U.S. patent application number 16/136227 was filed with the patent office on 2020-03-19 for head gimbal assembly thin-film piezoelectric-material element arranged in step part configuration with protective films.
The applicant listed for this patent is SAE Magnetics (H.K.) Ltd.. Invention is credited to Atsushi Iijima, Wei Xiong.
Application Number | 20200091402 16/136227 |
Document ID | / |
Family ID | 69773172 |
Filed Date | 2020-03-19 |
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United States Patent
Application |
20200091402 |
Kind Code |
A1 |
Xiong; Wei ; et al. |
March 19, 2020 |
HEAD GIMBAL ASSEMBLY THIN-FILM PIEZOELECTRIC-MATERIAL ELEMENT
ARRANGED IN STEP PART CONFIGURATION WITH PROTECTIVE FILMS
Abstract
A thin-film piezoelectric-material element includes a laminated
structure part having a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film, a lower piezoelectric-material protective-film being formed
with alloy material, and an upper piezoelectric-material
protective-film being formed with alloy material. The lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed respectively in
the lower side of the lower electrode film and the upper side of
the upper electrode film, of the laminated structure part, so as to
sandwich the laminated structure part.
Inventors: |
Xiong; Wei; (Hong Kong,
HK) ; Iijima; Atsushi; (Hong Kong, HK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAE Magnetics (H.K.) Ltd. |
Hong Kong |
|
HK |
|
|
Family ID: |
69773172 |
Appl. No.: |
16/136227 |
Filed: |
September 19, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 41/29 20130101;
H01L 41/332 20130101; H01L 41/1876 20130101; H01L 41/0477 20130101;
H01L 41/0533 20130101; H01L 41/083 20130101; H01L 41/27 20130101;
H01L 41/0986 20130101; H01L 41/1871 20130101; G11B 5/483 20150901;
H01L 41/0815 20130101; H01L 41/09 20130101; H01L 41/316 20130101;
G11B 5/4873 20130101 |
International
Class: |
H01L 41/053 20060101
H01L041/053; H01L 41/047 20060101 H01L041/047; H01L 41/187 20060101
H01L041/187; H01L 41/23 20060101 H01L041/23; H01L 41/29 20060101
H01L041/29; H01L 41/316 20060101 H01L041/316; H02N 2/04 20060101
H02N002/04; H02N 2/00 20060101 H02N002/00; G11B 5/48 20060101
G11B005/48 |
Claims
1. A thin-film piezoelectric-material element comprising: a
laminated structure part comprising a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film; a lower piezoelectric-material protective-film being formed
with alloy material; and an upper piezoelectric-material
protective-film being formed with alloy material, wherein the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed to sandwich the
laminated structure part, respectively in the lower side of the
lower electrode film and the upper side of the upper electrode
film, wherein the lower piezoelectric-material protective-film has
a film-size larger than the piezoelectric-material film.
2. The thin-film piezoelectric-material element according to claim
1, further comprising: a film-size extended structure which
film-sizes, of an upper film part including the upper
piezoelectric-material protective-film and the upper electrode
film, a middle film part including the piezoelectric-material film,
and a lower film part including the lower electrode film and the
lower piezoelectric-material protective-film, are extended in
order, wherein the lower electrode film and the upper electrode
film are formed respectively only within the lower side and the
upper side of the piezoelectric-material film.
3. A thin-film piezoelectric-material element comprising: a
laminated structure part comprising a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film; a lower piezoelectric-material protective-film being formed
with alloy material; and an upper piezoelectric-material
protective-film being formed with alloy material, wherein the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed to sandwich the
laminated structure part, respectively in the lower side of the
lower electrode film and the upper side of the upper electrode
film, wherein the thin-film piezoelectric-material element, further
comprising: a film-size extended structure which film-sizes, of an
upper film part including the upper piezoelectric-material
protective-film and the upper electrode film, a middle film part
including the piezoelectric-material film, and a lower film part
including the lower electrode film and the lower
piezoelectric-material protective-film, are extended in order; and
a surface layer insulating film, which is disposed on the side
surfaces of the laminated structure part, the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film and on the top surface of
the upper piezoelectric-material protective-film, wherein the
surface layer insulating film comprises: a top disposed part
arranged on the top surface of the upper piezoelectric-material
protective-film; a through hole formed in the top disposed part;
step parts formed based on size differences of the upper film part,
the middle film part, and the lower film part; and a
shift-arrangement structure which an upper side part along with the
side surface of the upper film part, a middle side part along with
the side surface of the middle film part, and a lower side part
along with the side surface of the lower film part are arranged in
the positions where they shift to outside in order.
4. The thin-film piezoelectric-material element according to claim
2, wherein a long-side width along with a long-side direction and a
short-side width along with a short-side direction, of the upper
film part, the middle film part, and the lower film part, are
extended in order of the upper film part, the middle film part, and
the lower film part.
5. The thin-film piezoelectric-material element according to claim
1, wherein the lower piezoelectric-material protective-film and the
upper piezoelectric-material protective-film are formed with alloy
material including Fe as main ingredient and having Co and Mo, by
sputtering.
6. The thin-film piezoelectric-material element according to claim
1, further comprising: a lower diffusion-barrier-film laminated
between the lower electrode film and the piezoelectric-material
film; and an upper diffusion-barrier-film laminated between the
upper electrode film and the piezoelectric-material film, wherein
the lower diffusion-barrier-film and the upper
diffusion-barrier-film include strontium and ruthenium.
7. The thin-film piezoelectric-material element according to claim
3, further comprising: an upper electrode pad being directly in
contact with an exposed surface, of the upper electrode film,
exposed inside the through hole, wherein the upper electrode pad
penetrates the upper piezoelectric-material protective-film.
8. A method of manufacturing a thin-film piezoelectric-material
element comprising: a thin-films laminated part forming step of
forming the thin-film laminated part on an insulated Si substrate
comprises a substrate for deposition made of silicon and an
insulating layer formed on a surface of the substrate for
deposition; wherein the thin-films laminated part forming step
comprising: a lower piezoelectric-material protective-layer forming
step of forming a lower piezoelectric-material protective-layer
with alloy material on the insulated Si substrate; a lower
electrode layer forming step of forming a lower electrode layer on
the lower piezoelectric-material protective-layer by sputtering; a
piezoelectric-material layer forming step of forming a
piezoelectric-material layer on the lower electrode layer by
epitaxial growth of a thin-film made of lead zirconate titanate,
shown by general formula Pb (Zr.sub.xTi.sub.(1-x)) O.sub.3 by
sputtering; an upper electrode layer forming step of forming an
upper electrode layer on the piezoelectric-material layer by
sputtering; and an upper piezoelectric-material protective-layer
forming step of forming an upper piezoelectric-material
protective-layer with alloy material on the upper electrode
layer.
9. The method of manufacturing a thin-film piezoelectric-material
element according to claim 8, further comprising: an element region
forming step of forming plural element regions in the thin-films
laminated part formed by the thin-films laminated part forming
step; and a laminated structure part forming step of forming a
laminated structure part having a lower electrode film made of the
lower electrode layer, a piezoelectric-material film made of the
piezoelectric-material layer and an upper electrode film made of
the upper electrode layer, by partially removing the thin-films
laminated part, in planned-element regions, which forming plural
element regions are planned, or in each element region after
performing the element region forming step, wherein the laminated
structure part forming step has a piezoelectric-material
protective-film forming step of forming a lower
piezoelectric-material protective-film made of the lower
piezoelectric-material protective-layer and un upper
piezoelectric-material protective-film made of the upper
piezoelectric-material protective-layer so as to sandwich the
laminated structure part, in the respective lower side of the lower
electrode film and upper side of the upper electrode film of the
laminated structure part.
10. The method of manufacturing a thin-film piezoelectric-material
element according to claim 9, wherein the laminated structure part
forming step and the piezoelectric-material protective-film forming
step are performed so that film-sizes, of an upper film part
including the upper piezoelectric-material protective-film and the
upper electrode film, a middle film part including the
piezoelectric-material film, and a lower film part including the
lower electrode film and the lower piezoelectric-material
protective-film, are extended in order.
