JP2002270410A - Method of manufacturing electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable thin film layers to be formed with high efficiency without causing damage to a board or the thin film layers which have been already formed and to be precisely laminated on the other thin film layers in an electronic part manufacturing method including a process of laminating a plurality of thin film layers. SOLUTION: An electronic part manufacturing method includes a process of forming a second thin film 61 (62) on a board 5, overlapping partially with a first thin film 60 by the use of a second mask M5a' (M5a") which is formed as another body separate from the board 5, after a first thin film 60 has been formed on a board 5 by the use of a first mask M5a which is formed as another body separate from the board 5. The first mask M5a is equipped with a through- hole 10Ea used for forming the first thin film 60 and an additional through-bole 10Eb used for forming an alignment mark 70 on the board 5, and the alignment mark 70 is formed at the same time when the first thin film 60 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic component having a form in which a plurality of thin films are laminated on a substrate, for example, an electronic component in which an electrode layer and an insulating layer (piezoelectric layer or dielectric layer) or a resistance layer are formed. The present invention relates to a method for manufacturing a part.

[0002]

2. Description of the Related Art When manufacturing an electronic component such as a piezoelectric thin-film vibrator, it is necessary to laminate a lower electrode layer, an insulating layer (such as a piezoelectric layer) and an upper electrode layer on a substrate. As a method for selectively forming a thin film having a desired shape on a predetermined portion on a substrate, one of the following three methods is generally adopted.

In the first method, first, as shown in FIG. 17A, an entire thin film 80A is formed of a thin film material on the entire surface of a substrate 8A, and then a desired thin film is formed as shown in FIG. A resist 81A is formed at a position where an 80A '(see FIG. 17D) is to be formed. Next, as shown in FIG. 17C, a portion of the entire thin film 80A that is not covered with the resist 81A is removed by etching, and then the desired thin film is removed by removing the resist 81A as shown in FIG. 17D. 80A 'are formed.

In the second method, first, as shown in FIG. 18A, an opening 81 corresponding to a thin film 80B 'to be formed is formed.
After forming the resist 81B having b, thin film materials are supplied by vapor deposition or sputtering to form thin films 80B ′ and 80B ″ on the substrate 8B and the resist 81B. Then, as shown in FIG. Thin film 8 on resist 81B together with resist 81B by processing or the like
0B ″, the thin film 80 on the substrate 8B is removed.
B 'is formed.

In the third method, as shown in FIG. 19A, a thin film 80 to be formed is formed separately from the substrate 8C.
A mask M having an opening Ma corresponding to C 'is placed on the substrate 8
After fixing on the substrate 8C, a thin film material is supplied by vapor deposition or sputtering to form a thin film 80 on the substrate 8C and the mask M.
Next, as shown in FIG. 19B, a thin film 80C 'is formed on the substrate 8C by separating the mask M from the substrate 8C.

A technique for forming a film using the mask M is also disclosed, for example, in Japanese Patent Application Laid-Open Nos. 62-297457 and 4-236758.

[0007]

By the way, in an electronic component including elements such as a piezoelectric vibrator, a capacitor and a resistor, for example, an insulating layer (a piezoelectric layer or a dielectric layer) is provided for a lower electrode layer (a first thin film layer). , A resistive layer, or an upper electrode layer (second thin film layer).

In the case of manufacturing a piezoelectric element or the like by the first and second methods, a series of steps described with reference to FIGS. 17 and 18 respectively include the first thin film layer and the second thin film layer. It is required in the formation process. For this reason,
When thin film layers are formed by the first and second methods, operations such as formation and removal of a resist must be repeated, which is not only inefficient in work efficiency but also disadvantageous in manufacturing cost.

On the other hand, in the case of forming a piezoelectric element or the like by the third method, after forming a first thin film layer using a first mask, the formation position of the opening differs from that of the first mask. Using the second mask, a second thin film layer is formed so as to partially overlap the first thin film. Therefore, the second
The second thin film layer cannot be accurately formed on the first thin film layer unless the mask is accurately positioned with respect to the substrate. In particular, as the size of electronic components becomes smaller, the demand for such positioning accuracy becomes higher.

In the above-mentioned publication, no consideration is given to the positioning of the mask, and it cannot be said that it is suitable as a second or subsequent mask in forming a plurality of thin films.

Further, the conventional thin film forming method has another problem that the substrate is easily damaged, and in particular, the first thin film layer already formed when the second thin film layer is formed is easily damaged.
That is, in the first method, when the entire thin film layer is etched using the resist pattern as a mask, the substrate and the first thin film layer are easily damaged. In the second method, the resist components are volatilized during the film formation to deteriorate the film formation components, or the resist is deteriorated, and the subsequent removal becomes difficult.
In the third method, since the mask is stuck on the substantially entire surface of the substrate via an adhesive or the like, the substrate and the first thin film layer are easily damaged when the mask is separated.

The present invention has been conceived under such circumstances, and in a method of manufacturing an electronic component including a step of laminating a plurality of thin film layers, the thin film layers are formed with high work efficiency. It is another object of the present invention to form the thin film layer without damaging the substrate and the already formed thin film layer, and to accurately form another thin film layer on the already formed thin film layer.

[0013]

According to the present invention, the following technical measures are taken to solve the above-mentioned problems.

According to a method for manufacturing an electronic component provided by the first aspect of the present invention, a first thin film is formed on a substrate by using a first mask formed separately from the substrate.
Forming a second thin film on the substrate using a second mask formed separately from the substrate so as to at least partially overlap the first thin film. A thin film forming step, wherein the second mask comprises: an alignment mark formed at a portion corresponding to the alignment mark on the substrate;
And a through hole for forming the second thin film. In the second thin film forming step, the alignment mark of the substrate is aligned with the alignment mark of the second mask, and A first step of positioning the second mask with respect to the second mask; a second step of fixing the second mask with respect to the substrate; and a thin film material formed on the substrate through a through hole of the second mask. And forming a third thin film on the substrate by supplying the second thin film on the substrate.

