JPS6373639A - Trimming wiring in semiconductor device - Google Patents

Abstract

PURPOSE:To enable an Al interconnection to be melted down with lower energy by a method wherein a step difference part is provided immediately below an Al interconnection at the specific position to make use of the difference in the film thickness of Al interconnection. CONSTITUTION:An SiO2 film 7 is formed on a semiconductor (Si) substrate 1 by thermooxidation or CVD process to provide step deference parts by photoetching technology assuming a part 8 as the deepest step difference part. Next, Al is evaporated on overall surface to form an Al interconnection 2 in the specific pattern by photoetching process. This Al interconnection 2 is formed traversing the step difference part 8 of the SiO2 film 7. When the Al interconnection 2 is supplied with current with a pad 3 in contact with a probe 4, a part 10 of the step difference part 8 is supplied with overcurrent to be melted down so that the Al interconnection 2 may be melted down with lower energy scattering the least Al to prevent a protective film from breaking down or being contaminated as well as the reliability of the probe 4 from deteriorating etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to wiring trimming technology in semiconductor devices, and mainly relates to AA fusing when selectively trimming an A (aluminum) wiring layer connected to a parallel diffused resistor. Targeting technology.

[Prior art]

In the manufacture of ICs (semiconductor integrated circuit devices).

As shown in FIG. 7, a plurality of diffused resistors R, , R, , R, .・)
A trimming technique is known in which only the necessary resistor (R1) is left by trimming (partially cutting) two wires to a drawer.

This trimming method includes a method in which the resistance value of each diffused resistor is measured during a general glove inspection, and a current is passed through a probe needle to the lead wire of the unnecessary resistor, and another method is to use a laser. There is a method of trimming a silver alloy resistor etc. on a dielectric material (resistance laser trimming on a dielectric material).

Among these, the trimming method using a laser is excluded because it requires a large-scale laser device and is not suitable for trimming human 4 wiring, and here we will limit it to methods that mainly utilize probe inspection.

Usually, as shown in Figure 8, people! A probe needle 4 is brought into contact with an external terminal (ponding pad) 3 connected to the wiring 2, and an overcurrent is applied with the other end of the Al wiring 2 grounded. It is designed to melt.

[Problem that the invention seeks to solve]

In the above trimming method, the tip of the probe needle that comes into contact with the pad that is part of the A1 wiring deteriorates quickly. There are problems such as the wiring being difficult to cut.

Another person! If a large enough current is applied to the wiring 5 to cut the wiring, as shown in Figure 9, the A4 will scatter when it melts, destroying the surface protection insulating film 6, or causing short circuits with other AJ3 wiring due to contamination. Because of this, there was a risk that the reliability of the IC would drop significantly.

As a result of various studies, the inventors of the present invention found that the above-mentioned problem can be solved by humans! It was discovered that this problem occurred because too much energy was required during cutting, and an attempt was made to solve this problem.

Therefore, it is an object of the present invention to obtain A! The purpose of this invention is to provide a technology for melting wiring.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, when trimming the Al wiring by flowing current through the l wiring formed on the conductor substrate and melting the Al wiring at a specific location, the A! of the specific location is trimmed. A step is provided directly below the distribution, and people can use this step! This utilizes the difference in wiring film thickness.

[For production]

According to the above-mentioned means, A! l Wiring film thickness becomes thinner! As a result of the cross-sectional area becoming smaller, it becomes possible to fuse the semiconductor device with less energy, and the reliability of the semiconductor device can be maintained even after trimming, thereby achieving the above object.

〔Example〕

Figures 1 to 5 show an embodiment of the present invention! FIG. 3 is a process sectional view and a plan view of the heddle forming process.

The steps will be explained below in order.

(1) Active thermal oxidation or CvD on semiconductor (St) substrate 1
A film 7 of Sin is formed by a (vapor phase chemical deposition) method, and a stepped portion is provided by a photoetching technique. Of these, 8 are the step portions with the deepest steps. Photoetching for these steps may be accompanied by a selective diffusion (paste, emitter diffusion) process into the semiconductor body (FIG. 1).

