U.S. patent application number 11/336881 was filed with the patent office on 2006-06-01 for method for manufacturing a magnetic field detecting element.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Sang-on Choi, Jun-sik Hwang, Kyung-won Na, Hae-seok Park, Dong-sik Shim.
Application Number | 20060115918 11/336881 |
Document ID | / |
Family ID | 36567864 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060115918 |
Kind Code |
A1 |
Shim; Dong-sik ; et
al. |
June 1, 2006 |
Method for manufacturing a magnetic field detecting element
Abstract
A method for manufacturing a magnetic field detecting element
having a soft magnetic core formed on a substrate, first and second
coils, each having coil lines, arranged above and below the core,
the method including forming a seed film on the substrate, removing
a portion of the seed film using a predetermined pattern so that
coil lines constituting the first coil subsequently formed on the
seed film are separated, forming a first plating mold having
grooves corresponding to the predetermined pattern on an upper
portion of the seed film, forming coil lines constituting the first
coil by filling the grooves of the first plating mold with metal,
forming the soft magnetic core and the second coil on an upper
portion of the substrate and on the seed film where the first coil
is formed, and cutting off edges of the substrate so that the
separated coil lines are insulated.
Inventors: |
Shim; Dong-sik; (Seoul,
KR) ; Na; Kyung-won; (Yong-si, KR) ; Choi;
Sang-on; (Suwon-si, KR) ; Park; Hae-seok;
(Seoul, KR) ; Hwang; Jun-sik; (Ohsan-si,
KR) |
Correspondence
Address: |
LEE & MORSE, P.C.
1101 WILSON BOULEVARD
SUITE 2000
ARLINGTON
VA
22209
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
36567864 |
Appl. No.: |
11/336881 |
Filed: |
January 23, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10784479 |
Feb 23, 2004 |
|
|
|
11336881 |
Jan 23, 2006 |
|
|
|
Current U.S.
Class: |
438/48 |
Current CPC
Class: |
G01R 33/02 20130101;
G01R 33/04 20130101; H01F 41/046 20130101; G01R 33/05 20130101;
H01F 17/0006 20130101 |
Class at
Publication: |
438/048 |
International
Class: |
H01L 21/00 20060101
H01L021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2003 |
KR |
2003-11807 |
May 28, 2003 |
KR |
2003-34191 |
Claims
1-8. (canceled)
9. A method for manufacturing a magnetic field detecting element,
comprising: forming a well to a predetermined depth in a
semiconductor substrate; forming a first coil on the semiconductor
substrate, the first coil being arranged within the well at or
below an upper surface of the semiconductor substrate; forming a
first insulating film on an upper portion of the first coil and
forming a soft magnetic core on an upper portion of the first
insulating film; forming a second insulating film on an upper
portion of the soft magnetic core; and forming a second coil on an
upper portion of the second insulating film.
10. A method for manufacturing a magnetic field detecting element,
comprising: preparing a semiconductor substrate; forming a well to
a predetermined depth in the semiconductor substrate; forming a
first coil consisting of a plurality of coil lines within the well
of the semiconductor substrate; forming a first insulating film on
an upper portion of the semiconductor substrate including the well;
forming a soft magnetic core on an upper portion of the first
insulating film; forming a second insulating film on an upper
portion of the first insulating film including the soft magnetic
core; and forming a second coil corresponding to the first coil, on
an upper portion of the second insulating film.
11. The method as claimed in claim 10, wherein forming the well
comprises etching inner sidewalls of the well to be gradually
inclined from an upper portion of the well to a bottom of the
well.
12. The method as claimed in claim 10, wherein forming the first
coil further comprises: forming a first seed film on a surface of
the well; forming a first plating mold having a plurality of
grooves on the first seed film; forming a plurality of coil lines
constituting the first coil by filling the plurality of grooves of
the first plating mold with metal; and removing the first plating
mold and the first seed film under the first plating mold.
13. The method as claimed in claim 12, wherein filling the
plurality of grooves of the first plating mold with metal comprises
electric plating.
14. The method as claimed in claim 10, wherein forming the second
coil further comprises: forming a via hole by etching the first and
second insulating films on both sides of the soft magnetic core;
forming a second seed film on an upper surface of the second
insulating film in which the via hole is formed; forming a second
plating mold having a plurality of grooves on the second seed film;
forming a plurality of coil lines constituting a second coil by
filling the plurality of grooves of the second plating mold with
metal and connecting the first coil with the second coil through
the via hole; and removing the second plating mold and the second
seed film under the second plating mold.
15. The method as claimed in claim 14, wherein filling the
plurality of grooves of the second plating mold with metal
comprises electric plating.
16. The method as claimed in claim 10, further comprising forming a
protection film on the semiconductor substrate including the second
coil to protect a structure formed thereon.