In a preferred embodiment, the first
Has a through-hole for forming the first thin film on the substrate, and an additional through-hole for forming an alignment mark on the substrate; Forming a thin film on the substrate through a first step of fixing the first mask on the substrate, and supplying a thin film material to the substrate through both the through hole and the additional through hole. And a second step of simultaneously forming the first thin film and the alignment mark.

In the present invention, since the mask is formed separately from the substrate, when forming the first and second thin films, it is necessary to repeat the operation of forming a resist on the substrate and removing it. It is advantageous in terms of work efficiency and manufacturing cost. Then, after using the first and second masks, if the thin film formed on the mask is removed,
Since the first and second masks can be used repeatedly, this is advantageous in cost from this point.

Further, when the first thin film layer is formed, an alignment mark is formed on the substrate, so that it is not necessary to separately provide a step of forming the alignment mark, and the work efficiency and the manufacturing cost are reduced. This is advantageous.

Moreover, in the above-described manufacturing method, the alignment mark provided on the substrate is aligned with the alignment mark of the second mask, and the second thin film layer is formed after positioning the second mask. The second thin film layer can be accurately formed on the first thin film layer.

The alignment mark of the second mask may be formed by applying ink or the like to the surface of the second mask, or may be formed simultaneously with the formation of the through hole when forming the second mask. It may be formed as an additional through hole or as a depression.

However, if the alignment mark of the second mask is formed as an additional through hole, there is no need to provide a separate step for forming the alignment mark, which is advantageous in terms of work efficiency. When a second mask provided with an additional through hole is used, in the second thin film forming step, in the third step, the substrate is connected to the substrate via the through hole of the second mask and the additional through hole. A thin film material is provided.
As a result, at the same time as the second thin film, an additional alignment mark is formed on the alignment mark of the substrate formed in the first thin film forming step.

The through holes of the first and second masks include, for example, one having an inclined surface or an upright surface, or a first portion having an inclined surface and a second portion having an upright surface. Examples of the form of communication are given.

The through hole having an upright inner surface has a tapered shape having a large opening and a small opening. Therefore, if the thin film is formed by fixing the mask so that the large opening faces the substrate, the edge of the thin film is inclined toward the center of the thin film. As a result, even if the thin film is formed so as to contact the inner surface of the through hole, the mask can be separated from the substrate without impairing the shape of the thin film.

In order to make the inner surface of the through hole of the substrate thin film an inclined surface, for example, a plate-like material made of single crystal silicon having a (100) cut surface is used as a mask forming material. Anisotropic etching may be performed.

On the other hand, if a thin film is formed using a mask having a through-hole whose inner surface is an upright surface, the end surface of the thin film becomes an upright surface. Therefore, if this mask is used, it is possible to form a thin film with high precision and a small width.

In order to make the inner surface of the through-hole upright,
For example, dry etching may be performed on the mask forming material.

Also, the through-hole may be formed such that the first portion having an inclined surface and the second portion having an upright surface communicate with each other, and a thin film may be formed by disposing a mask such that the first portion side is close to the substrate. A disadvantage in using a mask in which the inner surface of the through hole is an inclined surface or an upright surface as a mask (a disadvantage that it is difficult to form a narrow thin film with high accuracy on the inclined surface;
With respect to the upright surface, it is possible to reduce the disadvantage that a part of the thin film formed on the substrate is taken away when the mask is separated from the substrate), while also making the inner surface of the through hole an inclined surface or an upright surface. You can also enjoy the benefits.

In the case where the through hole is formed as a form in which the first portion having the inclined surface and the second portion having the upright surface communicate with each other, for example, (10)
0) A plate made of single crystal silicon having a cut surface is used, anisotropic etching is performed from the first surface of the mask forming material, and dry etching is performed from the second surface of the mask forming material. .

In a preferred embodiment, the first
Alternatively, the second mask is recessed from the first surface of at least one of the first and second masks,
A recess having a larger diameter than the through hole of the first or second mask and communicating with the through hole of the first or second mask, and a first thin film forming step of the first thin film forming step; The step or the second step of the second thin film forming step is such that the first surface of the first or second mask is in contact with the substrate, and the first or second mask is formed on the substrate. This is done by fixing.

In this manufacturing method, a recess having a larger diameter than the through hole is formed, and a mask having a through hole formed so as to communicate with the recess is used. When this mask is fixed on the substrate, since the concave portion having a larger diameter than the through hole is formed in the mask, the contact area between the substrate and the mask is:
The size is smaller than when no recess is formed. As a result, even when the mask is fixed to the substrate using an adhesive, damage to the substrate and damage to a thin film (first thin film layer) already formed on the substrate are suppressed. Will be able to

The first or second mask is formed by forming a flange portion protruding in the thickness direction from the peripheral edge of the base in which the through hole is formed, so that a recess having a diameter slightly smaller than the diameter of the substrate is provided. Alternatively, one or more concave portions may be provided locally.

The material constituting the first mask and the second mask is, for example, single crystal silicon or photosensitive glass.

Examples of the photosensitive glass include a glass material mixed with a negative or positive resin material.

Examples of the negative type resin material include monomers such as vinyl ester having a polymerizable vinyl group, styrene, acrylic acid ester and methacrylic acid ester, or oligomers of these monomers, unsaturated polyester resin, and urethane acrylate. Other examples include acrylic monomers or oligomers having a polymerizable unsaturated double bond.

On the other hand, as the positive type resin material, in addition to a polymer compound having an ether bond which is susceptible to photolysis (for example, polyethylene oxide, cellulose, polyacetal, etc.), a polymer such as polyethylene which easily generates radicals upon irradiation with light is used. A mixture of a low-molecular compound that is decomposed by light irradiation, such as a compound and a diazo compound, and another compound is given.

