JPS6034041A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an electrode having a favorable characteristic at low cost without using noble metals at manufacture of a semiconductor device by a method wherein the bump electrode to be provided to the semiconductor device is made to have the three layer construction of an Al layer, an Ni layer and an Ag layer from a semiconductor substrate. CONSTITUTION:An oxide film 6 is adhered on a semiconductor substrate 5 having a diffusion layer 7, and an opening is dug corresponding to the diffusion layer 7. Then an Al layer 13 is adhered making to come in contact with the diffusion layer 7, and making to exist nearby the opening edge part of the film 6, and an Ni layer 14 is laminated thereon. After then, an Ag layer 12 having the smaller shape than the layer 14 at the under part, while extended at the top part is adhered on the layer 14 to be used as a bump electrode. At this time, the Al layer 13 and the Ni layer 14 are formed according to the evaporation method, and the Ag layer 12 is formed according to the electrically plating method. Accodingly, the ohmic property of contact to the diffusion layer 7 is improved by using Al, and moreover adhesion of the Ag layer is also facilitated by making Ni to be interposed between them. Moreover, because the use of Pt, Au, etc. is unnecessitated, cost is reduced.

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to semiconductor devices having bump electrodes such as bin diodes and varactor diodes. Glass-sealed packages are widely used as packages for diode elements due to various factors and manufacturing costs. As shown in Fig. 1, there is a metal lead L, 2 between 9 pellets 31-J, and a full glass sleeve 4R.
Since the structure of this type of diode element is fusion-bonded, the pellet of this type of diode element is plated, etc. [Thus, a bang electrode is formed.

Generally, aluminum electrodes are widely used as the electrode metal for semiconductor devices, but in the case of glass-sealed diode pellets, it is difficult to completely modify the bang electrode directly on the aluminum, so various electrodes are used. The structure is considered
-1 is used, but the manufacturing process is complicated.

As an example, FIG. 2 shows the electrode structure of a conventionally used glass-sealed diode pellet. Then, mask the oxide film 6 on the predetermined semiconductor substrate 5 (and mask the semiconductor substrate 5).
A diffusion layer 7 having an opposite conductivity type is formed. A platinum silicide layer 8 is formed by performing platinum full vapor deposition and heat treatment at the interface of this diffusion layer 7. Then, a titanium layer 9 is formed.
．． Platinum layer 10. Means such as sequential vapor deposition or sputtering on metal M' such as gold layer it? After forming the silver bump electrode 12i on the back of the plated layer, a silver bump electrode 12i is formed.

In addition, in order to improve the ohmic ratio between the semiconductor layer and the upper metal layer, a platinum silicate layer 8'f! In order to improve adhesion between the silver bang electrode 12 and the titanium and platinum layer Q10, it is necessary to interpose the Au layer 11t, resulting in a very complicated structure, and the manufacturing process is complicated. In this case, expensive precious metals such as platinum and gold are used, so it is difficult to supply pellets at a low price. The object of the present invention is to provide an entire semiconductor device having a bang electrode in which the above-mentioned drawbacks are eliminated without any damage.

[Structure of the invention]

In the semiconductor device of the first aspect of the present invention, in the semiconductor device having a bump electrode, the bump electrode has a round shape 5y on the semiconductor substrate.
, a nickel layer formed on the aluminum layer, and a silver pan 1 electrode formed on the nickel layer (shaped 5y). , a semiconductor device having a pan 111L pole (in which the bump electrode includes an aluminum layer formed on the semiconductor substrate, a titanium layer formed on the aluminum layer, and a nickel layer formed on the titanium layer). and a silver bang electrode formed on the nickel layer [Explanation of Example] Hereinafter, Example rc of the present invention will be described with reference to FIG. III.

FIG. 3 is a sectional view showing a main part of an embodiment of the first invention.

In this embodiment, the present M1 invention is applied to the conventional example shown in FIG.
3, a nickel layer 14 with a thickness of about 0.3 to 0.5 μm formed on the aluminum layer 13 by rc vapor deposition,
A silver bump electrode 12 is formed on the nickel layer 14 by electroplating, and a pan 1 electrode slit is formed. Ohmic kennel with Maritime 7 can be easily obtained, and furthermore,
By interposing the nickel layer 13i, the silver bang electrode 12t can be easily formed, and the silver bang electrode 12U can be brought into close contact with the aluminum layer 13 via the nickel layer 13.

Therefore, according to this embodiment yc, it does not impair special orders such as ohmic injection and fixed injection necessary for electrode binding, has a simple structure, and does not use precious metals such as platinum or gold as in the conventional case, so it is inexpensive. FIG. 4 is a sectional view showing a main part of an embodiment of the second invention.

In this embodiment, in an embodiment of the first invention shown in FIG.
Approximately O91 between the aluminum layer 14 and the nickel layer 15
A titanium layer 15 with a thickness of .mu.m is formed with a back V by vapor deposition or sputtering. Since this titanium layer 15 acts as a bonding layer between the aluminum layer 13 and the nickel layer 14,
According to this embodiment, a semiconductor device having a stronger bump electrode can be obtained. [Effects of the Invention] As described above in detail, the semiconductor device of the present invention can be manufactured using platinum, Since the bump electrode has a simpler structure without using noble metals such as gold, it is possible to obtain the effect of feature 8: being able to supply pellets at low cost without causing any damage.

[Brief explanation of drawings]

Figure 1 shows the structure of an example of a conventional semiconductor device? A sectional view showing,
FIG. 2 is a sectional view showing a main part of an example of a conventional semiconductor device;
FIG. 3 is a sectional view showing a main part of an embodiment of the first invention, and FIG. 4 is a sectional view showing a main part of an embodiment of the second invention. 1, 2...metal lead, 3...pellet, 4...
・Crow sleeve, end...Semiconductor substrate, 6...Oxide film, 7...Diffusion layer, 8...Platinum silicide layer, 9...
・Titanium layer, IO・-・Platinum layer-11... Gold layer, 12
... Silver bump electrode, 13 ... Aluminum layer, 14
...Nickel layer, 15...Titanium layer. Figure 1, Section 2, Figure 3, Figure 4

Claims (2)

[Claims] (1) In a semiconductor device having a bang electrode, the bang electrode includes an aluminum layer formed on a semiconductor substrate, a nickel layer formed on the aluminum layer, and a silver bang electrode formed on the nickel layer. What does it consist of? ! -Featured semiconductor device. (2) On a semiconductor substrate having a bump electrode, the bump electrode includes an aluminum layer formed on the semiconductor substrate, a titanium layer formed on the aluminum layer, and a nickel layer formed on the titanium layer. A semiconductor device comprising a layer and a silver bang electrode formed on the nickel layer.