end portion of the cross section of the first mask region 32 and the second mask region 34). And substantially the same.

  Next, a method for manufacturing a diamond structure when a mask pattern for a diamond substrate is formed using dry etching will be described. When a thick mask pattern is formed by dry etching, there is a difficulty that the resist disappears before the mask pattern is formed. Such a difficulty can be solved by simply increasing the thickness of the resist, but the accuracy of the pattern is reduced. Therefore, in order to obtain a thick mask using dry etching even if the resist 10 has a normal thickness (for example, about 200 nm to 500 nm), the stacked body is configured to have two or more layers, and the materials of the layers are different from each other. It shall have etching resistance.

  First, the concept of this manufacturing method using dry etching will be described. A diamond substrate is prepared (preparation process). Next, by laminating a plurality of materials on the diamond substrate, a laminate composed of a plurality of layers is formed on the diamond substrate (laminated body forming step). Next, a resist having a mask pattern is formed on the stacked body (resist forming step). Next, the laminate is dry-etched using a resist for each layer constituting the laminate, thereby forming a mask having a mask pattern and used for etching the diamond substrate (mask formation step). Next, this diamond substrate is processed into a diamond structure by etching the diamond substrate using a mask (diamond substrate processing step). Of the plurality of layers, the layer formed last in the stacked body formation step is the dry layer formed in the mask formation step for each of the plurality of layers other than the last layer formed. It is made of a material having etching resistance against etching.

This will be specifically described below. First, the diamond substrate 2 is prepared (preparation process). After the preparation step, a first layer made of Mo is formed on the diamond substrate 2, and a second layer made of Al is formed on the first layer (laminated body forming step). After the stacked body forming step, a resist 10 patterned with high accuracy is formed on the second layer (resist forming step). After the resist forming step, the second layer made of Al is dry-etched using a Cl ₂ gas, and after the etching on the second layer is completed, the first layer made of Mo is dried using an SF _6- based gas. Etch. Since Al, which is the material of the second layer, has an etching resistance to SF ₆ -based gas, the second layer functions as a resist when the first layer made of Mo is etched. For this reason, the resist 10 only needs to function at least during the etching of the second layer. Although the second layer is slightly reduced by the etching of the first layer, the etching of the first layer proceeds faster than the etching of the second layer, so that high-precision patterning of a thick mask can be performed using dry etching. . As a result, a mask having a large thickness in which Al and Mo are laminated with the same accuracy as the resist 10 (the width of the cross section of the resist 10 and the width of the end of the cross section of the mask are substantially the same size). It is formed (mask forming process). After the mask formation step, the diamond substrate 2 is etched using the mask obtained as described above using a RIE apparatus in a CF ₄ / O ₂ = 1% plasma (diamond substrate processing step). .

As shown in FIG. 3C, the material of the second layer may be Ti, and the material of the first layer may be W. Further, the material of the first layer may be SiO _2. When SiO ₂ is used, vertical processing to diamond is difficult with SiO ₂ alone, but it is effective because vertical processing becomes possible when used in combination with metal.

  In addition, the mask is not limited to the two-layer configuration as described above, and may have a three-layer configuration. In this case, the first layer is formed on the diamond substrate 2, the second layer is formed on the first layer, and the third layer is formed on the second layer. Then, a resist patterned with high accuracy is formed on the third layer. The material of the first layer may be any material that is difficult to be etched when etching the second layer and the third layer. That is, the material of the first layer has etching resistance to each etching agent for the second layer and the third layer. Each material of the first to third layers is shown in FIG. Moreover, even if the kind of gas is the same, the etching agent can be used when the etching ratio increases according to the etching conditions (gas composition, pressure, power, temperature, and etching method).

  Next, a method for manufacturing a diamond structure when a mask pattern for a diamond substrate is formed by using both wet etching and dry etching will be described. There are relatively few types of materials and etching agents that can be used in the case of only wet etching, but if dry etching is used in combination with wet etching, variations in the combination of materials and etching agents in the laminated body are widened.

  First, the concept of this manufacturing method using both wet etching and dry etching will be described. A diamond substrate is prepared (preparation process). Next, by laminating a plurality of materials on the diamond substrate, a laminate composed of a plurality of layers is formed on the diamond substrate (laminated body forming step). Next, a resist having a mask pattern is formed on the stacked body (resist forming step). Next, wet etching and dry etching of this laminated body are performed using a resist for each layer constituting the laminated body, thereby forming a mask having a mask pattern and used for etching a diamond substrate (mask formation). Process). Next, this diamond substrate is processed into a diamond structure by etching the diamond substrate using a mask (diamond substrate processing step). One layer of the plurality of layers is etched with respect to this wet etching when the layered body includes another layer that is formed before the formation of the one layer in the layered body forming step and is wet etched in the mask forming step. Of the plurality of layers, the last layer formed in the stack formation process is a layer other than the last layer formed in the plurality of layers and is dry-etched in the mask formation process. When other layers are included, they are made of a material having etching resistance against this dry etching.

