JPH03215941A - Semiconductor device, insulating film forming method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method and apparatus for forming an insulating film on the surface of a semiconductor device, and a semiconductor device in which an insulating film is formed by the t-1+ film forming method and apparatus. In particular, the present invention relates to an insulating film forming method and apparatus suitable for identifying the location and cause of a defect partially existing in a prototype semiconductor device, or repairing the defect, and a semiconductor device.

[Conventional technology]

2. Description of the Related Art In order to improve the performance and speed of semiconductor devices, semiconductor devices are becoming smaller and more highly integrated. Along with this,
Developing semiconductor devices is becoming more difficult, leading to longer development periods. This situation indicates that the cut-and-try circuit fabrication technique is also necessary for LSI design. In other words, you can identify a defective part on a chip that does not work satisfactorily with the conventional design, cut the wiring existing in that part, route the wiring to an arbitrary location, repair the defective wiring, and temporarily fix the defective part. Once a semiconductor device is manufactured that can operate perfectly, subsequent characteristic evaluations and design changes can be made quickly, and it can also be shipped directly to users as technical samples.

On the other hand, as a conventional technology, for example, Semiconductor World
As described in pages 27 to 32 of the September 1987 issue, after passivating the surface of the LSI chip with FIB (focused ion beam) and drilling holes in the glabellar insulating film to expose the wiring, CVD A method is introduced in which metal wiring is formed using the same <FIB method by introducing gas.

Also, the Extended Abstracts of the Seventeenth Conference on Solid State Devices and Materials Tokyo (
1985) pp. 193-196 (Extend
ed Abstracts of the 17thC
onference on solid S
tate D evicesand Materi
als, Tokyo, 1985 pp] 93-19
6), a method has been introduced in which Mo wiring is formed on a Si substrate coated with Si○2 using laser CVD technology.

In addition, as prior art, Japanese Patent Application Laid-open No. 62-229956, Japanese Patent Application Laid-open No. 62-229957, 1988 Autumn Proceedings of the Japanese Society of Applied Physics 1988.10. p534 is known.

[Problem to be solved by the invention]

By using the first conventional technique or a combination of the first conventional technique and the second conventional technique, it is possible to cut unnecessary wiring and form additional wiring, thereby eliminating LSI chips that do not function due to design or process defects. Repairs can be made to obtain a fully operational L'S I. However, the LSI chip obtained in this manner has a problem in that sufficient reliability cannot be obtained.

Furthermore, although the third to fifth conventional techniques disclose a method of forming an insulating film by laser CVD, there are problems such as a slow 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 provide a highly reliable insulating film forming method that enables repaired semiconductor devices by cutting and connecting any wiring on a semiconductor device and shipping the semiconductor device so that it is fully operational. An object of the present invention is to provide a device thereof, and a semiconductor device.

[Means to solve the problem]

The above purpose is to apply insulating film material to an area including at least the cut points and the repair wiring, but excluding the connection electrodes (pads or bumps), on the chip where the cut points and wiring for repair have been formed. This is achieved by depositing the oxide and forming an insulating film.

In other words, the above purpose is to cover the repaired area with a protective film,
The aim is to obtain reliability of repair chips.

[Effect]

The LSI that has been repaired by cutting or forming wiring is faced to the tip of a nozzle, and fine droplets of a material for forming an insulating film are discharged from the nozzle to form a film of the material on the surface including the repaired portion. do.

Here, Spi-6 is used as a material for forming the insulating film. Selected materials include glass-on-glass and polyimide.

After forming the above material film, the chip is baked to remove the solvent in the case of spin-on glass.
Sio. 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 an insulating film (protective film), and the reliability of the repaired LSI can be ensured.

That is, according to the present invention, since At at the cut portion is not exposed, there is no risk of short circuiting due to electromigration of Al or the like. Also FI B (Focused I
(on Beam) Since the wiring formed by CVD or laser CVD is not exposed, there is no need for mechanical force, heating, or
The wire will not break due to corrosion due to moisture penetration.