According to a second aspect of the present invention, a first thin film is formed on the substrate while a first mask, which is formed separately from the substrate and has a through hole, is fixed on the substrate. A first thin film forming step of forming a second mask, and a state in which after removing the first mask from the substrate, a second mask formed as a separate body from the substrate and having a through hole is fixed on the substrate. A second thin film forming step of forming a second thin film on the substrate so that at least a part of the first thin film overlaps with the first thin film.
The first mask or the second mask may be recessed from the first surface of the first mask or the second mask, and may be more than a through hole of the first mask or the second mask. The one having a large diameter and having a concave portion communicating with the through hole of the first mask or the second mask is used, and the first mask or the second mask is formed of the first mask or the second mask. A method for manufacturing an electronic component is provided, wherein the first surface of the second mask is fixed in contact with the substrate.

In this manufacturing method, a concave portion having a diameter larger than that of the through hole is formed, and a mask having a through hole formed so as to communicate with the concave portion is used. When this mask is fixed on the substrate, since the concave portion having a larger diameter than the through hole is formed in the mask, the contact area between the substrate and the mask is:
The size is smaller than when no recess is formed. As a result, damage to the substrate and damage to a thin film already formed on the substrate can be suppressed.

Here, examples of the first thin film and the second thin film include those which are components of a piezoelectric vibrator, a capacitor, or a resistor. For example, in a piezoelectric vibrator or a capacitor, an insulator layer and an upper electrode layer are laminated on a lower electrode layer. In this case, for example, the lower electrode corresponds to the first thin film, and the insulator layer or the upper layer is formed. The electrode corresponds to the second thin film. On the other hand, in the case of a resistor, a resistance layer is formed on a pair of electrodes, or a pair of electrodes is formed at each of both ends of the resistance layer. Corresponds to the second thin film layer, and in the latter case, the resistance layer becomes the first thin film layer,
The electrode corresponds to the second thin film layer.

Further, the technical idea described in the second aspect of the present invention is not limited to the case where an electronic component is manufactured, but is also applicable to a case where a conductor wiring is formed on a circuit board, for example. That is, in a state where a mask having a through hole is fixed on a substrate, a thin film material is supplied through the through hole to form a thin film on the substrate. If a mask that has a recess and is larger in diameter than the through hole and has a recess communicating with the through hole is used, and the mask is fixed with the first surface of the mask in contact with the substrate, damage to the substrate may occur. The effect of being able to form a thin film while avoiding it can be enjoyed.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

The method for manufacturing an electronic component according to the present invention includes a step of forming a plurality of thin film layers on a substrate using a mask.

FIGS. 1, 4 and 7 show the masks.
(E), FIGS. 8, 10 to 12, and 14
The form shown in (a) is mentioned. The planar shape of these masks M1 to M8 corresponds to the planar shape of the substrate on which the thin film is to be formed. For example, when the substrate is a circular shape in plan view such as a wafer, it is shown in FIG. Thus, it is formed in a circular shape in plan view. Then, each of the masks M1 to M8
On the periphery of the cross-shaped alignment mark 10Ab ~
10 Hb is formed.

FIGS. 1, 4, 7 (e) and 8
The masks M1, M2, M3 and M4 shown in FIG.
a, 10Ba, 10Ca, and 10Da, and only one of the masks M1 to M8 shown in FIGS.
Two windows 10E, 10F, 10G are shown. However, in actual masks M5 to M7, a larger number of windows 10A, 10B, and 10C may be formed, and these are illustrated in a simplified manner in the drawings.

The mask M1 shown in FIG. 1 is obtained by forming a window 10Aa as a through hole and a window 10Ab as an additional through hole in a substrate 1A made of silicon. The window 10Aa is for forming a thin film constituting an electronic component on a substrate, and has a plan view form such as a rectangular shape or a circular shape. On the other hand, the window 10Ab is for forming an alignment mark on the substrate,
For example, it has a cross shape in plan view.

The first surface 11A and the second surface 12A of the silicon substrate 1A are (100) cut surfaces. Window 1
0Aa and 10Ab are the first surface 11A of the silicon substrate 1A.
Of the openings 13Aa and 13Ab in the second surface 12A
Are larger than the areas of the openings 14Aa and 14Ab in the first embodiment, and have a tapered shape. These windows 1
0Aa and 10Ab are inclined surfaces whose inner surfaces 15Aa and 15Ab are (111) planes. Window 10Aa,
In the cross-sectional form of 10Ab, the inner surfaces 15Aa, 15A
The oblique angle of b is 55 ° with respect to the second surface 12A.

In such a mask M1, the thin films 18A and 19A are formed through the steps shown in FIGS. 2A and 2B. First, as shown in FIG. 2A, a first surface 11A is formed on one surface 17A of a substrate 16A on which a thin film is to be formed.
Are temporarily contacted to make the mask M1 contact. In this state, the window 1 is formed by a technique such as sputtering or vapor deposition.
After the thin film material is supplied through OAa and 10Ab, FIG.
As shown in (b), by removing the mask M1, thin films 18A and 19A having a smaller peripheral portion than the central portion are formed on one surface 17A of the substrate 16A.

In such a mask M1, the thin film 18A,
Since the side surface of 19A is inclined, the thin films 18A, 19A
The advantage that the mask M1 can be separated from the substrate 16A without damaging the substrate M can be enjoyed.

The mask M1 shown in FIG.
It is manufactured through the process shown in (e).

First, as shown in FIG. 3A, a silicon substrate 1A having a thickness of about 200 μm and a (100) cut surface of the first surface 11A and the second surface 12A is prepared. Next, as shown in FIG. 3B, the first surface 11A and the second surface 12A of the silicon substrate 1A are
Thermal oxide films 20A and 21A having a thickness of about 1 μm are formed. These thermal oxide films 20A and 21A are formed by wet-oxidizing the silicon substrate 1A at 1050 to 1150 ° C. for 6 to 10 hours and oxidizing the surfaces 11A and 12A of the silicon substrate 1A to silicon oxide.

