JPH103174A - Conductor pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductor pattern forming method for forming plural conductor patterns adjacently to each other at very small gaps. SOLUTION: Plural kinds of masks 8a-8e being different from each other in positions where through-holes 7 for prescribing positions where the conductor patterns 12 are formed on the surface of a substrate 1 are prepared in advance. First, the conductor pattern 12 of the first pattern is formed by the mask 8a and then, the conductor pattern 12 of the second pattern is formed by the mask 8b in the same way as the above-mentioned one. Thus, the kinds of masks 8 are successively changed to form the plural conductor patterns 12 on the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a conductor pattern constituting a semiconductor device such as a microgyro or an electrostatic sensor.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a main structure of a microgyro 2 manufactured using a semiconductor substrate 1 such as a Si substrate. As shown in the figure, the microgyro 2 has a comb-shaped first electrode 4 and the first electrode 4.
Of a comb-shape formed so as to mesh with each other with an interval
Electrode 5. The manufacturing process of the first electrode 4 and the second electrode 5 will be briefly described with reference to FIG. FIG. 6 schematically shows a cross section taken along line AA of FIG.

For example, on a substrate 1 shown in FIG. 6A, a plurality of through-holes 7 (positions of conductor patterns to be formed) defining positions where conductor patterns to be the first electrode 4 and the second electrode 5 are to be formed are formed. Number) One type of formed mask 8 is formed in advance, and first, an oxide film (for example, SiO ₂ film) 14 and a base electrode film (for example, a Cu / Ni two-layer structure film) 15 thereabove.
A negative photosensitive resin (for example, a negative polyimide or a negative resist (a part irradiated with ultraviolet rays is cured)) 10 is applied and formed on the surface of the substrate 1 on which is formed.
Then, the photosensitive resin 10 is covered with the mask 8 and ultraviolet rays (UV) are applied to the photosensitive resin 10 through the through holes 7 of the mask 8.
Irradiate the portion of the photosensitive resin 10 where the conductor pattern is to be formed.
Is exposed and cured. Next, as shown in FIG. 6B, the portions of the photosensitive resin 10 that have not been exposed are removed from the substrate surface using a chemical solution or the like.

[0004] Thereafter, aluminum (Al) 11 is deposited by plating on the surface of the substrate 1 where the photosensitive resin 10 has been removed, and then the photosensitive resin in the exposed portion is removed.
10 is peeled off from the substrate 1 using a peeling liquid or the like (FIG. 6C). Then, as shown in FIG. 6D, a metal (for example, a first electrode 4 or a second electrode 5) that becomes a conductive pattern is formed on the surface of the substrate 1 where the photosensitive resin 10 is removed. , Cu) 12 are deposited by a plating technique.

[0007] Finally, as shown in FIG. 6 E, the aluminum 11 is removed from the substrate surface by wet etching, and the first electrode 4 having a plurality of comb patterns and the second electrode 4 are formed. The electrode 5 is completed.

[0006]

As shown in FIGS. 5 and 6 (e), the first electrode 4 and the second electrode 5
Become width d of each conductor pattern 12 is very narrow, Therefore, necessarily, also becomes very small width L _d of the through holes 7 of the mask 8 shown in FIG. 7 (a). Thus, when the width L _d of the through-hole 7 of the mask 8 is very narrow, as shown in the drawing, ultraviolet (UV) when irradiating the photosensitive resin 10 through the through hole 7 of the mask 8, ultraviolet Then, a diffraction phenomenon occurs, and diffracted light such as +1 order light and −1 order light is generated.

Although the intensity of the diffracted light alone such as the +1 order light and the −1 order light is not strong enough to cure the photosensitive resin 10, if the distance L _D between the through holes 7 is small (FIG. 6). (E) When the distance D between the conductor patterns 12 shown in FIG. 7E is small), the photosensitive resin 10 passes, for example, the diffracted light of ultraviolet light (for example, + 1st-order light) passing through the through hole 7a and passing through the through hole 7b. For example, a portion irradiated with the overlapped ultraviolet diffracted light (eg, −1st order light), for example, reflected light generated by diffracted light of the through-hole 7a side irregularly reflected on the substrate surface and diffracted light of the through-hole 7b side Overlapping portions occur, and the intensity of light in the portions where the diffracted light and reflected light of ultraviolet light passing through the adjacent through holes overlap each other becomes large until the photosensitive resin 10 is exposed,
The photosensitive resin 10 in that portion is exposed and hardened (hereinafter, this phenomenon is called a diffraction exposure phenomenon).

