JP3410259B2 - Manufacturing method of semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, for example, on each electrode of each semiconductor integrated circuit (semiconductor IC) formed on one surface of a semiconductor wafer (hereinafter, simply referred to as a wafer). This is suitable when applied to collectively forming bumps.

[0002]

2. Description of the Related Art Conventionally, for example, in an IC chip for mounting a bare chip, a plurality of semiconductors are formed by subjecting one surface of a semiconductor single crystal plate called a wafer to a predetermined process such as edging, oxidation and / or impurity implantation. IC
Is formed, bump electrodes called bumps are formed on the respective electrodes of the respective semiconductor ICs, and then the respective semiconductor ICs are individually separated. In this case, in the process of manufacturing such an IC chip, the process of forming bumps on each electrode of each semiconductor IC formed on the wafer is usually performed by the following procedure shown in FIGS. 2 (A) to 2 (C). Has been done.

That is, first, as shown in FIG. 2A, on one surface 1A of a wafer 1 on which a plurality of semiconductor ICs are formed,
The metal mask 2 provided with the openings 2A corresponding to the respective electrode positions of the respective semiconductor ICs is brought into close contact, or the one surface 1A of the wafer 1 is opened corresponding to the respective electrode positions of the respective semiconductor ICs. Then, a resist layer 3 made of a photoresist that has been patterned is laminated. Then, as shown in FIG. 2B, bumps are formed on the electrodes of the semiconductor ICs exposed through the openings 2A and 3A of the metal mask 2 or the resist layer 3 by vapor deposition or plating. The bump metal layer 4 is formed by depositing a metal material (hereinafter referred to as a bump metal material) for a predetermined thickness.

Subsequently, the metal mask 2 or the resist layer 3 is removed from the one surface 1A of the wafer 1, and then each bump metal layer 4 formed on each electrode of each semiconductor IC is heated and melted. As a result, spherical bumps 5 as shown in FIG. 2C are formed on the electrodes of the semiconductor ICs formed on the wafer 1.
Can be formed.

[0005]

By the way, in such a conventional bump forming method, all the openings 2A and 3A of the metal mask 2 or the resist layer 3 are formed in the same size. However, in such a bump forming method, when the vapor deposition method is used as a method of depositing the bump metal material on the one surface 1A of the wafer 1, the vapor deposition apparatus is provided between the electrodes of the semiconductor IC portions formed on the wafer 1. When the fold method is used because of the difference in the distance to the evaporation source, the resistance distribution in the one surface 1A of the wafer 1 is varied, so that the electrodes are finally formed on each electrode of each semiconductor IC. There is a problem that the height of the bumps 5 to be formed varies by ± 10% or more.

For this reason, conventionally, in order to eliminate such a variation in the height of the bump 5, the structure of the vapor deposition apparatus or the plating apparatus has been devised, but this variation cannot be completely absorbed, which causes a problem. The solution was still inadequate. In addition, such a variation in the height of the bumps 5 increases as the diameter of the wafer 1 increases (for example, 6 inches or more).
There was a growing problem.

The present invention has been made in consideration of the above points, and an object thereof is to propose a method of manufacturing a semiconductor device capable of forming bumps of uniform height on each electrode.

[0008]

In order to solve such a problem, in the present invention, a mask used in the step of depositing a metal material for bumps on each electrode of each semiconductor integrated circuit formed on one surface of a semiconductor wafer. As the above, the size of each opening is selected so that the volume of the metal material deposited in each opening is constant. That is, by using such a mask, it is possible to deposit a metal material in a constant volume on each electrode of each semiconductor integrated circuit and its peripheral portion, and therefore, on each electrode of each semiconductor integrated circuit. Bumps having the same volume can be formed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIGS. 1A to 1D, in which parts corresponding to those in FIGS. 2A to 2C are designated by the same reference numerals, particularly bump formation in the method of manufacturing a semiconductor device according to the embodiment. First, a plurality of semiconductor ICs are formed on one surface 1A of the wafer 1 by performing a predetermined process such as edging, oxidation, and / or impurity implantation on the wafer 1 in a predetermined pattern, and then one surface of the wafer 1 is shown. As shown in FIG. 1A, a metal mask 10 having openings 10A corresponding to respective electrodes of each semiconductor IC is adhered onto 1A, or each electrode of each semiconductor IC is associated with each other. A resist layer 11 made of a photoresist that is patterned so as to have openings is laminated.

In this case, the size of each opening 10A, 11A of the metal mask 10 or the resist layer 11 is such that the bump layer formed when the bump metal material is deposited on the one surface 1A of the wafer 1 by the vapor deposition method or the plating method. In consideration of variations in height, the area of the openings 10A, 11A of the metal mask 10 or the resist layer 11 and the opening 10A,
The product of the thickness of the bump metal material deposited on the one surface 1A of the wafer 1 via 11A is always constant (that is, each opening 10
The bump metal material in A and 11A has a constant volume. Further, by the end of this step, a metal base layer made of a metal having a good wettability with the bump metal material is laminated and formed on each electrode of each semiconductor IC formed on the wafer 1 in a predetermined area.