17-20. (canceled)
21. The method as claimed in claim 9, wherein forming the well
comprises etching inner sidewalls of the well to be gradually
inclined from an upper portion of the well to a bottom of the
well.
22. The method as claimed in claim 9, wherein forming the first
coil further comprises: forming a first seed film on a surface of
the well; forming a first plating mold having a plurality of
grooves on the first seed film; forming a plurality of coil lines
constituting the first coil by filling the plurality of grooves of
the first plating mold with metal; and removing the first plating
mold and the first seed film under the first plating mold.
23. The method as claimed in claim 22, wherein filling the
plurality of grooves of the first plating mold with metal comprises
electric plating.
24. The method as claimed in claim 9, wherein forming the second
coil further comprises: forming a via hole by etching the first and
second insulating films on both sides of the soft magnetic core;
forming a second seed film on an upper surface of the second
insulating film in which the via hole is formed; forming a second
plating mold having a plurality of grooves on the second seed film;
forming a plurality of coil lines constituting a second coil by
filling the plurality of grooves of the second plating mold with
metal and connecting the first coil with the second coil through
the via hole; and removing the second plating mold and the second
seed film under the second plating mold.
25. The method as claimed in claim 24, wherein filling the
plurality of grooves of the second plating mold with metal
comprises electric plating.
26. The method as claimed in claim 9, further comprising forming a
protection film on the semiconductor substrate including the second
coil to protect a structure formed thereon.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application based on pending
application Ser. No. 10/784,479, filed Feb. 23, 2004, the entire
convents of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a magnetic field detecting
element and a method for manufacturing the same. More particularly,
the present invention relates to a magnetic field detecting element
and a method for manufacturing the same by forming a soft magnetic
core and a coil in a thin film type on a semiconductor substrate
using a semiconductor process.
[0004] 2. Description of the Related Art
[0005] Conventionally, a high sensitivity magnetic sensor has
included a soft magnetic material and a coil. Such a magnetic
sensor is generally manufactured by winding a coil on a soft
magnetic core, and requires an electronic circuit for obtaining a
magnetic field proportional to a measured magnetic field. Recently,
a method for realizing a magnetic field detecting element of such a
magnetic sensor has been suggested, in which a soft magnetic thin
film core and a plane thin film coil are formed on a semiconductor
substrate using a semiconductor process.
[0006] A general method for manufacturing a magnetic field
detecting element using a semiconductor process is illustrated in
FIGS. 1A through 1J.
[0007] Referring to FIG. 1A, a first seed film 2 is formed on a
semiconductor substrate 1. A photoresist of a predetermined height
(not shown) is formed on the first seed film 2. In FIG. 1B, a first
plating mold 3 having a plurality of grooves 3a is formed by
exposing and developing the photoresist. Next, the grooves 3a of
the first plating mold 3 are filled with metal by a process, e.g.,
electric plating, so that a plurality of coil lines 4a, 4b, etc.
are formed, as shown in FIG. 1C. Then, the first plating mold 3 and
the seed film under the first plating mold 3 are removed, thereby
forming a first coil 4 consisting of a plurality of coil lines 4a,
4b, etc., which are insulated from each other, as shown in FIG.
1D.
[0008] After the first coil 4 is formed, a first insulating film 5
is formed to cover the first coil 4 on the semiconductor substrate
1, as shown in FIG. 1E. Then, a soft magnetic material film (not
shown) is formed on an upper surface of the first insulating film
5, and the soft magnetic material film is patterned and etched to
form a soft magnetic core 6, as shown in FIG. 1F.
[0009] Subsequently, a second insulating film 7 of a predetermined
thickness is formed on the soft magnetic core 6 of the
semiconductor substrate 1, as shown in FIG. 1G. Then, as shown in
FIG. 1H, via holes 8a and 8b for communicating with the coil lines
4a and 4o at either end of the first coil 4, are formed, and a
second seed film 9 is formed to a predetermined thickness on an
upper surface of the second insulating film 7. Next, a thick
photoresist (not shown) is formed on the second seed film 9 and a
second plating mold 10 having a plurality of grooves 10a and having
the via holes 8a, 8b formed therethrough is formed by exposing and
developing the thick photoresist.
[0010] As shown in FIG. 1I, metal is formed in the plurality of
grooves 10a of the second plating mold 10 so that a plurality of
coil lines 11a, 11b, etc. is formed. Then, the second plating mold
10 and the second seed film 9 under the second plating mold 10 are
removed, thereby forming a second coil 11 consisting of the
plurality of coil lines 11a, 11b, etc., which are insulated each
other, as shown in FIG. 1J.
[0011] Finally, although not shown, a protection film is spread on
an upper portion of the second coil 11, whereby manufacturing of
the magnetic field detecting element is complete.
