JP3153219B2 - Semiconductor device, insulating film forming method and device therefor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, a method for repairing a semiconductor device, and a device therefor. And a method of repairing a semiconductor device suitable for repairing a defect.

[Conventional technology]

2. Description of the Related Art In order to achieve higher performance and higher speed of semiconductor devices, miniaturization and higher integration of semiconductor devices have been performed. Along with this, the development of semiconductor devices has become more difficult, leading to a longer development period. This situation indicates that LSI design also requires a circuit manufacturing technique of cut and try. That is, the defective part on the chip that does not operate sufficiently with the conventional design is specified, the wiring existing in the part is cut, the wiring is arbitrarily arranged, the defective wiring is repaired, and the provisional is temporarily determined. If a semiconductor device capable of obtaining a complete operation is manufactured, subsequent characteristic evaluation and design change can be quickly performed, and the device can be directly shipped to a user as a technical sample.

On the other hand, as a prior art, as described in, for example, Semiconductor World, September 1987, pages 27 to 32, the passivation of the LSI chip surface and the interlayer insulating film by FIB (focused ion beam) are described. And exposing the wiring, and then introducing a CVD gas to form a metal wiring by FIB.

Also, Extended Abstracts of the Seventeens Conference on Solid State Devices and Materials Tokyo (1985), pages 193 to 196 (Extended Abstracts)
of the 17th Conference on Solid State Dev
As described in ices and Materials, Tokyo, 1985, pp. 193 to 196), a method of forming Mo wiring on a Si substrate coated with SiO ₂ using a laser CVD technique has been introduced.

In addition, as the prior art, JP-A-62-229956, JP-A-62-229957, 1988 Autumn Proceedings of the Society of Applied Physics, 1988.1
0.p534 is known.

[Problems to be solved by the invention]

The first prior art or the first prior art and the second
With the combination of the conventional technologies, it is possible to cut unnecessary wiring and form additional wiring, thereby repairing LSI chips that do not work due to design failure or process failure, and completely operating L chips.
You can get SI. But obtained in this way
The LSI chip has a problem that sufficient reliability cannot be obtained.

The third to fifth prior arts disclose a method of forming an insulating film by laser CVD, but have problems such as a low deposition rate and a complicated process. An object of the present invention is to provide a method for forming an insulating film more easily. That is, an object of the present invention is to cut or connect an arbitrary wiring of a semiconductor device once completed through a predetermined process, and repair the semiconductor device so that complete operation can be obtained with high reliability. It is an object of the present invention to provide a method of repairing a semiconductor device and a device capable of obtaining a simple semiconductor device.

[Means for solving the problem]

The above-mentioned object is to provide an insulating film material by ink jet in a region including at least the cut portion and the repair wiring on the chip on which the cut portion and the wire for repair are formed, and excluding on the connection electrode (pad or bump). To form an insulating film.

That is, the object is to obtain the reliability of the repair chip by covering the repair portion with a protective film.

[Action]

The LSI that has been repaired by cutting or wiring formation is made to face the tip of the nozzle, and a fine droplet of a material for forming an insulating film is discharged from the nozzle to form the material film on the surface including the repaired part. I do.

Here, spin-on-glass, polyimide, or the like is selected as a material for forming the insulating film.

After forming the above material film, the chip is baked to remove the solvent in the case of spin-on glass.
The OH groups are eliminated to form a SiO ₂ film or, in the case of polyimide, a dehydration polymerization reaction proceeds to obtain a polyimide film. As a result, the surface of the repaired portion is covered with the insulating film (protective film), and the reliability of the repaired LSI can be ensured.

That is, according to the present invention, since Al in the cut portion is not exposed, there is no possibility of short circuit due to Al electromigration or the like. Also, FIB (Focused Ion Beam) CVD and laser
Since the wiring formed by CVD is not exposed, there is no disconnection due to mechanical force during assembly, heating, corrosion due to moisture penetration, and the like.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an entire configuration of an insulating film forming apparatus according to one embodiment of the present invention. Wire cutting and connection hole formation by FIB (Focused Ion Beam) processing and laser CVD or F
The LSI chip for which the wiring connection by IBCVD has been completed, that is, the LSI chip 1 for which repair has been completed, is mounted on the XYZ-θ stage 2. The stage 2 is driven by, for example, motors 3 and 4 in the XY directions. (Although Z-θ is not shown, it is driven by a motor.) The positioning / observation optical system includes an objective lens 5, an illumination light source 6, an eyepiece 7,
It is composed of an imaging lens (relay lens) 8 and a TV camera 9, and the positioning and observation of the chip 1 can be performed by the eyepiece 7 or the monitor 10. In addition, the insulating film material discharge section is a nozzle having a ring 11 formed of a piezoelectric element.
It comprises a reservoir 12 connected by a pipe 13 and an insulating film material 15. In addition, a protective plate 17 that can be opened and closed by a drive mechanism 16 is installed directly below the nozzle. Further, control of the XYZ-θ stage 2 and the piezoelectric element ring
A control device 18 for controlling the protection plate 11 and the protection plate 17 is provided.

