KR100546880B1 - Fabricating method for micro field sensor - Google Patents

Abstract

The present invention relates to a method of manufacturing a fine magnetic field detection device having a simple manufacturing process since it is not necessary to remove the plating mold after the completion of plating to remove the seed film. In order to achieve the above object, a method of manufacturing a fine magnetic field detection device according to the present invention includes forming a lower coil on an upper surface of a semiconductor substrate, forming a soft magnetic core thereon, and then forming an upper coil. A manufacturing method, comprising: forming a seed film on an upper surface of a semiconductor substrate; Removing the seed film such that the plurality of coil wires constituting the lower coil are insulated from each other, and the plurality of coil wires are connected to the outer circumferential portion of the lower coil; Applying a photoresist to the upper surface of the semiconductor substrate from which the seed film is partially removed, and forming a pattern corresponding to the lower coil through exposure and development; Forming a metal film on the upper surface of the semiconductor substrate so that the metal is filled in the recessed portion of the pattern; Forming a soft magnetic core on the upper surface of the semiconductor substrate on which the lower coil is formed and forming an upper coil; Cutting a semiconductor substrate corresponding to an outer circumferential portion of the lower coil so that a plurality of coil wires constituting the lower coil are insulated.

Fine magnetic field detector, semiconductor substrate, seed film, insulated wire, cutting

Description

Manufacturing method of micro magnetic field detection device {Fabricating method for micro field sensor}

1A to 1H are cross-sectional views showing a manufacturing process of a fine magnetic field detector according to the prior art;

2A to 2D are cross-sectional views illustrating one embodiment of a lower coil manufacturing process in detail in the manufacturing process of the fine magnetic field detector of FIG. 1;

3A is a plan view showing a lower coil before removing the seed film in FIG. 2C, and FIG. 3B is a plan view showing a lower coil after removing the seed film of FIG. 2D;

4A to 4D are cross-sectional views illustrating a manufacturing process of a lower coil in a method of manufacturing a fine magnetic field detection device according to the present invention;

FIG. 5A is a plan view showing a state in which a part of the seed film of FIG. 4B is removed, and FIG. 5B is a plan view showing a cutting line cut to insulate the lower coil after completing the fine magnetic detection device.

6a to 6h are cross-sectional views showing a manufacturing process according to an embodiment of the method for manufacturing a fine magnetic field detection device according to the present invention;

FIG. 7 is a cross-sectional view illustrating a state in which a first insulating film is formed by a modified embodiment of the method of manufacturing the fine magnetic field detector of FIG. 6;

8A to 8I are cross-sectional views illustrating a manufacturing process according to another embodiment of the method of manufacturing the micro magnetic field detection device according to the present invention.

* Description of the symbols for the main parts of the drawings *

100; Semiconductor substrate 102; Seed film

103; Insulated wire 104; Bottom plating frame

106; Bottom coil 110; Cutting line

120; A first insulating film 122; Soft Magnetic Core

125; A second insulating film 130; Upper seed film

131; Upper seed layer insulation line 135; Through hole

136; Upper coil 137; Coil wire

140, 150; Protective layer 142; Upper plating frame

143; waist

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a micro device integrated with a semiconductor substrate, and more particularly to a method for manufacturing a micro magnetic field detection device for detecting a magnetic field.

In general, a fine magnetic field detection device is manufactured by forming a soft magnetic core, an excitation coil and a magnetic field detection coil winding the soft magnetic core on a semiconductor substrate. When external magnetism acts on the fine magnetic field detecting element, voltage is generated from the magnetic field detecting coil, so that the external magnetic field can be detected using the fine magnetic field detecting element.

An embodiment of a method of manufacturing such a fine magnetic field detector will be described with reference to FIGS. 1 and 2 as follows.