11. The method of manufacturing a thin-film piezoelectric-material
element according to claim 10, wherein the laminated structure part
forming step and the piezoelectric-material protective-film forming
step are performed so that the long-side width along with the
long-side direction and the short-side width along with the
long-side direction, of the upper film part, the middle film part,
the lower film part, are extended in order of the upper film part,
the middle film part, the lower film part.
12. The method of manufacturing a thin-film piezoelectric-material
element according to claim 8, the thin-films laminated part forming
step further comprising: a lower diffusion-barrier-layer forming
step of forming a lower diffusion-barrier-layer, made of material
including strontium and ruthenium, between the lower electrode
layer and the piezoelectric-material layer by sputtering; and an
upper diffusion-barrier-layer forming step of forming an upper
diffusion-barrier-layer, made of material including strontium and
ruthenium, between the piezoelectric-material layer and the upper
electrode layer.
13. The method of manufacturing a thin-film piezoelectric-material
element according to claim 9, further comprising: a surface layer
insulating film forming step of forming a surface layer insulating
film, which are arranged on the side surfaces of the laminated
structure part, the lower piezoelectric-material protective-film
and the upper piezoelectric-material protective-film and on the top
surface of the upper piezoelectric-material protective-film, in
planned-element regions, which forming plural element regions are
planned, or in each element region after performing the element
region forming step.
14. A head gimbal assembly comprising a head slider having a
thin-film magnetic head; a suspension for supporting the head
slider; and a thin-film piezoelectric-material element for
displacing the head slider relatively to the suspension; wherein
the thin-film piezoelectric-material element comprises: a laminated
structure part comprising a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film; a lower piezoelectric-material protective-film being formed
with alloy material; and an upper piezoelectric-material
protective-film being formed with alloy material, wherein the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed so as to sandwich
the laminated structure part between them, wherein the lower
piezoelectric-material protective-film has a film-size larger than
the piezoelectric-material film.
15. A hard disk drive comprising a head gimbal assembly including a
head slider having a thin-film magnetic head, a suspension for
supporting the head slider, a thin-film piezoelectric-material
element for displacing the head slider relatively to the
suspension; and a recording medium; wherein the thin-film
piezoelectric-material element comprises: a laminated structure
part comprising a lower electrode film, a piezoelectric-material
film laminated on the lower electrode film and an upper electrode
film laminated on the piezoelectric-material film; a lower
piezoelectric-material protective-film being formed with alloy
material; and an upper piezoelectric-material protective-film being
formed with alloy material, wherein the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed so as to sandwich
the laminated structure part between them, wherein the lower
piezoelectric-material protective-film has a film-size larger than
the piezoelectric-material film.
Description
BACKGROUND
Field of the Invention
[0001] The present invention relates to a thin-film
piezoelectric-material element which has a piezoelectric-material
and electrodes having thin-film like shape, method of manufacturing
the thin-film piezoelectric-material element, head gimbal assembly
and hard disk drive having the thin-film piezoelectric-material
element.
Related Background Art
[0002] A hard disk drive has a large recording capacity and is used
as the heart of a storage device. The hard disk drive records and
reproduces data to/from a hard disk (recording medium) by a
thin-film magnetic head. A part, which the thin-film magnetic head
is formed, is called as a head slider, and a part, which the head
slider is mounted on the edge part, is a head gimbal assembly (will
also be referred to as HGA).
[0003] Further, recording and reproducing of data to/from the
recording medium is performed by flying the head slider from a
surface of the recording medium while rotating the recording
medium, in the hard disk drive.
[0004] On the other hand, it has become difficult to control a
position of the thin-film magnetic head accurately by control with
only a voice coil motor (VCM), because heightening a recording
density of the recording medium has developed in company with
increase of a capacity of the hard disk drive. Therefore formerly,
a technology, which an actuator having supplementary function (a
supplementary actuator) is mounted on the HGA in addition to a main
actuator with the VCM, and the supplementary actuator controls a
minute position that is not able to be controlled by the VCM, is
known.
[0005] A technology, which the main actuator and the supplementary
actuator control the position of the thin-film magnetic head, is
also called two stage actuator system (dual-stage system).
[0006] In the two stage actuator system, the main actuator makes
drive arms rotate to decide a position of the head slider on a
specific track of the recording medium. Further, the supplementary
actuator adjusts the position of the head slider minutely so that
the position of the thin-film magnetic head may become an optimum
position.
[0007] A micro actuator using a thin-film piezoelectric-material
element is known formerly as the supplementary actuator. The
thin-film piezoelectric-material element has a
piezoelectric-material and a pair of electrodes formed to sandwich
the piezoelectric-material, and each of them is formed to be a
thin-film shape.
SUMMARY OF THE INVENTION
[0008] By the way, the hard disk drive has a hard disk (magnetic
recording medium) rotating at a high speed and the HGA, and these
parts are accommodated in a housing together with other parts.
[0009] Then, the hard disk drive, which helium gas is filled up
into the housing, is formerly known (for example see JP2000-231768
(also referred to as Patent document 1), for extending the life and
saving power by lightening the hard disk drive. Further, the
following hard disk drive is disclosed in the U.S. Pat. No.
8,638,524 (also referred to as Patent document 2). In the hard disk
drive, the housing, which the hard disk and HGA are accommodated,
are accommodated in the enclosure together with helium gas.
[0010] However, in the conventional hard disk drive, helium gas is
filled up into the housing or enclosure, thereby a failure in the
HGA sometimes occurs.
[0011] For lightening the hard disk drive, it is preferable that
air is discharged from inside the housing or enclosure as much as
possible to fill up helium gas all over them. Therefore, in the
conventional hard disk drive, helium gas, with pressured, is
sometimes filled up tightly.
[0012] However, when helium gas is filled up tightly, pressure of
helium gas, stronger than the ambient air, sometimes reach the
thin-film piezoelectric-material element of the HGA, during the
filling up. Therefore, a piezoelectric-material, constituting the
thin-film piezoelectric-material element, sometimes takes stronger
pressure from the surrounding. Thereby, there is a problem that
characteristic of the piezoelectric-material deteriorates with the
passage of time and the performance of the thin-film
piezoelectric-material element deteriorates.
[0013] The present invention is made to solve the above problem,
and it is an object to maintain a performance of the thin-film
piezoelectric-material element as much as possible even if helium
gas is filled up into the housing or enclosure, in the thin-film
piezoelectric-material element, method of manufacturing the
thin-film piezoelectric-material element, head gimbal assembly and
hard disk drive,
[0014] To solve the above problem, the present invention is a
thin-film piezoelectric-material element including: a laminated
structure part including a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film; a lower piezoelectric-material protective-film being formed
with alloy material; and an upper piezoelectric-material
protective-film being formed with alloy material, the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed to sandwich the
laminated structure part, respectively in the lower side of the
lower electrode film and the upper side of the upper electrode
film.
[0015] In case of the above-described thin-film
piezoelectric-material element, it is preferable that the thin-film
piezoelectric-material element, further including: a film-size
extended structure which film-sizes, of an upper film part
including the upper piezoelectric-material protective-film and the
upper electrode film, a middle film part including the
piezoelectric-material film, and a lower film part including the
lower electrode film and the lower piezoelectric-material
protective-film, are extended in order.
[0016] Further, in case of the above-described thin-film
piezoelectric-material element, it is preferable that the thin-film
piezoelectric-material element, further including: a surface layer
insulating film, which are disposed on the side surfaces of the
laminated structure part, the lower piezoelectric-material
protective-film and the upper piezoelectric-material
protective-film and on the top surface of the upper
piezoelectric-material protective-film, the surface layer
insulating film including: a top disposed part arranged on the top
surface of the upper piezoelectric-material protective-film; a
through hole formed on the top disposed part; step parts formed
based on the size differences of the upper film part, middle film
part, the lower film part; and a shift-arrangement structure which
an upper side part along with the side surface of the upper film
part, a middle side part along with the side surface of the middle
film part, and a lower side part along with the side surface of the
lower film part are arranged in the positions where they shift to
the outside in order.