This will be specifically described below. First, the diamond substrate 2 is prepared (preparation process). After the preparation step, a laminate 38 is formed on the diamond substrate 2 as shown in FIG. The stacked body 38 includes a first layer 40 formed on the diamond substrate 2, a second layer 42 formed on the first layer 40, and a third layer 44 formed on the second layer 42. . The material of the first layer 40 is Mo, the material of the second layer 42 is Ti, and the material of the third layer 44 is Au (stacked body forming step). After the laminated body forming step, the resist 10 patterned with high accuracy is formed on the laminated body 38. The resist 10 is formed on the third layer 44 (resist forming step). After the resist formation step, the third layer 44 made of Au is wet-etched using aqua regia. The second layer 42 made of Ti has etching resistance against aqua regia. After the etching of the third layer 44 is completed, the second layer 42 is dry etched using a Cl ₂ gas. Since the third layer 44 has an etching resistance to the Cl ₂ gas, the third layer 44 can function as a resist even after the resist 10 disappears, and the second layer 42 can be etched. After the etching of the second layer 42 is completed, the first layer 40 made of Mo is dry-etched using SF ₆ -based gas. Since the third layer 44 has etching resistance to SF ₆ -based gas, even after the resist 10 is extinguished, the third layer 44 exhibits the function of a resist, and the first layer 40 can be etched. After the above etching, the stacked body 38 becomes a mask 46 as shown in FIG. The mask 46 has a first mask region 48, a second mask region 50, and a third mask region 52. The first mask region 48 is formed on the diamond substrate 2, the second mask region 50 is formed on the first mask region 48, and the third mask region 52 is formed on the second mask region 50. (Mask forming process). After the mask formation step, the diamond substrate 2 is etched using the mask 46 using a RIE apparatus in a plasma of CF ₄ / O ₂ = 1% (diamond substrate processing step).

The material of the first layer 40 may be Mo, the material of the second layer 42 may be Au, and the material of the third layer 44 may be Ti. In this case, the third layer 44 made of Ti is dry-etched using a Cl ₂ gas, and the second layer 42 made of Au is wet-etched using aqua regia after completion of the etching on the third layer 44, After the etching of the layer 42 is completed, the first layer 40 made of Mo is dry-etched using a CF ₄ gas. Since the third layer 44 made of Ti has etching resistance against aqua regia and CF ₄ gas, the third layer 44 exhibits the function of the resist even after the resist 10 disappears, and the second layer 42 and the second layer 42 are formed. One layer 40 can be etched.

The material of the first layer 40 may be Au, the material of the second layer 42 may be Si, and the material of the third layer 44 may be Ti. In this case, the third layer 44 made of Ti is dry-etched using a Cl ₂ -based gas, and the second layer 42 made of Si is dry-etched using an SF _6- based gas after the etching of the third layer 44 is completed, After the etching of the second layer 42 is completed, the first layer 40 made of Au is wet-etched using aqua regia. Since the third layer 44 made of Ti has etching resistance against SF ₆ -based gas and aqua regia, the third layer 44 exhibits the function of the resist even after the resist 10 disappears, and the second layer 42 and the second layer 42 are formed. One layer 40 can be etched. As described above, when the first layer 40 and the second layer 42 are etched by the etchant having the etching resistance of the third layer 44, any one of the first layer 40 to the third layer 44 is performed by dry etching or wet etching. There is no restriction on the use of these layers. Furthermore, for example, when the third layer is etched, the first layer may be made of a material that is etched by an etching agent used for etching the third layer. This is because when the third layer is etched, if the second layer has etching resistance, the second layer serves as a protective film for the first layer, and the first layer is affected by the etching of the third layer. It is because it does not receive. Further, as shown in FIG. 4C, a laminate 54 of five layers may be formed on the diamond substrate 2.