The photosensitive resin 10 in the portion A shown in FIG. 7B where the above-mentioned diffraction exposure phenomenon has occurred remains after the photosensitive resin 10 in the unexposed portion is removed, as shown in FIG. Will be. Since aluminum is not deposited on the photosensitive resin 10 by a plating method, the remaining photosensitive resin 10
However, if the conductive pattern has a continuous shape as shown in the figure, the aluminum 11 cannot be formed at the interval D between the portions where the conductor patterns are desired to be formed as indicated by the dotted lines in the figure, that is, the metal to be the conductive pattern 12 When depositing aluminum
The conductor patterns 12 cannot be separated from each other by 11, and a plurality of conductor patterns 12 cannot be formed independently with an interval therebetween.

[0009] To form adjacent the plurality of conductive patterns independent to prevent the occurrence of the diffraction exposure phenomenon, increase the distance L _D between the through holes 7 of the mask 8, that is, the conductor patterns 12 The distance D between them must be increased, and FIG.
However, there is a problem that miniaturization of the semiconductor device as described above is hindered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to prevent a diffraction exposure phenomenon from occurring, and to form a plurality of conductor patterns adjacent to each other at a fine interval. It is an object of the present invention to provide a method for forming a conductor pattern, which can be realized.

[0011]

Means for Solving the Problems In order to achieve the above object, the present invention has the following structure to solve the above problems. That is, the present invention relates to a conductor pattern forming method for forming a plurality of conductor patterns adjacent to each other on a substrate surface with an interval therebetween, wherein the formation positions of the through holes that define the positions where the conductor patterns are formed on the substrate surface are mutually different. A plurality of different masks are prepared in advance, a negative photosensitive resin is formed on the substrate surface, and after covering the negative photosensitive resin with one of the plurality of masks, The negative photosensitive resin is irradiated with ultraviolet rays through the through holes of the mask to expose the exposed portions of the negative photosensitive resin determined by the positions where the through holes of the mask are formed, and then the negative portions of the unexposed portions are exposed. Pattern transfer and development process to remove the mold photosensitive resin from the substrate surface,
Aluminum was deposited by plating on the substrate surface of the portion where the negative photosensitive resin was removed, and then the exposed negative photosensitive resin was removed from the substrate surface, and the negative photosensitive resin was removed. From the step of forming the negative photosensitive resin to the step of removing the mold, such as performing a mold removing step of removing the aluminum after the metal plating, by depositing a metal to be a conductive pattern on the substrate surface by a plating technique. A series of steps is the pattern transfer
The above-mentioned problem is solved by a configuration in which the type of mask used in the developing process is sequentially changed and the process is repeatedly performed to sequentially form a plurality of conductor patterns on the substrate surface.

In the present invention having the above structure, for example, the first
A first mask having a through-hole defining a position on the substrate surface where the second conductor pattern is to be formed, and a second mask having a through-hole defining the position on the substrate surface where the second conductor pattern is to be formed. A mask is prepared in advance for each conductor pattern to be formed, such as preparing the mask in advance. First, a series of steps from a negative photosensitive resin forming step to a mold removing step through a pattern transfer / phenomenon step using a first mask is performed to form a first conductor pattern. A series of steps from the step of forming the negative photosensitive resin to the step of removing the mold, such as performing the above series of steps again using the second mask instead of the first mask to form the second conductive pattern. The process is repeated by sequentially changing the type of the mask, and a plurality of conductor patterns are sequentially formed on the substrate surface.

As described above, when a plurality of conductor patterns are sequentially formed one by one, for example, when the first conductor pattern is formed, the first conductor pattern is formed. The negative photosensitive resin used for the above has been removed from the substrate surface, and when the next conductive pattern is to be formed, a new negative photosensitive resin will be formed on the substrate surface, Even if the negative photosensitive resin other than the portion serving as the conductor pattern is irradiated with ultraviolet diffracted light or reflected light, there is no overlap between the ultraviolet diffracted light and reflected light passing through the adjacent through-holes, so that The light intensity does not increase until the negative photosensitive resin is exposed, that is, it is possible to prevent the occurrence of the diffraction exposure phenomenon, and to form a plurality of conductor patterns adjacent to each other with very fine intervals. It can become.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The characteristic feature of the conductor pattern forming method of this embodiment is different from that of the conventional conductor pattern forming method is that only one through hole for defining a position where a conductor pattern is formed on a substrate surface is provided. In this case, a plurality of masks are formed in advance, and a plurality of conductor patterns are sequentially formed one by one.