Subsequently, as shown in FIG. 3C, a resist 3A is formed on one surface 22A of the thermal oxide film 20A. This resist 3A is formed by known photolithography. For example, the resist 3A is formed by forming a photosensitive film with a photosensitive resin on one surface 22A of the thermal oxide film 20A,
The photosensitive film is exposed with a photomask interposed, and unnecessary portions are removed by wet etching, thereby forming openings 30Aa and 30Ab. As the etchant, for example, an alkaline developer that dissolves both the photosensitive film and the thermal oxide film 20 but does not dissolve silicon is used. Of course, fluoric acid may be used as an etching solution. In this case, if the etching process is performed only from the side where the photosensitive film is formed, a portion of the thermal oxide film 20A is removed at the same time as the portions corresponding to the openings 30Aa and 30Ab in the photosensitive film are removed. The film 20A also has openings 23Aa and 23Ab.

Next, as shown in FIG. 3D, windows 10Aa and 10Ab are formed in the silicon substrate 1A.
The windows 10Aa and 10Ab are formed on the first surface 11A of the silicon substrate 1A after the resist 3A is removed by etching.
A, openings 23Aa and 23Ab of thermal oxide film 20A in FIG.
Is formed by performing an etching process from a portion exposed through the substrate. The etching process is performed by, for example, wet etching (anisotropic etching) using a KOH aqueous solution, an EDP solution, or a TMAH solution.

In the silicon crystal, the (111) plane is inclined at an angle of 55 ° with respect to the (100) plane.
The (0) plane has a higher etching rate than the (111) plane. As a result, when the (100) cut surface is wet-etched, the windows 10Aa and 10Ab
a, 13Ab are tapered so that the area of each of the openings 14Aa, 14Ab is larger than the area of each of the openings 14Aa, 14Ab. . Of course, without removing the resist 3A, the window 10 with respect to the silicon substrate 1A.
Aa and 10Ab may be formed.

Finally, by removing the thermal oxide films 20A and 21A as shown in FIG. 3E, a mask M1 as shown in FIG. 1 is formed. Thermal oxide films 20A, 21A
Is removed by, for example, wet etching using fluorine acid as an etchant.

The mask M2 shown in FIG. 4 has a window 10Ba as a through hole for forming a thin film constituting an electronic component and a substrate for forming an alignment mark on the substrate 1B made of silicon. Window 1 as additional through hole
0Bb is formed.

The first surface 11B and the second surface 12B of the silicon substrate 1B are, for example, (100) cut surfaces or (1)
11) It is a cut surface. Windows 10Ba, 10Bb
Are openings 13 in the first surface 11B of the silicon substrate 1B.
Area of Ba, 13Bb and opening 14 in second surface 12B
Ba and 14Bb have the same area, and the inner surface 15B
a, 15Bb are erect surfaces.

In such a mask M2, a thin film is formed through the steps shown in FIGS. 5A and 5B. First, as shown in FIG. 5A, the mask M2 is temporarily fixed such that the second surface 12B is in contact with one surface 17B of the substrate 16B on which a thin film is to be formed. In this state, the windows 10Ba, 1Ba are formed by a technique such as sputtering or vapor deposition.
After supplying the thin film material to the substrate through OBb, FIG.
As shown in (b), by removing the mask M2, a thin film 18 having a uniform thickness is formed on one surface 17B of the substrate 16B.
B and 19B are formed.

In such a mask M2, the windows 10Ba,
Since the thin films 18B, 19B are formed in contact with the inner surfaces 13Ba, 13Bb of 10Bb, the thin films 18Aa, 1B are formed.
The advantage that 8Ab can be formed with a narrow width and a fine pitch with high accuracy can be enjoyed.

The mask M2 used in this manner is
It is manufactured through the steps shown in FIGS.

First, as shown in FIG. 6A, the first surface 11B and the second surface 12B are about 200 μm thick.
For example, a silicon substrate 1 having a (100) cut surface or a (111) cut surface is prepared. Then, FIG.
As shown in (b), the first surface 11 of the silicon substrate 1B
A resist 3B is formed on B. The resist 3B is formed to have openings 30Ba and 30Bb by exposing and developing after forming a photosensitive film with a photosensitive resin, for example.

Subsequently, as shown in FIG. 6C, windows 10Ba and 10Bb are formed in the silicon substrate 1B.
The windows 10Ba and 10Bb correspond to the first surface 1 of the silicon substrate 1B.
Openings 30Ba, 30Bb of resist 3B in 1B
Is formed by performing an etching process from a portion exposed through the substrate. The etching process is performed by dry etching (isotropic etching) such as RIE (reactive ion etching) using oxygen gas. As a result, whether the cut surface of the substrate 1B is (100) (11
Regardless of 1), the windows 10Ba, 10Bb are formed such that the areas of the openings 13Ba, 13Bb are the same as the areas of the openings 14Ba, 14Bb.

Finally, as shown in FIG. 6D, by removing the resist 3B, a mask M2 as shown in FIG. 4 is formed. The removal of the resist 3B is performed by, for example, wet etching using a stripping solution-106 (manufactured by Tokyo Ohka) as an etching solution.

The mask M4 having the same form as the mask M2 shown in FIG. 4 is formed from a substrate made of photosensitive glass as described below with reference to FIGS. 7A to 7E. Can also.

First, as shown in FIG. 7A, a substrate 1C having a thickness of about 200 μm made of a photosensitive glass material is prepared. As the photosensitive glass material, for example, a negative type is used.

Next, as shown in FIG.
A reticle (photomask) 3C is placed on the first surface 11C of C. The reticle 3C is connected to the window 10 in the substrate 1C.
The regions where Ca, 10Cb (see FIG. 7 (e)) are to be formed are the ultraviolet transmitting regions 3Ca, 3Cb, and the other portions are the ultraviolet non-transmitting regions 3Cc, and the thickness thereof is about 500 μm. ing.