[0012] However, according to the foregoing general method for
manufacturing the magnetic field detecting element, the seed film 2
between the coil lines 4a, 4b, etc. should be removed so that the
coil lines 4a, 4b, etc. constituting the first coil 4 are insulated
from each other. For that purpose, after the first plating mold 3
is removed, the insulating film 5 must be formed on the first coil
4 for subsequent processes, thereby complicating the manufacturing
process.
[0013] In addition, performance of the soft magnetic core 6 in the
foregoing magnetic field detecting element is poor because the
semiconductor substrate 1 for supporting the soft magnetic core 6
is uneven. Since the first coil 4 is projected onto the
semiconductor substrate 1, the general magnetic field detecting
element has a weakness in that the thickness of the first and the
second insulating films 5, 7 may become thick. If the insulating
films 5, 7 become thick, not only does the entire element become
thick, but the process for forming the via holes 8a, 8b, which
connect the first coil 4 with the second coil 11, becomes
difficult. Also, a pitch between the coil lines, which influences
performance of the sensor becomes large, causing further negative
effects in the element.
SUMMARY OF THE INVENTION
[0014] The present invention is therefore directed to a magnetic
field detecting element and a method for manufacturing the same,
which substantially overcome one or more of the problems due to the
limitations and disadvantages of the related art.
[0015] It is a feature of an embodiment of the present invention to
provide a method for manufacturing a magnetic field detecting
element having a simple manufacturing process, in which a plating
mold need not be removed for removal of a seed film to provide
insulation between coil lines, thereby reducing restrictions on a
material suitable for use as an insulating film.
[0016] It is another feature of an embodiment of the present
invention to provide a method for manufacturing a magnetic field
detecting element having a simple manufacturing process, in which
planarization of a semiconductor substrate on which a coil is
formed may be easily performed, and in which a thickness of a
planarization material and a film for constructing the magnetic
field detecting element are thin.
[0017] It is still another feature of an embodiment of the present
invention to provide a magnetic field detecting element having
improved performance manufactured by a simplified process.
[0018] At least one of the above and other features and advantages
of the present invention may be realized by providing a method for
manufacturing a magnetic field detecting element having a soft
magnetic core formed on a semiconductor substrate, first and second
coils arranged on upper and lower surfaces of the soft magnetic
core, respectively, the first and second coils each having a
plurality of coil lines, the method including forming a seed film
to a predetermined thickness on the semiconductor substrate,
removing a portion of the seed film using a predetermined pattern
so that each of the plurality of coil lines constituting the first
coil that is subsequently formed on a remaining portion of the seed
film is separated from the others, forming a first plating mold
having a plurality of grooves corresponding to the predetermined
pattern, on an upper portion of the seed film, forming the
plurality of coil lines constituting the first coil by filling the
plurality of grooves of the first plating mold with metal, forming
the soft magnetic core and the second coil on an upper portion of
the semiconductor substrate and on the remaining portion of the
seed film where the first coil is formed, and cutting off edges of
the semiconductor substrate so that each of the plurality of coil
lines separated by the predetermined pattern are insulated from
each other.
[0019] Removing the portion of the seed film may further include
forming a photoresist layer on an upper surface of the seed film,
exposing and developing the photoresist to form the predetermined
pattern, and etching the seed film according to the predetermined
pattern.
[0020] Filling the plurality of grooves of the first plating mold
with metal may include electric plating.
[0021] Forming the soft magnetic core may further include
planarizing an upper surface of the semiconductor substrate on
which the first coil is formed, spreading an insulating film on the
planarized upper surface of the semiconductor substrate, spreading
a soft magnetic material film on an upper surface of the insulating
film, forming a photoresist layer on the soft magnetic material
film and exposing and developing the photoresist layer to form a
pattern of the soft magnetic core, and etching the soft magnetic
material film according to the pattern.
[0022] Forming the soft magnetic core may include removing the
first plating mold, forming an insulating film to a height greater
than a height of the first coil on an upper surface of the
semiconductor substrate from which the first plating mold has been
removed, spreading a soft magnetic material film on an upper
surface of the insulating film, forming a photoresist layer on the
soft magnetic material film and exposing and developing the
photoresist layer to form a pattern of the soft magnetic core, and
etching the soft magnetic material film according to the
pattern.