First, the seed film 12 is formed on the upper surface of the semiconductor substrate 10, and then the lower plating mold 14 is formed through exposure and development processes (see FIG. 1A). Then, when the yaw portion 15 of the lower plating mold 14 is filled and the lower plating mold 14 is removed through electroplating, the winding composed of the excitation coil and the magnetic field detection coil as shown in FIG. The lower part 16 is formed. A more detailed process of forming the winding bottom 16 of the excitation coil and the magnetic field detection coil is shown in FIG. Referring to FIG. 2, first, an oxide film (not shown) is formed on the semiconductor substrate 10 for electrical insulation, and a seed layer 12 for plating is formed on the oxide film (see FIG. 2A). Thereafter, the photoresist is thickly coated on the seed film 12, and then a pattern corresponding to the lower shapes of the excitation coil and the magnetic field detection coil, that is, the lower plating mold 14, is formed through exposure and development processes (see FIG. 2B). . Thereafter, metal is filled in the recessed portions 15 of the pattern through electroplating to form coil lines 17 of the excitation coil and the magnetic field detection coil (see FIG. 2C). Thereafter, the photoresist on which the lower plating mold 14 is formed and the seed film 12a under the photoresist are removed to form the winding 16 of the excitation coil and the magnetic field detection coil (see FIG. 2D). FIG. 3A is a plan view when the lower plating mold 14 is removed after the metal 15 is filled in the groove 15 of the lower plating mold 14 by the electroplating process in FIG. 2. At this time, the coil lines 17 of the excitation coil and the magnetic field detection coil are connected to each other by the surrounding seed film 12a under the photoresist. FIG. 3B is a plan view after removing the seed film 12a under the photoresist from FIG. 3A, and corresponds to FIG. 2D. In this case, it can be seen that the coil wires 17 of the excitation coil and the magnetic field detection coil are electrically insulated from each other.

As such, the first insulating layer 20 is formed on the upper surface of the semiconductor substrate 10 on which the winding coil 16 of the excitation coil and the magnetic field detection coil are formed (see FIG. 1C). In addition, a soft magnetic film is stacked on the first insulating film 20 to form a soft magnetic core 22 through pattern formation and etching (see FIG. 1D). Subsequently, a second insulating layer 25 is formed on the semiconductor substrate 10 on which the soft magnetic core 22 is formed (see FIG. 1E). Through holes 35 and 35 ′ are formed in the second insulating layer 25 to communicate with the metal 17 forming both ends of the lower part of the winding 16. The seed film 30 is formed on the second insulating film 25. Next, after the photoresist is thickly coated on the upper seed film 30, the pattern corresponding to the upper shapes of the excitation coil and the magnetic field detection coil, that is, the upper plating frame 32, is formed through exposure and development processes (see FIG. 1F). ). Subsequently, a metal is filled in the recess 33 of the pattern through electroplating to form coil lines 37 of the excitation coil and the magnetic field detection coil (see FIG. 1G). Thereafter, the photoresist on which the upper plating frame 32 is formed and the seed film 30a under the photoresist may be removed to form the winding upper portion 36 of the excitation coil and the magnetic field detection coil (see FIG. 1H). Subsequently, the protective film (not shown) is laminated on the winding coil 36 of the excitation coil and the magnetic field detection coil to complete the manufacture of the magnetic field detection element.

However, in manufacturing the fine magnetic field detection device in the above manner, the seed film between each coil wire must be removed to insulate between the coil wires of the lower winding. To this end, there is a problem in that the manufacturing process is complicated because the lower plating mold has to be removed and the insulating film needs to be applied again for the subsequent process.

In addition, there is a problem that the material that can be used to form the insulating film in the lower winding from which the seed film is removed is limited. This is because the insulating film must have good insulating property with the soft magnetic core and good flattening properties to form the soft magnetic core, and have properties that can fill the narrow windings of the lower windings and the high coil lines. to be.

Therefore, the necessity of the invention for the manufacturing method of the fine magnetic field detection element which has a simple manufacturing process, and the restriction | limiting of the material which can be used as an insulating film has been raised.

The present invention has been devised in view of the above problems, and since the plating frame does not need to be removed to remove the seed film, the manufacturing process is simple, and the fine magnetic field detection has little restriction on the type of material that can be used as the insulating film. Its purpose is to provide a method for manufacturing a device.

An object of the present invention as described above, in the method of manufacturing a fine magnetic field detection device for forming a lower coil on the upper surface of the semiconductor substrate, a soft magnetic core thereon and then forming the upper coil, the seed film is formed on the upper surface of the semiconductor substrate Making; Removing the seed film such that the plurality of coil wires constituting the lower coil are insulated from each other, and the plurality of coil wires are connected to the outer circumferential portion of the lower coil; Applying a photoresist to the upper surface of the semiconductor substrate, on which the seed film is partially removed, and forming a pattern corresponding to the lower coil through exposure and development; Forming a metal film on the upper surface of the semiconductor substrate so that the metal is filled in the recessed portion of the pattern; Forming a soft magnetic core on the upper surface of the semiconductor substrate on which the lower coil is formed and forming an upper coil; And cutting a semiconductor substrate corresponding to an outer circumferential portion of the lower coil so that a plurality of coil wires constituting the lower coil are insulated.

