Semiconductor device manufacturing: process – Coating with electrically or thermally conductive material – To form ohmic contact to semiconductive material
Reexamination Certificate
2000-03-24
2001-09-11
Nelms, David (Department: 2818)
Semiconductor device manufacturing: process
Coating with electrically or thermally conductive material
To form ohmic contact to semiconductive material
C438S617000
Reexamination Certificate
active
06287950
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 89101951, filed Feb. 3, 2000.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to an integrated circuit device structure and a manufacturing method thereof. More particularly, the present invention relates to a bonding pad structure and a manufacturing method thereof.
2. Description of Related Art
As semiconductor technologies continue to advance, deep submicron devices are now routinely manufactured. Due to a reduction in feature size, many formerly minor technical problems now become prominent and demand special consideration. For example, quality of connection between a bonding pad and a bonding wire can seriously affect the reliability of a device.
As dimensions of a device shrink, contact area between a conductive wire and a bonding pad is reduced correspondingly. Hence, when a wire is attached to a bonding pad, the bonding pad has to support a larger stress. Furthermore, adherence of the bonding wire to the bonding pad is likely to drop due to a smaller junction area. In general, a conventional bonding pad has a very flat surface.
FIG. 1A
is a cross-sectional side view of a conventional bonding pad. As shown in
FIG. 1A
, the bonding pad
110
is formed over a substrate
100
. A passivation layer
120
is formed over the substrate
100
and the peripheral region of the bonding pad
110
.
FIG. 1B
is a cross-sectional side view of a conventional bonding pad
110
with a bonding wire
150
attached to the bonding pad surface. In general, contact area between a conductive wire and a bonding pad in a highly integrated circuit chip is very small. Therefore, the conductive wire can be easily pulled off causing low production yield.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a bonding pad structure and a method of forming the bonding pad structure on a substrate for increasing contact area and hence adherence with a conductive wire.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a bonding pad structure. The structure includes a metallic bonding pad with a patterned surface, a first passivation layer having an opening above the metallic bonding pad and a second passivation layer over the first passivation layer also having an opening above the metallic bonding pad.
The invention also provides a method of forming the bonding pad structure. First, a metallic bonding pad is formed over a substrate, and then a first passivation layer is formed over the substrate and the bonding pad. The first passivation layer above the bonding pad is patterned. Using the first passivation layer as a mask, a portion of the exposed metal pad material is removed. A patterned second passivation layer is formed over the first passivation layer. The second passivation layer has an opening that exposes the bonding pad. Finally, residual material from the first passivation layer inside the bonding pad region is removed to expose the bonding pad surface.
Since the bonding pad of this invention has a rugged surface profile, contact area of the bonding pad is increased. Hence, a conductive wire bonded to the bonding pad can have a higher adhesive strength resulting in a higher production yield.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
FIG. 1A
is a cross-sectional side view of a conventional bonding pad;
FIG. 1B
is a cross-sectional side view of a conventional bonding pad with a bonding wire attached to the bonding pad surface;
FIGS. 2A through 2E
are schematic cross-sectional views showing the progression of steps for producing a bonding pad structure according to one preferred embodiment of this invention;
FIGS. 2F and 2G
are top views of
FIG. 2E
showing two different patterns on the surface of the metallic bonding pads; and
FIG. 3
is a cross-sectional view showing the metallic bonding pad of this invention with an attached conductive wire.
REFERENCES:
patent: 4628590 (1986-12-01), Udo et al.
patent: 5731243 (1998-03-01), Peng et al.
patent: 5807787 (1998-09-01), Fu et al.
patent: 6060378 (2000-05-01), Rolfson
patent: 6200889 (2001-03-01), Rolfson
Liu Chia-Chen
Wu Jyh-Ren
Dang Phuc T.
Huang Jiawei
J. C. Patents
Nelms David
Taiwan Semiconductor Manufacturing Co. Ltd.
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