A method for forming an insulating film by the insulating film forming apparatus shown in FIG. 1 will be described. First, as shown in FIG. 2, the repaired LSI chip 1 (wafer may be used) is placed on the XYZ-θ stage 2 shown in FIG. On the surface of the LSI chip 1, openings 21 and 21 'of holes formed through a protective film or, if necessary, an interlayer insulating film for cutting wiring by focused ion beam (FIB) processing and the like. CVD connecting between connection holes formed by
Alternatively, the connection wirings 22, 22 'formed by FIBCVD are exposed. Normally, the surface of the LSI chip has a final passivation film (protective film) 24 except for the pad 23 which is an input / output terminal.
Covered with.

After the chip 1 is placed on the stage 2, the chip 1 moves below the optical system, and two target marks (positioning marks) in the chip 1 or specific positions whose coordinates are known (for example, corners of the chip). , The position of a specific pad or wiring) is aligned with the center of the monitor screen. At that time, although not shown in FIG. 1, the linear encoder attached to the stage 2, the rotary encoder attached to the motors 3 and 4, or the laser interference It can be known by means such as a meter. XY-θ is adjusted from the coordinates. For Z,
By using a high magnification lens as the objective lens 5, 10
In the case of a 0 × objective lens, it can be adjusted to about ± 0.5 μm.

Thereafter, the tip 1 moves to a position immediately below the nozzle 12. The nozzle 12 has a function of a so-called inkjet nozzle, and discharges an insulating film material 15 instead of ink. The relationship between the center on the TV monitor 10 and the position where it is ejected and adhered from the nozzle 12 is known, and it is easy to adhere the insulating film material to any position according to the relative coordinates on the chip 1. Incidentally, this ink jet is a technique similar to that shown in Japanese Patent Publication No. 47-7847, for example. The microparticles of the insulating film material 15 are transported to a predetermined position by a signal from the substrate and adhered thereto. Here, an example in which the adjustment of the adhesion position is performed only by the XYZ-θ stage 2 on which the chip 1 is mounted is shown, but the same result can be obtained by relatively moving the position of the nozzle 12. Can be

Here, a ring 11 formed of a piezoelectric element is installed on the glass tube forming the nozzle 12 such that the inner surface of the ring is in contact with the ring 11. When a DC voltage pulse is applied to the ring 11, the ring 11 becomes adjacent. Then, the glass tube is subjected to a contraction force, and a part of the insulating film material 15 inside comes out as fine droplets, is crushed on the chip 1, and covers a substantially circular region with the insulating film material 15.
The piezoelectric element does not necessarily need to be a ring, but may be any structure that can compress the glass tube by the piezoelectric effect. nozzle
12 When the inside diameter of the tip is about 50 μm,
When a pulse of msec is applied, a droplet having a diameter of about 100 μm is ejected. It is possible to control the size of the droplet to be ejected by the viscosity of the liquid, the nozzle diameter, and the voltage applied to the piezoelectric element.
50 μm diameter to 200 μm as the size when attached on the chip
The diameter can be obtained. That is, hole entrance 2 formed by FIB processing
Repair wiring 22 formed by coordinates 1 or laser CVD
At a constant pitch while moving the stage 2 according to the formation data of
G) The droplets of the insulating film material are deposited.

At this time, the opening and closing of the protection plate 16, the movement of the stage 2 according to the data, the application of a voltage to the piezoelectric element 11, and the like are all controlled by the controller 18.

FIG. 3 shows a state in which one insulating film material droplet 25 has adhered to the starting point of the repair wiring 22. Thereafter, while moving the stage 2 in accordance with the wiring data, droplets of the insulating film material are applied at a constant pitch, and finally, the entire repaired portion is covered with the insulating film material film 26 as shown in FIG.

Here, a case where spin-on-glass is used as an insulating film material will be described.