The removing of the seed film may include applying a photoresist on the seed film; Forming a seed film pattern to be removed through exposure and development on the photoresist applied on the seed film; And etching and removing the seed film according to the pattern.

In addition, the forming of the soft magnetic core may include planarizing a top surface of the semiconductor substrate filled with a metal in a recess of the pattern; Applying an insulating film to an upper surface of the planarized semiconductor substrate; Applying a soft magnetic film on top of the insulating film; Applying a photoresist to the soft magnetic film to form a pattern of the soft magnetic core through exposure and development; And etching the soft magnetic film according to the pattern to form a soft magnetic core.

In addition, the forming of the soft magnetic core according to another embodiment may include removing the photoresist forming the pattern; Applying an insulating film to the lower coil from which the pattern is removed; Applying a soft magnetic film on top of the insulating film; Applying a photoresist to the soft magnetic film to form a pattern of the soft magnetic core through exposure and development; And etching the soft magnetic film according to the pattern to form a soft magnetic core.

The forming of the upper coil may include forming a seed film on an upper surface of the second insulating film; Removing the seed film such that the plurality of coil wires constituting the upper coil are insulated from each other, and the plurality of coil wires are connected to each other with the outer circumferential portion of the upper coil; Applying a photoresist to an upper surface of the second insulating film from which the seed film is partially removed, and forming a pattern corresponding to the upper coil through exposure and development; Forming a metal film on the upper surface of the second insulating film so that metal is filled in the recessed portion of the pattern; Forming a protective film on an upper surface of the semiconductor substrate on which the upper coil is formed; And cutting the semiconductor substrate corresponding to the outer circumference of the lower coil and the upper coil so that the plurality of coil wires constituting the lower coil and the upper coil are insulated from each other.

Hereinafter, with reference to the accompanying Figures 4 to 6 will be described in detail a preferred embodiment of a method of manufacturing a fine magnetic field detection device according to the present invention.

4A to 4D are views illustrating a process of forming a lower coil of the fine magnetic field detector by the method of manufacturing the fine magnetic field detector according to the present invention.

First, an oxide film (not shown) is formed on the semiconductor substrate 100 for electrical insulation, and a seed layer 102 for plating is formed on the oxide film. Thereafter, the photoresist is applied on the seed film 102, and then the pattern 103 of the seed film to be removed is formed through exposure and development. At this time, the pattern 103 of the seed film to be removed is insulated from each other between the seed film 102b on which the plurality of coil lines 107 constituting the lower coil 106 are to be formed, as shown in FIG. 5A. The seed film 102a constituting the outer circumferential portion of the 106 is formed to be connected to each of the seed films 102b on which the plurality of coil lines 107 are to be formed. That is, although the seed film 102 is electrically shorted as a whole of the semiconductor substrate 100, the plurality of coil wires 107 constituting the lower coil 106 each cut a connection with the seed film 102a of the outer circumference. The lower surface is formed to be electrically insulated from each other. Here, the lower coil 106 is generally formed to have a structure in which the excitation coil and the magnetic field detection coil are alternately wound one by one. In addition, only one coil of the excitation coil or the magnetic field detection coil may be wound in the form of a solenoid. Thereafter, the portion 103 of the seed layer 102 to be removed is removed by etching, and then the photoresist in which the seed layer pattern 103 to be removed is formed is removed. The seed film pattern 103 that is removed hereinafter is referred to as an insulating line 103.

Thereafter, the photoresist is thickly coated on the seed film 102 on which the insulation line 103 is formed, and then a pattern corresponding to the lower coil 106, that is, the lower plating mold 104 is formed through exposure and development (FIG. 4c). Then, a metal film is formed so that metal is filled in the concave portion 105 of the lower plating mold 104. At this time, when the electroplating is performed, metal is attached to and grown on the seed film 102b under the recess 105 of the lower plating mold 104 to form respective coil wires 107 of the lower coil 106. As shown in FIG. 4D, the metal 107 is filled in the recess 105 of the lower plating mold 104.

In this manner, the upper surface of the semiconductor substrate 100 in which the main portion 105 of the lower plating mold 104 is filled with the metal 107 is flattened (see FIG. 6B). This is to allow the metal 107 filled in the recess 105 of the lower plating mold 104 to be insulated from each other, and to form the soft magnetic core 122 thereon. The planarization process is preferably a chemical mechanical polishing (CMP) process. The first insulating layer 120 is formed on the semiconductor substrate 100 on which the planarization process is completed (see FIG. 6C). In addition, a soft magnetic film is stacked on the first insulating layer 120 to form a soft magnetic core 122 through pattern formation and etching (see FIG. 6D).