Subsequently, as shown in FIG. 7C, the substrate 1C is irradiated with ultraviolet rays via the reticle 3C. Since the reticle 3C is provided with the ultraviolet ray transmitting areas 3Ca, 3Cb and the ultraviolet ray non-transmitting area 3Cc, only the ultraviolet ray transmitted through the ultraviolet ray transmitting areas 3Ca, 3Cb is irradiated on the substrate 3C, and the ultraviolet ray irradiation area 19Ca on the substrate 1C. ,
A latent image is selectively formed on 19Cb. Subsequently, the substrate 1C is heated, for example, at about 580 ° C. to crystallize the ultraviolet irradiation regions 19Ca and 19Cb, so that the ultraviolet irradiation regions 19Ca and 19Cb are easily dissolved in acid.

Next, as shown in FIG. 7 (d), the substrate 1 is directly irradiated with ultraviolet rays without passing through the reticle 3C, so that the ultraviolet irradiation areas 19Ca, 19C
The portion 19Cc other than b is in a state where it is easily crystallized by heating.

Finally, as shown in FIG. 7E, after the windows 10C are formed by dissolving and removing the ultraviolet irradiation regions 19Ca and 19Cb in the substrate 1C with dilute nitric acid or the like, the substrate 1C is heated at about 850 ° C. Then, the whole is crystallized to be in a physically stable state.

The mask M4 shown in FIG. 8 has openings 13Da and 13Db in the first surface 11D of the silicon substrate 1D and the first window portion 10D having an inclined inner surface.
c, 10De and openings 14Da, 14Db in the second surface 12D
Second window portion 1 having a vertical surface
It has windows 10Da and 10Db communicating with 0Dd and 10f. That is, these windows 10Da and 10Db are
This has a form in which the windows 10Aa and 10Ab of the mask M1 in FIG. 1 communicate with the windows 10Ba and 10Bb of the mask M2 in FIG.

Such a mask M4 is shown in FIGS.
It is manufactured through the process shown in (e).

First, as shown in FIG. 9A, for example, the first surface 11D and the second surface 1 have a thickness of about 200 μm.
Thermal oxide films 20D and 21D are formed on a first surface 11D and a second surface 12D of a silicon substrate 1D whose 2D is a (100) cut surface. Next, as shown in FIG. 9B, openings 23Da, 23Db, 24Da, and 24Db are formed in these thermal oxide films 20D and 21D.
Such thermal oxide films 20D, 21D and opening 23D
a, 23Db, 24Da and 24Db are shown in FIG.
It can be formed in the same manner as described with reference to FIG.

Subsequently, as shown in FIG. 9C, second windows 10Dd and 10Df are formed in the silicon substrate 1D. The second windows 10Dd and 10Df are connected to the silicon substrate 1
Opening 24 of thermal oxide film 21D on second surface 12D of D
It is formed by performing an etching process (isotropic etching) from a portion exposed through Da and 24Db. The etching process is performed, for example, by RIE using an oxygen gas, similarly to the windows 10Ba and 10Bb of the mask M2 shown in FIG.
This is performed by dry etching (isotropic etching) such as (reactive ion etching).

Next, as shown in FIG. 9D, first windows 10Dc and 10De are formed on the silicon substrate 1D, and the entire windows 10Da and 10Db are formed. The first windows 10Dc and 10De are connected to the first surface 11 of the silicon substrate 1D.
D, openings 23Da and 23Db of thermal oxide film 20D
Is formed by performing an etching process (anisotropic etching) from a portion exposed through the substrate. The etching process is performed by, for example, wet etching using a KOH aqueous solution. As described above, when a silicon substrate 1D made of a silicon single crystal having a (100) cut plane is wet-etched, its inner surface is an inclined surface.

Finally, as shown in FIG. 9E, the thermal oxide films 20D and 21D are removed by wet etching using, for example, an etching solution such as fluoric acid to form a mask M4 as shown in FIG. Is formed.

In FIG. 8, the first window 10D
Although the depths of c and 10De are substantially the same as the depths of the second windows 10Dd and 10Df, these windows 10Dc and 10Df have the same depth.
Windows 10Da and Db may be formed as those having different depths of 10Dd, 10De and 10Df.

The masks M5 to M5 shown in FIGS.
M7 has a flange portion 41 protruding in the thickness direction from the peripheral portion of the base portion 40, and the first surfaces 11E, 11F, 11
A concave portion 42 which is recessed from G is provided. The base 40 has openings 14Ea, 14Fa, 14Ga, 14Eb, and 14F in the second surfaces 12E, 12F, and 12G.
b, a plurality of windows 10Ea, 10Eb, 1 having 14Gb
0Fa, 10Fb, 10Ga, and 10Gb are provided. These windows 10Ea to 10Ga, 10Eb to 10G
b is an opening 13Ea of the first surface 11E to 11G of the base 40.
To 13Ga, 13Eb to 13Gb and communicate with the recess 42.

As will be described later, when the masks M5 to M7 are mounted on the substrate when forming the thin film, the mask M5 can be formed by making the opening 43 of the concave portion 42 face the substrate.
As for M7, only the flange portion 41 comes into contact with the substrate. Therefore, the thin film formed by these masks M5 to M7 is inferior to the case where the entirety of the masks M5 to M7 is in contact with the substrate, but the base 40 of the masks M5 to M7 does not contact the substrate. The damage of the substrate can be suppressed by the amount. Further, when a plurality of thin films are formed by lamination as in the case of forming a piezoelectric thin film vibrator, a plurality of types of masks may be used. In this case, as masks to be used after the second, FIGS.
If the masks M5 to M7 as shown in FIG. 2 are used, only the peripheral portions (flange portions 41) of the masks M5 to M7 are in contact with the substrate, so that damage to the previously formed thin film can be suppressed. . Such an advantage is obtained by using the masks M5 to M7.
Can be enjoyed even when it is fixed to a substrate via an adhesive.