Spin-on-glass is a solution in which a silicon compound represented by RnSi (OH) _4-n and an additive are dissolved in an organic solvent such as ethanol, and the organic solvent is removed by baking at a temperature of 200 ° C or more. , A film having properties similar to SiO ₂ can be obtained. In particular, when baking is performed at a temperature of 600 ° C. or more, the OH component disappears, and an SiO ₂ film is obtained. However, the baking temperature is selected to be an allowable temperature for the LSI chip. Usually, the temperature is preferably 400 ° C. or less to minimize the damage to the Al wiring.

As described above, the repaired portion is covered with the protective film having a property close to SiO ₂ or SiO _2, and the reliability as the LSI is secured.

Next, a case where a polyimide resin is used will be described.
As a material, a resin material in the prepolymer (or monomer) state is dissolved in a solvent such as pyrrolidone or dimethylacetamide. By baking at a temperature of 200 to 400 ° C., the solvent is removed and the dehydration polymerization reaction proceeds, and a polyimide film is formed. Is formed. As a result, the repaired portion is covered with the polyimide film, and the reliability as an LSI is secured.

Here, the method of repair, that is, the method of cutting unnecessary wiring, forming connection holes, and forming connection wiring is not particularly described, but a method described in, for example, JP-A-63-164240 can be employed. .

However, the present invention is not limited to this, and the gist of the present invention is to cover the repaired portion of the semiconductor chip repaired (modified) by any method or means with a protective film, thereby ensuring reliability.

Next, an insulating film forming apparatus and a forming method according to another embodiment will be described. FIG. 5 shows the entire configuration of the insulating film forming apparatus.

An XYZ-.theta. Stage 32 for mounting the repaired chip 31 (or wafer) and motors 33 and 34 for driving the stage (not shown, but also a motor for Z-.theta.). Drive), an objective lens 35, an illuminating device 36, an eyepiece 37, a photographing relay lens 38, a TV camera 39, an observation optical system including a monitor 40, and an image of a stripe pattern mask 41 on a chip 1.
A cylindrical lens for linearly condensing the stripe pattern image separated by the light source 42 and the prism 43 for projection on the top
44,44 'linear image sensor 45,45' and control circuit 46
, A piezoelectric element ring 51, a nozzle 52, a pipe 53, an insulating film material discharge section including a liquid reservoir 55 containing an insulating film material 54, and a control device 56 for controlling the whole. The major difference from the embodiment shown in FIG. 1 lies in that it has an automatic focusing function and that the observation position and the insulating film attachment position are the same, and the insulating film can be formed while observing.

First, the chip (or wafer) 31 having been repaired, such as cutting the wiring and forming the connection wiring, is placed on the XYZ-θ stage 32. When the surface of the chip 31 enters the field of view of the observation optical system, the stripe pattern mask 41 is illuminated by the light source 42 and the transmitted image is projected on the surface of the chip 31. This may be normal visible light or infrared light (however, the objective lens 35
With a wavelength in the range that can be imaged by
It may be within the field of view of the 37 or TV camera 39 or outside the field of view. This fringe pattern image is divided by a prism 43 (separation is possible in the case of infrared light), and the cylindrical lenses 44, 4
At 4 ', the image is converted into an image compressed in the fringe direction and input to the linear image sensors 45, 45'. The case where the contrast of the image at this time is the largest is the focal point, and the linear image sensor and the cylindrical lens may be a pair, but they are placed in a positional relationship slightly before and after the focal point position, and the contrast becomes equal. May be used as the focal point. In particular, the latter case is excellent as an automatic focusing system because it is possible to detect which one is out of focus. With this system, the observation optical system is always in focus by driving the Z stage so that the contrasts of the signals obtained by the linear image sensors 45 and 45 'are always equal, and if the chip (or wafer) is temporarily There is no problem even if it swells or inserts a foreign object underneath and tilts.

Here, two target marks (marks for positioning) in the chip 31 or specific positions whose coordinates are known (for example, a corner of a chip, a specific pad, or a wiring position) are located at the center of the monitor 40 screen (or an electronic line or the like). Then, the position coordinates are obtained by means such as a linear encoder (not shown), and the stage 32 is adjusted, particularly in the θ direction.