Meanwhile, the first insulating layer 120 for forming the soft magnetic core 122 may be formed by another method. The method first removes the photoresist forming the lower plating mold 104 from the semiconductor substrate 100 in which the metal 107 is filled in the recess 105 of the lower plating mold 104 as shown in FIG. 4D. Thereafter, an insulating material is coated on the lower coil 106 to form a first insulating film 120 ′ (FIG. 7). In this case, there is an advantage that the planarization processing is not necessary for the insulation of the lower coil 106 and the lamination of the soft magnetic core. In addition, a soft magnetic layer is stacked on the first insulating layer 120 ′, and the soft magnetic core 122 is formed through pattern formation and etching.

Subsequently, a second insulating layer 125 is formed on the semiconductor substrate 100 on which the soft magnetic core 122 is formed. A through hole 135 is formed in the second insulating film 125 to communicate with the coil wire 107 forming both ends of the lower coil 106 (see FIG. 6E). The seed film 130 is formed on the second insulating film 125. Next, after the photoresist is thickly coated on the seed film 130, a pattern corresponding to the shape of the upper coil 136, that is, the upper plating mold 132, is formed through exposure and development (see FIG. 6F). In this case, the upper coil 136 corresponds to the lower coil 106 and is formed to have a structure in which the excitation coil and the magnetic field detection coil are alternately wound once, or only one coil of the excitation coil or the magnetic field detection coil is in the form of solenoid. It is recommended.

Subsequently, a plurality of coil lines 137 constituting the upper coil 136 are formed by filling metal into the recess 133 of the upper plating mold 132 through electroplating (see FIG. 6G). Thereafter, the seed film 130a under the photoresist of the photoresist and the seed film 130 having the upper plating frame 132 formed thereon may be removed to form the upper coil 136 (see FIG. 6H). Subsequently, the protective film 140 is stacked on the winding of the upper coil 136 to complete the manufacture of the magnetic field detection device (see FIG. 6I).

Thereafter, as shown in FIG. 5B, the portion 102b corresponding to the outer peripheral portion of the seed film 102 of the lower coil 106 is cut along the cutting line 110 through dicing. Then, as can be seen in the figure, the plurality of coil wires 107 constituting the lower coil 106 are electrically separated from each other.

In the above, the process of forming the upper coil 136 has been described an embodiment using the same method as in the prior art. However, as another embodiment of the method of manufacturing the fine magnetic field detector according to the present invention, the upper coil 136 of the fine magnetic field detector may also be manufactured through the same process as the method of forming the lower coil 106 described above. The manufacturing process will be described with reference to FIG. 8 as follows.

Since the process of forming the second insulating layer 125 after the oxide layer is formed on the semiconductor substrate 100 (see FIGS. 8A to 8E) is the same as the above-described embodiment, a detailed process is omitted.

An upper seed layer 130 for plating is formed on the semiconductor substrate 100 on which the second insulating layer 125 is formed. Thereafter, the photoresist is coated on the upper seed layer 130, and then a pattern 131 of the seed layer to be removed is formed through exposure and development. At this time, the pattern 131 of the seed film to be removed is insulated from each other between the seed films on which the plurality of coil lines 137 forming the upper coil 136 are to be formed, and the seed films forming the outer circumference of the upper coil 136 are formed in plurality. Coil lines 137 are formed to be connected to each of the seed films to be formed (see seed film pattern 103 of the lower coil of FIG. 5A). That is, although the entirety of the semiconductor substrate 100 is electrically shorted, the plurality of coil lines 137 constituting the upper coil 136 are formed to be electrically separated from each other. Here, the upper coil 136 is formed to correspond to the lower coil 106 as described above. At this time, the upper coil 136 and the lower coil 106 when the outer peripheral portion of the upper coil 136 and the outer peripheral portion 102a of the lower coil 106 are simultaneously cut along the cutting line 110 through dicing in the last process. It is important to match the cutting line 110 of the lower coil 106 with the cutting line of the upper coil 136 so that the plurality of coil wires 137 and 107 constituting the (). Thereafter, the portion 131 to be removed of the seed film 130 is removed through etching, and then the photoresist that forms the seed film pattern 131 to be removed is removed (see FIG. 8F). The seed layer pattern 131 removed afterwards is referred to as an insulating line 131.