〔Example〕

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

FIG. 1 shows the overall configuration of an insulating film forming apparatus which is an embodiment of the present invention. F I B (Focused I
LSI chips that have undergone wiring cutting, connection hole formation, and wiring connection using laser CVD or FIT3CVD processing (on beam) processing, in other words, LSI chips that have been repaired.
chip]- is placed on the xyz-0 stage 2. For example, the stage 2 has a motor 3 in the X-Y direction.
4.

(Z and θ are also rotated by a motor, although they are not particularly shown.) The positioning/observation optical system is the objective lens 5.
, an illumination light source 6, an eyepiece 7, an imaging lens (relay lens) 8, and a TV camera 9. The chip 1 can be positioned and observed using the eyepiece 7 or a monitor 10. The insulating film material discharging section includes a nozzle 12 equipped with a ring 11 formed of a piezoelectric element, and a liquid reservoir 14 connected by a pipe 13.
is stored. Further, a protection plate 17 that can be opened and closed by a drive mechanism 16 is installed directly below the nozzle. Furthermore, the control of the x-y-z-e stage 2, the piezoelectric element ring 1
1 and a control device 18 that controls the protection plate 17.

) A method for forming an insulating film using the insulating film forming apparatus shown in FIG. 1 will be described. First, a repaired LSI chip 1 (or a wafer may be used) as shown in FIG. 2 is placed on the X-Y-Z stage 2 shown in FIG. This LSI
On the surface of the chip 1, hole openings 21 are formed by focused ion beam (FIB) processing to penetrate the protective film or, if necessary, the interlayer insulating film to cut the wiring.
21' and a connecting wire 22 formed by laser CVD or FIBCVD to connect the connecting wires 22. 22' is exposed. Normally, the surface of the LSI chip is covered with a final passivation film (protective film) 24 except for pads 23 which are input/output terminals.

After placing the chip 1 on the stage 2, the chip 1 is moved under the optical system, and two target marks (positioning marks) within the chip 1 or a specific position with known coordinates (for example, a corner of the chip) are placed on the chip 1. , specific pad or wiring position) with the center of the monitor screen, and then
(not shown), but it can be determined by means such as a linear encoder attached to the stage 2, a rotary encoder attached to the motors 3 and 4, or a laser interferometer. from coordinates
-Y-θ adjustment. Regarding Z, by using a high-magnification lens as the objective lens 5, it is possible to adjust it to about ±0.5 μm in the case of a 100x objective lens.

After this, the chip 1 moves directly below the nozzle 12.

This nozzle 12 has the function of a so-called inkjet 1 nozzle, and instead of ink, the insulating film material 1
5 is discharged. The relationship between the center on the TV monitor 10 and the position discharged from the nozzle 12 and deposited is known, and it is easy to deposit the insulating film material at an arbitrary position according to the relative coordinates on the chip 1. Note that this inkjet is a technology similar to that shown in, for example, Japanese Patent Publication No. 47-7847, but here, instead of deflecting ink using a signal from another source to form a specific print, The fine particles of the insulating film material 15 are transported to a predetermined position and attached thereto by a signal from the insulating film material 15. Here, the adhesion position is adjusted by
Although shown as an example performed only by Z10 Stage 2,
Similar results can be obtained by relatively moving the nozzle 12 position.

Here, a ring 11 formed of a piezoelectric element is installed in the glass tube forming the nozzle 12 so that the inner surface of the ring is in contact with the glass tube, and when a DC voltage pulse is applied to this ring 11, the adjacent When the glass tube is subjected to a contraction force, a part of the insulating film material 15 inside it becomes a fine droplet and collapses on the chip 5, causing the insulating film material 15 to cover a nearly circular area.
cover with Piezoelectric elements do not necessarily have to be rings;
Any structure that can compress the glass tube by piezoelectric effect may be used. When the inner diameter of the tip of the nozzle 12 is about 50 μm, when a pulse of 70 V and 20 to 40 msec is applied to the piezoelectric element, droplets with a diameter of about 100 μm are ejected. The size of the ejected droplet can be controlled by the viscosity of the liquid, the nozzle diameter, and the voltage applied to the piezoelectric element, and the size of the droplet when deposited on the chip can be 50 μm to 200 μm. That is, at a constant pitch while moving the stage 2 according to the coordinates of the six inlets 21 formed by FIB processing or the formation data of the repair wiring 22 formed by laser CVD etc. (in the case of only holes, only the coordinates of the holes) -q) Droplets of insulating film material are deposited.