[0017] Further, in case of the above-described thin-film
piezoelectric-material element, it is preferable that the long-side
width along with the long-side direction and the short-side width
along with the long-side direction, of the upper film part, the
middle film part, the lower film part, are extended in order of the
upper film part, the middle film part, the lower film part.
[0018] Further, in case of the above-described thin-film
piezoelectric-material element, it is preferable that the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed with alloy
material including Fe as main ingredient and having Co and Mo, by
sputtering.
[0019] It is preferable that the thin-film piezoelectric-material
element, further including: a lower diffusion-barrier-film
laminated between the lower electrode film and the
piezoelectric-material film; and an upper diffusion-barrier-film
laminated between the upper electrode film and the
piezoelectric-material film, the lower diffusion-barrier-film and
the upper diffusion-barrier-film include strontium and
ruthenium.
[0020] Further, in case of the above-described thin-film
piezoelectric-material element, it is preferable that the thin-film
piezoelectric-material element, further including: an upper
electrode pad being directly contact with an exposed surface, of
the upper electrode film, exposed inside the through hole, the
upper electrode pad penetrates the upper piezoelectric-material
protective-film.
[0021] Further, the present invention provides a method of
manufacturing a thin-film piezoelectric-material element including:
a thin-films laminated part forming step of forming the thin-film
laminated part on an insulated Si substrate comprises a substrate
for deposition made of silicon and an insulating layer formed on a
surface of the substrate for deposition; the thin-films laminated
part forming step including: a lower piezoelectric-material
protective-layer forming step of forming a lower
piezoelectric-material protective-layer with alloy material on the
insulated Si substrate; a lower electrode layer forming step of
forming a lower electrode layer on the lower piezoelectric-material
protective-layer by sputtering; a piezoelectric-material layer
forming step of forming a piezoelectric-material layer on the lower
electrode layer by epitaxial growth of a thin-film made of lead
zirconate titanate, shown by general formula Pb
(Zr.sub.xTi.sub.(1-x)) O.sub.3 by sputtering; an upper electrode
layer forming step of forming an upper electrode layer on the
piezoelectric-material layer by sputtering; and an upper
piezoelectric-material protective-layer forming step of forming an
upper piezoelectric-material protective-layer with alloy material
on the upper electrode layer.
[0022] Further, in case of the above-described method of
manufacturing the thin-film piezoelectric-material element, it is
preferable that the method of manufacturing a thin-film
piezoelectric-material element, further including: an element
region forming step of forming plural element regions in the
thin-films laminated part formed by the thin-films laminated part
forming step; and a laminated structure part forming step of
forming a laminated structure part having a lower electrode film
made of the lower electrode layer, a piezoelectric-material film
made of the piezoelectric-material layer and an upper electrode
film made of the upper electrode layer, by partially removing the
thin-films laminated part, in planned-element regions, which
forming plural element regions are planned, or in each element
region after performing the element region forming step, the
laminated structure part forming step has a piezoelectric-material
protective-film forming step of forming a lower
piezoelectric-material protective-film made of the lower
piezoelectric-material protective-layer and un upper
piezoelectric-material protective-film made of the upper
piezoelectric-material protective-layer so as to sandwich the
laminated structure part, in the respective lower side of the lower
electrode film and upper side of the upper electrode film of the
laminated structure part.
[0023] Further, in case of the above-described method of
manufacturing the thin-film piezoelectric-material element, it is
preferable that the laminated structure part forming step and the
piezoelectric-material protective-film forming step are performed
so that film-sizes, of an upper film part including the upper
piezoelectric-material protective-film and the upper electrode
film, a middle film part including the piezoelectric-material film,
and a lower film part including the lower electrode film and the
lower piezoelectric-material protective-film, are extended in
order.
[0024] Further, in case of the above-described method of
manufacturing the thin-film piezoelectric-material element, it is
preferable that the laminated structure part forming step and the
piezoelectric-material protective-film forming step are performed
so that the long-side width along with the long-side direction and
the short-side width along with the long-side direction, of the
upper film part, the middle film part, the lower film part, are
extended in order of the upper film part, the middle film part, the
lower film part.
[0025] It is possible that the thin-film laminated part forming
step further including: a lower diffusion-barrier-layer forming
step of forming a lower diffusion-barrier-layer, made of material
including strontium and ruthenium, between the lower electrode
layer and the piezoelectric-material layer by sputtering; and an
upper diffusion-barrier-layer forming step of forming an upper
diffusion-barrier-layer, made of material including strontium and
ruthenium, between the piezoelectric-material layer and the upper
electrode layer.
[0026] Further, it is preferable that the method of manufacturing a
thin-film piezoelectric-material element, further including: a
surface layer insulating film forming step of forming a surface
layer insulating film, which are arranged on the side surfaces of
the laminated structure part, the lower piezoelectric-material
protective-film and the upper piezoelectric-material
protective-film and on the top surface of the upper
piezoelectric-material protective-film, in planned-element regions,
which forming plural element regions are planned, or in each
element region after performing the element region forming
step.
[0027] Further, the present invention provides a head gimbal
assembly including: a head slider having a thin-film magnetic head;
a suspension for supporting the head slider; and a thin-film
piezoelectric-material element for displacing the head slider
relatively to the suspension; the thin-film piezoelectric-material
element including: a laminated structure part comprising a lower
electrode film, a piezoelectric-material film laminated on the
lower electrode film and an upper electrode film laminated on the
piezoelectric-material film; a lower piezoelectric-material
protective-film being formed with alloy material; and an upper
piezoelectric-material protective-film being formed with alloy
material, the lower piezoelectric-material protective-film and the
upper piezoelectric-material protective-film are formed so as to
sandwich the laminated structure part between them.
[0028] Further, the present invention provides a hard disk drive
including: a head gimbal assembly including a head slider having a
thin-film magnetic head, a suspension for supporting the head
slider, a thin-film piezoelectric-material element for displacing
the head slider relatively to the suspension; and a recording
medium; the thin-film piezoelectric-material element including: a
laminated structure part comprising a lower electrode film, a
piezoelectric-material film laminated on the lower electrode film
and an upper electrode film laminated on the piezoelectric-material
film; a lower piezoelectric-material protective-film being formed
with alloy material; and an upper piezoelectric-material
protective-film being formed with alloy material, the lower
piezoelectric-material protective-film and the upper
piezoelectric-material protective-film are formed so as to sandwich
the laminated structure part between them.
[0029] The present invention will be more fully understood from the
detailed description given hereinbelow and the accompanying
drawings which are given by way of illustration only, and thus are
not to be considered as limiting the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a perspective view showing a whole of the HGA,
from front side, according to an embodiment of the present
invention;
[0031] FIG. 2 is a perspective view showing a principal part of the
HGA from front side;
[0032] FIG. 3 is a perspective view showing a principal part of the
suspension constituting the HGA in FIG. 1 from front side;
[0033] FIG. 4 is a perspective view showing a part, which a
thin-film piezoelectric-material element is fixed, of a flexure
with enlargement;
[0034] FIG. 5 is a sectional view taken along the line 5-5 in FIG.
4;
[0035] FIG. 6 is a plan view showing the thin-film
piezoelectric-material element and the peripheral part of the
HGA;
[0036] FIG. 7 is a sectional view taken along the line 7-7 in FIG.
6;
[0037] FIG. 8 is a sectional view taken along the line 8-8 in FIG.
6;
[0038] FIG. 9 is a sectional view taken along the line 9-9 in FIG.