(2) To form wiring for person 1, A2 is deposited on the entire surface and formed into wiring 2 with a specific pattern by photo-etching (Figure 2).

+31g3 Figure shows an example of one pattern of A1 wiring.

3 is a bonding pad, and 2 is an AJl wiring.

For example, this person! The other end of the wiring is in ohmic contact with a diffused resistor (not shown) and is connected to a ground potential. It is assumed that this layer 1 is formed across the step 8 of the Sin@ film 70.

Figure 4 is people! This figure shows another example of a wiring pattern. In this example, people! An m-width portion 9 is formed at a portion where the wiring 2 crosses the step 8.

Oni 41 As shown in Figure 5, a person is in contact with the probe needle 4 on the pad 3! When a current flows through the wiring 2, an excessive current flows through the stepped portion, and this portion 10 is fused and trimmed.

[Reason why it is effective]

Regardless of whether the A4 film is formed by vapor deposition or sputtering, the thickness of the AA film at the step portion will be small. This person 1
The larger the difference in level, the greater the film thickness.

The cross-sectional area of the Al wiring at that portion is small and current tends to concentrate there. For this reason, A1 fusing is possible with low energy and therefore less human! There is little scattering, there is no destruction or contamination of the protective film, and there are no problems such as reduced reliability or deterioration of the probe needle. As a result, trimming is reliable and easy, resulting in an IC with high added value.

LSI can be realized.

By providing a step directly below the A-shaped ball and forming an m-width part in the I-pattern, the synergistic effect of the A2 thickness and the wiring width reduces the cross-sectional area of the A-2 ball by -5. ,
Trimming is possible with a small amount of energy.

Although the invention made by the present invention has been specifically explained based on Examples, the present invention is not limited to the above-mentioned Examples (it goes without saying that various changes can be made without departing from the gist of the invention). Mona~ゝ.

For example, A) There is not only one level difference under the membrane, but there are multiple levels as shown in Figure 6. By crossing the wiring, Affl can be reliably fused at the stepped portion and trimming can be achieved.

The present invention can be applied to ICs and LSIs in general, and is particularly effective when applied to high-density to high-performance semiconductor devices.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In other words, even if the IC is trimmed, reliability can be maintained and the deterioration of the glove can be prevented, so a multi-functional LSI can be realized. Furthermore, by doing so, it is possible to realize a high value-added semiconductor product with fewer external parts and no adjustment required.

[Brief explanation of the drawing]

1 to 5 show some embodiments of the present invention, and among these, FIGS. 1, 2, and 5 are process sectional views of the proverb formation process. 3 and 4 are plan views corresponding to FIG. 2. FIG. 6 is a partial process sectional view showing an application example of the present invention. Figure 7 shows how to selectively connect multiple resistors. J It is a circuit diagram when minking. FIG. 8 is a partial plan view of a semiconductor chip showing one form of trimming using probe inspection. FIG. 9 is a sectional view showing a plurality of shapes of A during trimming. 1... board, 2... people! Wiring, 3... Bonding pad, 4... Probe needle, 7... Sin, if
f, 8...Step, 9...Narrow width part, 10...Fusion part. Agent: Patent attorney Katsuo Ogawa. Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1. Trimming wiring in a semiconductor device in which a specific portion of the wiring layer is cut by blowing a current through a wiring layer formed on an insulating film on a semiconductor substrate, wherein the wiring layer to be trimmed is Trimming wiring in a semiconductor device, wherein a stepped portion is formed on the surface corresponding to the specific portion, and the thickness of the wiring layer at the specific portion is thinner than the thickness of the wiring layer other than the specific portion. . 2. The trimming wiring in a semiconductor device according to claim 1, wherein the step is formed due to a step of the insulating film.