The mask is, for example, a first conductive pattern forming mask 8a for defining a position where the first conductive pattern 12a shown in FIG. 3A is formed, and a first conductive pattern forming mask 8a shown in FIG. 3B. For example, a mask 8b for forming a second conductor pattern that defines a position where the second conductor pattern 12b is formed, a plurality of types (a plurality of conductor patterns to be formed) of the conductor pattern 12 are formed by shifting the formation positions of the through holes 7 for each conductor pattern 12. 12 numbers) to be formed.

Hereinafter, a method of forming a conductor pattern according to this embodiment will be described with reference to FIGS. First, as shown in FIG. 1A, an oxide film (for example, SiO ₂ film (thickness: 6000 °)) 14 and a base electrode film (for example,
Si on which a two-layer structure film of Au film (thickness of 2000 mm) / Cr film (thickness of 500 mm) or a two-layer structure film of Cu film / Ni film is formed.
A negative photosensitive resin (for example, a negative photosensitive polyimide or a negative photosensitive photoresist) 10 is applied and formed on a surface of a semiconductor substrate 1 such as a substrate by a spin coating method (for example, the photosensitive resin 10 is formed to have a film thickness). About 50 μm).

Then, after the substrate 1 is heated to 80 to 110 ° C. and subjected to a heat treatment, a pattern transfer / developing step is performed.
First, the photosensitive resin 10 is covered with one of a plurality of masks 8 prepared, for example, a mask 8 for forming a first conductive pattern, and then ultraviolet (UV) is passed through the mask 8. Irradiate the photosensitive resin 10 through the hole 7.
By this ultraviolet irradiation, only the portion of the photosensitive resin 10 where the first conductor pattern predetermined by the through hole 7 of the mask 8 is formed is exposed and cured.

Next, as shown in FIG. 1B, the unexposed portion of the photosensitive resin 10 is removed from the surface of the substrate 1 by wet etching, and the pattern transfer / developing process is completed.

After the pattern transfer / developing step, as shown in FIG. 1C, aluminum 11 is deposited by plating on the surface of the substrate 1 where the photosensitive resin 10 has been removed. Then, the exposed portion of the photosensitive resin 10 is removed from the surface of the substrate 1 using a stripper or the like. And FIG.
As shown in (d), a metal (for example, Ni or Cu) to be the conductive pattern 12 is deposited by plating on the surface of the substrate 1 where the photosensitive resin 10 is removed.

Thereafter, a mold removing step is performed. In this step, as shown in FIG. 1E, a chemical solution (for example, a mixed solution of nitric acid, phosphoric acid, acetic acid, and water) is used as shown in FIG.
Is used to remove from the surface of the substrate 1. As mentioned above,
The first conductive pattern 12a is formed through a series of steps from a step of forming the photosensitive resin 10 to a step of removing the mold through a pattern transfer / development step using the first conductive pattern forming mask 8 and a mold removing step.

Next, instead of the first conductive pattern forming mask 8, for example, a second conductive pattern forming mask 8 shown in FIG. A series of steps from the forming step to the mold removing step is repeated again as shown in FIGS. 2F to 2J to form the second conductor pattern 12b.

As described above, in this embodiment, a mask 8 for forming a conductor pattern is prepared in advance for each conductor pattern, and a series of steps from the step of forming the photosensitive resin 10 to the step of removing the mold are performed. The process is repeated by sequentially changing the type of the mask 8 used in the pattern transfer / developing process, and a plurality of conductor patterns 12 are formed on the surface of the substrate 1 as shown in FIGS. We decided to form one by one.