6;
[0039] FIG. 10 (a) is a perspective view showing whole of the
thin-film piezoelectric-material substrate, which are used for
manufacturing the thin-film piezoelectric-material element
according to the embodiment of the present invention, FIG. 10 (b)
is a plan view showing the surface of the thin-film
piezoelectric-material substrate after forming of element regions
with enlargement;
[0040] FIG. 11 is a sectional view taken along the line 11-11 in
FIG. 10 (b);
[0041] FIG. 12 is a sectional view, partially omitted, showing a
thin-films laminated part forming step and a laminated structure
part forming step;
[0042] FIG. 13 is a sectional view, partially omitted, showing a
manufacturing step of the laminated structure part forming step
subsequent to that in FIG. 12;
[0043] FIG. 14 is a sectional view, partially omitted, showing
manufacturing step subsequent to that in FIG. 13;
[0044] FIG. 15 is a sectional view, partially omitted, showing
manufacturing step subsequent to that in FIG. 14;
[0045] FIG. 16 is a sectional view, partially omitted, showing
manufacturing step subsequent to that in FIG. 15;
[0046] FIG. 17 is a sectional view, partially omitted, showing a
surface layer insulating film forming step;
[0047] FIG. 18 (a) is a sectional view, partially omitted, showing
an element region forming step, FIG. 18 (b) is a sectional view,
partially omitted, showing a manufacturing step subsequent to that
in FIG. 18 (a);
[0048] FIG. 19 is a sectional view showing the state before forming
the element region, corresponding to FIG. 11;
[0049] FIG. 20 is a graph showing change of stroke of the thin-film
piezoelectric-material element with the passage of time; and
[0050] FIG. 21 is a perspective view showing a hard disk drive
equipped with the HGA according to the embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0051] In the following, embodiments of the present invention will
be described with reference to the drawings. Note that the same
components will be referred to with the same numerals or letters,
while omitting their overlapping descriptions.
[0052] (Structure of HGA)
[0053] To begin with, a structure of the HGA according to the
embodiment of the present invention will be explained with
reference to FIG. 1 to FIG. 4. Here, FIG. 1 is a perspective view
showing a whole of the HGA 91, from front side, according to an
embodiment of the present invention. FIG. 2 is a perspective view
showing a principal part of the HGA 91 from front side. FIG. 3 is a
perspective view showing a principal part of the suspension 50
constituting the HGA 91 from front side. Further, FIG. 4 is a
perspective view showing a part, which a thin-film
piezoelectric-material element 12b is fixed, of a flexure 6 with
enlargement.
[0054] As illustrated in FIG. 1, the HGA 91 has the suspension 50
and a head slider 60. The suspension 50 has a base plate 2, a load
beam 3, the flexure 6 and a dumper not illustrated, and it has a
structure which these parts are joined to be united one body by a
weld and so on.
[0055] The base plate 2 is a part which is used to fix the
suspension 50 to a drive arms 209 of a later-described hard disk
drive 201, and it is formed with a metal such as stainless steel or
the like.
[0056] The load beam 3 is fixed on the base plate 2. The load beam
3 has a shape in which the width gradually decreases as it is
distanced more from the base plate 2. The load beam 3 has a load
bending part which generates a power for pressing the head slider
60 against the later-described hard disk 202 of the hard disk drive
201.
[0057] Further, as illustrated in FIG. 1 to FIG. 4, the flexure 6
has a flexure substrate 4, a base insulating layer 5, a connecting
wiring 81 and thin-film piezoelectric-material elements 12a, 12b.
The flexure 6 has a structure which the base insulating layer 5 is
formed on the flexure substrate 4, the connecting wiring 81 and
thin-film piezoelectric-material elements 12a, 12b are adhered on
the base insulating layer 5. Further, the not illustrated
protective insulating layer is formed so as to cover the connecting
wiring 81 and thin-film piezoelectric-material elements 12a,
12b.
[0058] The flexure 6 has piezoelectric-material elements attached
structure which thin-film piezoelectric-material elements 12a, 12b
are fixed on the surface of the base insulating layer 5 in addition
to the connecting wiring 81 to become a structure with
piezoelectric-material element.
[0059] Further, the flexure 6 has a gimbal part 90 on the tip side
(load beam 3 side). A tongue part 19, which the head slider 60 is
mounted, is secured on the gimbal part 90, and a plurality of
connecting pads 20 are formed near an edge side than the tongue
part 19. Connecting pads 20 are electrically connected to
not-illustrated electrode pads of the head slider 60.
[0060] This flexure 6 expands or shrinks thin-film
piezoelectric-material elements 12a, 12b and expands or shrinks
stainless part (referred to out trigger part) jut out outside of
the tongue part 19. That makes a position of the head slider 60
move very slightly around not-illustrated dimple, and a position of
the head slider 60 is controlled minutely.
[0061] The flexure substrate 4 is a substrate for supporting a
whole of the flexure 6, and it is formed with stainless. Rear side
of the flexure substrate 4 is fixed to the base plate 2 and the
load beam 3 by weld. As illustrated in FIG. 1, the flexure
substrate 4 has a center part 4a fixed to surfaces of the load beam
3 and the base plate 2, and a wiring part 4b extending to outside
from the base plate 2.
[0062] The base insulating layer 5 covers s surface of the flexure
substrate 4. The base insulating layer 5 is formed with for example
polyimide, and it has a thickness of about 5 .mu.m to 10 .mu.m.
Further, as illustrated in detail in FIG. 3, a part of the base
insulating layer 5, disposed on the load beam 3, is divided two
parts. One part of them is a first wiring part 5a, the other part
of them is second wiring part 5b. The thin-film
piezoelectric-material element 12a and thin-film
piezoelectric-material element 12b are adhered on surfaces of each
wiring part.
[0063] A plurality of connecting wirings 81 are formed on surfaces
of each of the first wiring part 5a and the second wiring part 5b.
Each connecting wiring 81 is formed with conductor such as copper
or the like. One end parts of each connecting wiring 81 are
connected to the thin-film piezoelectric-material elements 12a, 12b
or each connecting pad 20.
[0064] The not-illustrated protective insulating layer is formed
with for example polyimide. The protective insulating layer has a
thickness of about 1 .mu.m to 2 .mu.m, for example.
[0065] Further, a not illustrated thin-film magnetic head, which
records and reproduces data, is formed on the head slider 60.
Furthermore, a plurality of not illustrated electrode pads are
formed on the head slider 60, and each electrode pad is connected
to the connecting pad 20.
[0066] (Structure of Thin-Film Piezoelectric-Material Element)
[0067] Subsequently, the structure of thin-film
piezoelectric-material element 12b will be explained with reference
to FIG. 5 to FIG. 9. Here, FIG. 5 is a sectional view taken along
the line 5-5 in FIG. 4, FIG. 6 is a plan view showing the thin-film
piezoelectric-material element 12b and the peripheral part of the
HGA 91. FIG. 7 is a sectional view taken along the line 7-7 in FIG.
6, FIG. 8 is a sectional view taken along the line 8-8 in FIG. 6.
FIG. 9 is a sectional view taken along the line 9-9 in FIG. 6. Note
that the connecting electrode 18b is omitted in FIGS. 6-8 for
convenience of illustration.
[0068] The thin-film piezoelectric-material element 12b (similar to
thin-film piezoelectric-material element 12a), as illustrated in
FIG. 5-FIG. 9, has a laminated structure part 21, a lower
piezoelectric-material protective-film 14, an upper
piezoelectric-material protective-film 24, a surface layer
insulating film 22, an upper electrode pad 44A, a lower electrode
pad 44B and an adhesive resin layer 28. In the thin-film
piezoelectric-material element 12b, the lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are formed to sandwich
the laminated structure part 21.
[0069] The thin-film piezoelectric-material elements 12b, 12a are
adhered to the surface of the base insulating layer 5 with epoxy
resin. A resin layer 29, made of the epoxy resin, and a support
layer 30 (for example SiO.sub.2) are formed between the thin-film
piezoelectric-material element 12b and the base insulating layer
5.
[0070] The thin-film piezoelectric-material element 12b is formed
with a rectangular shape in a plan view, as illustrated in FIG. 6.
A pad region 25 is secured at one side along with a long-side
direction of the thin-film piezoelectric-material element 12b. The
pad region 25 is a region from a boundary line 22e, of a top
disposed part 22a and a side disposed part 22b of the
later-described surface layer insulating film 22, to the upper
electrode pad 44A and the lower electrode pad 44B. An upper through
hole 23A, a lower through hole 23B, the upper electrode pad 44A and
the lower electrode pad 44B are formed in the pad region 25.
