JPS63177441A - Working method for wirings - Google Patents

Abstract

PURPOSE:To obtain a working method for wirings at the time of opening a window at a wiring layer by ion beam for precipitating a CVD film with a laser beam of low energy for causing no damage by varying an ion beam deflection signal at a stage in which the wiring layer is exposed to form a wiring layer surface in which an optical reflectivity is reduced. CONSTITUTION:When the wiring layer 15 of a semiconductor device is formed by an ion beam working apparatus, a deflection signal of an ion beam 2 is varied at a stage in which the layer 15 is exposed to form a wiring layer surface in which its optical reflectivity is reduced. For example, continued to a step of opening a window for exposing wirings 15 in a semiconductor device by an ion beam 2, a step of surface treating for reducing the reflectivity of the surface of wirings 15 is conducted, the device is conveyed to a laser CVD side to execute a wiring forming step. The wiring layer surface in which the optical reflectivity is reduced uses many groove, one or more wedgeshaped grooves, or one or more conical holes. Thus, preferable CVD wirings 17 are formed on the surface of the exposed layer 15 with a laser beam 14 of low energy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for adding a number wire on the surface of a semiconductor device, and is particularly suitable for forming additional wires in ion beam processing, which is a pre-treatment process for forming additional wires. The present invention relates to a method of processing a wiring layer in a semiconductor device.

[Conventional technology]

When developing semiconductor devices, usually due to various factors,
Wiring errors, etc. occur. For this reason, the semiconductor development process includes inspection, failure analysis, and wiring correction processes. Since shortening the debugging process is directly linked to shortening the development period of semiconductor devices, many debugging means are currently being studied. As shown in Figure 4, one of the methods is to cut the wiring of the semiconductor device using a focused ion beam, add wiring to the surface of the semiconductor device, and place the exposed wiring layer in a gas atmosphere using the focused ion beam. Among these methods, effective is a method that combines methods of forming wiring by irradiating energy beams such as ion beams, electron beams, and laser beams and performing CVD. As a method for forming this wiring, Extended Abstracts on the Seventeenth Conference on Solid State Devices and Materials (1
985), pages 193 to 196 (Extende
d Abs-tracts of the 17th,
Conferen*e on 5solid 5tate
Devices and Materials, T
okyo 1985. Currently, laser CVD, which is discussed in 2003, p. 193-196), is currently being actively researched because it is superior in terms of wiring formation speed and wiring resistance.

However, according to experiments conducted by the inventors, the following problems were found when depositing a CVD film by laser irradiation after opening a window in the wiring layer with an ion beam. In other words, aluminum is normally used for wiring, but aluminum has a high light reflectance and absorbs only 10% of laser energy. Therefore, it is necessary to increase laser energy to deposit a CVD film.

On the other hand, the absorption rate of the CVD film is about 50%, and the laser energy absorbed at the same time as the CVD film is deposited increases five times at once, so the temperature of the laser irradiated area increases rapidly, causing bumping of the aluminum, etc. Damage will occur. Therefore, it was necessary to develop a method for depositing CVD films using a low energy laser beam.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, no consideration is given to the damage caused by the difference between the reflectance of the wiring inside the semiconductor device and the reflectance of the CVD film, and it is difficult to actually draw out the wiring from inside the semiconductor device.

An object of the present invention is to provide a wiring processing method in which a window is formed in a wiring layer using an ion beam for depositing a CVD film using a low-energy laser beam that does not cause the above-mentioned damage.

[Means for solving problems]

The above objective is achieved by reducing the reflectance of aluminum. For this reason, a method is adopted in which the exposed aluminum surface is processed to reduce the reflectance of the aluminum.

[Effect]

A window is opened in the wiring inside the semiconductor device using ion beam processing to expose the surface of the wiring such as aluminum.

Next, the wiring surface is processed by switching the ion beam deflection signal from the beam scanning state until the opening of the window to a deflection signal that reduces the reflectance of light on the wiring surface by forming unevenness on the wiring surface. Next, the exposed portion of the wiring is irradiated with a laser beam in a CVD gas atmosphere.

At this time, the reflectance of the wiring surface is reduced by the above processing, so the laser energy is efficiently absorbed.
It is possible to deposit a CVD film with a low-energy laser beam, and even if the surface that absorbs laser energy changes from the wiring surface to the CVD film surface as the CVD film is deposited, damage due to bumping etc. will not occur, and the semiconductor It becomes possible to draw out the CVD wiring from the internal wiring.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figure 3 shows wiring cutting for cutting and connecting semiconductor device wiring.
FIG. 2 is a diagram showing a schematic configuration of a connecting device.