[0023] At least one of the above and other features and advantages
of the present invention may be realized by providing a method for
manufacturing a magnetic field detecting element having a soft
magnetic core formed on a semiconductor substrate, first and second
coils respectively arranged on upper and lower surfaces of the soft
magnetic core, the first and second coils each having a plurality
of coil lines, the method including forming a first seed film to a
predetermined thickness on the semiconductor substrate, removing a
portion of the first seed film using a predetermined first pattern
so that each of the plurality of coil lines constituting the first
coil to be subsequently formed on the first seed film is separated
from the others, forming a first plating mold having a plurality of
grooves that corresponds to the predetermined first pattern, on an
upper portion of the first seed film, forming the plurality of coil
lines constituting the first coil by filling the plurality of
grooves of the first plating mold with metal, forming the soft
magnetic core on the semiconductor substrate where the first coil
is formed, forming a second insulating film on the semiconductor
substrate where the soft magnetic core is formed, forming a second
seed film on an upper surface of the second insulating film,
removing the second seed film using a predetermined second pattern
so that a plurality of coil lines constituting the second coil to
be subsequently formed on the second seed film are separated from
each other, forming a second plating mold having a plurality of
grooves corresponding to the second pattern, on an upper portion of
the second seed film, forming a plurality of coil lines
constituting the second coil by filling the plurality of grooves of
the second plating mold with metal, and cutting off edges on sides
of the semiconductor substrate so that each of the plurality of
coil lines constituting the first and the second coils separated by
the first and the second patterns are insulated from each
other.
[0024] Filling the plurality of grooves of the first and the second
plating molds with metal may include electric plating.
[0025] Forming the soft magnetic core may further include
planarizing an upper surface of the semiconductor substrate on
which the first coil is formed, spreading a first insulating film
on the planarized upper surface of the semiconductor substrate,
spreading a soft magnetic material film on an upper portion of the
first insulating film, forming a photoresist layer on the soft
magnetic material film and exposing and developing the photoresist
layer to form a pattern of the soft magnetic core, and etching the
soft magnetic material film according to the pattern.
[0026] At least one of the above and other features and advantages
of the present invention may be realized by providing a method for
manufacturing a magnetic field detecting element, including forming
a well to a predetermined depth in a semiconductor substrate,
forming a first coil on the semiconductor substrate, the first coil
being arranged within the well below an upper surface of the
semiconductor substrate, forming a first insulating film on an
upper portion of the first coil and forming a soft magnetic core on
an upper portion of the first insulating film, forming a second
insulating film on an upper portion of the soft magnetic core, and
forming a second coil on an upper portion of the second insulating
film.
[0027] At least one of the above and other features and advantages
of the present invention may be realized by providing a method for
manufacturing a magnetic field detecting element including
preparing a semiconductor substrate, forming a well to a
predetermined depth in the semiconductor substrate, forming a first
coil consisting of a plurality of coil lines within the well of the
semiconductor substrate, forming a first insulating film on an
upper portion of the semiconductor substrate including the well,
forming a soft magnetic core on an upper portion of the first
insulating film, forming a second insulating film on an upper
portion of the first insulating film including the soft magnetic
core, and forming a second coil corresponding to the first coil, on
an upper portion of the second insulating film.
[0028] Forming the well may include etching inner sidewalls of the
well to be gradually inclined from an upper portion of the well to
a bottom of the well.
[0029] Forming the first coil may further include forming a first
seed film on a surface of the well, forming a first plating mold
having a plurality of grooves on the first seed film, forming a
plurality of coil lines constituting the first coil by filling the
plurality of grooves of the first plating mold with metal, and
removing the first plating mold and the first seed film under the
first plating mold.
[0030] Filling the plurality of grooves of the first plating mold
with metal may include electric plating.
[0031] Forming the second coil may further include forming a via
hole by etching the first and second insulating films on both sides
of the soft magnetic core, forming a second seed film on an upper
surface of the second insulating film in which the via hole is
formed, forming a second plating mold having a plurality of grooves
on the second seed film, forming a plurality of coil lines
constituting a second coil by filling the plurality of grooves of
the second plating mold with metal and connecting the first coil
with the second coil through the via hole, and removing the second
plating mold and the second seed film under the second plating
mold.
[0032] Filling the plurality of grooves of the second plating mold
with metal may include electric plating.
[0033] The method may further include forming a protection film on
the semiconductor substrate including the second coil to protect a
structure formed thereon.
[0034] At least one of the above and other features and advantages
of the present invention may be realized by providing a magnetic
field detecting element including a semiconductor substrate, a soft
magnetic core formed on an upper portion of the semiconductor
substrate, an insulating film positioned on an upper and a lower
portions of the soft magnetic core, and first and second coils,
each including a plurality of coil lines, formed to enclose the
soft magnetic core with the insulating film intervening
therebetween, wherein a well of a predetermined depth is formed in
the semiconductor substrate and the plurality of coil lines
constituting the first coil are arranged within the well.
[0035] A height of the coil lines and a depth of the well may be
the same.
[0036] The first coil may be positioned at a lower portion of the
soft magnetic core and the second coil may be positioned at an
upper portion of the soft magnetic core, and the plurality of coil
lines of the first and second coils may be connected by a third
coil filling a via hole formed through the insulating film on both
sides of the soft magnetic core.