The stacked body 54 includes a first layer 56, a second layer 58, a third layer 60, a fourth layer 62, and a fifth layer 64. The first layer 56 is formed on the diamond substrate 2, the second layer 58 is formed on the first layer 56, the third layer 60 is formed on the second layer 58, and the fourth layer 62 is formed on the third layer 60. The fifth layer 64 is formed on the fourth layer 62. The material of the first layer 56 is Al, the material of the second layer 58 is Mo, the material of the third layer 60 is SiO ₂ , the material of the fourth layer 62 is Ti, and the material of the fifth layer 64 is The material is Au. In this case, the fifth layer 64 made of Au is wet-etched using aqua regia, and the fourth layer 62 made of Ti is dry-etched using a Cl ₂ -based gas after the etching on the fifth layer 64 is completed. After the etching of the layer 62 is completed, the third layer 60 made of SiO ₂ is dry-etched using CF ₄ based gas, and after the etching of the third layer 60 is completed, the second layer 58 made of Mo is made using SF _6- based gas. After the etching for the second layer 58 is completed, the first layer 56 made of Al is dry-etched using a Cl ₂ gas. Since the fifth layer 64 made of Au has etching resistance to Cl ₂ gas, CF ₄ gas and SF ₆ gas, the fifth layer 64 exhibits the resist function even after the resist 10 disappears. Thus, the fourth layer 62 to the first layer 56 can be etched.

  After the etching, the stacked body 54 becomes a mask 66 as shown in FIG. The mask 66 has a first mask region 68, a second mask region 70, a third mask region 72, a fourth mask region 74, and a fifth mask region 76. The first mask region 68 is formed on the diamond substrate 2, the second mask region 70 is formed on the first mask region 68, and the third mask region 72 is formed on the second mask region 70. The fourth mask region 74 is formed on the third mask region 72, and the fifth mask region 76 is formed on the fourth mask region 74. In addition, when a laminated body is two layers, each material of a 1st layer and a 2nd layer may be what is shown in FIG.3 (E). In this case, FIG. 3E shows a first etching agent used when etching the second layer and a second etching agent used when etching the first layer.

  According to the embodiment described above, by forming a laminated body (for example, the laminated body 4) including two or more layers on the diamond substrate 2, patterning of a thick mask (for example, the mask 16) is high. It can be done accurately. And the etching tolerance of a mask is also improved. Moreover, even if the adhesiveness between the resist 10 and the laminated body (for example, the laminated body 4) is reduced by long-time etching, the adhesiveness between a plurality of layers constituting the laminated body can be maintained. For this reason, since these several layers can exhibit the function of a resist, the laminated body can be etched with high accuracy. As described above, since a mask having a large thickness (for example, the mask 16) can be formed on the diamond substrate 2 with high accuracy, the diamond substrate 2 can be etched with high accuracy and relatively deep. Further, if the above-described mask is used, the diamond substrate 2 can be cut efficiently by etching (with a small cutting allowance), so that a polycrystalline diamond chip having a 20 μm to 50 μm square can be cut out.

  Thereby, for example, an element in which the device is mounted on a 50 μm square (L5) on the diamond substrate 2 having a thickness of 30 μm or more and 300 μm or less can be separated. The height difference of the concavo-convex representing the roughness of the side surface (etched surface, hereinafter referred to as an etched surface) of this element can be realized to be 1/1000 or more and 1/10 or less of the thickness of this element (FIG. 5). (See the diamond structure 78 shown in (A)). Further, for example, the convex portion B1 having a height (L6) of about 10 μm (further 30 μm or more and 300 μm or less) and a width (L7) of about 1 μm (1/100 or more and 1/3 or less of the height L6) is a diamond. It can be formed on the substrate 2. The height difference of the unevenness representing the surface roughness (Ra) of the side surface (etched surface) of the convex portion B1 can be realized to be 1/1000 or more and 1/10 or less of the height of the convex portion B1 (FIG. 5B and FIG. (See the diamond structure 80 shown in FIG. 5C). Further, for example, the groove B2 having a depth (L8) of about 10 μm (further 30 μm or more and 300 μm or less) and a width (L9) of about 1 μm (1/100 or more and 1/3 or less of the depth L8) is a diamond substrate. 2 can be formed. The height difference of the unevenness representing the surface roughness of the etched surface of the groove B2 can be realized to be 1/1000 or more and 1/10 or less of the depth of the groove B2. (See the diamond structure 82 shown in FIGS. 5D and 5E). Further, for example, the through-hole B3 having a depth (L10) of about 10 μm (further 30 μm or more and 300 μm or less) and a width (L11) of about 1 μm (1/100 or more and 1/3 or less of the depth L10) is diamond. It can be formed on the substrate 2. The height difference of the unevenness representing the surface roughness of the etched surface of the through hole B3 can be realized to be 1/1000 or more and 1/10 or less of the depth of the through hole B3 (see FIGS. 5F and 5G). See diamond structure 84 shown). Here, FIG. 5 (C) is a cross-sectional view of the diamond substrate 2 taken along the line II shown in FIG. 5 (B), and FIG. 5 (E) is shown in FIG. 5 (D). FIG. 5G is a cross-sectional view of the diamond substrate 2 taken along the line II-II, and FIG. 5G is a cross-sectional view of the diamond substrate 2 taken along the line III-III shown in FIG. is there.