[0071] Note that "upper" and "lower" in the present invention do
not show necessarily upper side, lower side in a condition which
the thin-film piezoelectric-material element is adhered on the base
insulating layer 5. These words are terms for reasons of
convenience so as to distinguish two upper, lower electrode films
21b, 21c and so on opposing each other sandwiching the
piezoelectric-material film 13 between them. In the actual
products, the upper electrode film 27 is sometimes disposed lower
side, and the lower electrode film 17 is sometimes disposed upper
side.
[0072] The laminated structure part 21 has a piezoelectric-material
film 13, a lower electrode film 17 and an upper electrode film 27.
The piezoelectric-material film 13 is laminated on the lower
electrode film 17, the upper electrode film 27 is laminated on the
piezoelectric-material film 13. The laminated structure part 21 has
a laminated structure formed of the piezoelectric-material film 13,
the lower electrode film 17 and the upper electrode film 27.
Besides, the laminated structure part 21 further has a lower
diffusion-barrier-film 16a, laminated between the lower electrode
film 17 and the piezoelectric-material film 13, and an upper
diffusion-barrier-film 16b, laminated between the upper electrode
film 27 and the piezoelectric-material film 13.
[0073] The piezoelectric-material film 13 is formed to be a
thin-film shape using a piezoelectric-material made of lead
zirconate titanate, shown by general formula Pb
(Zr.sub.xTi.sub.(1-x)) O.sub.3 (referred to also as "PZT" in the
following). The piezoelectric-material film 13 is an epitaxial film
formed by epitaxial growth, and for example it has a thickness of
about 1 .mu.m-5 .mu.m. Further, the piezoelectric-material film 13
is sputter film formed by sputtering.
[0074] A piezoelectric ceramics (much of them are ferroelectric
substance) such as barium titanate, lead titanate or the like,
non-lead system piezoelectric ceramics not including titanium or
lead are able to be used for the piezoelectric-material film 13
instead of using PZT.
[0075] The lower electrode film 17 is a thin-film (thickness about
100 nm) made of metal element which has Pt (it may include Au, Ag,
Pd, Ir, Ru, Cu, in addition to Pt) as main ingredient, it is formed
on the lower piezoelectric-material protective-film 14. A crystal
structure of the lower electrode film 17 is a face-centered cubic
structure.
[0076] The upper electrode film 27 is a polycrystal thin-film
(thickness about 50 nm) with metal element which has Pt (it may
include Au, Ag, Pd, Ir, Rh, Ni, Pb, Ru, Cu, in addition to Pt) as
main ingredient, it is formed on the upper diffusion-barrier-film
16b. The upper electrode film 27 has a figure which the part under
the lower through hole 23B and the peripheral part are lacked
(hereinafter, referred also to as "partial lacked figure"), so as
not to be in touch with later-described lower electrode pad
44B.
[0077] The lower diffusion-barrier-film 16a is a thin-film
(thickness about 20 nm) made of conductive material, including
strontium and ruthenium, such as SrRuO.sub.3 (also referred SRO) or
the like formed by epitaxial growth. The lower
diffusion-barrier-film 16a is formed by sputtering. The lower
diffusion-barrier-film 16a is formed on the upper surface of the
lower electrode film 17 of the piezoelectric-material film 13 side.
The piezoelectric-material film 13 is formed on the lower
diffusion-barrier-film 16a.
[0078] The upper diffusion-barrier-film 16b is a thin-film
(thickness about 10 nm-35 nm) made of amorphous conductive
material, including strontium and ruthenium, such as SrRuO.sub.3
(also referred SRO) or the like, and it is formed on the upper
surface of the upper electrode film 27 of the
piezoelectric-material film 13 side. The upper
diffusion-barrier-film 16b is also formed by sputtering.
[0079] The lower piezoelectric-material protective-film 14, upper
piezoelectric-material protective-film 24 are respectively formed
on the lower side of the lower electrode film 17, on the upper side
of the upper electrode film 27. The lower piezoelectric-material
protective-film 14, upper piezoelectric-material protective-film 24
are polycrystal thin-films (thickness about 100 nm) using alloy
material.
[0080] The lower piezoelectric-material protective-film 14, the
upper piezoelectric-material protective-film 24 are formed with
alloy material which has iron (Fe) as main ingredient, for example.
It is preferable that crystal structures of the lower
piezoelectric-material protective-film 14, the upper
piezoelectric-material protective-film 24 are body-centered cubic
structure. It is preferable that the lower piezoelectric-material
protective-film 14, the upper piezoelectric-material
protective-film 24 are formed with alloy material which include Fe
and at least any one of Co, Mo, Au, Pt, Al, Cu, Ag, Ta, Cr, Ti, Ni,
Ir, Nb, Rb, Cs, Ba, V, W, Ru. Further, it is more preferable that
the lower piezoelectric-material protective-film 14, the upper
piezoelectric-material protective-film 24 are formed with alloy
material which includes Fe and Co, Mo.
[0081] Then, the thin-film piezoelectric-material element 12b has a
film-size extended structure. The film-size extended structure
means a structure which sizes of a later-described upper film part
40A, middle film part 40B and lower film part 40C are extended in
that order. Namely, in the thin-film piezoelectric-material element
12b, the size of the middle film part 40B is larger than the size
of the upper film part 40A, the size of the lower film part 40C is
larger than the size of the middle film part 40B. In this
embodiment, the upper film part 40A means a part including the
upper electrode film 27 and the upper piezoelectric-material
protective-film 24, the middle film part 40B means a part including
the piezoelectric-material film 13, and the lower film part 40C
means a part including the lower electrode film 17 and lower
piezoelectric-material protective-film 14.
[0082] Further, in the thin-film piezoelectric-material element
12b, long-side widths and short-side widths, about all of the lower
piezoelectric-material protective-film 14, lower electrode film 17,
piezoelectric-material film 13, upper piezoelectric-material
protective-film 24 and upper electrode film 27, are extended in the
order of the upper film part 40A, middle film part 40B and lower
film part 40C. In this case, the long-side width means a width
along with long-side direction of the thin-film
piezoelectric-material element 12b, short-side width means a width
along with short-side direction of the thin-film
piezoelectric-material element 12b.
[0083] Namely, in the thin-film piezoelectric-material element 12b,
as illustrated in FIG. 7, when the long-side width of the upper
piezoelectric-material protective-film 24 and upper electrode film
27 is L24, the long-side width of the piezoelectric-material film
13 is L13, and long-side width of the lower piezoelectric-material
protective-film 14 and lower electrode film 17 is L14,
L24<L13<L14.
[0084] Further, as illustrated in FIG. 9, when the short-side width
of the upper piezoelectric-material protective-film 24 and upper
electrode film 27 is W24, the short-side width of the
piezoelectric-material film 13 is W13, and short-side width of the
lower piezoelectric-material protective-film 14 and lower electrode
film 17 is W14, W24<W13<W14.
[0085] The surface layer insulating film 22 is disposed on the top
surface and side surfaces of four directions of the laminated
structure part 21, and it is formed so as to cover the top surface
and side surfaces of four directions of the laminated structure
part 21. The surface layer insulating film 22 is formed with
insulating material such as polyimide or the like. The surface
layer insulating film 22 has a top disposed part 22a and a side
disposed part 22b.
[0086] The top disposed part 22a is a part disposed on the top
surface of the laminated structure part 21. The top disposed part
22a is formed directly on the top surface 24ba of the upper
piezoelectric-material protective-film 24. One end side of the
long-side direction of the top disposed part 22a is assigned to the
pad region 25. The upper through hole 23A and lower through hole
23B are formed on the top disposed part 22a.
[0087] The upper through hole 23A is formed in the pad region 25 of
the top disposed part 22a. The upper through hole 23A penetrates
the top disposed part 22a of the surface layer insulating film 22
and the upper piezoelectric-material protective-film 24, as
illustrated in FIG. 7. The top surface of the upper electrode film
27 is exposed, inside the upper through hole 23A, as an exposed
surface 27b. Further, because the upper piezoelectric-material
protective-film 24 is formed with alloy material, a not-illustrated
insulating film is formed on a part, through the upper
piezoelectric-material protective-film 24, inside the upper through
hole 23A.