[0037] Inner sidewalls of the well may be gradually inclined from
an upper portion of the well to a bottom of the well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The above and other features and advantages of the present
invention will become more apparent to those of ordinary skill in
the art by describing in detail exemplary embodiments thereof with
reference to the attached drawings in which:
[0039] FIGS. 1A through 1J illustrate cross-sectional views of
stages in a general method for manufacturing a magnetic field
detecting element;
[0040] FIGS. 2A through 2K illustrate cross-sectional views of
stages in a method for manufacturing a magnetic field detecting
element according to an embodiment of the present invention;
[0041] FIG. 3A illustrates a plan view showing a status that a seed
film formed on a semiconductor substrate is removed by a
predetermined pattern;
[0042] FIG. 3B illustrates a plan view showing a cut-off line for
cutting off the semiconductor substrate in order to insulate coil
lines after forming a plurality of coil lines on the seed film
shown in FIG. 3A;
[0043] FIG. 4 illustrates a cross-sectional view of a modified
example of a method for manufacturing a magnetic field detecting
element according to an embodiment of the present invention;
[0044] FIGS. 5A through 5I illustrate cross-sectional views of
stages in a method for manufacturing a magnetic field detecting
element according to another embodiment of the present
invention;
[0045] FIGS. 6A through 6H illustrate cross-sectional views of
stages in a method for manufacturing a magnetic field detecting
element according to still another embodiment of the present
invention; and
[0046] FIGS. 7A through 7H illustrate cross-sectional views taken
along line III-III of FIGS. 6A through 6H, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0047] Korean Patent Application Nos. 2003-11807, filed Feb. 25,
2003, and 2003-34191, filed May 28, 2003, are incorporated herein
by reference in their entirety.
[0048] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. The invention
may, however, be embodied in different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. In the drawings, the
thickness of layers and regions are exaggerated for clarity. Like
reference numerals refer to like elements throughout.
[0049] The matters defined in the description such as a detailed
construction and elements are nothing but the ones provided to
assist in a comprehensive understanding of the invention. Thus, it
is apparent that the present invention can be performed without
those defined matters. Also, well-known functions or constructions
are not described in detail since they would obscure the invention
in unnecessary detail.
[0050] FIGS. 2A through 2K illustrate views showing stages in a
method for manufacturing a magnetic field detecting element
according to an embodiment of the present invention. Referring to
FIG. 2A, an oxidation film (not shown) for electric insulation is
formed on a semiconductor substrate 100, and a first seed film 102
for plating is formed on the oxidation film.
[0051] Next, as shown in FIG. 2B, the first seed film 102 formed on
the semiconductor substrate 100 is partially removed using a
predetermined pattern such as that shown in FIG. 3A. The partial
removal of the first seed film 102 is for insulating, in a simple
manner, a plurality of coil lines constituting a first coil that is
subsequently formed on the first seed film 102. In FIGS. 2B and 3A,
reference numeral 103 indicates a seed film pattern to be removed
from the first seed film 102. In FIG. 3A, reference numeral 107
indicates a position of a subsequently formed plurality of coil
lines. As shown in FIG. 3A, the pattern 103 is positioned between
adjacent coil lines of the plurality of coil lines 107, and each
one of the plurality of coil lines is partitioned from adjacent
coil lines and connected through the seed film 102 (of FIG. 2B) at
edges thereof 102a. As a result, as shown in FIG. 3B, if four lines
110 connecting the edges 102a of the pattern 103 are cut, the
positions of the coil lines are insulated from each other.
[0052] Partial removal of the first seed film 102 of FIG. 2A is
performed by first applying a photoresist layer (not shown) on the
first seed film 102 and exposing and developing the photoresist
layer to form a pattern. Then, the seed film pattern 103 to be
removed is etched using the photoresist pattern as an etching mask.
The seed film pattern 103 to be removed is formed such that parts
102b, where a plurality of coil lines 107 constituting a first coil
106 (of FIG. 2D) are to be formed, are insulated from each other,
and edges 102a are connected to each other as shown in FIG. 3A.
[0053] The seed film 102 is electrically connected from a viewpoint
of the entire semiconductor substrate 100, but the parts 102b,
where the plurality of coil lines 107 constituting the first coil
106 are to be formed, are formed in such a way that the parts 102b
can be electrically insulated from each other if the connection
parts, i.e., the edges 102a, are cut. Here, generally, the first
coil is formed in such a way that an exciting coil and a magnetic
field detecting coil are wired one time by turns. Also, only one of
either the exciting coil or the magnetic field detecting coil may
be wired in a form of a solenoid. Then, the pattern 103 of the seed
film 102 is removed through etching, the photoresist is removed,
and partial removal of the seed film 102 is complete, as shown in
FIG. 2B.