  Therefore, for example, it is possible to form an electron emitter made of diamond that is higher and sharper than before, and a practical single-chip electron source can be manufactured. Further, since the metal component generated when using a laser or a cutting device when a laser is used is not formed on the etched surface (the surface of the diamond formed by etching), the insulation of the diamond substrate 2 can be maintained. In addition, it is possible to produce a diamond probe that can be efficiently attached to a cantilever, and it can be applied to a mold having a size of μm or more, even if it is not as small as nanoimprint.

(First Embodiment) The present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples. First, the first embodiment will be described with reference to FIGS. 6 (A) and 6 (B). The first example is a test result for the diamond substrate 2 that has been etched using a mask composed of a plurality of layers formed by wet etching. First, films made of various laminates or single layers were formed on a 2 inch diameter diamond substrate 2 whose surface was polished flat (to a surface roughness of 10 nm or less). The thicknesses (combination of thicknesses) of the first to third layers of each laminate are different from each other.

  Specifically, a laminate composed of three layers of the first layer to the third layer, a laminate composed of two layers of the first layer and the second layer (a laminate in which the third layer has a thickness of zero), the first layer, A laminated body composed of two layers of the third layer (a laminated body in which the thickness of the second layer is zero), a laminated body composed of two layers of the second layer and the third layer (a laminated body in which the thickness of the first layer is zero), A film consisting of only the first layer (the thickness of each of the second layer and the third layer is zero), a film consisting of only the second layer (the thickness of each of the first layer and the third layer is zero), and only the third layer A film made of (the thickness of each of the first layer and the second layer is zero) was formed on the diamond substrate 2. When the laminate is composed of three layers of the first layer to the third layer, the first layer is formed on the diamond substrate 2, the second layer is formed on the first layer, and the third layer is formed on the second layer. Been formed. When the laminate was composed of two layers of the first layer and the second layer, the first layer was formed on the diamond substrate 2 and the second layer was formed on the first layer. When the laminate was composed of two layers of the first layer and the third layer, the first layer was formed on the diamond substrate 2 and the third layer was formed on the first layer. When the laminate was composed of two layers of the second layer and the third layer, the second layer was formed on the diamond substrate 2 and the third layer was formed on the second layer. When a film composed of only the first layer was used, the first layer was formed on the diamond substrate 2. When a film composed of only the second layer was used, the second layer was formed on the diamond substrate 2. When a film composed of only the third layer was used, the third layer was formed on the diamond substrate 2.

Each laminate of Example 01 to Example 09 shown in FIG. 6A and Example 11 to Example 19 shown in FIG. 6B is composed of at least two layers among the first layer to the third layer. . In addition, each film | membrane of the comparative example 01-comparative example 09 and the comparative example 11-comparative example 16 consists of only any one layer among the 1st layer-the 3rd layer except the comparative example 01 and the comparative example 11. FIG. Each film of Comparative Example 01 and Comparative Example 11 has a first layer and a second layer, but is treated with a single layer because it is etched with the same etching agent. Material of the first layer is Ti, the material of the second layer is SiO _2, the material of the third layer is Mo. The first layer made of Ti and the third layer made of Mo were formed using a sputtering method, and the second layer made of SiO ₂ was formed using a CVD method using TEOS gas.

Then, a resist (TSMR) pattern was formed on each stacked body using photolithography. Thereafter, each laminated body was wet-etched using aqua regia and BHF. After this etching process, a mask composed of a plurality of layers having the same pattern as the resist pattern was formed on the diamond substrate 2. Thereafter, etching of the diamond substrate 2 using this mask is performed in a plasma in an atmosphere of CF ₄ / O ₂ = 1% using an RIE apparatus, and a diamond structure having convex portions (FIG. 5B and FIG. (See FIG. 5C). The etching results for the above-described diamond substrate 2 are summarized in FIGS. 6 (A) and 6 (B). Note that wet etching using aqua regia and BHF was also applied to the films of Comparative Examples 01 to 09 and Comparative Examples 11 to 16.