The masks M5 to M7 shown in these figures are:
After the recesses 42 are formed by etching the silicon substrates 1E, 1F, and 1G as shown in FIG. 13, the mask M5 of FIG. 10 is the same as that described with reference to FIGS. 3A to 3E. Through the same steps as the method of forming M1, FIG.
The first mask M6 goes through the same steps as the method of forming the mask M2 described with reference to FIGS.
The mask M7 of FIG. 12 is formed through the same steps as the method of forming the mask M4 described with reference to FIGS. 9A to 9E.

Of course, as the mask, the window 10Aa of the mask M1 shown in FIG. 1, the window 10Ba of the mask M2 shown in FIG. 4, and the window 10Da of the mask M4 shown in FIG.
Windows 10Aa, 10Ba, 10Da of two or more of
May be used in combination.

Further, as shown in FIG.
Masks M5 to M7 having recesses 40 as shown in FIGS. 0 to 12 combined with masks M1 to M3 having no recesses as shown in FIG. 1, FIG. 4 or FIG. The mask M8 may be used. That is, the mask M8 has a portion that can cover the substrate via the concave portion 42H and a portion that comes into contact with the substrate, and has windows 10Ha, 10Hb, and 10Hc formed in the respective portions. In such a mask M8, for example, FIG.
As shown in (b), the wiring 19H can be simultaneously formed on the substrate 16H in addition to the thin film 17H constituting the electronic element and the alignment mark 18H. In the case of forming a circuit board (electronic component) including the thin film 17H of the electronic element and the wiring 19H, it is necessary to form the wiring 19H with high accuracy and a fine pattern. Accuracy is not required. In such a case, if the mask M8 is used, the thin film 17H of the electronic element can be connected to the wiring 1 while preventing the substrate 16H from being damaged by the portion where the concave portion 42H is formed.
As for 9H, a thin film is formed in a state where the portions where the concave portions 42H are not formed are in contact with each other, and the wiring 19H can be formed with high accuracy.

Next, taking as an example the case where three types of masks M5a, M5b and M5c having windows 10Ea, 10Eb and 10Ec having the same sectional shape as the mask M5 shown in FIG. The manufacturing method will be described with reference to FIGS. The masks M5a, M5b, and M5c shown in FIG.
For convenience of explanation, only one window 10Ea, 10Eb, 10Ec is provided so that one element can be formed. As the substrate 5, a single-crystal silicon mother substrate having a (100) cut surface with a thickness of about 500 μm is used. It is assumed that a material having silicon oxide films 51 and 52 with a thickness of about 500 nm provided on both surfaces of the material 50 is used.

First, as shown in FIG. 16A, the lower electrode layer 60 and the alignment mark 70 are formed on the substrate 5 with the first mask M5a temporarily fixed.

The first mask M5a is temporarily fixed by, for example, applying an epoxy-based adhesive or the like to the flange portion 4 of the mask M5a.
This is performed by interposing between the substrate 1 and the substrate 5.
In this case, the positioning of the first mask M5a with respect to the substrate 5 may be rough.

The lower electrode layer 60 and the alignment mark 70 are formed by sputtering, evaporation, CV
D, etc., using aluminum particles as a mask M5a
Is performed by supplying from above. Some of the supplied aluminum particles are supplied to the windows 10Ea and 10Ea of the mask M5a.
In order to reach the surface of the substrate 5 through 10Eb, the lower electrode layer 60 and the alignment mark 70 are formed on the substrate 5 as an Al thin film corresponding to the opening shapes of the windows 10Ea and 10Eb. At this time, the thickness of the lower electrode layer 60 and the alignment mark 70 is about 100 nm.

After the formation of the lower electrode layer 60 and the alignment marks 70 is completed, the first mask M5a is separated from the substrate 5 by dissolving the thermoplastic adhesive with an organic solvent such as IPA. Although an Al film is formed on the first mask M5a, the first mask M5a can be reused by removing the Al film with an aqueous hydrochloric acid solution or the like.

Next, as shown in FIG.
After the mask M5b is temporarily fixed, a piezoelectric layer 61 and additional alignment marks 71 are formed. The window 10Ea 'of the second mask M5b is connected to the window 1 of the first mask M5b.
0Ea is different from the formation position of the lower electrode layer 6.
The piezoelectric layer 61 can be formed so that a part of the piezoelectric layer 61 is overlapped with zero.

The temporary fixing of the second mask M5b is performed by using the window 10Eb 'as an alignment mark of the second mask M5b.
Is performed by interposing a thermoplastic adhesive between the substrate 5 and the flange portion 41b of the second mask M5b in the same manner as the first mask M5a after the alignment with the alignment mark 70 of the substrate 5. . Second disc M5b
The alignment of the window (alignment mark) 10Eb 'with the alignment mark 70 of the substrate 5 is performed by confirming these positions with an infrared microscope.

When a mask formed of photosensitive glass is used, the positioning of the mask with respect to the wafer may be performed using an optical microscope.

The piezoelectric layer 61 and the additional alignment mark 71 are formed by supplying ZnO particles from above the second mask M5b by, for example, sputtering. A part of the supplied ZnO particles is
In order to reach the surface of the substrate 5 from the windows 10Ea 'and 10Eb' of the substrate 5b, a piezoelectric layer 61 and an additional alignment mark 72 are formed on the substrate 5 as a ZnO thin film corresponding to the opening shape of the windows 10Ea 'and 10Eb'. . At this time, the thicknesses of the piezoelectric layer 61 and the additional alignment mark 72 are, for example, about 1 μm.

The second mask M5b includes the window 1
Instead of providing 0Eb ', a wafer provided with a mark corresponding to the alignment mark 70 of the wafer with ink or the like may be used. In that case, no additional alignment mark is formed.

After the formation of the piezoelectric layer 61 and the additional alignment mark 71 is completed, the second mask M5b is separated from the wafer 6 by dissolving the thermoplastic adhesive with an organic solvent such as IPA. The second mask M5b has ZnO
Although a film is formed, the second mask M5b can be reused by removing it with an acetic acid aqueous solution or the like.

