JPS6325954A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To use various metals as a plurality of conductors for connecting a first conductor layer and a bump on a semiconductor substrate and to form a polyimide film in contact with the side surface of the bump stably, by providing laminated films of an insulating films having a contact window and a resin film on the first conductor layer. CONSTITUTION:On a semiconductor substrate 1, on which a semiconductor element is formed, a first conductor layer 3, which is connected to said semiconductor element, is provided. Laminated films of a first insulating film 2 having a contact window at the specified position of the first conductor layer 3 and a second resin film 9 are provided so as to cover the first conductor layer 3. A plurality of conductor layers 4-6, which include the second conductor layer 4 for bonding with the first conductor layer 3 and the third conductor layer 5 as a barrier, are provided so as to cover said window in the laminated films and the surrounding part of said window at the second film 9 in a specified pattern. A bump electrode 8 is provided on a plurality of the conductor layers 4-6. For example, the contact window, which is narrower than the opening part in the insulating film 2 is provided. The polyimide film 9 is provided so as to cover the insulating film 2. A plurality of the metal layers 4-6 are provided so as to cover the contact window and the polyimide film 9 around the window.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly to a semiconductor device having protruding electrodes and a method for manufacturing the same.

[Conventional technology]

Recently, tape automatic bonding (TAB) technology has been used in place of conventional wire bonding for high-density packaging of semiconductor devices and for the very recent thin ICs for cards. For this reason, in semiconductor wafer processes, it has become common to provide protruding electrodes (hereinafter referred to as bumps) in the bonding regions of IC chips.

FIG. 4 is a sectional view of an example of a conventional semiconductor device.

In this conventional example, an Aff electrode 3 connected to an internal semiconductor element is provided on a silicon substrate 1, an insulating film 2 having an opening is provided on the A2 electrode 3, and the opening and the surrounding area of the opening are provided. The metal layers 4'', 5'', 6'' and the pan 18'' are stacked so as to cover the insulating film 2 of the metal layers 4'', 5'', 6''.
'' and the sides of the pan 18''.
It has a structure with ``.

FIGS. 5(a) to 5(g) are cross-sectional views of a semiconductor chip for explaining an example of a conventional method for manufacturing a semiconductor device.

In this example, first, as shown in FIG. 5(a), a hole is formed in the insulating film 2 in the bonding region on the silicon substrate 1 by photoetching to expose the surface of the Af electrode 3 in the bonding region.

Next, as shown in FIG. 5(b), there is a metal layer N4'' for adhesion to the Ae electrode 3, and a metal layer 5'' located in the middle that serves as a barrier.
and a metal layer 6 in direct contact with the bump formed by plating.
``For example, gold is continuously deposited on the entire surface.

Next, as shown in FIG. 5C, photoresist 7'' is formed in a predetermined pattern except for the openings where bumps are to be formed.

After this, as shown in FIG. 5(d), the photoresist 7''
is plated with gold or copper as a protective film to form a metal pan 18'' of a desired height.

Next, as shown in FIG. 5(e), after removing the unnecessary photoresist 7'', the metal layer 6'', the metal layer 5'' and the first metal layer 4'' are sequentially etched to remove the bumps. Form.

After this, a polyimide film 9'' is usually formed on the surface of the semiconductor chip to cover the bumps, as shown in FIG. 5(f), for the purpose of protecting the element surface and absorbing mechanical shock and stress during bonding. do.

Next, as shown in FIG. 5(g>), a photoresist 10'' is formed with holes formed in the upper part of the pan 18''.

Finally, by etching the polyimide film 9'' using the photoresist 10'' as a mask and removing the photoresist 10'', an example of a conventional semiconductor device as shown in FIG. 4 is obtained.

[Problem that the invention seeks to solve]

In the conventional semiconductor device and its manufacturing method described above, the first
AI! which is the conductor layer of Since multiple conductor layers including a second conductor layer for direct adhesion and a third conductor layer for barrier are laminated on the surface of an insulating film having openings on the electrode, the type of metal used for the conductor layer is The drawback is that it is very limited depending on conditions such as etching for patterning. For example p
t3 When used for the third conductor layer, patterning by wet etching requires hot aqua regia, so there is no appropriate protective mask, and general dry etching such as ion milling or recent reactive ion etching Etched platinum re-adheres to various step portions that occur during the process of forming semiconductor devices on a silicon substrate, causing short-circuit defects. The disadvantage is that it cannot be used.