  Hereinafter, a description will be given with reference to FIG. The item “minimum dot size that can be formed” in FIG. 6A is more precise processing as the dot size that can be formed on the diamond substrate 2 (this dot pattern is assumed to be circular) is smaller. (The same applies hereinafter). That is, it can be seen that each of the laminates of Example 01 to Example 03 composed of a plurality of layers can be processed with higher accuracy than each film of Comparative Example 01 to Comparative Example 04 having the same thickness (see FIG. (See the item “Minimum dot size that could be formed” in 6 (A)). Each layered product of Example 04 and Example 05 composed of a plurality of layers was thicker than the layers of Example 01 to Example 03, and it was difficult to perform highly accurate processing (FIG. 6). (Refer to (A) “Minimum dot size that could be formed”), which was effective in that a convex portion having a relatively large height could be formed (“convex portion” “height” in FIG. 6A). ”Item). Each film of Comparative Example 05 and Comparative Example 06 of a single layer was thicker than each of the laminates of Example 01 to Example 03, and was almost the same as the thickness of the laminate of Example 05. It was difficult to perform processing with higher accuracy than in any of Examples 01 to 05 and Comparative Examples 01 to 04 (the item of “minimum dot size that could be formed” in FIG. 6A). reference). As described above, the laminated body composed of a plurality of layers as in Example 01 to Example 05 is used as a mask compared to the case where a single layer film is used as a mask as in Comparative Example 01 to Comparative Example 06. Thus, the diamond substrate 2 can be processed with high accuracy, and a finer and higher protrusion can be formed.

  In addition, Examples 06 to 09 are cases where etching is performed more thickly than Examples 01 to 05. In Example 06 to Example 09, a diamond structure made of a diamond substrate provided with a convex portion having a height of 30 μm or more was manufactured. The width of this convex part is 1/3 or less of the height of the convex part, and the height difference of the unevenness representing the surface roughness of the side surface of this convex part is 1/10 or less of the height of this convex part. The etching method used in Examples 06 to 09 is the same as the etching method used in Examples 01 to 05. As shown in Comparative Examples 07 to 09, the height of the convex portion that can be formed when a single layer mask is used has a limit of about 20 μm, but as shown in Examples 06 to 09. In addition, when the laminate mask was used, the height of the convex portion exceeded the 20 μm limit and was 30 μm or more. This is the first wet etching process example in which the height of the convex portion exceeds 25 μm and the width of the convex portion is 1/3 or less of the height of the convex portion.

  Next, a description will be given with reference to FIG. Each laminated body of Example 11 to Example 13 composed of a plurality of layers could be processed with higher accuracy than each film of Comparative Example 11 to Comparative Example 14 having a single thickness (FIG. 6B). (See “Minimum hole size that could be formed” in). Each of the laminates of Example 14 and Example 15 composed of a plurality of layers had a large thickness and it was difficult to perform high-precision processing (the item “Minimum hole size that could be formed” in FIG. 6B). This is effective in that a hole having a relatively large depth can be formed (see the “hole” and “depth” items in FIG. 6B). Each film of Comparative Example 15 and Comparative Example 16 of a single layer was thicker than each of the laminates of Examples 11 to 13, and was comparable to the thickness of the laminate of Example 15, It was difficult to perform processing with higher accuracy than in any of Examples 11 to 15 and Comparative Examples 11 to 14 (the item of “minimum hole size that could be formed” in FIG. 6B). reference). As described above, the laminated body composed of a plurality of layers as in Example 11 to Example 15 is used as a mask compared to the case where a single layer film is used as a mask as in Comparative Examples 11 to 16. Thus, the diamond substrate 2 can be processed with high accuracy, and a narrower and deeper hole can be formed.

