Semiconductor device and method for producing the semiconductor device

Abstract

A semiconductor device of the present invention is includes a semiconductor device comprising: a semiconductor chip having a passivation film on an electrode forming surface thereof on which a plurality of electrodes are formed; a protective film which is provided on an upper surface of the passivation film and patterned into a predetermined form; rewiring which is provided on an upper surface of each portion of the protective film divided by patterning and is connected to the electrode; a post connected to the rewiring; and a sealing resin layer which covers the rewiring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of a main portion of a semiconductor device according to an embodiment of the present invention;

FIG. 2 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 3 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 4 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 5 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 6 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 7 is a schematic sectional view for describing the production process of the semiconductor device;

FIG. 8 is a schematic sectional view for describing a production process of a conventional semiconductor device;

FIG. 9 is a schematic sectional view for describing the production process of the conventional semiconductor device;

FIG. 10 is a schematic sectional view for describing the production process of the conventional semiconductor device;

FIG. 11 is a schematic sectional view for describing the production process of the conventional semiconductor device;

FIG. 12 is a schematic sectional view for describing the production process of the conventional semiconductor device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

A semiconductor device of the present invention is composed of a semiconductor chip called a wafer level CSP and a sealing resin layer which overlaps one surface of the semiconductor chip in the thickness direction. In the sealing resin layer, posts to be used for electrical connection to the exterior, rewiring connected to both of the posts and electrodes of the semiconductor chip, and a protective film serving as a base of the rewiring are provided.

Particularly, conventionally, the protective film is provided so as to cover the entirety of the semiconductor chip except for the electrodes independently of the pattern of the rewiring. On the other hand, in the present invention, the protective film is divided to be independent for each wiring by patterning according to rewiring patterning.

That is, between adjacent rewirings, a groove is formed by removing the protective film. When forming a carbon-rich conductive layer on the upper surface of the protective film by Ar sputtering, the conductive layer is not formed at the groove portion. Accordingly, the respective conductive layers can be completely divided by the grooves.

Therefore, O₂ ashing processing for removing the conductive layer is made unnecessary, and the process can be shortened. Further, due to omission of O₂ ashing processing, the protective film can be prevented from being damaged by O₂ ashing processing. In addition, leak checks for checking the degree of this damage can be omitted, and the process can be shortened further.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view of a main portion of a semiconductor device A according to the present embodiment.

The semiconductor device A of the present embodiment includes a semiconductor chip 10 having a passivation film 12 on an electrode forming surface thereof on which a plurality of electrodes 11 are formed, a protective film 13 which is provided on the upper surface of the passivation film 12 and patterned into a predetermined form, rewiring 16 which is provided on the upper surfaces of the respective protective films 13 divided into respective portions by grooves 19 and is connected to the electrodes 11, posts 17 connected to the rewiring 16, and a sealing resin layer 18 which covers the rewiring 16.

On the upper surfaces of the respective protective films 13 divided by grooves 19, a conductive layer 14 and a barrier metal layer 150 are provided. The conductive layer 14 is electrically isolated for each protective film 13 by providing the grooves 19 between the protective films 13.

Therefore, the rewirings 16 on the protective films 13 adjacent to each other are not short-circuited via the conductive layer 14, so that short-circuiting can be prevented.

Hereinafter, a method for producing the sealing resin layer 18 portion will be described in detail.

First, as shown in FIG. 2, on a semiconductor substrate 10 having a predetermined circuit formed thereon, the electrodes 11 are provided at predetermined positions. On the electrode forming surface of the semiconductor substrate 10 on which the electrodes 11 are provided, the passivation film 12 is provided. At this point in time, the semiconductor substrate 10 is in a wafer state before being divided into semiconductor chips by dicing.

The semiconductor substrate 10 thus provided with the passivation film 12 is used. As shown in FIG. 3, on the passivation film 12, a polyimide film is formed to serve as the protective film 13. In detail, on the upper surface of the semiconductor substrate 10, a polyimide solution that forms a polyimide film is coated by means of spin-coating or the like. Successively, a predetermined mask is set on the upper surface of the semiconductor substrate 10, and the mask is irradiated with ultraviolet rays, whereby the polyimide solution at the portion irradiated with ultra violet rays is cured. Thereafter, the uncured polyimide solution is removed by washing and the cured portion is left to form the protective film 13 made of a polyimide film in a predetermined pattern.

In a conventional production method, the polyimide solution coated on the semiconductor substrate 10 was entirely cured except for the electrode 11 portions of the semiconductor substrate 10. On the other hand, in the present embodiment, the polyimide film patterned according to the forming pattern of the rewiring 16 is formed, whereby the grooves 19 are formed by removing the protective film between rewiring forming regions in which the rewiring 16 is formed. Therefore, the protective film 13 is provided at least as many as the number of rewirings 16. Moreover, between the protective films 13, the grooves 19 with a predetermined width are provided, and the width of the grooves 19 is desirably as wide as possible. In the patterned polyimide film forming process, the grooves 19 are formed by removing the uncured polyimide solution, so that this process of removing the uncured polyimide solution corresponds to the process of removing the protective film positioned between the rewiring forming regions in which rewiring 16 is formed.

