JP2002170932A - Aluminum wiring and resistance controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a fine zapping adjustment without scattering an aluminum material to short-circuit other wiring parts or without giving damage to elements on lower layers. SOLUTION: A first and second contacts 2, 3 are electrically connected by an aluminum wiring 1, a part of this wiring 1 is oxidated to form a non-conductor region 4, and the resistance value between the first and second contacts 2, 3 is controlled by this region 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum wiring body and a method of controlling a resistance value, and more particularly to an aluminum wiring body and a method of controlling a resistance value which reliably realize a precise zapping adjustment of a resistance in a semiconductor IC.

[0002]

2. Description of the Related Art In recent semiconductor devices, various adjustments are used to increase the yield of finished products or to provide various functions as options. Zapping is one of the means used for this adjustment. . In the zapping adjustment, for example, both ends of a resistor having a predetermined resistance value are short-circuited in advance with an aluminum wiring body, and the aluminum wiring body is trimmed by a laser beam as necessary, thereby adjusting the resistance of the semiconductor device. .

FIG. 4 is a circuit diagram showing an example of zapping adjustment. In the figure, R1, R2 and R3 are resistors arranged in series between power supply terminals T1 and T2,
S is a wiring that electrically shorts the resistor R3. Here, in the state shown in the figure, the resistance between the power supply terminals T1 and T2 is a resistance value obtained by adding the values R1 and R2, and when the wiring S is cut, the resistance value obtained by adding R1, R2 and R3 is obtained. Becomes

FIG. 5 is a diagram showing a part of a conventional aluminum wiring. FIG. 5A shows the aluminum wiring body 10 that has not been laser-trimmed, that is, is in a conductive state.
(B) shows the aluminum wiring body 11 which has been laser-trimmed, that is, is in a non-conductive state.

In the case of FIG. 4, the state of FIG.
The resistance value between the power supply terminals T1 and T2 is a value obtained by adding R1 and R2, and in FIG. 5B, it becomes a value obtained by adding R1, R2 and R3.

[0006]

In the laser trimming of the aluminum wiring body used in the above-mentioned zapping adjustment, it is necessary to raise the temperature of the laser beam to the boiling point of aluminum in order to melt the aluminum wiring body. Irradiation with a high-temperature laser not only melts the aluminum wiring but also damages the resistive element under the aluminum wiring. Further, in the fusing step, the aluminum material in the cut portion may be scattered and short-circuit other wirings, which may adversely affect the yield of the semiconductor chip.

Further, the above zapping adjustment is simply performed by the power supply T
Fine adjustment could not be performed by an adjustment method in which only the resistance R3 generated by fusing the alumina wiring was added to the resistance value (sum of R1 and R2) between T1 and T2.

In view of the above, the present invention has been made in view of the above-mentioned problem, and fine adjustment of the resistance value at the time of zapping adjustment is performed by providing the aluminum wiring as a resistor without fusing, so that the aluminum wiring is scattered. An object of the present invention is to provide an aluminum wiring body and a resistance value control method that can solve problems such as short-circuiting of wiring made of aluminum material and damage to elements under the aluminum wiring body.

[0009]

In order to achieve the above-mentioned object, an aluminum wiring body according to the present invention is connected to first and second contacts, and supplies current between the first and second contacts. In the realized aluminum wiring body, a non-conductive area formed by oxidizing a part of the aluminum wiring body is provided, and the resistance value between the first and second contacts is controlled by the non-conductive area. Features.

Further, in the resistance control method according to the present invention, the first and second contacts are electrically connected by an aluminum wiring body, and the non-conductive area is formed by oxidizing a part of the aluminum wiring body. And the first region is formed by the non-conductive region.
And controlling the resistance value between the second contacts. In particular, the step of forming a non-conductive region in the aluminum wiring body includes a step of cooling a wafer provided with the aluminum wiring body and a step of irradiating a predetermined region of the aluminum wiring body with a laser in an oxygen atmosphere. And characterized in that:

In the aluminum wiring body and the resistance value control method according to the present invention, fine adjustment of the resistance value is performed without scattering the aluminum wiring material.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for controlling an aluminum wiring value and a resistance value according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an aluminum wiring body 1 to which the present invention is applied.
FIG. The aluminum wiring body 1 is for electrically connecting the first contact 2 and the second contact 3. Part of the aluminum wiring body 1 is formed with an L-shaped non-conductive region 4 having a length A1 in the width direction of the aluminum wiring body 1 and a length A2 and a width W between the contacts 2 and 3. I have.

A method of forming the non-conductive region 4 will be described. First, the wafer on which the aluminum wiring body 1 is formed is cooled by a cooling device such as a cryostat. continue,
For example, a cooled wafer is placed in a chamber kept in a high-purity oxidizing atmosphere such as ozone. Then, the aluminum wiring body 1 on the wafer is locally irradiated with laser to a desired region and heated. As a result, the region irradiated with the laser is oxidized to form an Al2O3 region, that is, a nonconductive region 4.

As described above, the purpose of cooling the wafer before forming the nonconductive region 4 by heating with a laser is to promote an oxidation reaction only in a very narrow range irradiated with the laser. When laser irradiation is performed at room temperature, the temperature around the laser-irradiated region also increases, and the oxidation reaction is diffused. Therefore, it is difficult to form the nonconductive region 4 only in a very small area.