[0088] The lower through hole 23B is also formed in the pad region
25 of the top disposed part 22a. The lower through hole 23B
penetrates the top disposed part 22a, similar with the upper
through hole 23A, as illustrated in FIG. 8. Because the upper
electrode film 27 and the upper piezoelectric-material
protective-film 24 are formed with the above-described partial
lacked figure, the top surface of the lower electrode film 17 is
exposed, inside the lower through hole 23B, as an exposed surface
17b.
[0089] Then, the upper electrode pad 44A, lower electrode pad 44B
are respectively formed in the upper through hole 23A, lower
through hole 23B. The upper electrode pad 44A is formed in a
rectangular parallelepiped shape. The upper electrode pad 44A is in
directly contact with the exposed surface 27b of the upper
electrode film 27. The lower electrode pad 44B is formed in a
rectangular parallelepiped shape. The lower electrode pad 44B in
directly contact with the exposed surface 17b of the lower
electrode film 17. The long-side width of the upper electrode pad
44A, lower electrode pad 44B are L44, the short-side width of the
upper electrode pad 44A, lower electrode pad 44B are W44.
[0090] The side disposed part 22b is a part disposed on side
surfaces of the laminated structure part 21, the lower
piezoelectric-material protective-film 14 and upper
piezoelectric-material protective-film 24. The side disposed part
22b has an upper side part 22a1, a middle side part 22a2 and a
lower side part 22a3, as illustrated in FIG. 9. The upper side part
22a1 is a part along with the side surface of the upper film part
40A. The middle side part 22a2 is a part along with the side
surface of the middle film part 40B, the lower side part 22a3 is a
part along with the side surface of the lower film part 40C.
[0091] Further, the surface layer insulating film 22 has a
shift-arrangement structure. The shift-arrangement structure means
a structure which the upper side part 22a1, the middle side part
22a2 and the lower side part 22a3 are arranged in the positions
where they shift to the outside in order. Further, the surface
layer insulating film 22 has step part 22S1, step part 22S2.
[0092] The step parts 22S1, 22S2 are formed based on the size
differences, of surface layer insulating film 22, of the upper film
part 40A, middle film part 40B, the lower film part 40C. The step
parts 22S1, 22S2 project respectively from the upper side part
22a1, the middle side part 22a2 along with the surface of the
piezoelectric-material film 13 and connect with the middle side
part 22a2, lower side part 22a3. Namely, the part between the upper
side part 22a1 and the middle side part 22a2 is the step part 22S1,
the part between the middle side part 22a2 and the lower side part
22a3 is the step part 22S2.
[0093] The, as illustrated in FIG. 4, the thin-film
piezoelectric-material element 12b, having the above-described
structure, is connected to suspension pads 26, 26 with connecting
electrodes 18b (referred to also connecting pad, can be formed with
solder, for example). In this case, connecting electrodes 18b, 18b
connect respective outer end surfaces of the upper, lower electrode
pads 44A, 44B to suspension pads 26, 26.
[0094] Note that connecting wiring 81 and thin-film
piezoelectric-material elements 12b, 12a are shown in FIG. 2 to
FIG. 4, for illustration of convenience, they are not exposed in
the surface of the flexure 6, because they are cover with
not-illustrated protective insulating layer.
[0095] (Method of Manufacturing the Thin-Film
Piezoelectric-Material Element)
[0096] Subsequently, the method of manufacturing the thin-film
piezoelectric-material element 12b will be explained with reference
to FIG. 10-FIG. 18. Here, FIG. 10 (a) is a perspective view showing
whole of the thin-film piezoelectric-material substrate 1, which
are used for manufacturing the thin-film piezoelectric-material
element 12b according to the embodiment of the present invention,
FIG. 10 (b) is a plan view showing the surface of the thin-film
piezoelectric-material substrate 1 after forming of element regions
with enlargement. FIG. 11 is a sectional view taken along the line
11-11 in FIG. 10 (b). FIG. 12 is a sectional view, partially
omitted, showing a thin-films laminated part forming step and a
laminated structure part forming step. FIG. 13 is a sectional view,
partially omitted, showing a manufacturing step of the laminated
structure part forming step subsequent to that in FIG. 12. FIG.
14-FIG. 16 are sectional views, partially omitted, showing
manufacturing step respectively subsequent to that in FIG. 13-FIG.
15. FIG. 17 is a sectional view, partially omitted, showing a
surface layer insulating film forming step. FIG. 18 (a) is a
sectional view, partially omitted, showing an element region
forming step, FIG. 18 (b) is a sectional view, partially omitted,
showing a manufacturing step subsequent to that in FIG. 18 (a).
[0097] The thin-film piezoelectric-material element 12b is
manufactured with the thin-films piezoelectric-material substrate
1. The thin-films piezoelectric-material substrate 1 is a substrate
for manufacturing the thin-film piezoelectric-material element 12b,
and it is manufactured by performing a substrate manufacturing
step. A thin-films laminated part forming step, according to the
embodiment, is included in the substrate manufacturing step.
[0098] In the substrate manufacturing step, at first, a silicon
wafer is prepared. Thermal oxidation is performed for the silicon
wafer, thereby the insulating layer 2a is formed on one side of the
silicon wafer. Then, an insulated Si substrate 2 is obtained. A
surface of the silicon wafer, of the side which the insulating
layer 2a is formed, is a first surface 1a, and the rear surface is
a second surface 1b.
[0099] The insulated Si substrate 2 has, as illustrated in FIG. 11,
the silicon wafer, as substrate for deposition, and the insulating
layer 2a made of SiO.sub.2, formed on the surface.
[0100] Then, a thin-films laminated part 3 is formed on the first
surface 1a of the insulated Si substrate 2, by performing a
thin-films laminated part forming step, as illustrated in FIG. 10
(a). Thereby, the thin-films piezoelectric-material substrate 1 is
manufactured. The thin-films laminated part 3 is formed on the
insulating layer 2a.
[0101] The thin-films laminated part forming step has a
later-described a lower piezoelectric-material protective-layer
forming step, a lower electrode layer forming step, a lower
diffusion-barrier-layer forming step, a piezoelectric-material
layer forming step, an upper diffusion-barrier-layer forming step,
an upper electrode layer forming step and an upper
piezoelectric-material protective-layer forming step.
[0102] In the lower piezoelectric-material protective-layer forming
step, as illustrated in FIG. 12, a lower piezoelectric-material
protective-layer 14L is formed. The lower piezoelectric-material
protective-layer 14L is formed with alloy material (for example,
alloy material including Fe, Co and Mo) having iron (Fe) as main
ingredient, by sputtering. In this case, resin for adhesive is
applied on the insulating layer 2a of the insulated Si substrate 2,
and the lower piezoelectric-material protective-layer 14L is formed
with the resin for adhesive. The adhesive resin layer 28 is formed
with the resin for adhesive.
[0103] Next, the lower electrode layer forming step is performed.
In the lower electrode layer forming step, epitaxial growth, of
metal element which has Pt as a main ingredient, is performed on
the lower piezoelectric-material protective-layer 14L by
sputtering. This epitaxial growth makes the lower electrode layer
17L.
[0104] Next, the lower diffusion-barrier-layer forming step is
performed. In this step, the lower diffusion-barrier-layer 16aL is
formed with SRO for example, on upper surface of the lower
electrode layer 17L by sputtering.
[0105] Subsequently, the piezoelectric-material layer forming step
is performed. In this step, as illustrated in FIG. 12, epitaxial
growth of thin-film made of PZT is performed on the lower
diffusion-barrier-layer 16aL by sputtering to form the
piezoelectric-material layer 13L.
[0106] More subsequently, an upper diffusion-barrier-layer forming
step is performed. In this step, the upper diffusion-barrier-layer
16bL is formed with SRO for example, on the piezoelectric-material
layer 13L by sputtering, as illustrated in FIG. 12.
[0107] Further, the upper electrode layer forming step is
performed. In this step, growth of metal material having Pt as main
ingredient is performed on the upper diffusion-barrier-layer 16bL
by sputtering to form the upper electrode layer 27L. The upper
electrode layer 27L is able to be no-oriented polycrystal film or a
preferentially oriented film with the (110) plane, or (111) plane,
not epitaxial growth film.