The configuration is such that the ion beam processing equipment side that processes the wiring and the laser CVD equipment side that forms the wiring are separated by a central gate valve 8. Usually, the ion beam 2 uses a high-intensity ion source 1 such as a liquid metal ion source, and the ion beam 2 extracted from the source is focused with an electrostatic lens 3 to a spot of 1 μm or less on the target semiconductor device 5. . The ion beam 2 is deflected by a deflector 4 installed under the electrostatic lens 3, and in combination with the movement of the stage 6, it is possible to process an arbitrary shape at an arbitrary position on the semiconductor device 5. In addition, on the laser CVD side, CVD gas is supplied from the gas supply device ratio, and the laser oscillator 1
A laser beam 14 is introduced into the vacuum chamber 13 from 0 through the window 11 while being focused by the lens 9, and the semiconductor device 5 is
By moving the stage to a predetermined position above and irradiating the
Form VD wiring.

FIG. 1 is a diagram showing an actual wiring connection process.

The first step is a window opening step in which the wiring 15 in the semiconductor device 5 is exposed by the ion beam 2. Conventionally, for window opening, the semiconductor device was immediately transported to the laser CVD side after the process.
It was thought that the process would involve the wiring formation process. However, the damage described above occurs. Therefore, as described above, a surface treatment step is inserted to reduce the reflectance of the wiring surface. The processing carried out in the surface treatment step is a processing for forming irregularities on the wiring surface, as shown in FIG. FIG. 2(a) shows an example in which a narrow groove is machined. It is desirable that the groove width is approximately equal to or less than the wavelength of the laser beam. - For example, when using an argon laser, the wavelength of the laser light is 488 nm and 5 nm.
It is 14.5 nm. Therefore, the groove width is also 0.5 μm.
Formed below. The groove of this width is 0.1μ
Since it can be focused up to m, it can be formed. Further, FIG. 2(b) shows an example in which a deep wedge-shaped groove is formed, and FIG. 2(C) shows an example in which a conical hole is formed. In either case, the incident laser light is reflected within the processed groove or hole, but is ultimately absorbed, so that a CVD film can be deposited on the exposed wiring portion even with low energy. Among these methods, the method of digging a conical hole is 0.1μ
It is practical because the process can be carried out relatively easily and in a short time by simply irradiating an ion beam focused at a diameter of about 100 m in diameter by fixing it at the center of the exposed wiring part for a certain period of time after the process is completed. However, if the reflectance cannot be reduced sufficiently at one point, it is effective to form a large number of holes as shown in FIG. 2(d).

For example, a circular through hole is opened to expose the aluminum wiring layer in advance, and the ion beam is stopped for 10 seconds to form a conical hole in the center of the hole. Note that this example uses a wiring pattern in which the aluminum wiring is exposed from the beginning. By irradiating this exposed portion with laser, a CVD film could be deposited. The energy required for this CVD film deposition is the same as that of conventional CVD film deposition.
It was 20 inches when the aluminum wiring was damaged at the same time as the film was deposited, and it became possible to deposit the CVD film without damaging the aluminum wiring underneath.

〔Effect of the invention〕

According to the present invention, since a CVD film can be deposited on the exposed surface of the wiring layer of a semiconductor device using a low-energy laser beam, it is possible to form good CVD wiring without damaging the wiring layer.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a wiring connection process including the present invention, FIG. 2 is a cross-sectional perspective view of a processed part showing the processed evaturn of the present invention, FIG. 3 is a schematic configuration diagram of a wiring cutting/connection device, and FIG. The figure is an explanatory diagram of a wiring cutting/connecting method. 1...Ion source 2...Ion beam. 3... Electrostatic lens, 4... Deflector. 5...Semiconductor device 6...Stage. 7...Vacuum pump, 8...Gate valve. 9... Lens j10... Laser oscillator. 11...Window j12...CVD gas supply device 13...
・Vacuum chamber, 14...laser beam. 15... Wiring, 16... Optical path 17
...CVD film

Claims (1)

[Claims] 1. When processing a wiring layer of a semiconductor device using an ion beam processing device, the deflection signal of the ion beam is changed at the stage when the wiring layer is exposed to reduce the reflectance of light. A wiring processing method characterized by forming a surface of a wiring layer. 2. The wiring processing method according to claim 1, characterized in that a large number of groove structures are formed as the surface of the wiring layer in which the reflectance of the light is reduced. 3. The wiring processing method according to claim 1, characterized in that one or several wedge-shaped grooves are formed as the surface of the wiring layer in which the reflectance of light is reduced. 4. The wiring processing method according to claim 1, characterized in that one or several conical holes are formed as the surface of the wiring layer in which the reflectance of light is reduced.