Subsequently, as shown in FIG. 16 (c), after the third mask M5c having different windows 10Ea ″ and 10Eb ″ from the first mask M5a is temporarily fixed to the wafer 6. , An upper electrode 62 is formed. Third mask M
The temporary fixing of 5c is performed in the same manner as the temporary fixing of the second mask M5b, and the formation of the upper electrode 62 is performed by forming an Al thin film by sputtering or the like as in the case of the lower electrode 60.

Next, as shown in FIG. 16D, a thermoplastic adhesive is dissolved using
After the third mask M5c is separated from the substrate, as shown in FIG. 16E, a cavity 73 is formed immediately below a portion where the lower electrode 60, the piezoelectric film 61, and the upper electrode 62 overlap. The cavity 73 is provided to facilitate deformation of the piezoelectric thin film element.

The cavity 73 is formed by forming a resist (not shown) on one surface 52a of the oxide film 52 by photolithography and then removing a part of the oxide film 52 by etching to form an opening 52b. Membrane 5
The etching is performed by etching the silicon base material 50 using the mask 2 as a mask.

In FIG. 15, the case where one piezoelectric thin-film vibrator is formed from the substrate 5 has been described. However, usually, a plurality of piezoelectric thin-film vibrators are simultaneously formed from a wafer as a substrate. In that case, the individual piezoelectric thin film vibrators are finally obtained by dicing the wafer.

[Supplementary Note] (Supplementary Note 1) A first thin film is formed on the substrate by using a first mask formed separately from the substrate and having a through hole for forming a thin film on the substrate. A first thin film forming step of forming the first thin film by using a second mask formed separately from the substrate and having a through hole for forming a thin film on the substrate; A second thin film forming step of forming a second thin film on the substrate so as to at least partially overlap the substrate. Further comprising an alignment mark formed at a portion corresponding to the above, wherein the second thin film forming step aligns the alignment mark of the substrate with the alignment mark of the second mask, The second machine A first step of positioning a mask; a second step of fixing the second mask to the substrate;
Supplying a thin film material to the substrate through the through hole of the mask to form the second thin film on the substrate. . (Supplementary Note 2) The first mask further has an additional through hole for forming an alignment mark on the substrate, and the first thin film forming step includes the first thin film forming step.
Fixing the mask on the substrate, supplying thin film material to the substrate through both the through hole and the additional through hole, and forming the first thin film and the substrate on the substrate. 2. The method of manufacturing an electronic component according to claim 1, further comprising: forming a second alignment mark simultaneously. (Supplementary Note 3) At least one of the first mask and the second mask is recessed from the first surface of the first mask or the second mask, and the first mask or the second mask is A first step of the first thin film forming step, the recess having a larger diameter than the through hole of the second mask and communicating with the through hole of the first mask or the second mask; Alternatively, the second step of the second thin film forming step is such that the first surface of the first mask or the second mask is in contact with the substrate, and the first mask or the 3. The method of manufacturing an electronic component according to claim 1, wherein the method is performed by disposing a second mask. (Supplementary Note 4) A plurality of through holes of the first mask or the second mask are formed, and the plurality of through holes communicate with a concave portion of the first mask or the second mask. 3. The method for manufacturing an electronic component according to supplementary note 3. (Supplementary note 5) The electronic device according to Supplementary note 3 or 4, wherein the concave portion of the first mask or the second mask is provided by forming a flange portion protruding from a peripheral edge of the base in a thickness direction of the base. The method of manufacturing the part. (Supplementary Note 6) At least one of the first mask and the second mask is made of single-crystal silicon.
A method for manufacturing an electronic component according to any one of supplementary notes 1 to 5. (Supplementary Note 7) The method for manufacturing an electronic component according to any one of Supplementary Notes 1 to 5, wherein at least one of the first mask and the second mask is made of photosensitive glass. (Supplementary Note 8) At least one of the through holes of the first mask and the second mask is anisotropic with respect to a plate-shaped mask forming material made of single crystal silicon having a (100) cut surface. Any one of appendices 1 to 5, wherein the inner surface is formed as an inclined surface by performing the etching.
4. A method for manufacturing an electronic component according to any one of the above. (Supplementary Note 9) At least one of the through holes of the first mask and the second mask is subjected to isotropic etching with respect to a mask forming material, so that the inner surface is an upright surface. A method for manufacturing an electronic component according to any one of supplementary notes 1 to 5. (Supplementary Note 10) At least one of the through holes of the first mask and the second mask is formed from a first surface of a plate-shaped mask forming material made of single crystal silicon having a (100) cut surface. By using both isotropic etching and isotropic etching performed from the second surface of the mask forming material, a first portion whose inner surface is an inclined surface and a second portion whose inner surface is an upright surface 6. The method for manufacturing an electronic component according to any one of supplementary notes 1 to 5, wherein the electronic component is configured to communicate with the electronic component. (Supplementary Note 11) A first thin film forming step of forming a first thin film on the substrate in a state where a first mask having a through hole and formed separately from the substrate is fixed on the substrate. After removing the first mask from the substrate, a second mask having a through hole and formed separately from the substrate is fixed on the substrate,
A second thin film forming step of forming a second thin film on the substrate so that at least a part of the first thin film overlaps with the first thin film. As at least one of the second masks,
The first mask or the second mask is recessed from the first surface of the first mask or the second mask and has a diameter larger than the through hole of the first mask or the second mask. And a mask having a concave portion communicating with the through hole of the first mask, and the first mask or the second mask is a first mask of the first mask or the second mask.
A method for manufacturing an electronic component, wherein a surface is fixed in a state of being in contact with the substrate. (Supplementary Note 12) The method of manufacturing an electronic component according to any one of Supplementary Notes 1 to 11, wherein the first thin film and the second thin film are components of a piezoelectric vibrator, a capacitor, or a resistor. (Supplementary Note 13) With a mask having a through hole and formed separately from the substrate fixed on the substrate,
A method of forming a thin film on the substrate by supplying a thin film material through the through hole, wherein the mask is recessed from a first surface of the mask and has a larger diameter than the through hole. A method for manufacturing an electronic component, wherein a mask having a concave portion communicating with the through hole is used, and the mask is fixed with a first surface of the mask in contact with the substrate.