In general, the above-mentioned negative photosensitive resin 10 is exposed and cured when irradiated with ultraviolet rays including g-rays. UV light is used. Further, the metal forming the conductor pattern 12 is preferably a substance that does not precipitate on the aluminum 11 by a plating technique. That is, when the metal deposited on the aluminum 11 is used as the metal of the conductor pattern 12, the metal of the conductor pattern 12 is naturally deposited on the aluminum 11 when the conductor pattern 12 is deposited and formed on the surface of the substrate 1. Will also precipitate. For this reason, in the mold removing step, the deposited metal on the aluminum 11 must be removed, and if the deposited metal on the aluminum 11 is to be removed by, for example, wet etching, the metal of the portion to be the conductor pattern 12 is also removed. This is because there is a problem that the conductor pattern 12 cannot be formed.

According to this embodiment, a mask 8 for forming a conductor pattern is prepared in advance for each conductor pattern, and from the step of forming the photosensitive resin 10, one of the plurality of types of masks 8 is formed. Pattern transfer using different types of masks 8
A series of steps from the development step to the mold removal step are repeated by sequentially changing the type of the mask 8 used in the pattern transfer / development step, and a plurality of conductor patterns 12 are formed.
Are sequentially formed. For example, when the photosensitive resin 10 is irradiated with ultraviolet rays through the through holes 7 of the mask 8 in the step of forming the first conductor pattern, the ultraviolet rays are emitted through only one through hole. 7 irradiates the photosensitive resin 10, and the situation where the diffracted light or reflected light of the ultraviolet light passing through the adjacent through-hole does not occur, that is, other than the portion where the first conductive pattern 12 is formed, As described above, the photosensitive resin 10 does not undergo the above-described diffraction exposure phenomenon, and only the photosensitive resin 10 in a portion to be a conductor pattern is exposed, and as shown in FIG. A narrow conductor pattern can be formed.

Further, as described above, the first conductor pattern
When the second conductive pattern 12 is completed, the photosensitive resin 10 used to form the first conductive pattern 12 is removed from the substrate surface. Since the photosensitive resin 10 is formed on the substrate surface,
The following exposure phenomenon of the photosensitive resin 10 can also be prevented. For example, the second conductive pattern 12 is applied to the portion of the photosensitive resin 10 irradiated with the diffracted light or the reflected light of the ultraviolet light applied to the photosensitive resin 10 to form the first conductive pattern 12.
The diffracted light or the reflected light of the ultraviolet light for forming the second conductive pattern 12 is irradiated again, and the light intensity in that portion increases until the photosensitive resin 10 is exposed, and the photosensitive portion other than the portion where the second conductive pattern 12 is formed is exposed. There is no occurrence of an exposure phenomenon such that the resin 10 is exposed.

From the above, a plurality of conductor patterns 12
Is very narrow, and the interval D between the conductor patterns 12 is very small, so that a plurality of conductor patterns 12 can be reliably formed adjacent to each other with an interval therebetween.

As described above, it is possible to form a plurality of conductor patterns 12 adjacent to each other in which the width d of the conductor patterns 12 is very small and the interval D between the conductor patterns 12 is very small. 5, a comb-shaped electrode 4, as shown in FIG.
5, the width of each electrode (conductor pattern) in the comb-tooth portion and the interval between each electrode can be made extremely fine, and the semiconductor device such as the microgyro 2 shown in FIG. It becomes possible.

Further, in the conventional method for forming a conductor pattern, as shown by dotted lines M and N in FIG. 3A, the conductor pattern 12 rises or falls, but this is not the case. When the conductor pattern forming method of the embodiment is used, the rising and falling of the conductor pattern 12 can be sharply formed as shown by solid lines R and S in FIG.

The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above embodiment, as shown in FIGS. 3A to 3E, after the first conductor pattern 12 is formed,
The second conductor pattern 12 is formed next to the first conductor pattern 12, and the third conductor pattern 12 is formed next to the first conductor pattern 12. However, when the first conductor pattern 12 is formed,
Next, the fifth conductor patterns 12 may be formed, and then the third conductor patterns 12 may be formed, and may be formed one by one in any order other than the arrangement order.

Further, in the above embodiment, only one through-hole 7 is formed in the mask 8, but as shown in FIG. The plurality of through holes 7 may be formed in the mask 8 at intervals such that the light intensity of the portion does not increase until the photosensitive resin 10 is exposed, that is, at intervals that can avoid the occurrence of the diffraction exposure phenomenon. . Also in this case, FIGS.
As shown in FIGS. 4A to 4D, a plurality of types of masks 8 having different positions for forming the through holes 7 are prepared in advance, and as shown in FIGS. Photosensitive resin
A series of steps from the step of forming the mold 10 to the step of removing the mold are repeated by changing the type of the mask 8 in order, so that a plurality of conductor patterns 12 are sequentially formed.