[0054] Referring to FIG. 2C, a first plating mold 104 is formed on
an upper surface of the first seed film 102, which has been
partially removed using the predetermined pattern 103, and a thick
photoresist layer is formed, exposed and developed on the first
plating mold 104, thereby forming a plurality of grooves 104a in
the first plating mold 104. Each of the plurality of grooves 104a
of the first plating mold 104 is filled with metal, thereby forming
a plurality of coil lines 107, 107a, etc., which form the first
coil 106, as shown in FIG. 2D. If the metal is deposited by
electric plating, metal sticks to and grows on the seed film 102 at
a bottom of the grooves 104a, whereby the plurality of coil lines
107, 107a, etc. is formed.
[0055] After planarizing or otherwise leveling an upper surface of
the first plating mold 104, a first insulating film 120 is formed
to a predetermined thickness on the level upper surface of the
first plating mold 104, as shown in FIG. 2E. Then, a soft magnetic
material film (not shown) is stacked on an upper surface of the
first insulating film 120 and a soft magnetic core 122 is formed by
pattern formation and etching of the soft magnetic material film,
as shown in FIG. 2F.
[0056] An insulating film for forming the soft magnetic core 122
may be formed such that the first plating mold 104 is removed and
the insulating material is formed on the semiconductor substrate
100 to have a height greater than that of the first coil 106, so
that a first insulating film 120a is formed, as shown in FIG. 4.
Forming the insulation film 120a for forming the soft magnetic core
122 according to such a method eliminates the need to perform a
planarization process.
[0057] After the soft magnetic core 122 is formed, a second
insulating film 125 is formed to a predetermined thickness on the
first insulating film 120 of the semiconductor substrate 100, as
shown in FIG. 2G. Then, via holes 135 for communicating with coil
lines that form both ends of the first coil 106 are formed through
the second insulating film 125.
[0058] Then, as shown in FIG. 2H, a second seed film 130 is formed
on an upper surface of the second insulating film 125 and a
photoresist (not shown) is thickly spread on the second seed film
130. A second plating mold 132 having a pattern that corresponds to
a shape of a second coil 136 (of FIG. 2I), i.e., a plurality of
grooves 132a, is formed by exposing and developing processes. At
this time, the second coil 136, which corresponds to the first coil
106, may be formed in such a way that an exciting coil and an
magnetic field detecting coil are wired one time by turns, or only
one of either the exciting coil or the magnetic field detecting
coil may be wired in a form of a solenoid.
[0059] Each of the plurality of grooves 132a of the second plating
mold 132 is then filled with metal by electric plating so that a
plurality of coil lines 137, 137a, etc. constituting the second
coil 136 is formed, as shown in FIG. 2I. Then, if the second
plating mold 132 and the seed film under that second plating mold
132 are removed, a magnetic field detecting element having the
second coil 136 is obtained, as shown in FIG. 2J.
[0060] In FIG. 2K, a protection film 140 for protecting structures
including the second coil 136 is formed on an upper portion of the
second coil 136.
[0061] As previously described, after the first coil 106, the soft
magnetic core 122, and the second coil 136 are formed on the
semiconductor substrate 100, edge portions 102a of the first seed
film 102 are cut off along a cut-off line 110, as shown in FIG. 3B,
by a dicing process. Thus, as shown in FIG. 3B, each of the
plurality of coil lines 107 constituting the first coil 106 is
electrically separated and insulated from the others.
[0062] FIGS. 5A through 5I illustrate cross-sectional views showing
stages in another method for manufacturing a magnetic field
detecting element according to an embodiment of the present
invention.
[0063] In FIGS. 5A through 5I, processes up to a process for
forming the second insulating film 125 after forming the oxidation
film on the semiconductor substrate 100, as shown in FIGS. 5A
through 5E, are the same as those in the foregoing embodiment shown
in FIGS. 2A through 2G. Therefore, a detailed description thereof
will be omitted.
[0064] As shown in FIG. 5F, a second seed film 141 is formed on an
upper surface of the second insulating film 125, and the second
seed film 141 is partially removed in a manner similar to that used
for partial removal of the first seed film 102. Namely, after a
photoresist (not shown) is thickly spread on the second seed film
141, a seed film pattern 141a to be removed is formed by exposing
and developing processes. At this time, the seed film pattern 141a
to be removed is formed in such a way that each one of the
plurality of coil lines 137 constituting the second coil 136 is
insulated from each adjacent coil line, but each of the plurality
of coil lines 137 is connected at edges of the seed film 141. More
specifically, the seed film pattern 141a is formed in the same
manner as the seed film pattern 103 of the above-described first
seed film 102.
[0065] Therefore, if the semiconductor substrate 100 is cut off
along its edges, each of the plurality of coil lines 137 is
electrically separated and insulated from the others. It is
preferable that a cut-off line (not shown) of the second coil 136
is overlapped on the cut-off line 110 of the first coil 106 so that
the pluralities of coil lines 107, 137 constituting the first and
the second coils 106, 136, respectively, are separated and
insulated simultaneously by a single dicing process.