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

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

Here, a case will be described in which spin-on glass is used as the insulating film material.

Spin-on glass is RnSi(○H). −．
．． A silicon compound and additives shown by are dissolved in an organic solvent such as ethanol, and by baking at a temperature of 200°C or higher, the organic solvent is removed and the silicon is dissolved.
n. A film with properties similar to those of the above can be obtained. In particular, when baking at a temperature of 600° C. or higher, the ◯H component disappears and a Si◯2 film is obtained, but the baking temperature is selected to be a temperature that is permissible for the LSI chip. Normally, the temperature is preferably 400° C. or lower in order to minimize damage to the AQ wiring.

As a result of the above, the repaired portion is covered with a protective film having properties similar to Si○2 or Sin2, thereby ensuring reliability as an LSI.

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

Here, repair methods, ie, methods of cutting unnecessary wiring, forming connection holes, and forming connection wiring, will not be particularly mentioned; ．． ′\, the method described can be adopted.

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

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

An X-Y-Z one-theta stage 32 on which a repaired chip 31 (or wafer) is placed, and motors 33 and 34 to drive it (Although not shown, the motor also drives the Z-theta stage. ), objective lens 35, illumination device 36, eyepiece lens 37, photographing relay lens 38, TV
An observation optical system consisting of a camera 39 and a monitor 40, a light source 42 for projecting the image of the striped pattern mask 41 onto the chip 1, and a cylindrical power lens for linearly focusing the striped pattern image separated by a prism 43. 44. 44' Linear image sensor 45, 45' and control circuit 46
an automatic focusing system consisting of a piezoelectric element ring 51, and a nozzle 52;
, a pipe 53, an insulating film material discharge section consisting of a liquid reservoir 55 containing an absolute film material 54, and a control device 56 for controlling the entire system. 1st
The major difference from the embodiment shown in the figure is that it has an automatic focus function, and that the observation position and the insulating film deposition position are the same.
The advantage is that the insulating film can be formed while observing the process.

First, the chip (or wafer) 31 that has been repaired by cutting wiring and forming connection wiring is placed on the Xyzo stage 32 . When the surface of the chip 31 enters the field of view of the observation optical system, the light source 42 illuminates the striped pattern mask 4.
1 is illuminated and its transmitted image is projected onto the surface of the chip 31. This may be normal visible light or infrared light (with a wavelength within the range that can be imaged by the objective lens 35),
It may be within the field of view of the eyepiece lens 37 or the TV camera 39, or it may be outside the field of view. This striped pattern image is divided by a prism 43 (separation is also possible in the case of infrared light) and then divided by a cylindrical lens 44. At 44', the image is converted into a compressed image in the stripe direction and input to linear image sensors 45, 45'. The focal point is when the contrast of the image is greatest at this time.Although a pair of linear image sensor and cylindrical lens may be used, each is placed in a position slightly before and after the focal point position, and the focus point is the one where the image contrast is greatest. The point where they are equal may be set as the focal point. Particularly in the latter case, it is excellent as an automatic focusing system because it can detect in which direction the focus has shifted. With this system, the observation optical system is always in focus by moving the Z stage so that the signals obtained by the linear image sensors 45 and 45' are always equal. There is no problem even if the wafer (or wafer) is undulating or tilted due to foreign objects stuck underneath.

Here, two target marks (positioning marks) within the chip 31 or a specific position with known coordinates (for example, a corner of the chip, a specific pad, or the position of a wiring) are monitored at the center of the screen of the monitor 40 (or an electronic line, etc.). The position coordinates are obtained by means such as a linear encoder (not shown), and the stage
Adjust especially in the O direction.

Thereafter, the control device 56 aligns the cut point or the starting point position of the repair wiring with the center of the monitor 40 (or a specific position) based on the repair data.