In addition, in a structure in which the side surface of the bump is covered with a polyimide film as in this conventional example, the polyimide film is not stable when it is in contact with the side surface of the bump due to misalignment during the photolithography process or undercut during etching of the polyimide film. It is very difficult to form the same, and there is also the drawback that manufacturing yield is reduced due to bonding defects caused by these.

An object of the present invention is to use various metals as the plurality of conductor layers connecting the first conductor layer on the semiconductor substrate and the bumps, and to form a polyimide film in stable contact with the side surfaces of the bumps, thereby reducing the manufacturing yield. An object of the present invention is to provide a high quality semiconductor device and a method for manufacturing the same.

[Means for solving problems]

In the semiconductor device of the present invention, a first conductor layer connected to the semiconductor element is provided on a semiconductor substrate on which a semiconductor element is formed, and a predetermined conductor layer is provided on the first conductor layer and covers the first conductor layer. A laminated film of an insulating first film and a resinous second film having a contact window at a position is provided, and the window of the laminated film and the periphery of the window of the resinous second film are arranged. a plurality of conductor layers including at least a second conductor layer for adhesion to the first conductor layer and a third conductor layer for a barrier are provided in a predetermined pattern so as to cover the plurality of conductor layers; A protruding electrode is provided on the top.

The method for manufacturing a semiconductor device of the present invention includes the steps of: forming a first conductor layer connected to the semiconductor element on a semiconductor substrate on which a semiconductor element is formed; forming a laminated film of an insulating first film and a resinous second film having contact windows at predetermined positions on the conductor layer; a plurality of conductor layers including at least a second conductor layer for adhesion to the first conductor layer and a third conductor layer for a barrier so as to cover the second film around the window; a step of laminating, a step of forming a photoresist film having an aperture surrounding the window on the plurality of conductor layers, a step of forming a protruding electrode so as to cover the aperture of the photoresist film; The method includes a step of removing the plurality of conductor layers using the protruding electrode as a mask after removing the photoresist film.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a four-sided view of a first embodiment of the semiconductor device of the present invention.

In this first embodiment, an Al electrode 3 connected to the semiconductor element is provided on a silicon substrate 1 on which a semiconductor element is formed, and an Ae
The electrode 3 has an opening at a predetermined position, and AI! An insulating film 2 is provided to cover the electrode 3 and the silicon substrate 1, and a polyimide film 9 is provided to have a contact window for the Al electrode 3 that is narrower than the opening of the insulating film 2 and to cover the insulating film 2. , AJ? so as to cover the contact window and the polyimide film 9 around the window. Electric f! A plurality of metal layers are provided in which three layers are laminated: a metal layer 4 for adhesion with the bumps 3, a metal layer 5 for a barrier, and a metal layer 6 in direct contact with the bumps, and the bumps 8 are placed on top of the metal layers 4, 5, and 6. It has a set structure.

FIG. 2 is a sectional view of a second embodiment of the semiconductor device of the present invention.

In the second embodiment, A! ! The provision of the electrode 3 and the insulating film 2 is the same as in the first embodiment described above, but above the insulating film 2 there is a polyimide film 9 with large openings surrounding the opening of the insulating film 2. ' are provided on the insulating film 2, and metal layers 4' and 5' are laminated so as to cover the window, the insulating film 2 around the window, and the polyimide film 9', using the opening of the insulating film 2 as a contact window. and 6' are provided, and a pan 18' is provided on the metal layers 4', 5' and 6'.

FIGS. 3A to 3G are cross-sectional views of a semiconductor chip shown in the order of steps for explaining an embodiment of the method for manufacturing a semiconductor device of the present invention.

In this embodiment, first, as shown in FIG. 3(a), an AI
! A hole is opened in the insulating film 2 at a predetermined position on the electrode 3 by a normal etching method, and the surface of the Al electrode 3 is exposed.

