Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead – Beam leads
Reexamination Certificate
2003-03-28
2004-11-02
Lee, Hsien Ming (Department: 2823)
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
Beam leads
C257S737000, C257S750000, C438S612000, C438S613000, C438S614000
Reexamination Certificate
active
06812568
ABSTRACT:
TECHNICAL FIELD
The present invention relates to an electrode structure that is formed by using a semiconductor processing technique and a manufacturing method of a thin-film structural body.
BACKGROUND ART
FIG. 17
is a cross-sectional view showing a conventional electrode structure, which shows a thin-film structural body
101
installed in the electrode structure. The thin-film structural body
101
includes a supporting portion
103
and a floating portion
105
supported by the supporting portion
103
, and is formed above a substrate
107
by using a conductive material. The floating portion
105
, which is placed with a predetermined distance from the substrate
107
, extends outwards from an upper portion of the supporting portion
103
.
The substrate
107
includes a substrate main body
111
, a first insulating film
113
, a wiring
115
and a second insulating film
117
. The first insulating film
113
is formed on the substrate main body
111
. The wiring
115
is provided on the surface of the first insulating film
113
, and the surface of the first insulating film
113
and the surface of the wiring
115
are substantially flattened without a step portion. The second insulating film
117
covers the surfaces of the wiring
115
and the first insulating film
113
and side faces thereof. Here, the second insulating film
117
has a hole section
117
a
which opens on the surface of the wiring
115
so that the surface of the wiring
115
is selectively exposed. The supporting portion
103
is formed on the wiring
115
through the hole section
117
a.
FIGS. 14
to
16
are cross-sectional views showing a sequence of conventional manufacturing processes of a thin-film structural body. First, as shown in
FIG. 14
, a sacrifice film
121
is formed on the entire surface of the substrate
107
. In this stage, the second insulating film
117
has no hole section
117
a
in the substrate
107
.
Next, a dry etching process is carried out from the surface side of the sacrifice film
121
so that an opening
121
a
is formed in the sacrifice film
121
while a hole section
117
a
is formed in the second insulating film
117
; thus, an anchor hole
122
is formed so that the surface of the wiring
115
is selectively exposed. Consequently, a structure shown in
FIG. 15
is obtained.
Next, as shown in
FIG. 16
, a thin-film layer
123
is formed on the sacrifice film
121
and the substrate
107
exposed through the anchor hole
122
by using a conductive material.
Thereafter, the thin-film layer
123
is selectively removed, with the result that residual portions of the thin-film layer
123
thus patterned are allowed to form a thin-film structural body
101
. Successively, the sacrifice film
121
is removed so that a structure shown in
FIG. 17
is obtained. Among the residual portions of the thin-film layer
123
, the portion fitted into the anchor hole
122
forms the supporting portion
103
and the portion located on the sacrifice film
121
forms the floating portion
105
.
In such a conventional manufacturing method, the sacrifice film
121
is desirably formed by using a material which is easily removed by etching, and, for example, a silicon oxide film is employed. With respect to the substrate main body
111
, a silicon substrate is employed so that a semiconductor processing technique capable of fine manufacturing processes can be applied thereto. Further, in order to easily form the first insulating film
113
on the silicon substrate, a silicon oxide film is also employed to the first insulating film
113
in the same manner as the sacrifice film
121
.
In order to prevent the first insulating film
113
from being also etched upon etching the sacrifice film
121
, a material which is less susceptible to etching for the silicon oxide film and is easily processed, such as a silicon nitride film, is employed as the second insulating film
117
.
However, in the case where the second insulating film
117
allows the surface of the wiring
115
to be completely exposed, etchant used for etching the sacrifice film
121
tends to invade between the side face of the wiring
115
and the second insulating film
117
and reach the first insulating film
113
.
FIG. 18
is a plan view showing the structure of
FIG. 15
when viewed from the opening side of the anchor hole
122
. In the case where the anchor hole
122
on a plan view has a rectangular shape, a square or the like, with acute corners
122
a
stresses tend to concentrate on these corners. For this reason, there is a high possibility that a crack generates from each of these corners into the sacrifice film
121
, the first insulating film
113
and the second insulating film
117
. In particular, in the case where a silicon nitride film is used to form the second insulating film
117
, its residual stress is exerted in the stretching direction while the residual stresses in the sacrifice film
121
and the first insulating film
113
, made of a silicon oxide film, are exerted in the compressing direction; therefore, it is considered that this structure is more susceptible to cracks. The generation of such cracks not only causes a problem with strength, but also results in a higher possibility of etchant for use in etching the sacrifice film
121
reaching the first insulating film
113
.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide an electrode structure and a manufacturing method of a thin-film structural body, which can remove a sacrifice film without removing other insulating films. Moreover, another object of the present invention is to provide an electrode structure and a manufacturing method of a thin-film structural body, which can suppressing the generation of cracks.
In a first aspect of an electrode structure, the electrode structure includes: a wiring (
45
) selectively placed on a first insulating film (
33
); a second insulating film (
47
) covering the first insulating film, selectively covering the wiring, and having a hole section (
47
c
), said hole section entering the wiring inward by a first predetermined distance (d
1
) from an edge (
45
a
) of a surface of the wiring to selectively expose the surface of the wiring; a sacrifice film (
51
) having an opening (
51
a
) selectively exposing the surface of the wiring, and selectively formed on at least the second insulating film; and a thin-film layer (
53
) made of conductive material connected to the surface of the wiring selectively exposed through the opening and the hole section.
According to the first aspect of the electrode structure, since the hole section covers the first predetermined distance from the edge of the surface of the wiring, the invading path into the first insulating film of etchant to be used for etching the sacrifice film is lengthened. This reduces the possibility of that the etchant reaches the first insulating film. Thus, even when the first insulating film and the sacrifice film are made of the same material, it is possible to reduce the possibility of the first insulating film being etched in the etching process of the sacrifice film.
A second aspect of the electrode structure according to the present invention is the first aspect of the electrode structure, and the hole section (
47
c
) is filled with the thin-film layer (
53
).
According to the second aspect of the electrode structure, it is possible to effectively prevent the invasion of the etchant to be used for etching the sacrifice film.
A third aspect of the electrode structure according to the present invention is the second aspect of the electrode structure, and the opening (
51
a
) is opened so as to retreat from the hole section (
47
c
) by a second predetermined distance (d
2
).
According to the third aspect of the electrode structure, it is possible to make a portion supporting a floating structure of the thin-film layer thicker, and consequently to increase the strength of the structure.
A fourth aspect of the electrode structure according to the present invention is the third aspect of the electrode structure, and
Horikawa Makio
Ishibashi Kiyoshi
Okumura Mika
Lee Hsien Ming
Mitsubishi Denki & Kabushiki Kaisha
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
LandOfFree
Electrode structure, and method for manufacturing thin-film... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrode structure, and method for manufacturing thin-film..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrode structure, and method for manufacturing thin-film... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3290533