As described above, when the plurality of through-holes 7 are formed in the mask 8 at intervals so as to avoid the occurrence of the diffraction exposure phenomenon, the occurrence of the above-described diffraction exposure phenomenon can be prevented. Since a plurality of conductor patterns 12 can be formed adjacent to each other with an interval therebetween, and a plurality of conductor patterns can be simultaneously formed each time a series of steps from the step of forming the negative photosensitive resin to the step of removing the mold are performed. The number of repetitions of the series of steps can be reduced as compared with the case where the mask 8 having only one through hole 7 is used.

Further, in the above embodiment, a method of forming a conductor pattern to be a comb-shaped electrode as shown in FIG. 6 has been described as an example. The present invention can be applied to the case where the electrodes are adjacent to each other via the interposition, and is not limited to the comb-shaped electrode.

[0033]

According to the present invention, a plurality of types of masks having mutually different through-hole formation positions are prepared in advance, and the mold removal process is performed from the negative photosensitive resin formation process through the pattern transfer / development process. The series of steps up to this point are repeated by repeatedly changing the type of mask used in the pattern transfer / development step, and a plurality of conductor patterns are sequentially formed on the substrate surface. It is possible to prevent the diffracted light and reflected light of the ultraviolet light applied to the resin from overlapping each other, and the diffracted light and reflected light of the ultraviolet light from the adjacent through-holes to the negative photosensitive resin other than the part where the conductor pattern is formed When light overlaps, the light intensity in that part increases until the negative photosensitive resin is exposed, exposing the negative photosensitive resin in areas where no conductive pattern is formed. The occurrence of a diffraction exposure phenomenon can be reliably avoided. Accordingly, it is possible to expose only the negative photosensitive resin in the portion that becomes the conductor pattern determined by the formation position of the through hole of the mask. As a result, a very fine conductor pattern can be formed with high precision, and a plurality of conductor patterns can be formed adjacent to each other with a very fine interval.

As described above, it is possible to form a very small space between adjacently formed conductor patterns. Therefore, by forming a small space between each conductor pattern, a semiconductor having the conductor patterns can be formed. The size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a conductive pattern forming method according to the present embodiment.

FIG. 2 is an explanatory view showing a method of forming a conductor pattern according to the present embodiment, following FIG. 1;

FIG. 3 is an explanatory diagram schematically showing a state in which a plurality of conductor patterns are sequentially formed.

FIG. 4 is an explanatory diagram showing another embodiment.

FIG. 5 is an explanatory diagram showing an example of a main structure of a microgyro.

FIG. 6 is an explanatory diagram showing a conventional example.

FIG. 7 is an explanatory diagram showing a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 7 Through hole 8 Mask 10 Photosensitive resin 11 Aluminum 12 Conductor pattern

Claims (1)

[Claims] In a conductor pattern forming method for forming a plurality of conductor patterns adjacent to each other with a space therebetween on a substrate surface, formation positions of through holes for defining positions where the conductor patterns are formed on the substrate surface are different from each other. A plurality of types of masks are prepared in advance, a negative photosensitive resin is formed on the surface of the substrate, and the negative photosensitive resin is covered with one of the plurality of types of masks. The negative photosensitive resin is irradiated with ultraviolet rays through the through holes to expose the exposed portions of the negative photosensitive resin determined by the formation positions of the through holes in the mask, and then, the negative mold of the unexposed portions is exposed. Perform a pattern transfer and development process to remove the photosensitive resin from the substrate surface, and then deposit aluminum by plating on the portion of the substrate surface where the negative photosensitive resin has been removed. The exposed negative-type photosensitive resin is removed from the substrate surface, and a metal serving as a conductive pattern is deposited on the substrate surface from which the negative-type photosensitive resin has been removed by a plating technique. After the metal plating is completed, the aluminum is removed. A series of steps from the step of forming the negative-type photosensitive resin to the step of removing the mold are repeatedly performed by sequentially changing the type of mask used in the pattern transfer / development step. A method for forming a conductor pattern, comprising sequentially forming a pattern on a substrate surface.