Thereafter, the control unit 56 aligns the cut point from the repair data or the starting point position of the repair wiring with the center (or a specific position) of the monitor 40. This position is adjusted in advance so that the droplet of the insulating film material 54 discharged from the nozzle 52 coincides with the adhesion. As the objective lens 35, a lens having a relatively long working distance is selected, and fine droplets of the insulating film material 54 are discharged obliquely from the nozzle 52. Adjusted position (monitor
40 screen center). Thereafter, in the case of the repair wiring, the stage 32 moves according to the data (coordinates of the starting point, the folding point, and the ending point) when the wiring is formed. A material droplet is discharged, and as shown in FIG. 4, the cut hole and the repair wiring can be covered with a film of an insulating film material. At this time, the operator can observe and confirm how the droplets of the insulating film material are attached by using the eyepiece 37 or the TV monitor 40. After covering all the repaired portions with the film of the insulating film material, the chip (or wafer) 31 is subjected to a heat treatment (baking). As the insulating film material, SOG (sin-on-glass), polyimide resin, or the like is selected, and each is baked at an optimum baking temperature. This allows
The repaired portion of the LSI chip is covered with a protective film (insulating film), and the reliability of the LSI is ensured.

Next, an insulating film forming apparatus according to another embodiment will be described.
Shown in the figure. This is obtained by coupling a laser optical system via a dichroic mirror 61 to the optical system of the apparatus shown in FIG. That is, the laser beam 63 oscillated from the laser oscillator 62
Is formed into a rectangle of an arbitrary size by an aperture slit 66 via mirrors 64 and 65, and is reduced and projected on the chip 1 by the objective lens 5.
The irradiation position / dimension of can be adjusted. Although the insulating film material discharge section including the nozzle 12 is the same as in FIG. 1, it is omitted here. A method for forming an insulating film using this apparatus will be described. First, the chip 1 having completed repairs such as disconnection and connection of the wiring is placed on the XYZ-θ stage 2 and XYθ is adjusted at a specific position where the target mark or coordinates are known. Thereafter, the chip 1 is moved immediately below the nozzle, and fine droplets of the insulating film material are adhered at a fixed pitch on the repaired portion, that is, the opening of the cut portion, and the repair wiring, thereby forming a film of the insulating film material. This is as described in the description of FIG. 1 to FIG.

Thereafter, the chip 1 moves again immediately below the optical system. Then, the image position of the rectangular aperture slit 66 by the reference light is aligned with the film of the insulating film material covering the repaired portion, and the laser oscillator 62
The stage is moved in accordance with the repair wiring data while irradiating the laser beam 63 from. Spin as an insulating film material
When using on-glass, a CO ₂ laser is most preferable as the laser. This is because the wavelength is 10.6 μm and is well absorbed by the insulating film material. However, if local heating can be achieved with a YAG laser (wavelength 1.06 μm), its harmonics, and an Ar laser, the purpose can be achieved. . Also, even when polyimide is used as the insulating film material,
An Ar laser, a YAG laser and its harmonics, a CO ₂ laser, and the like can be used. However, a laser having a wavelength of 350 nm or less cannot be used because polyimide is decomposed.

As described above, in both the case of spin-on glass and the case of polyimide, only the insulating film material film can be baked by laser irradiation without baking the entire chip after film formation. Same as when baking.

Although not described in detail here, the laser optical system shown in FIG. 6 can be added to the optical system of the insulating film forming apparatus shown in FIG. 5, and the same effect can be obtained. Is clear.

Next, another embodiment will be described. FIG. 7 shows that a polyimide film 72 is also formed on a substrate 71 of ceramic or the like as an interlayer insulating film by using Al, C
This figure shows a process of manufacturing an electronic circuit board on which a multilayer wiring of a metal thin film such as u or W is formed. That is, a polyimide film 72 is formed on a ceramic substrate 71, an Al thin film is formed and then patterned to form an Al wiring 73, on which a polyimide film 74 as an interlayer insulating film is formed. Usually after this,
A contact hole is formed by applying an etching technique to the polyimide film 74 and a second wiring layer is formed. However, a defect 75 may occur in the polyimide film 74 due to a foreign substance or the like. That is, the polyimide film is locally removed, and the first-layer wiring is exposed. If the subsequent process is continued as it is, a short circuit occurs in the first and second wiring layers, and this electronic circuit board becomes defective.