[0108] As described above, the lower diffusion-barrier-layer
forming step and the upper diffusion-barrier-layer forming step are
performed in the thin-films laminated part forming step. Therefore,
the piezoelectric-material layer 13L is formed on the lower
electrode layer 17L via the lower diffusion-barrier-layer 16aL, the
upper electrode layer 27L is formed on the piezoelectric-material
layer 13L via the upper diffusion-barrier-layer 16bL.
[0109] After that, the upper piezoelectric-material
protective-layer forming step is performed. In the upper
piezoelectric-material protective-layer forming step, the upper
piezoelectric-material protective-layer 24L is formed, on the upper
electrode layer 27L, with alloy material common with the lower
piezoelectric-material protective-layer forming step, by
sputtering.
[0110] When the thin-films laminated part 3 is formed on the top
surface of the insulating layer 2a, by performing the thin-films
laminated part forming step as described above, the thin-films
piezoelectric-material substrate 1 is manufactured. Each layer from
the lower piezoelectric-material protective-layer 14L to the upper
piezoelectric-material protective-layer 24L are included in the
thin-films laminated part 3, as illustrated in FIG. 12.
[0111] Then the laminated structure part forming step is performed
subsequently to the thin-films laminated part forming step. In the
laminated structure part forming step, the thin-films laminated
part 3 is removed partially, thereby the above-described laminated
structure part 21 is formed.
[0112] The laminated structure part forming step is performed for
each element region 10, as illustrated in FIG. 10(a), FIG. 11.
Element regions 10 are formed by dividing the thin-films laminated
part 3 regularly in longitudinal direction and horizontal
direction. The thin-film piezoelectric-material element 12b is
formed from each element region 10. The element regions 10 are
separated by gap parts 11, and they are formed by performing
later-described element region forming step.
[0113] The laminated structure part forming step is able to be
performed for planned-element regions 10A, as illustrated in FIG.
19, which forming the plural element regions 10 are planned,
instead of the element regions 10 illustrated in FIG. 11. Note that
the case, which the laminated structure part forming step is
performed for the planned-element regions 10A before being divided,
is illustrated in FIG. 12 to FIG. 17.
[0114] A piezoelectric-material protective-film forming step, which
the lower piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are formed, is included
in the laminated structure part forming step. Accordingly, when the
laminated structure part forming step is performed, the lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are formed together with
the laminated structure part 21.
[0115] In the laminated structure part forming step, at first, a
cap layer 31, made of alumina (Al.sub.2O.sub.3), is formed on the
upper piezoelectric-material protective-layer 24L, as illustrated
in FIG. 12. Subsequently, as illustrated in FIG. 13, a resist
pattern 61 with not-illustrated photoresist is formed on the cap
layer 31. An ion milling or RIE (Reactive Ion Etching) is performed
with the resist pattern 61 as a mask to remove the unnecessary
parts of the cap layer 31, the upper piezoelectric-material
protective-layer 24L, the upper electrode layer 27L and the upper
diffusion-barrier-layer 16bL.
[0116] Then, as illustrated in FIG. 14, the upper
piezoelectric-material protective-film 24, the upper electrode film
27 and the upper diffusion-barrier-film 16b are respectively formed
from the upper piezoelectric-material protective-layer 24L, the
upper electrode layer 27L and the upper diffusion-barrier-layer
16bL. In this case, the upper piezoelectric-material
protective-film 24, the upper electrode film 27 and the upper
diffusion-barrier-film 16b are formed by the size of the
above-described upper film part 40A.
[0117] Subsequently, not-illustrated resist pattern is used as a
mask, a pattering, for the piezoelectric-material layer 13L and the
lower diffusion-barrier-layer 16aL, is performed to remove
unnecessary parts of the piezoelectric-material layer 13L and the
lower diffusion-barrier-layer 16aL. Then the piezoelectric-material
film 13 and the lower diffusion-barrier-film 16a are formed from
the piezoelectric-material layer 13L and the lower
diffusion-barrier-layer 16aL, as illustrated in FIG. 15. In this
case, the piezoelectric-material film 13 and the lower
diffusion-barrier-film 16a are formed by the size of the
above-described middle film part 40B.
[0118] More subsequently, not-illustrated resist pattern is used as
a mask, a pattering, for the lower electrode layer 17L and the
lower piezoelectric-material protective-layer 14L, is performed to
remove unnecessary parts of the lower electrode layer 17L and the
lower piezoelectric-material protective-layer 14L. Then the lower
electrode film 17 and the lower piezoelectric-material
protective-film 14 are formed from the lower electrode layer 17L
and the lower piezoelectric-material protective-layer 14L. In this
case, the lower electrode film 17 and the lower
piezoelectric-material protective-film 14 are formed by the size of
the above-described lower film part 40C.
[0119] The above-described steps are performed to form the
laminated structure part 21. Further, the lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are formed to sandwich
the laminated structure part 21.
[0120] Then, the upper piezoelectric-material protective-film 24
and the upper electrode film 27 of the laminated structure part 21,
the piezoelectric-material film 13 of the laminated structure part
21, the lower electrode film 17 of the laminated structure part 21
and the lower piezoelectric-material protective-film 14 are
respectively formed with the size of the upper film part 40A, the
middle film part 40B, the lower film part 40C. Therefore, the
formed upper piezoelectric-material protective-film 24, the
laminated structure part 21 and lower piezoelectric-material
protective-film 14 have the above-described film-size extended
structure. Further, in each film, both long-side width and
short-side width are extended in order of the upper film part 40A,
the middle film part 40B, the lower film part 40C.
[0121] After performing the laminated structure part forming step,
RIE (Reactive Ion Etching), with oxygen gas, is performed, to
remove the unnecessary part of the adhesive resin layer 28. In this
case, as illustrated in FIG. 16, RIE is performed in a state which
the cap layer 31 remains on the upper piezoelectric-material
protective-film 24. By this, the upper piezoelectric-material
protective-film 24 is protected so as not to be oxidized. After
that, ion-milling or RIE is performed to remove the cap layer
31.
[0122] Next, a surface layer insulating film forming step is
performed. In the surface layer insulating film forming step, as
illustrated in FIG. 17, the surface layer insulating film 22 is
formed with polyimide. The surface layer insulating film 22 is
arranged on the side surfaces of the laminated structure part 21,
the lower piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24, and the top surface of
the upper piezoelectric-material protective-film 24, in each
element region 10 or each planned-element region 10A.
[0123] In this case, the laminated structure part 21, the lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 have the film-size
extended structure. Therefore, the surface layer insulating film 22
is formed so as to have the above-described shift-arrangement
structure and step parts 22S1, 22S2.
[0124] On the other hand, the element region forming step is
performed as following. In the element region forming step, at
first, not-illustrated photoresist is applied on the surface of the
thin-films piezoelectric-material substrate 1 to form a photoresist
layer on the thin-films laminated part 3, as illustrated in FIG. 18
(a). Subsequently, a patterning, with not-illustrated photo mask,
is performed to form a resist pattern 38.
[0125] After that, ion-milling, RIE or etching is performed for the
thin-films laminated part 3 with the resist pattern 38 as a mask to
remove unnecessary parts of the thin-films laminated part 3 and
adhesive resin layer 28. Then, as illustrated in FIG. 18 (b), the
thin-films laminated part 3 and adhesive resin layer 28 are divided
into the plural element region 10 via gap parts 11.
[0126] An electrode pad forming step is performed after the element
region forming step. In the electrode pad forming step, unnecessary
parts of the surface layer insulating film 22 and upper
piezoelectric-material protective-film 24 are removed by etching to
form the upper through hole 23A, lower through hole 23B. After
that, plating or the like is performed to form the upper electrode
pad 44A, lower electrode pad 44A in the upper through hole 23A,
lower through hole 23B, in each element region 10.
[0127] In case of HDD, the insulated Si substrate 2 is removed from
the thin-films piezoelectric-material substrate 1, by etching or
the like. Thereby the plural thin-film piezoelectric-material
elements 12b are formed. For example, the formed thin-film
piezoelectric-material elements 12b are adhered to the surface of
the base insulating layer 5 of the HGA 91.