In the aluminum wiring body 1 formed by the above procedure, the resistance value of the aluminum wiring body 1 can be changed by changing the lengths A1 and A2 of the nonconductive region 4. For example, if the length A1 of the non-conductive region 4 is set to の of the width of the aluminum wiring 1, the resistance of the aluminum wiring 1 can be doubled, and the length A2 is further increased. Thereby, the resistance value of the aluminum wiring body 1 can be made several times or more.

FIG. 2 is a circuit diagram showing zapping adjustment to which the present invention is applied. In the figure, R1, R
2, R3 are resistors arranged in series between the power supply terminals T1 and T2, and S is a wiring that electrically shorts the resistor R3. The configuration up to this point is the same as that of the conventional zapping adjustment, but the resistance Rs is generated by the nonconductive region 4 on the short wiring S, and the resistance between the power supply terminals T1 and T2 is the value R
1 and R2, the combined resistance Rn between P1 and P2 (1 / Rn = 1
/ R3 + 1 / Rs).

By varying the resistance Rs of the nonconductive region 4, the resistance between the power supplies T1 and T2 can be finely adjusted when the combined resistance Rn of the resistance 3 and the resistance Rs is equal to or less than the resistance R3. Can be. Therefore, the present invention can realize precise zapping adjustment of the semiconductor device.

Further, in the method according to the present invention, the aluminum wiring is not cut unlike the conventional method, so that the cut aluminum material does not scatter and short-circuit other wiring. Further, since the temperature required for oxidizing aluminum is lower than the temperature required for fusing aluminum, according to the present invention, there is a possibility that the element under the aluminum wiring may be damaged during laser trimming. Absent.

FIG. 3 is a diagram showing a second specific example of the present invention. In the aluminum wiring body 5 shown in FIG. 2, a nonconductive region 6 is formed over the entire width direction. This non-conductive area 6
Are formed in the same manner as described above. Thus, by forming the non-conductive region 6 over the entire width of the aluminum wiring body 5, the aluminum wiring body 5 can be opened, that is, completely non-conductive.

Such an aluminum wiring body 5 is suitable for use in a conventional zapping adjustment circuit as shown in FIG.
In this resistance value adjustment circuit, in the initial state, the connection points P1 and P2 are short-circuited by the wiring S, and therefore, the resistance value between the electrodes T1 and T2 is equal to the resistance R1 and the resistance R2.
And the resistance value. Here, connection points P1 and P2
By cutting the wiring S that shorts the space between the electrodes T
The resistance value between 1 and T2 is a resistance value obtained by adding the resistance R1, the resistance R2, and the resistance R3.

Conventionally, the wiring S is cut by fusing the wiring pattern. However, the aluminum wiring body 5 shown in FIG. By forming the non-conductive region 6 extending over the wiring S, the wiring S can be cut.

Also in this case, there is no problem that the aluminum material is scattered and short-circuits other wirings, and the high-temperature laser light does not damage the resistance element.

[0024]

As described above, the aluminum wiring body according to the present invention has the nonconductive region formed by oxidizing a part of the aluminum wiring body, and the first and second nonconductive regions are formed by the nonconductive region.
Since the resistance value between the contacts is controlled, it is possible to precisely control the resistance value by the length and shape of the non-conductive region, and it is possible to perform fine resistance adjustment of zapping adjustment.
Further, since the aluminum wiring body is not cut and the aluminum material is not scattered, the problem of wiring short-circuit due to the scattered aluminum material can be solved. Further, since the processing by the laser at a lower temperature is performed as compared with the method of fusing the aluminum wiring, there is no possibility of damaging the element under the aluminum wiring body.

[Brief description of the drawings]

FIG. 1 is a diagram showing an aluminum wiring body to which the present invention is applied.

FIG. 2 is a circuit configuration diagram showing zapping adjustment to which the present invention is applied.

FIG. 3 is a diagram showing a second specific example of the aluminum wiring body to which the present invention is applied.

FIG. 4 is a circuit diagram showing an example of a conventional zapping adjustment.

FIG. 5 is a diagram showing a conventional aluminum wiring body and an aluminum wiring body after fusing.

[Explanation of symbols]

 1,5 Aluminum wiring body 2 First contact 3 Second contact 4,6 Non-conductive area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F033 HH08 QQ53 QQ68 QQ76 QQ88 RR03 SS26 VV09 XX31 5F038 AR07 AR23 AV03 CD18 EZ20

Claims (3)

[Claims] A first contact connected to the first and second contacts;
An aluminum wiring body for realizing current conduction between the first and second contacts, comprising: a nonconductive region formed by oxidizing a part of the aluminum wiring body; 2
An aluminum wiring body characterized by controlling a resistance value between contacts. A step of electrically connecting the first and second contacts with an aluminum wiring body; and a step of oxidizing a part of the aluminum wiring body to form a non-conductive region. Controlling the resistance value between the first and second contacts. 3. The step of forming a non-conductive region in the aluminum wiring body includes the steps of: cooling a wafer on which the aluminum wiring body is disposed; and applying a laser to a predetermined region of the aluminum wiring body in an oxygen atmosphere. 3. The method according to claim 2, further comprising irradiating.