JP3988690B2 - Semiconductor device and its manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device such as an LSI having a probe pad electrode connected to a bonding pad electrode and a method for manufacturing the same, and more particularly to a probe for inspection by forming a probe pad electrode covering the side wall of an electrode hole provided in an insulating film. The contact failure between the probe and the probe pad electrode due to repeated use is eliminated.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a semiconductor device such as an LSI, a device provided with a probe pad electrode connected to a bonding pad electrode in an IC (integrated circuit) chip region formed on a semiconductor wafer is known (for example, see Patent Document 1). . According to such a semiconductor device, when the wafer probing test is performed before the assembly process, the inspection probe is brought into contact with the probe pad electrode instead of the bonding pad electrode. However, it is possible to prevent a situation in which bonding failure is caused by rubbing and damaging the tip of the inspection probe.
[0003]
Patent Document 1
Japanese Patent Application Laid-Open No. 7-111282
[Problems to be solved by the invention]
According to the above-described conventional technology, the probe pad electrode is usually made of a conductive material such as Al or an Al alloy in the same manner as the bonding pad electrode. Since metal such as Al or Al alloy is a soft material, for example, if the probe is contacted multiple times, such as once in the memory test and once in the logic test, the probe pad electrode is displaced and touches the tip of the probe. In some cases, metal scraps adhered and good contact could not be obtained. In addition, when the probe is used a plurality of times, the flatness of the tip surface deteriorates, and even if the upper surface of the probe pad electrode is flat, good contact may not be obtained.
[0005]
An object of the present invention is to provide a novel semiconductor device and a method for manufacturing the same that can eliminate poor contact between the probe and the probe pad electrode due to repeated use of the inspection probe.
[0006]
[Means for Solving the Problems]
A semiconductor device according to the present invention is a semiconductor device having a probe pad electrode connected to a bonding pad electrode,
An electrode hole is provided in one or a plurality of insulating films below the bonding pad electrode, and the probe pad electrode is formed so as to cover a side wall of the electrode hole.
[0007]
According to the semiconductor device of the present invention, since the probe pad electrode is formed so as to cover the side wall of the electrode hole provided in the insulating film, the tip of the inspection probe can be easily locked to the probe pad electrode. Good contact is obtained.
[0008]
In the semiconductor device of the present invention, when the electrode hole is formed so that the size is reduced in the depth direction, the inspection probe can be easily inserted into the electrode hole.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a semiconductor device according to an embodiment of the present invention. The pad electrode arrangement of the device of FIG. 1 is shown in FIG. The cross section shown in FIG. 1 corresponds to the cross section along the line QQ ′ of FIG.
[0010]
On the insulating film 12 covering one main surface of the semiconductor substrate 10, an interlayer insulating film 24 such as BPSG (boron / phosphorus / silicate glass) is formed so as to cover a polysilicon wiring (not shown). A wiring layer 26 is formed on the insulating film 24, and an electrode hole 24 a is provided in the insulating film 24 adjacent to the wiring layer 26. A W (tungsten) layer 28 is formed to cover the side wall of the electrode hole 24a.
[0011]
An interlayer insulating film 30 is formed on the insulating film 24 so as to cover the wiring layer 26, and a wiring layer 32 is formed on the insulating film 30. The wiring layer 32 has a wide area where the bonding pad electrode 40 is to be arranged in a square shape and has an extension extending from the electrode 40 to the vicinity of the electrode hole 24a. Used as 32A. The insulating layer 30 is provided with an electrode hole 30a adjacent to the connection layer 32A. The electrode hole 30a is formed so as to be continuously larger than the electrode hole 24a. As an example, if the connection hole 24a is a square having a side length A of 20 μm, the electrode hole 30a is formed in a size enlarged by D ₁ = 5 μm on the connection layer 32A side. W layer 34 is formed to cover the sidewalls of the electrode apertures 30a, W layer 34 covers the W layer 28 in the portion other than the enlarged portion of the D ₁ as described above. The connection layer 32 </ b> A interconnects the planned placement portion of the electrode 40 in the wiring layer 32 and the W layer 34.