[0128] (Operation and Effect of Thin-Film Piezoelectric-Material
Element)
[0129] In the above-described thin-film piezoelectric-material
element 12b, the lower piezoelectric-material protective-film 14
and the upper piezoelectric-material protective-film 24 are formed
to sandwich the laminated structure part 21. Therefore, the
piezoelectric-material film 13, included in the laminated structure
part 21, is protected by the lower piezoelectric-material
protective-film 14 and the upper piezoelectric-material
protective-film 24. Therefore, the piezoelectric-material film 13
hardly takes both downward pressure and upward pressure of helium
gas.
[0130] By the way, the HGA 91, which the thin-film
piezoelectric-material element 12b is mounted, is accommodated in
the not-illustrated housing of the later-described HDD 201 together
with the other parts. Helium gas is filled up into the housing of
the HDD 201 with certain pressure. Therefore, the pressured helium
gas reaches the HGA 91, and also reaches the thin-film
piezoelectric-material element 12b. Then the downward pressure of
the helium gas possibly reaches the piezoelectric-material film 13
via the surface layer insulating film 22. Further, upward pressure
possibly reaches the piezoelectric-material film 13 via the flexure
substrate 4, the base insulating layer 5. Because, the
piezoelectric-material film 13 is formed by a thin-film-shaped, the
piezoelectric-material film 13 easily takes both upward pressure
and downward pressure. The piezoelectric-material film 13 possibly
causes crooked displacement (not intended displacement).
[0131] However, in thin-film piezoelectric-material element 12b,
the lower piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are formed to sandwich
the laminated structure part 21. Both the upper surface side and
lower surface side of the piezoelectric-material film 13, which
pressure reaches easily, are protected by the upper
piezoelectric-material protective-film 24 and the lower
piezoelectric-material protective-film 14. Therefore, pressure of
helium gas hardly reaches the piezoelectric-material film 13.
Accordingly, in thin-film piezoelectric-material element 12b, the
possibility, which the piezoelectric-material film 13 cause crooked
displacement, is lowered than the case which the lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24 are not formed.
[0132] Accordingly, in thin-film piezoelectric-material element
12b, the possibility, which characteristic of the
piezoelectric-material film 13 deteriorates with the passage of
time, is lowered, thereby the performance of the thin-film
piezoelectric-material element 12b is able to be maintained as much
as possible, even if helium gas is filled up into the housing or
enclosure.
[0133] Here, FIG. 20 is a graph showing change of stroke of the
thin-film piezoelectric-material element with the passage of time.
g1 is a graph showing change of stroke of the conventional
thin-film piezoelectric-material element, having neither lower
piezoelectric-material protective-film 14 and the upper
piezoelectric-material protective-film 24. g2 is a graph showing
change of stroke of the thin-film piezoelectric-material element
12b, having the lower piezoelectric-material protective-film 14 and
the upper piezoelectric-material protective-film 24.
[0134] As illustrated in FIG. 20, in the thin-film
piezoelectric-material element 12b, change of stroke is smaller
than the conventional thin-film piezoelectric-material element,
almost constant stroke is maintained with the passage of time.
Accordingly, by having the lower piezoelectric-material
protective-film 14 and the upper piezoelectric-material
protective-film 24, the performance of thin-film
piezoelectric-material element 12b is able to be maintained as much
as possible.
[0135] As described above, the thin-film piezoelectric-material
element 12b has a structure which the performance is hardly lowered
even if helium gas is filled up into the housing or enclosure.
[0136] In the HGA91, in case of the thin-film
piezoelectric-material elements 12b, the flexure substrate 4, the
base insulating layer 5, other than the thin-film
piezoelectric-material element 12b, are arranged in the lower side
of the thin-film piezoelectric-material element 12b though, another
member than the thin-film piezoelectric-material element 12b is not
arranged in the upper side. Therefore, the piezoelectric-material
film 13 receives easily influence of the downward pressure from
outside the surface layer insulating film 22 than the upward
pressure.
[0137] However, because the thin-film piezoelectric-material
element 12b has the film-size extended structure, each film sizes
are extended in order of the upper piezoelectric-material
protective-film 24 to the lower piezoelectric-material
protective-film 14. Therefore, the downward pressure, from outside
the surface layer insulating film 22, is dispersed easily without
concentration. The pressure, reaches the piezoelectric-material
film 13, is also dispersed easily without concentration. Therefore,
the possibility, which the piezoelectric-material film 13 cause
crooked displacement, is surely lowered. Accordingly, the
possibility, which characteristic of the piezoelectric-material
film 13 deteriorates, is surely lowered. The possibility, which the
performance of the thin-film piezoelectric-material element 12b
deteriorates, is also surely lowered.
[0138] Moreover, both long-side widths and short-side widths, about
all of the upper piezoelectric-material protective-film 24, the
upper electrode film 27, the piezoelectric-material film 13, the
lower piezoelectric-material protective-film 14 and the lower
electrode film 17, are extended in order of the upper film part
40A, the middle film part 40B, the lower film part 40C. Therefore,
the pressure, which reaches the piezoelectric-material film 13, are
dispersed entirely, hardly concentrates.
[0139] Further, because the surface layer insulating film 22,
covering the thin-film piezoelectric-material element 12b, has the
step parts 22S1, 22S2, influence of the downward pressure reaches
not only the top disposed part 22a but also the step parts 22S1,
22S2. Therefore, the pressure, which reaches the
piezoelectric-material film 13, is dispersed easily without
concentration. Furthermore, because the surface layer insulating
film 22 has the shift arrangement structure, the downward pressure
also reaches the outside than the piezoelectric-material film 13,
therefore, the downward pressure, which reaches the
piezoelectric-material film 13, is surely lowered.
[0140] Because the thin-film piezoelectric-material element 12b has
the lower diffusion-barrier-film 16a and the upper
diffusion-barrier-film 16b, diffusion barrier strength of the lower
electrode film 17, the piezoelectric-material film 13 and the upper
electrode film 27 has been elevated.
[0141] (Embodiments of Hard Disk Drive)
[0142] Next, embodiments of the hard disk drive will now be
explained with reference to FIG. 21.
[0143] FIG. 21 is a perspective view illustrating a hard disk drive
201 equipped with the above-mentioned HGA 91. The hard disk drive
201 includes a hard disk (magnetic recording medium) 202 rotating
at a high speed and the HGA 91. The hard disk drive 201 is an
apparatus which actuates the HGA 91, so as to record/reproduce data
onto/from recording surfaces of the hard disk 202. The hard disk
202 has a plurality of (4 in the drawing) platters. Each platter
has a recording surface opposing its corresponding the head slider
60.
[0144] The hard disk drive 201 positions the head slider 60 on a
track by an assembly carriage device 203. A thin-film magnetic
head, not illustrated, is formed on this head slider 60. Further,
the hard disk drive 201 has a plurality of drive arms 209. The
drive arms 209 pivot about a pivot bearing shaft 206 by means of a
voice coil motor (VCM) 205, and are stacked in a direction along
the pivot bearing shaft 206. Further, the HGA 91 is attached to the
tip of each drive arm 209.
[0145] Further, the hard disk drive 201 has a control circuit 204
controlling recording/reproducing.
[0146] In the hard disk drive 201, when the HGA 91 is rotated, the
head slider 60 moves in a radial direction of the hard disk 202,
i.e., a direction traversing track lines.
[0147] In case such hard disk drive 201 are formed with the
above-described thin-film piezoelectric-material elements 12a, 12b,
the performance of the thin-film piezoelectric-material elements
12a, 12b are able to be maintained as much as possible, even if
helium gas is filled up into the housing or enclosure.
[0148] This invention is not limited to the foregoing embodiments
but various changes and modifications of its components may be made
without departing from the scope of the present invention. Besides,
it is clear that various embodiments and modified examples of the
present invention can be carried out on the basis of the foregoing
explanation. Therefore, the present invention can be carried out in
modes other than the above-mentioned best modes within the scope
equivalent to the following claims.
* * * * *