Thereafter, the photoresist is thickly coated on the seed film 130 on which the insulating line 131 is formed, and then a pattern corresponding to the upper coil 136, that is, the upper plating frame 142 is formed through exposure and development (FIG. 8g). Then, a metal film is formed to fill the recessed portion 143 of the upper plating mold 142. In this case, when the electroplating is performed, a metal is attached to and grown on the seed film under the recessed portion 143 of the upper plating mold 142 to form a plurality of coil wires 137 constituting the upper coil 136. As shown in FIG. 8H, the main portion 143 of the upper plating mold 142 is filled with metal. Subsequently, when the protective film 150 is applied on the upper coil 136, the fine magnetic field detecting device is completed.

Thereafter, the portions corresponding to the seed film outer peripheral portion 102a of the lower coil 106 and the upper coil 136 are cut by dicing (see lower coil cutting line 110 in FIG. 5B). Then, as can be seen in the figure, the plurality of coil wires 107 and 137 constituting the lower coil 106 and the upper coil 136 are electrically separated from each other.

As described above, according to the method of manufacturing the fine magnetic field detection device according to the present invention, the manufacturing process is simplified because it is not necessary to remove the plating mold in order to remove the seed film.

In addition, since the plating mold is not removed, there is an advantage that the constraint of the material used as the plating mold is small.

As described above, according to the method of manufacturing the fine magnetic field detection device according to the present invention, since the plating frame does not need to be removed to remove the seed film, the manufacturing process is simple and the fineness of the material that can be used as the insulating film is small. A magnetic field detecting element can be provided.

The present invention is not limited to the above-described specific embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the invention as claimed in the claims. Such changes will fall within the scope of the claims.

Claims (7)

In the manufacturing method of the fine magnetic field detection device of forming a lower coil on the upper surface of the semiconductor substrate, a soft magnetic core formed thereon and then forming the upper coil, Forming a seed film on an upper surface of the semiconductor substrate; Removing the seed film such that the plurality of coil wires constituting the lower coil are insulated from each other, and the plurality of coil wires are connected to an outer circumferential portion of the lower coil; Applying a photoresist to an upper surface of the semiconductor substrate from which the seed film is partially removed, and forming a pattern corresponding to the lower coil through exposure and development; Forming a metal film on an upper surface of the semiconductor substrate so that metal is filled in the recessed portion of the pattern; Forming the soft magnetic core and forming an upper coil on the upper surface of the semiconductor substrate on which the lower coil is formed; And cutting the semiconductor substrate corresponding to the outer circumferential portion of the lower coil so that the plurality of coil wires constituting the lower coil are insulated from each other. The method of claim 1, wherein the removing of the seed layer comprises: Applying a photoresist on the seed film; Forming a seed film pattern to be removed through exposure and development on the photoresist applied on the seed film; And And etching the seed film and removing the seed film according to the pattern. The method of claim 1, wherein the forming of the metal film on the recessed portion of the pattern comprises forming a metal film using electroplating. The method of claim 1, wherein the forming of the soft magnetic core comprises: Planarizing an upper surface of the semiconductor substrate filled with a metal portion of the pattern; Applying an insulating film to an upper surface of the planarized semiconductor substrate; Applying a soft magnetic film over the insulating film; Applying a photoresist to the soft magnetic film to form a pattern of a soft magnetic core through exposure and development; And etching the soft magnetic film to form the soft magnetic core according to the pattern. The method of claim 1, wherein the forming of the soft magnetic core comprises: Removing the photoresist forming the pattern; Applying an insulating film to the lower coil from which the pattern is removed; Applying a soft magnetic film over the insulating film; Applying a photoresist to the soft magnetic film to form a pattern of a soft magnetic core through exposure and development; And etching the soft magnetic film to form the soft magnetic core according to the pattern. The method of claim 1, wherein the forming of the upper coil, Forming a seed film on an upper surface of the second insulating film; Removing the seed film such that the plurality of coil wires constituting the upper coil are insulated from each other, and the plurality of coil wires are connected to each other with an outer circumferential portion of the upper coil; Applying a photoresist to an upper surface of the second insulating film from which the seed film is partially removed, and forming a pattern corresponding to the upper coil through exposure and development; Forming a metal film on an upper surface of the second insulating film so that metal is filled in the recessed portion of the pattern; Forming a protective film on an upper surface of the semiconductor substrate on which the upper coil is formed; And cutting a semiconductor substrate corresponding to the outer circumferential portion of the lower coil and the upper coil so that the plurality of coil wires constituting the lower coil and the upper coil are insulated from each other. . The method of claim 6, wherein the forming of the metal film on the recess of the pattern comprises forming a metal film by electroplating.

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