[0012]
An interlayer insulating film 36 is formed on the insulating film 30 so as to cover the wiring layer 32 and the connection layer 32A. The insulating film 36 includes a connection hole 36a corresponding to a portion where the electrode 40 is to be arranged in the wiring layer 32, and An electrode hole 36b continuous with the electrode hole 30a is provided. The electrode hole 36b is formed in a size enlarged by D ₂ = 5 μm on the connection layer 32A side. The electrode holes 36b, 30a, 24a constitute a continuous hole whose size decreases in the depth direction. W layer 38 is formed to cover the sidewalls of the electrode apertures 36b, W layer 38 overlaps the connecting layer 32A in the enlarged portion of the _{D 2} mentioned above (connected), W layer 34 in the portion other than the enlarged portion of the _{D 2} Cover. The W layer 38a is formed in the connection hole 36a along with the formation of the W layer 38, but the W layer 38a may be omitted.
[0013]
A bonding pad electrode 40 made of Al or an Al alloy is provided on the insulating film 36 so as to be connected to the wiring layer 32 through the connection hole 36a. A protective insulating film 42 made of silicon nitride or the like is formed on the insulating film 36 so as to cover the electrode 40. The insulating film 42 includes a bonding hole 42a that exposes the central portion of the electrode 40, a W layer 28, A probe contact hole 42b that exposes the probe pad electrode 34, 38 is provided. As an example, the thickness of the insulating film 30 on the wiring layer 26 and the thickness of the insulating film 36 on the wiring layer 32 are both 0.8 μm, and the total thickness T of the insulating films 24, 30, 36 is 3 μm. It can be.
[0014]
In the wafer probing test, the inspection probe PB is brought into contact with the probe pad electrodes 28, 34, and 38 through the probe contact hole 42b. In this case, since the probe PB is locked by, for example, the W layer 34, good contact can be obtained even if the tip surface of the probe PB has deteriorated in flatness due to repeated use. Further, multipoint contact is possible by bringing the probe PB into contact with the W layer 38 at the opening end of the electrode hole 36b. Further, since the continuous hole made up of the electrode holes 24a, 30a, and 36b is formed so as to decrease in size in the depth direction, the probe PB can be easily inserted through the electrode hole 36b. In addition, since the probe pad electrodes 28, 34, 38 are made of W having a hardness higher than that of Al or Al alloy constituting the bonding pad electrode 40, damage to the probe pad electrode by the probe PB is reduced.
[0015]
Next, the manufacturing method of the apparatus of FIG. 1 is demonstrated with reference to FIGS. In the step of FIG. 3, after forming the insulating film 24 on the insulating film 12 covering one main surface of the semiconductor substrate 10, the wiring layer 26 is formed on the insulating film 24. Then, an electrode hole 24a adjacent to the wiring layer 26 is formed in the insulating film 24 by photolithography and selective dry etching. Thereafter, a W layer 28A is formed on the upper surface of the substrate by blanket CVD (chemical vapor deposition), and the W layer 28A is etched back so as to cover the side wall of the electrode hole 24a and to be connected to the wiring layer 26. Layer 28 is formed.
[0016]
Next, in the process of FIG. 4, the insulating film 30 is formed on the insulating film 24 so as to cover the wiring layer 26. The insulating film 30 can be formed using a coated insulating film so that the upper surface is flat. Then, after forming a wiring layer 32 and a connection layer 32A on the insulating film 30, an electrode hole 30a adjacent to the connection layer 32A is formed by photolithography and selective dry etching treatment. Electrode hole 30a is formed in a size enlarged than in succession electrode hole 24a only D ₁ of the foregoing. Thereafter, in the same manner as described with reference to FIG. 3, the W layer 34 is formed so as to cover the side wall of the electrode hole 30a and to be in contact with the connection layer 32A.
[0017]
Next, in the process of FIG. 5, an insulating film 36 is formed on the insulating film 30 so as to cover the wiring layer 32 and the connection layer 32A. The insulating film 36 can be formed flat like the insulating film 30. In the insulating film 36, a connection hole 36a corresponding to a part of the wiring layer 32 and an electrode hole 36b continuous with the electrode hole 30a are formed by photolithography and selective dry etching. Electrode hole 36b is formed in a size enlarged from the electrode hole 30a by _{D 2} mentioned above. Thereafter, the W layer 38 is formed so as to cover the side wall of the electrode hole 36b in the same manner as described in FIG. At this time, the W layer 38a remains along the side wall of the connection hole 36a larger than the electrode hole 36b.