Next, as shown in FIG. 3(b), a polyimide film 9 is formed over the entire surface by a spin coating method, and after being cured by an appropriate heat treatment, a polyimide film 9 is formed to have an opening corresponding to a contact window. A photoresist is formed by a conventional photolithography process.

Next, as shown in FIG. 3C, the polyimide film 9 is etched using the photoresist film as a mask, and then the unnecessary photoresist 7 is removed.

Next, as shown in FIG. 3(d), a metal layer 4 for adhesion to the A/electrode, a metal layer 5 for a barrier, and a metal layer 6 in direct contact with the bumps are successively deposited over the entire surface. In this example,
Although an example is given in which three metal layers are used, of course two metal layers may be used.

Next, as shown in FIG. 3(e), a photoresist 10 having an opening surrounding the contact window is formed.

Next, as shown in FIG. 3(f), bumps 8 of gold, copper, or the like are formed by plating using the photoresist 10 as a protective film.

Next, as shown in FIG. 3(g), the photoresist 10 is removed.

Finally, by sequentially removing the exposed portions of the metal layers 6.5 and 4, the first semiconductor device of the present invention as shown in FIG.
An example of this can be done.

〔Effect of the invention〕

As explained above, in the present invention, a polyimide film is formed under a conductor layer formed by laminating a plurality of metal layers under the bump.
When etching the conductor layer, it protects the surface of the semiconductor chip and evens out the uneven parts, eliminating the problem of re-adhering to the uneven parts during dry etching, making it possible to use dry etching. Ti-Pt-Au
Of course, the three layers are Cr-Cu-Au three layers, Ti-Pd
- There is an effect that conductor layers that can be combined with various combinations of three layers of Au and three layers of Ti-Cu-Au can be widely used.

In addition, since the polyimide film is provided in contact with the lower part of the side surface of the bump, this reduces mechanical and thermal shock and stress during bonding, prevents bonding peeling defects, and prevents the polyimide film from being used as in the conventional case. Another advantage is that there is almost no reduction in manufacturing yield due to misalignment or undercut, which was a problem when the bump was formed in contact with the entire side surface of the bump.

Cross-sectional views of the first and second embodiments, FIGS. 3(a) to (g)
) is a cross-sectional view of a semiconductor chip shown in the order of steps for explaining one embodiment of the method for manufacturing a semiconductor device of the present invention, FIG. 4 is a cross-sectional view of an example of a conventional semiconductor device, and FIGS. (
g) is a cross-sectional view of a semiconductor chip for explaining an example of a conventional method for manufacturing a semiconductor device.

1... Silicon substrate, 2... Insulating film, 3... AI
! Electrode, 4.4', 4", 5.5', 5", 6.6"
, 6"...metal layer, 7,7"...photoresist, 8
, 8', 8''...bump, 9.9', 9''...polyimide film, 10.10''...photoresist.

Claims (2)

[Claims] (1) A first conductor layer connected to the semiconductor element is provided on a semiconductor substrate on which a semiconductor element is formed, and a contact layer is provided at a predetermined position on the first conductor layer and covers the first conductor layer. A laminated film of an insulating first film and a resinous second film having a window is provided, and the window of the laminated film and the area around the window of the resinous second film are covered. A plurality of conductor layers including at least a second conductor layer for adhesion to the first conductor layer and a third conductor layer for a barrier are provided in a predetermined pattern, and protruding electrodes are provided on the plurality of conductor layers. A semiconductor device characterized by being provided with. (2) forming a first conductor layer connected to the semiconductor element on the semiconductor substrate on which the semiconductor element is formed; and covering the first conductor layer and positioning the first conductor layer at a predetermined position on the first conductor layer; forming a laminated film of an insulating first film and a resinous second film having a contact window in the laminated film and the window of the resinous second film; a step of sequentially laminating a plurality of conductor layers including at least a second conductor layer for adhesion to the first conductor layer and a third conductor layer for a barrier so as to cover the periphery; forming a photoresist film having an opening surrounding the window on the conductor layer; forming a protruding electrode to cover the opening of the photoresist film; and after removing the photoresist film. A method of manufacturing a semiconductor device, comprising the step of removing the plurality of conductor layers using the protruding electrode as a mask.