[0095]

As described above, according to the present invention, in a method for manufacturing an electronic component including a step of laminating a plurality of thin film layers, the thin film layers are formed with good work efficiency on a substrate or a thin film already formed. A layer can be formed without damaging the layer, and another thin film layer is accurately laminated on the already formed thin film layer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first example of a mask used in a method of manufacturing an electronic component according to the present invention.

FIG. 2 is a cross-sectional view for explaining a method of forming a thin film using the mask of FIG.

FIG. 3 is a cross-sectional view for explaining the method for manufacturing the mask in FIG.

FIG. 4 is a sectional view showing a second example of a mask used in the method for manufacturing an electronic component according to the present invention.

FIG. 5 is a cross-sectional view for explaining a method of forming a thin film using the mask of FIG.

FIG. 6 is a cross-sectional view for explaining the method for manufacturing the mask in FIG.

FIG. 7 is a sectional view illustrating a third example of a mask used in the method for manufacturing an electronic component according to the present invention and a method for manufacturing the mask.

FIG. 8 is a sectional view showing a fourth example of a mask used in the method for manufacturing an electronic component according to the present invention.

FIG. 9 is a cross-sectional view for explaining the method for manufacturing the mask in FIG.

FIG. 10 is a sectional view showing a fifth example of a mask used in the method for manufacturing an electronic component according to the present invention.

FIG. 11 is a sectional view showing a sixth example of a mask used in the method for manufacturing an electronic component according to the present invention.

FIG. 12 is a sectional view showing a seventh example of a mask used in the method for manufacturing an electronic component according to the present invention.

FIG. 13 is a cross-sectional view for explaining a method of manufacturing the mask shown in FIGS. 10 to 12.

FIG. 14 is a cross-sectional view for explaining an eighth example of a mask used in the method for manufacturing an electronic component according to the present invention and a method for forming a thin film using the same.

FIG. 15 is a plan view illustrating an alignment mark formed on a mask.

FIG. 16 is a cross-sectional view for explaining a method of manufacturing a piezoelectric thin-film vibrator using a mask similar to the mask of the fifth example described with reference to FIG.

FIG. 17 is a sectional view for explaining a first method of a conventional thin film forming method.

FIG. 18 is a cross-sectional view for explaining a second method of the conventional thin film forming method.

FIG. 19 is a cross-sectional view for explaining a third method of the conventional thin film forming method.

[Explanation of symbols]

M1 to M8 Mask 10Aa to 10Ha Window (through hole) 10Ab to 10Hb Window (additional through hole, alignment mark) 16A, 16B, 16H Substrate 18H Alignment mark 5 Substrate 60 (of piezoelectric thin film vibrator) Lower electrode layer 61 (piezoelectric) Piezoelectric layer 62 (of thin film oscillator) Upper electrode layer 70 (of piezoelectric thin film oscillator) 70 Alignment mark (of substrate)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Miyashita 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture F-term in Fujitsu Limited (Reference) 2H097 KA02 KA12 KA26 KA28 LA20 5E032 BA11 BB01 BB13 CB01 CC10 5E082 AB03 BC40 EE05 FG03 KK01 MM13 MM21 MM26

Claims (5)

[Claims] A first thin film forming step of forming a first thin film on the substrate using a first mask formed separately from the substrate; and forming the first thin film on the first substrate separately from the substrate. Forming a second thin film on the substrate by using a second mask so that the second thin film at least partially overlaps the first thin film;
A second thin film forming step, wherein the second mask forms an alignment mark formed at a portion corresponding to the alignment mark on the substrate, and the second thin film. Wherein the second thin film forming step aligns the alignment mark of the substrate with the alignment mark of the second mask, and aligns the alignment mark of the second mask with the substrate. A first step of positioning, a second step of fixing the second mask with respect to the substrate, and supplying a thin film material to the substrate through a through hole of the second mask; A method of manufacturing an electronic component, comprising: a third step of forming the second thin film. 2. The first mask has a through-hole for forming the first thin film on the substrate and an additional through-hole for forming an alignment mark on the substrate. And the first thin film forming step includes: a first step of fixing the first mask on the substrate; and a thin film on the substrate through both the through hole and the additional through hole. 2. The method according to claim 1, further comprising: supplying a material to form the first thin film and the alignment mark on the substrate at the same time. 3. At least one of the first mask and the second mask is recessed from a first surface of the first mask or the second mask, and the first mask or the second mask is recessed from a first surface of the second mask. A recess having a larger diameter than the through hole of the second mask and communicating with the through hole of the first mask or the second mask, and a first thin film forming step of the first thin film forming step; Step or second above
The second step of the thin film forming step of the above is such that the first surface of the first mask or the second mask is formed on the substrate such that the first surface of the first mask or the second mask is in contact with the substrate. The method for manufacturing an electronic component according to claim 1, wherein the method is performed by fixing a mask. 4. The method for manufacturing an electronic component according to claim 1, wherein the first thin film and the second thin film are components of a piezoelectric vibrator, a capacitor, or a resistor. . 5. A first thin film forming step of forming a first thin film on the substrate while fixing a first mask having a through hole formed separately from the substrate on the substrate. And removing the first mask from the substrate, and fixing the second mask, which is formed separately from the substrate and has a through hole, to the first thin film while fixing the second mask on the substrate. A second thin film forming step of forming a second thin film on the substrate so that at least a part thereof overlaps, wherein at least one of the first mask and the second mask is provided. On the other hand, the first mask or the second mask is recessed from the first surface of the first mask or the second mask and has a larger diameter than a through hole of the first mask or the second mask. Communicates with the through hole of the second mask With those having a recess that, and the first mask or the second mask, the first
The first surface of the mask or the second mask is fixed in contact with the substrate.