Subsequently, as shown in FIG. 1B, the openings 10A, 1A of the metal mask 10 or the resist layer 11 are formed on the metal underlayer formed on each electrode of each semiconductor IC.
A bump metal material is deposited through 1A by a vapor deposition method or a plating method. At this time, since the sizes of the openings 10A and 11A of the metal mask 10 or the resist layer 11 are selected as described above, the volume of the bump metal layer 12 formed on each electrode of each semiconductor IC (that is, Each opening 10A of the metal mask 10 or the resist layer 11,
The volume of the bump metal material deposited in 11A is the wafer 1
All are constant on one surface 1A.

Next, the metal mask 10 or the resist layer 11 is removed from the one surface 1A of the wafer 1, and thereafter the bump metal layer 12 formed on each electrode of each semiconductor IC and its peripheral portion is heated and melted. Thereby, as shown in FIGS. 1C and 1D, the spherical bumps 13 can be formed on the electrodes 14 of the semiconductor ICs formed on the wafer 1 via the metal underlayer 15. it can. Further, thereafter, the wafer 1 is divided so that each semiconductor IC is individually separated. This makes it possible to obtain an IC chip in which the spherical bumps 13 are formed on the respective electrodes 14.

With the above structure, in the method of manufacturing a semiconductor device according to this embodiment, the sizes of the openings 10A and 11A of the metal mask 10 or the resist layer 11 are set so that the volume of each bump metal layer 12 becomes constant as described above. Since the thickness is selected, a certain amount of bump metal material can be supplied onto each electrode 14 of each semiconductor IC and its peripheral portion. Therefore, by using such a method, each bump 13
The bumps 13 having a uniform height can be formed on the respective electrodes 14 of the respective semiconductor ICs formed on the wafer 1 by the amount that the volume can be made constant.

Accordingly, by applying such a bump forming method to the semiconductor device manufacturing process, a semiconductor device having bumps 13 of uniform height provided on each electrode 14 can be obtained. Further, since this method is not restricted by the wafer size, it can be applied to the case where the bump 13 is formed on each electrode 14 of each semiconductor IC formed on the wafer 1 having a large diameter of 6 inches or more. Also in this case, the bumps 13 of uniform height can be accurately formed on each electrode of each semiconductor IC.

According to the above structure, the metal mask 10 or the resist layer serving as a mask for depositing the bump metal material on each electrode 14 of each semiconductor IC formed on the wafer 1 by the vapor deposition method or the plating method. 11 openings 10A, 11
The size of A is selected so that the volume of the bump metal material deposited in each of the openings 10A and 11A is constant, so that each electrode 14 of each semiconductor IC is selected.
Can supply a certain volume of bump metal material on top,
Thus, it is possible to realize a method of manufacturing a semiconductor device in which the bumps 13 having a uniform height can be formed on each electrode 14.

In the above embodiment, the metal mask 10 or the patterning is used as a mask for depositing the bump metal material on each electrode 14 of each semiconductor IC formed on the wafer 1 by the vapor deposition method or the plating method. The case where the resist layer 11 made of the photoresist described above is applied has been described, but the present invention is not limited to this, and the point is that each electrode 1 of each semiconductor IC formed on one surface 1A of the wafer 1 is
4, a plurality of openings are provided in correspondence with each other, and the size of each opening is selected so that the volume of the bump metal material deposited in each opening 10A, 11A is constant. If so, various other masks can be applied.

[0018]

As described above, according to the present invention, the inside of each opening is used as a mask used in the step of depositing a metal material for bumps on each electrode of each semiconductor integrated circuit formed on one surface of a semiconductor wafer. Since the size of each opening is selected so that the volume of the metal material deposited on the substrate is constant, a constant amount of bumps is formed on each electrode and its peripheral portion of each semiconductor integrated circuit. It is possible to supply a metal material for use in the semiconductor device, and thus to realize a method for manufacturing a semiconductor device capable of forming bumps of uniform height on each electrode.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a bump forming method applied to a manufacturing process of a semiconductor device according to an embodiment.

FIG. 2 is a cross-sectional view provided for explaining a bump forming method that is applied in a conventional manufacturing process of a semiconductor device.

[Explanation of symbols]

1 ... Wafer, 1A ... One side, 10 ... Metal mask,
10A, 11A ... Aperture, 11 ... Resist layer, 12 ...
... bump metal layer, 13 ... bump, 14 ... electrode.

Claims (2)

(57) [Claims] 1. A first step of forming a plurality of semiconductor integrated circuits on one surface of a semiconductor wafer by subjecting the semiconductor wafer to a predetermined process, and to each electrode of each semiconductor integrated circuit on the one surface of the semiconductor wafer. A second step of arranging a mask provided with a plurality of openings corresponding to each other, and a metal material for bumps on the electrodes of the semiconductor integrated circuits exposed through the openings of the mask, respectively. A third step of forming bump metal layers by depositing, respectively, and removing the mask from the one surface of the semiconductor wafer, and then heating and melting each bump metal layer to form each of the semiconductor integrated circuits. A fourth step of forming bumps made of the bump metal layers on the electrodes, and dividing the semiconductor wafer so as to separate the semiconductor integrated circuits from each other. A mask including the fifth step, wherein the size of each opening is selected so that the volume of the metal material deposited in each opening is constant as the mask used in the second step. A method of manufacturing a semiconductor device, characterized in that 2. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor wafer has a diameter of 6 inches or more.