  In addition, Examples 16 to 19 are cases where etching was performed thicker than Examples 11 to 15. In Examples 16 to 19, a diamond structure comprising a diamond substrate provided with a hole having a depth of 30 μm or more was manufactured. The width of the hole is 1/3 or less of the depth of the hole, and the height difference of the unevenness representing the surface roughness of the side surface of the hole is 1/10 or less of the depth of the hole. The etching method used in Examples 16 to 19 is the same as the etching method used in Examples 11 to 15. As shown in Comparative Example 11 to Comparative Example 12, the depth of the hole that can be formed when using a single layer mask had a limit of about 20 μm, but as shown in Example 16 to Example 19, When the laminated mask was used, the limit of 20 μm was exceeded and the thickness was 30 μm or more. This is the first wet etching process example in which the hole depth exceeds 25 μm and the width of the hole is 1/3 or less of the depth of the hole.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. The second example is a test result with respect to the diamond substrate 2 etched using a mask composed of a plurality of layers or a single layer formed by wet etching and dry etching. First, various laminates and films were formed on a 2 inch diameter diamond substrate 2 whose surface was polished flat (to a surface roughness of 10 nm or less). The thicknesses (combination of thicknesses) of the first to third layers of each laminate are different from each other. Specifically, a laminate composed of three layers of the first layer to the third layer, a laminate composed of two layers of the second layer and the third layer (a laminate in which the thickness of the first layer is zero), only the first layer (The thickness of each of the second and third layers is zero), the film consisting of only the second layer (the thickness of each of the first and third layers is zero), and the film consisting of only the third layer ( Each thickness of the first layer and the second layer was zero) on the diamond substrate 2. When the laminate is composed of three layers of the first layer to the third layer, the first layer is formed on the diamond substrate 2, the second layer is formed on the first layer, and the third layer is formed on the second layer. Been formed. When the laminate was composed of two layers of the second layer and the third layer, the second layer was formed on the diamond substrate 2 and the third layer was formed on the second layer. When a film composed of only the first layer was used, the first layer was formed on the diamond substrate 2. When a film composed of only the second layer was used, the second layer was formed on the diamond substrate 2. When a film composed of only the third layer was used, the third layer was formed on the diamond substrate 2.

The laminated body of Example 21 shown in FIG. 7 consists of two layers of the second layer and the third layer among the first to third layers, and each laminated body of Example 22 and Example 23 is the first layer. -It consists of three layers of the third layer. In addition, each laminated body of the comparative example 21-comparative example 24 shown in FIG. 7 consists of any one layer among a 1st layer-a 3rd layer. Material of the first layer is Ti, the material of the second layer is SiO _2, the material of the third layer is Mo. The first layer made of Ti and the third layer made of Mo were formed using a sputtering method, and the second layer made of SiO ₂ was formed using a CVD method using TEOS gas.

And the pattern of the resist (TSMR) was formed on each laminated body of Example 21-Example 25 using photolithography. Thereafter, the third layer of each laminate was wet etched, and the lower part (second layer and further the first layer) was dry etched using RIE. The second layer made of SiO ₂ was etched using CF ₄ gas, and the first layer made of Ti was etched using Cl ₂ gas. After this etching process, a mask having a pattern similar to the resist pattern was formed on the diamond substrate 2. Thereafter, etching of the diamond substrate 2 using this mask is performed in a plasma in an atmosphere of CF ₄ / O ₂ = 1% using an RIE apparatus, and a diamond structure having convex portions (FIG. 5 (F) and (See FIG. 5G). The etching results for the diamond substrate 2 are summarized in FIG. The film of Comparative Example 24 was subjected to wet etching, and the films of Comparative Examples 21 to 23 were subjected to dry etching using RIE.

  Hereinafter, a description will be given with reference to FIG. Each laminated body of Example 21- Example 23 and each film | membrane of the comparative example 21 and the comparative example 22 are formed using the resist of the same thickness. Although each laminated body of Example 21- Example 23 and each film | membrane of the comparative example 21 and the comparative example 22 were able to process with the same high precision ("minimum dot size which could be formed" of FIG. 7). The thicknesses of the laminated bodies of Examples 21 to 23 are larger than those of the films of Comparative Example 21 and Comparative Example 22. The film of Comparative Example 23 has the same thickness as each of the laminates of Examples 21 to 23, but is more than the resist used when forming each of the laminates of Examples 21 to 23. It was formed using a thick resist. The film of Comparative Example 23 had a lower accuracy than the respective laminates of Examples 21 to 23 (see the item “Minimum Dot Size That Was Formable” in FIG. 7). In Comparative Example 24, the third layer subjected to wet etching was thickened, but the accuracy was low as in Comparative Example 23 (see “Minimum Dot Size That Can Be Formed” in FIG. 7). ). Therefore, even when wet etching and dry etching are used in combination, it is easier to use a laminate composed of a plurality of layers as a mask as in Examples 21 to 23 as in Comparative Examples 21 to 24. Compared to the case where the layer film was used as a mask, the diamond substrate 2 could be processed with high accuracy, and a narrower and higher protrusion could be formed. Moreover, although it verified also when the hole similar to the case of 1st Example (FIG.6 (B)) was formed in the diamond substrate 2 instead of a convex part, also when using wet etching and dry etching together, Diamonds are better when using a laminate composed of a plurality of layers as a mask as in Examples 21 to 23 than when using a single layer film as a mask as in Comparative Examples 21 to 24. The substrate 2 could be processed with high accuracy, and a thinner and higher protrusion could be formed.