[0066] After formation of the seed film pattern 141a, a photoresist
(not shown) is spread thickly on an upper surface of the second
seed film 141 that has been partially removed by a predetermined
pattern, and a second plating mold 142 having a pattern that
corresponds to the second coil 136, i.e., a plurality of the
grooves 142a, is formed by exposing and developing processes, as
shown FIG. 5G. Then, as shown in FIG. 5H, each of the plurality of
grooves 142a of the second plating mold 142 is filled with metal so
that the plurality of coil lines 137, 137a, etc. is formed.
[0067] In FIG. 5I, a protection film 150 is then formed on an upper
portion of a resultant structure including the second plating mold
142. Finally, the semiconductor 100 is cut off along edges thereof
according to a cut-off line 110 by the dicing process, as shown in
FIG. 3B.
[0068] According to methods for manufacturing a magnetic field
detecting element of the present invention as described in the
above embodiments, since a plating mold does not need to be removed
to perform partial removal of a seed film, it is possible to
provide a simplified manufacturing process for a magnetic field
detecting element in which a material used for an insulating film
is relatively unrestricted.
[0069] FIGS. 6A through 6H illustrate stages in a method for
manufacturing a magnetic field detecting element according to still
another embodiment of the present invention. FIGS. 7A through 7H
illustrate cross-sectional views taken along line III-III of FIG.
6A through FIG. 6H, respectively.
[0070] Referring to FIGS. 6H and 7H, a magnetic field detecting
element manufactured according to a manufacturing method of the
present invention includes a semiconductor substrate 200, a soft
magnetic core 220, first and second insulating films 230, 240
positioned at upper and lower portions of the soft magnetic core
220, and first and second coils 250, 260 formed in such a manner
that the first and second coils 250, 260 enclose the soft magnetic
core 220 with the insulating films 230, 240 intervening between the
soft magnetic core 220 and the first and second coils 250, 260,
respectively, the first and second coils 250, 260 each having a
plurality of coil lines 251, 252, . . . , and 261, 262, . . . ,
respectively.
[0071] The first coil 250 is positioned at a lower side of the soft
magnetic core 220, and the second coil 260 is positioned at an
upper side of the soft magnetic core 220. More particularly, the
semiconductor substrate 200 has a well 211 formed therein to a
depth (D of FIG. 6B) from an upper surface of the semiconductor
substrate 200, and the first coil 250 is arranged within the well
211. Therefore, the first coil 250 may not be exposed to the
surface of the semiconductor substrate 200.
[0072] A height (H of FIG. 6B) of the plurality of coil lines 251,
252, etc. constituting the first coil 250 formed within the well
211 is the same as the depth of the well 211. Therefore, an upper
surface of the coil lines 251 maintains a same plane as the upper
surface of the semiconductor substrate 200.
[0073] As described above, unlike a conventional magnetic field
detecting element, since the first coil 250 does not project beyond
the upper surface of the semiconductor substrate 200, but is formed
in the well 211 of the substrate 200 to have an upper surface at a
same plane as the upper surface of the semiconductor substrate 200,
it is easy to planarize the semiconductor substrate 200, and it is
possible to make a thickness of a planarization material, such as
the insulating films 230, 240, to be thin.
[0074] Therefore, performance deterioration of a soft magnetic core
generated due to unevenness in a conventional semiconductor
substrate and difficulty in an etching process generated due to a
thick insulating film in a conventional semiconductor substrate do
not occur in the magnetic field detecting element manufactured
according to an embodiment of the present invention, in which a
magnetic field detecting element having high sensitivity and fine
pitch between coils thereof may be formed.
[0075] The well 211 has an approximately rectangular shape, but has
inner sidewalls of that are gradually inclined from an upper
portion thereof to a bottom thereof, and which may be formed by a
variety of the etching technologies generally well known in the
art.
[0076] Also, as shown in FIGS. 7G and 7H, the first and second
coils 250, 260 are connected by means of a third coil 300, which is
formed upon formation of the second coil 260, by filling with metal
through holes 290, 290' formed on both ends of the soft magnetic
core 220 and passing through the first and second insulating films
230, 240.
[0077] A method for manufacturing the magnetic field detecting
element of FIGS. 6H and 7H according to an embodiment of the
present invention will now be described with reference to FIGS. 6A
through 6G and FIGS. 7A through 7G.
[0078] FIGS. 6A and 7A illustrate cross-sectional views showing a
first plating mold 270 for forming the first coil 250 formed on an
upper surface of the semiconductor substrate 200 in which the well
211 is formed. Although not specifically shown in FIG. 6A or 7A, a
seed film for plating is formed on a surface of the well 211, and
the first plating mold 270 is formed by exposing and developing
processes after a photoresist is thickly spread on the seed film.