Particularly, when forming the protective film 13, concurrently with patterning for forming the openings from which the electrodes 11 are exposed, patterning for forming the grooves 19 for dividing the protective film 13 into respective portions is performed and the protective film positioned between the rewiring forming regions is removed, whereby the protective film 13 can be divided without adding a new production process.

After forming the protective film 13, Ar sputtering is performed and hydrogen and fluorine on the upper surface of the protective film 13 are removed and carbon is left, whereby, as shown in FIG. 4, the carbon-rich conductive layer 14 is formed on the upper surface of the protective film 13. On the upper surface of the conductive layer 14, the barrier metal layer 15 is formed by copper sputtering. The barrier metal layer 15 is firmly bonded to the protective film 13 via the conductive layer 14.

When forming the conductive layer 14, at the groove portions between adjacent protective films 13, no carbon is left, so that the conductive layer 14 is not formed.

After forming the barrier metal layer 15, as shown in FIG. 5, on the upper surface of the barrier metal layer 15, the rewiring 16 patterned into a predetermined form is formed. Each rewiring 16 is formed on one protective film 13.

To form the rewiring 16 on the divided protective films 13, first, on the upper surface of the barrier metal layer 15, copper coating is formed by electrolytic plating processing. Then, on the upper surface of this copper coating, a resist mask (not shown) patterned into a predetermined form is formed. Thereafter, by etching the copper coating by using this resist mask, the rewiring 16 is formed. By adjusting the form of the resist mask, the rewiring 16 can be provided on the protective film 13. After forming the rewiring 16, the resist mask is removed.

After forming the rewiring 16, as shown in FIG. 6, at predetermined positions of the rewiring 16, the copper-made posts 17 are formed.

This post 17 is formed by providing a dry film resist (not shown) on the upper surface of the semiconductor substrate 10, forming an opening at a portion where the post 17 is formed in this dry film resist, and performing electrolytic plating processing to form a plating film on the opening portion of the dry film resist. After forming the post 17, the dry film resist is removed.

After forming the post 17, as shown in FIG. 7, the barrier metal layer 15 used as a base of formation of the rewiring 16 is removed by etching. By removing the barrier metal layer 15, each rewiring 16 on the protective film 13 is independently electrically insulated from other rewiring 16. Therefore, no short-circuiting occurs between each rewiring 16 and other rewiring 16.

Thus, according to removal of the barrier metal layer 15, each rewiring 16 is insulated from other rewiring 16 without performing O₂ ashing. Thereafter, a resin that becomes the sealing resin layer 18 is coated on the upper surface of the semiconductor substrate 10 and cured, whereby the sealing resin layer 18 which seals the rewiring 16 is formed as shown in FIG. 1.

When forming the sealing resin layer 18, the upper surfaces of the protective films 13 that are not covered by the rewiring 16 are covered by the conductive layer 14 which has become porous, so that due to its anchoring effect, the conductive layer 14 and the sealing resin layer 18 can be brought into close contact with each other. As a result, the close contact strength of the sealing resin layer 18 can be improved.

By dicing the semiconductor substrate 10 in which the sealing resin layer 18 is formed, the respective semiconductor devices A can be formed.

The conductive layer 14 on the protective film 13 that is not covered by the rewiring 16 can also be used as an extraction wiring. When the semiconductor substrate 10 on which the sealing resin layer 18 is formed is diced into the semiconductor devices A, dicing is performed so that the conductive layer 14 is exposed, and the resulting cut surface is coated with an electrode material and is made into a conduction state with the conductive layer 14, whereby the electrode provided on this cut surface can be used as a ground.

Although the embodiment of the present invention is described in detail above, the embodiment is merely a detailed example used for making clear the technical contents of the present invention, the present invention should not be interpreted to be limited to this detailed example, and the spirit and scope of the present invention are limited only by the accompanying claims.

The present application corresponds to Japanese Patent Application No. 2006-147456 filed with the Japanese Patent Office on May 26, 2006, the disclosure of which is incorporated herein by reference.

Claims

1. A semiconductor device comprising: a semiconductor chip having a passivation film on an electrode forming surface thereof on which a plurality of electrodes are formed;a protective film which is provided on an upper surface of the passivation film and patterned into a predetermined form;rewiring which is provided on an upper surface of each portion of the protective film divided by patterning and is connected to the electrode;a post connected to the rewiring; anda sealing resin layer which covers the rewiring.

2. A method for producing a semiconductor device comprising the steps of: preparing a semiconductor chip having a passivation film on an electrode forming surface thereof on which a plurality of electrodes are provided, and forming a protective film on an upper surface of the passivation film;forming rewiring connected to the electrode, on an upper surface of the protective film;forming a post connected to the rewiring;forming a sealing resin layer which covers the rewiring; andremoving the protective film positioned between rewiring forming regions in which the rewiring is formed.

3. The method for producing a semiconductor device according to claim 2, wherein the removing step of the protective film positioned between the rewiring forming regions is performed concurrently with patterning for forming an opening from which the electrode is exposed in the protective film formed on the entire upper surface of the passivation film.