  Moreover, Example 24 and Example 25 are the cases where it etched more thickly compared with Example 21-23. In Example 24 and Example 25, a diamond structure composed of a diamond substrate provided with a convex portion having a height of 30 μm or more was manufactured. The width of this convex part is 1/3 or less of the height, and the height difference of the unevenness representing the surface roughness of the side surface of this convex part is 1/10 or less of the depth of this convex part. The etching method used in Examples 24 and 25 is the same as the etching method used in Examples 21 to 23. As shown in Comparative Examples 21 to 24, the height of the convex portion that can be formed when a single-layer mask is used has a limit of about 20 μm, but as shown in Examples 24 and 25, When the mask of the laminated body was used, the height of the convex portion was 50 μm or more and the width of the convex portion was 1/3 or less of the height of the convex portion.

(Third Embodiment) Next, a third embodiment will be described with reference to FIGS. 8 (A) to 8 (C). The third example is a test result for the diamond substrate 2 that has been etched using a mask composed of a plurality of layers formed by dry etching. Material of the first layer is Mo, the material of the second layer is SiO _2, the material of the third layer is Ti (or Al). The first to third layers were dry etched by RIE using different etching agents (gases) for each layer. The first layer made of Mo is etched using SF ₆ -based gas, the second layer made of SiO ₂ is etched using CF ₄ -based gas, and the third layer made of Ti (or Al) is etched. The layer was etched using a Cl ₂ gas. The etching results for the diamond substrate 2 described above are summarized in FIGS. 8 (A) and 8 (B).

  The films of Comparative Examples 21 to 23 (see FIG. 7) and Comparative Examples 31 to 33 were also subjected to the same etching treatment as the stacked bodies of Examples 31 to 34. FIG. 8A shows the result when a convex portion is formed on the diamond substrate 2, and FIG. 8B shows the result when a hole is formed in the diamond substrate 2. . All obtained almost the same results, but the results were slightly different between Comparative Example 23 and Comparative Example 43 under the same conditions as Comparative Example 23. FIG. 8B shows this result. Even when Al was used as the material for the third layer instead of Ti, a result almost similar to the result shown in FIG. 8A using Ti was obtained. The result is shown in FIG. As described above, even in the case of using dry etching, Comparative Example 21 to Comparative Example 23 and Comparative Example 31 to Comparative Example are those in which the laminated body composed of a plurality of layers as in Examples 31 to 34 is used as a mask. Compared with the case of using a single-layer film as a mask as in No. 33, the diamond substrate 2 can be processed with high accuracy, and thinner and higher protrusions and thinner and deeper holes can be formed. In Example 35 and Example 54, a diamond structure made of a diamond substrate provided with a convex portion having a height of 30 μm or more was manufactured. The width of this convex part is 1/3 or less of the height of the convex part, and the height difference of the unevenness representing the surface roughness of the side surface of this convex part is 1/10 or less of the height of this convex part.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIGS. 9 (A) and 9 (B). The fourth example is a side evaluation result for the diamond substrate 2 that has been etched using a mask composed of a plurality of layers. “D” shown in FIG. 9A indicates that the etching process is performed by dry etching, and “W” indicates that the etching process is performed by wet etching. Each film of Comparative Examples 61 and 62 having a single layer is subjected to an etching process by RIE using a Cl ₂ gas, and the diamond substrate 2 is etched using a mask obtained by this etching process. To form a convex portion. Etching in Example 04 and Example 05, Example 21 to Example 23, Example 31 to Example 34, Example 51, Comparative Example 05, Comparative Example 23 and Comparative Example 22, and Comparative Example 61 and Comparative Example 62 The state of the surface (the level difference of the unevenness representing the surface roughness) was measured using a stylus type roughness meter. FIGS. 9A and 9B show the measurement results. The convex portions of Examples 04 and 05, Examples 21 to 23, Examples 31 to 34, and Example 51 have a height of 10 μm or more, and are etched surfaces (side surfaces of the convex portions). ) Is 80 degrees or more with respect to the surface of the diamond substrate 2, and the unevenness level representing the roughness of the etched surface is 1 μm or less. Therefore, the diamond substrate 2 has a relatively large and smooth surface and a diamond convex portion substantially perpendicular to the substrate surface. In Example 26, Example 36, and Example 52, a diamond structure composed of a diamond substrate provided with a convex portion having a height of 30 μm or more could be manufactured. The width of this convex part is 1/3 or less of the height of the convex part, and the height difference of the unevenness representing the surface roughness of the side surface of this convex part is 1/10 or less of the height of this convex part.