The first plating mold 270 has a plurality of grooves 270a.
[0079] If the seed film and the first plating mold 270 are removed
after the plurality of grooves 270a of the first plating mold 270
are filled with metal by means of an electric plating method so
that the plurality of coil lines 251, 252 is formed, the first coil
250 as shown in FIGS. 6B and 7B is formed in the well 211 of the
semiconductor substrate 200. The first coil 250 does not project
above the surface of the semiconductor substrate 200 but formed is
in the same plane as the semiconductor substrate 200.
[0080] After that, as shown in FIGS. 6C and 7C, an insulating
material is spread on the upper surface of the semiconductor
substrate 200 in which the first coil 250 is formed, so that the
first insulating film 230 for planarization and insulation is
formed. The first coil 250 formed in the well 211 is not projected
beyond an upper surface of the semiconductor substrate 200, but an
upper surface of the first coil 250 is at a same plane as the upper
surface of the semiconductor substrate 200, so that planarization
of the semiconductor substrate 200 is easily performed, and the
insulating film 230 may be formed to be very thin as well.
[0081] After the first insulating film 230 is formed, a soft
magnetic material film is stacked on the first insulating film 230
and the soft magnetic core 220 is formed by pattern formation and
etching of the soft magnetic material film, as shown in FIGS. 6D
and 7D.
[0082] Then, an insulating material is formed to a predetermined
thickness on an upper surface of the first insulating film 230
including the soft magnetic core 220, so that a second insulating
film 240, as shown in FIGS. 6E and 7E, is formed.
[0083] Portions of the second insulating film 240, which correspond
to both ends of the soft magnetic core 220, are etched so that
through holes 290, 290', as shown in FIG. 7F, are formed, and a
process for forming the second coil 260 proceeds. At this time,
since the thickness of the first and the second insulating films
230, 240 is very thin, according to a feature of the present
invention, etching for formation of the through holes 290, 290' may
be performed in a simple manner. Also, since it is possible to
realize fine-pitched coils due to such simplification of the
process, a magnetic field detecting element having high sensitivity
may be manufactured.
[0084] The formation of the second coil 260 is performed in such a
manner that a seed film (not shown) is formed on an upper surface
of the second insulating film 240 in which the through holes 290,
290' are formed, and a photoresist is formed on the seed film.
Then, the second plating mold 280 having a plurality of grooves
280a is formed by exposing and developing processes as shown in
FIGS. 6F and 7F.
[0085] After the second plating mold 280 is formed, each of the
plurality of grooves 280a is filled with metal by means of electric
plating, so that a plurality of coil lines 261, 262 forming the
second coil 260 is formed, as shown in FIGS. 6G and 7G. At this
time, the through holes 290, 290' are filled with metal, thereby
forming a third coil 300 connecting the first coil 250 at a lower
side of the soft magnetic core 220 to the second coil 260 at an
upper side of the soft magnetic core 220. Therefore, the coils 250,
260 are realized in such a manner that the coils 250, 260 enclose
the soft magnetic core 220.
[0086] If the seed film and the second plating mold 280 are removed
after the coil line 261 is formed, the second coil 260 is exposed,
whereby a thin type magnetic field detecting element as shown in
FIGS. 6H and 7H is manufactured. Here, the magnetic field detecting
element manufactured by the present invention may reduce an entire
height of the magnetic field detecting element by as much as the
depth of the well 211 formed in the semiconductor substrate 200,
thus a thin structure may be realized.
[0087] On an upper surface of the semiconductor substrate 200, a
protection film for protecting structures formed thereon may be
formed.
[0088] As is apparent from the foregoing, according to the present
invention, since a first coil is not projected beyond an upper
surface of a semiconductor substrate but is positioned within a
well formed in the semiconductor substrate, it is easy to perform
planarization of the semiconductor substrate, and it is possible to
reduce a thickness of a planarization material as well. Therefore,
performance improvement of a soft magnetic core is expected due to
improvement in a degree of planarization. Further, simplification
of an etching process for forming a through hole is expected due to
realization of a thin insulating film. Also, a pitch between coils
may be reduced due to simplification of the etching process, thus
sensitivity of a sensor may be improved.
[0089] According to the various embodiments of the present
invention, manufacturing of a magnetic field detecting element is
simplified, whereby productivity improvement is expected and a
thin-type element of good sensitivity may be manufactured as
well.
[0090] Exemplary embodiments of the present invention have been
disclosed herein and, although specific terms are employed, they
are used and are to be interpreted in a generic and descriptive
sense only and not for purpose of limitation. Accordingly, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made without departing from the
spirit and scope of the present invention as set forth in the
following claims.
* * * * *