[0018]
Thereafter, Al or an Al alloy is deposited on the upper surface of the substrate, and the deposited layer is patterned by photolithography and selective dry etching, thereby forming the bonding pad electrode 40 as shown in FIGS. Then, after forming a protective insulating film 42 such as silicon nitride on the insulating film 36, the bonding hole 42a and the probe contact hole 42b are formed in the insulating film 42 by photolithography and selective dry etching as shown in FIGS. To form.
[0019]
The present invention is not limited to the above-described embodiment, and can be implemented in various modifications. For example, as the material of the probe pad electrodes is not limited to W, M _O, a refractory metal or W such as Ti, M _O, it may be used silicides of refractory metals such as Ti.
[0020]
【The invention's effect】
As described above, according to the present invention, since the probe pad electrode is formed so as to cover the side wall of the electrode hole provided in the insulating film, even if the inspection probe is repeatedly used, the probe pad electrode is interposed between the probe and the probe pad electrode. The effect of ensuring good contact is obtained.
[Brief description of the drawings]
1 is a cross-sectional view of a substrate showing a semiconductor device according to an embodiment of the present invention;
FIG. 2 is a top view showing a pad electrode arrangement in the apparatus of FIG. 1;
3 is a cross-sectional view of a substrate showing a first W layer forming step in the manufacturing method of the apparatus of FIG. 1;
4 is a substrate cross-sectional view showing an insulating film forming step, a wiring forming step, a connection hole forming step, and a second W layer forming step subsequent to the step of FIG. 3;
5 is a substrate cross-sectional view showing an insulating film forming step, a connection hole forming step, and a third W layer forming step following the step of FIG. 4;
[Explanation of symbols]
10: semiconductor substrate, 12, 24, 30, 36, 42: insulating film, 26, 32: wiring layer, 28, 34, 38: probe pad electrode, 40: bonding pad electrode, 32A: connection layer, 42a: bonding hole 42b: probe contact hole.

Claims (4)

A semiconductor device having a probe pad electrode connected to a bonding pad electrode,
A semiconductor device, wherein an electrode hole is provided in one or a plurality of insulating films below the bonding pad electrode and the probe pad electrode is formed to cover a side wall of the electrode hole. The semiconductor device according to claim 1, wherein the electrode hole is formed so as to decrease in size in a depth direction. A semiconductor substrate;
A first insulating film formed to cover one main surface of the semiconductor substrate;
A wiring stack formed on the first insulating film, including one or a plurality of wiring layers and an insulating layer laid under each wiring layer, and each insulating layer includes a wiring thereon When electrode holes are provided adjacent to the layers, and there are multiple layers of insulating layers, the electrode holes of the multiple layers of insulating layers are formed to be continuous holes whose size decreases in the depth direction. ,
A second insulating film formed on the uppermost insulating layer in the wiring stack so as to cover the uppermost wiring layer, the connection hole corresponding to a part of the uppermost wiring layer and the connection hole An electrode hole spaced from the electrode hole, and the electrode hole is formed to have a size larger than that of the electrode hole of the uppermost insulating layer.
A probe pad electrode formed so as to cover a side wall of the electrode hole of each insulating layer and a side wall of the electrode hole of the second insulating film and to be connected to each wiring layer;
A semiconductor device comprising: a bonding pad electrode formed on the second insulating film so as to be connected to the uppermost wiring layer through the connection hole. Each time the formation of each wiring layer is completed, a predetermined conductive material is deposited on the insulating layer under the wiring layer so as to cover the electrode hole adjacent to the wiring layer, and the deposited layer is etched back to A part of the deposited layer is left in the electrode hole, a predetermined conductive material is deposited on the second insulating film so as to cover the electrode hole, and the deposited layer is etched back to thereby form the deposited layer. A part is left in the electrode hole, and the deposited layer remaining in the electrode hole adjacent to each wiring layer and the deposited layer remaining in the electrode hole of the second insulating film are used as the probe pad electrode. The method of manufacturing a semiconductor device according to claim 3.

Images