  While the principles of the invention have been illustrated and described in the preferred embodiments, it will be appreciated by those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. The present invention is not limited to the specific configuration disclosed in the present embodiment. We therefore claim all modifications and changes that come within the scope and spirit of the following claims.

It is sectional drawing for demonstrating the manufacturing method of the diamond structure which concerns on embodiment. It is sectional drawing for demonstrating the manufacturing method of the conventional diamond structure. It is a table | surface for demonstrating the manufacturing method of the diamond structure which concerns on embodiment. It is sectional drawing for demonstrating the manufacturing method of the diamond structure which concerns on embodiment. It is a figure which shows the diamond structure which concerns on embodiment. It is a table | surface for demonstrating 1st Example. It is a table | surface for demonstrating 2nd Example. It is a table | surface for demonstrating 3rd Example. It is a table | surface for demonstrating 4th Example.

Explanation of symbols

2 ... Diamond substrate, 4, 18, 22, 38, 54 ... Laminate, 6, 24, 40, 56 ... First layer, 8, 26, 42, 58 ... Second layer, 10 ... Resist, 12, 34, 50, 70 ... second mask region, 14, 32, 48, 68 ... first mask region, 16, 20, 30, 46, 66 ... mask, 28, 44, 60 ... third layer, 62 ... fourth layer, 64: Fifth layer, 36, 52, 72: Third mask region, 74: Fourth mask region, 76: Fifth mask region, 78, 80, 82, 84: Diamond structure.

Claims (5)

A method for manufacturing a diamond structure,
A laminate forming step of forming a laminate comprising a plurality of layers on the diamond substrate by laminating a plurality of materials on the diamond substrate;
A resist forming step of forming a resist having a mask pattern on the laminate;
A mask forming step of forming a mask to be used for etching the diamond substrate having the mask pattern by wet-etching the stack using the resist for each layer of the stack;
A diamond substrate processing step of processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask, and
One layer of the plurality of layers includes the one or more layers in the mask formation step when there is one or more layers formed before the formation of the one layer in the stacked body formation step. A method for producing a diamond structure, characterized by comprising a material having etching resistance to each wet etching performed for each layer. A method for manufacturing a diamond structure,
A laminate forming step of forming a laminate comprising a plurality of layers on the diamond substrate by laminating a plurality of materials on the diamond substrate;
A resist forming step of forming a resist having a mask pattern on the laminate;
A mask forming step of forming a mask for etching the diamond substrate having the mask pattern by dry-etching the laminate using the resist for each layer of the laminate;
A diamond substrate processing step of processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask, and
Of the plurality of layers, the layer formed last in the stacked body formation step is performed in the mask formation step for each one or a plurality of layers other than the last layer formed in the plurality of layers. A method for producing a diamond structure, characterized by comprising a material having etching resistance to dry etching. A method for manufacturing a diamond structure,
A laminate forming step of forming a laminate comprising a plurality of layers on the diamond substrate by laminating a plurality of materials on the diamond substrate;
A resist forming step of forming a resist having a mask pattern on the laminate;
Mask formation for forming a mask for etching the diamond substrate having the mask pattern by performing wet etching and dry etching of the stacked body using the resist for each layer forming the stacked body Process,
A diamond substrate processing step of processing the diamond substrate into the diamond structure by etching the diamond substrate using the mask, and
One layer of the plurality of layers is formed before the formation of the one layer in the layered body forming step, and when the layered body includes another layer wet-etched in the mask forming step, the wet etching is performed. It consists of a material with resistance to etching
Of the plurality of layers, the last layer formed in the stacked body formation step is other than the last layer formed in the plurality of layers, and is another layer that is dry-etched in the mask formation step. Is included, it is made of a material having etching resistance against the dry etching. A diamond structure comprising a diamond substrate including grooves or holes having a depth of 30 micrometers or more and 300 micrometers or less,
The width of the groove or the hole is 1/100 or more and 1/3 or less of the depth,
The diamond structure according to claim 1, wherein the height difference of the unevenness representing the roughness of the side surface of the groove or the hole is 1/1000 or more and 1/10 or less of the depth. A diamond structure comprising a diamond substrate having a thickness of 30 micrometers to 3000 micrometers,
The diamond structure according to claim 1, wherein the unevenness representing the roughness of the side surface of the diamond substrate is 1/1000 or more and 1/10 or less of the thickness of the diamond substrate.

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