This position is adjusted in advance so that the droplet of the insulating film material 54 discharged from the nozzle 52 coincides with the deposition position.

As the objective lens 35, one with a relatively long working distance is selected, and fine droplets of the insulating film material 54 are ejected from the nozzle 52 obliquely, but automatic focusing always operates and the adhesion position of the droplets is determined in advance. This corresponds to the adjusted position (the center of the screen of the monitor 40). After that, in the case of repair wiring, the stage 32 moves according to the data (coordinates of the starting point, corner point, and end point) when the wiring was formed, and the insulating film is The material droplet is ejected and the fourth
As shown in the figure, 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 the adhesion of the droplets of the insulating film material using the eyepiece 37 or the TV monitor 40. After covering all repair points with a film of insulating film material, the chip (or wafer) 31 is subjected to heat treatment 17 (bake). S○G (spin-on glass), polyimide resin, etc. are selected as the insulating film material.
Baking is performed at the optimal baking temperature for each. As a result, the repaired portion of the LSI chip is covered with a protective film (insulating film), ensuring reliability as an LSI.

Next, an insulating film forming apparatus according to another embodiment is shown in FIG. This is a device in which a laser optical system is coupled to the optical system of the apparatus shown in FIG. 1 via a dichroic mirror 61. That is, a laser beam 63 oscillated from a laser oscillator 62 is shaped into a rectangle of arbitrary size by an open loss slit 66 via mirrors 64 and 65, and is reduced and projected onto the chip 1 by an objective lens 5. The configuration is such that the irradiation position and dimensions of the laser beam 63 can be adjusted depending on the reference destination. Note that the insulating film material discharge section including the nozzle 12 is also the same as that in FIG. 1, but is omitted here. A method for forming an Il4Am film using this apparatus will be described. First, chip 1, which has undergone repairs such as cutting and connecting the wiring, is
It is placed on the Z10 stage 2, and XYθ adjustments are made at the target 1/18 mark or at a specific position whose coordinates are known. Thereafter, the chip 1 is moved directly below the nozzle, and fine droplets of the insulating film material are deposited at a constant pitch on the repaired part, that is, the opening of the cut part and the repaired wiring, to form a film of the insulating film material. This is as described in the explanation of FIGS. 1 to 4.

After this, the chip 1 moves directly below the optical system again.

Then, the image of the rectangular open loss slit 66 by the reference target is aligned with the film of the insulating film material covering the repaired part, and the stage is moved according to the repair wiring data while irradiating the laser beam 63 from the laser oscillator 62.

When spin-on glass is used as the insulating film material, the most desirable laser is a C2 laser. This is because the wavelength is 10.6 μm and is well absorbed by the insulating film material, but YAG laser (wavelength 1.06 μm
), its harmonics, Ar laser, etc., can achieve the purpose if local heating can be performed. Further, even when polyimide is used as the insulating film material, an Ar laser, a YAG laser and its harmonics, a CO2 laser, etc. can be used. However, a laser with a wavelength of 350 nm or less cannot be used because it decomposes polyimide.

As mentioned above, in both cases of spin-on glass and polyimide, it is possible to bake only the insulating material film by laser irradiation without beta testing the entire chip after film formation, and the effect is It is the same as if you baked the whole thing.

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

Next, another embodiment will be described. In FIG. 7, a polyimide film 72 is also used as an interlayer insulating film on a substrate 71 made of ceramic or the like.
This figure shows the process of manufacturing an electronic circuit board on which multilayer wiring made of metal thin films such as 0, Cu, and W is formed. That is, a polyimide film 72 is formed on a ceramic substrate 7, an AI thin film is formed and then patterned to form an AQ wiring 73, and a polyimide film 74 as a glabella insulating film is formed thereon. Usually, after this, an etching technique is applied to the polyimide film 74 to form a contact 1 hole and a 2Mth wiring layer is formed, but defects 75 may occur in the polyimide film 74 due to foreign matter or the like. That is, the polyimide film is partially removed and the first layer wiring is exposed. If the subsequent processes are continued in this state, a short circuit will occur between the first and second layer wiring, and this electronic circuit board will become defective.