Therefore, the XYZ-θ stage 32 of the insulating film forming apparatus shown in FIG. 1, FIG. 5, or FIG. 6 (this case will be described using the apparatus shown in FIG. 5). After placement and XY-θ adjustment, the defect 75 position is reproduced from the inspection result by the inspection device. While observing with the eyepiece 37 or the monitor 40, fine droplets of polyimide as an insulating film material are attached from the nozzle 52 to the inside of the defect,
Fill 75. Depending on the size of the defect 75, one droplet may be enough, or several droplets while moving the stage 32.
In some cases, tens of droplets may be required. As shown in FIG. 8, a defect 75 is formed to such an extent that the wiring film will not be disconnected in a later step.
After the portion is filled with a polyimide film 76 (exactly not yet polymerized), the electronic circuit board is baked to complete the repair. Then, proceed to the next manufacturing process as needed.

Thereby, the production yield of the electronic circuit board can be improved. In the case where a partial defect or a circuit change is necessary for the completed electronic circuit board, as in the case of the semiconductor device described above, cutting of the wiring by laser processing, FIB processing or photo etching process, laser CVD, ,
FIBCVD, partial deposition by masking, plating accelerated by laser, or wiring formation by a normal photo process, and covering these repair positions with an insulating film can ensure the reliability of the electronic circuit board.

〔The invention's effect〕

According to the present invention, since the wiring is not exposed at a portion where the wiring is cut for repairing the semiconductor device, a short circuit due to moisture penetration, electromigration, or the like does not occur.
In addition, since the repair wiring is not exposed, there is no disconnection due to mechanical force at the time of assembly, heating, corrosion due to moisture penetration, or the like. That is, the reliability of the repaired semiconductor device can be ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram of an insulating film forming apparatus showing one embodiment of the present invention, FIG. 2 is a view showing a repaired semiconductor chip to which the present invention is applied, and FIGS. FIGS. 5 and 6 are diagrams showing the construction of an insulating film forming apparatus showing another embodiment of the present invention, and FIGS. 7 and 8 are each a diagram showing the present invention. FIG. 6 is a diagram for explaining a method of forming an insulating film on an electronic circuit board. 1,31 ... LSI chip, 2,32 ... XYZθ stage, 12,52 ... Nozzle, 15,54 ... Insulating film material, 21 ... Opening, 22 ... Connection wiring, 26 ...... Insulating film material film , 62: Laser oscillator, 71: Electronic circuit board, 75: Defect.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hidezo Sano 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi, Ltd. Production Engineering Laboratory (56) References JP-A 1-278044 (JP, A) JP-A-62-229956 (JP, A) JP-A-64-2345 (JP, A) JP-A-3-120819 (JP, A) JP-A-52-119191 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H01L 21/3205 H01L 21/312 H01L 21/316 H01L 21/31

Claims (6)

(57) [Claims] 1. A semiconductor device in which a wiring pattern is formed through a predetermined process and the surface is covered with a protective film, wherein a portion of the protective film covering the wiring pattern is partially removed at a plurality of locations. A conductive film connecting the wiring patterns at a plurality of locations where the protective film is partially removed is formed on the protective film, and the entire conductive film formed on the protective film is A semiconductor device, wherein an insulating film to cover is locally formed on the protective film. 2. A part of the plurality of wiring patterns from which the protective film has been partially removed, a part of a wiring pattern under the removed protective film has also been removed, and the wiring pattern has been removed. 2. The semiconductor device according to claim 1, wherein an insulating film is locally formed at the formed location. 3. A semiconductor device in which a wiring pattern is formed through a predetermined process and a surface of the semiconductor device is covered with a protective film, and a plurality of portions of the protective film covering the wiring pattern are irradiated with a first energy beam. A plurality of portions of the protective film are partially removed to expose the wiring pattern at a plurality of locations, and the first energy beam is irradiated to other locations at a portion of the protective film covering the wiring pattern. Removing the plurality of other portions of the protective film and the wiring pattern thereunder,
A second energy beam is scanned and irradiated between the exposed portions of the wiring pattern to form a conductor pattern connecting the exposed portions of the wiring pattern on the protective film. Then, a liquid insulating film material is locally supplied to the formed conductor pattern and the removed wiring pattern, and is heated and solidified to locally insulate the conductor pattern and the removed wiring pattern. A method for repairing a semiconductor device, comprising forming a film. 4. The semiconductor device according to claim 3, wherein the local supply of the liquid insulating film material to the portion of the formed conductive pattern and the removed wiring pattern is performed using a nozzle. How to fix. 5. The method according to claim 3, wherein the step of heating and solidifying the locally supplied liquid insulating film material is performed using a laser. 6. The method according to claim 3, wherein the step of using the first energy beam and the step of using the second energy beam are performed in different processing chambers.