Therefore, it is placed on the x-y-zθ stage 32 of the insulating film forming apparatus shown in FIG. 1, FIG. 5, or FIG. After adjusting x-y-o, the position of the defect 75 is reproduced from the inspection results by the inspection device. While observing through the eyepiece 37 or the monitor 40, fine droplets of polyimide as an insulating film material are deposited inside the defect from the nozzle 52 to fill the defect 75. Depending on the size of the defect 75, one droplet may be sufficient, or several to several dozen droplets may be required while moving the stage 32.

After filling 75 defective parts with polyimide film 7G (to be precise, it has not been made into a volumizer yet) as shown in Figure 8, to the extent that the wiring film does not break in the wiring film in the later process, the electronic circuit board is baked. to complete the modification. After that, proceed to the next manufacturing process as necessary.

Thereby, the manufacturing yield of electronic circuit boards can be improved. In addition, if there is a partial defect or the need to change the circuit on the completed electronic circuit board as in the case of the semiconductor device described above, we can cut the wiring using laser processing, FIB processing, or photo-etching process. Laser C
The reliability of the electronic circuit board can be ensured by forming wiring by VD, FIBCVD, partial vapor deposition using masking, plating accelerated by a laser, or a normal photo process, and covering these repair positions with an insulating film.

〔Effect of the invention〕

According to the present invention, since the wiring is not exposed at the portion where the wiring is cut for repairing the semiconductor device, short circuits due to moisture penetration, electromigration, etc. do not occur. In addition, since the repair wiring is not exposed at 22°, it will not break due to mechanical force during assembly, heat, corrosion due to moisture penetration, etc. That is, the reliability of the repaired semiconductor device 1vC can be ensured.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an insulating film forming apparatus showing an embodiment of the present invention, FIG. 2 is a diagram showing a repaired semiconductor chip which is the subject of the present invention, and FIGS. 3 and 4 are each a diagram showing the present invention. FIG. 5 and FIG. 6 are diagrams for explaining the insulating film forming method of the present invention, respectively, and FIGS. 5 and 6 are block diagrams of an insulating film forming apparatus showing another embodiment of the present invention, and FIGS. FIG. 2 is a diagram for explaining a method of applying an insulating film to an electronic circuit board. 1,3]...LSI chip, 2,32...XYZO stage, 1.2.52...nozzle, 15. 54...I
IA membrane material, 21 opening, 22...
Connection wiring, 2G...Insulating film material film, 62 Laser oscillator, 23

Claims (1)

[Scope of Claims] 1. A semiconductor device that has been repaired by cutting unnecessary wiring and forming additional connection wiring, in which a liquid insulating film material is attached to at least the surface including the repaired portion and the solvent is removed. A semiconductor device characterized in that an insulating film is formed by solidifying the insulating film. 2. For a semiconductor device that has been repaired by cutting unnecessary wiring and forming additional connection wiring, apply a liquid insulating film material to at least the surface including the repaired portion, remove the solvent, and solidify it. Characteristic insulating film formation method. 3. The method of forming an insulating film according to claim 2, wherein the liquid insulating film material is deposited by ejecting it from an inkjet nozzle. 4. The method of forming an insulating film according to claim 2, wherein the liquid insulating film material contains spin-on glass as a main component. 5. The insulating film forming method according to claim 2, wherein the liquid insulating film material contains polyimide as a main component. 6. The method of forming an insulating film according to claim 2, wherein the solvent is removed and solidified by laser irradiation. 7. For defects where part of the insulating layer of an electronic circuit board that has multiple insulating layers and multiple wiring layers is missing, a liquid insulating film material is applied only to the defective part, and the solvent is removed and solidified. An insulating film forming method characterized by: 8. A stage on which the target substrate is placed, an observation optical system for observing the substrate surface, a means for discharging the liquid insulating film material, and a control device for controlling the drive of the stage and the discharging of the insulating film material. An insulating film forming apparatus comprising: 9. Claim 8, wherein the control device is configured to control the discharge of the insulating film material within the field of view observed by the observation optical system, so that the adhesion of the insulating film material and the observation of the surface can be performed simultaneously. The insulating film forming apparatus described above.