KR20010030491A - Target for providing film on semiconductor substrate using laser emission and method of making the same - Google Patents

Abstract

PURPOSE: A target for forming a film on a semiconductor substrate by laser irradiation and a method of production are provided to form a film of metal or insulator on a semiconductor substrate using a laser. CONSTITUTION: A film for generating gas(gas generation film)(11) is formed on a quartz substrate(10) transmitting laser light by laser irradiation. A nirtocellulose film(explosives) is employed as the gas generating film(11) for example. In addition, a target film(12) of gold, aluminum, copper, silicon, silicon oxide(SiO2), or silicon nitride(Si3N4) is formed on the gas generating film(11). A semiconductor substrate is disposed oppositely to the target film(12) which is then irradiated with a laser light having a specified shape, e.g. square shape, from above the quartz substrate(10) thus transferring a target film(12) of specified shape onto the semiconductor substrate.

Description

TARGET FOR PROVIDING FILM ON SEMICONDUCTOR SUBSTRATE USING LASER EMISSION AND METHOD OF MAKING THE SAME}

The present invention relates to a target for forming a metal, an insulator or the like on a semiconductor substrate using a laser, and a method for forming a film using the target.

BACKGROUND ART Conventionally, as a means for depositing a metal film or the like on a semiconductor substrate used in a semiconductor device, a method of using a material such as a metal film as a target, evaporating the target using a laser, and depositing it on a semiconductor substrate is known.

It is sectional drawing which shows typically the vapor deposition apparatus which used the conventional laser. The conventional laser vapor deposition method shown here is a method of forming a thin film in the board | substrate 1 provided above the target by irradiating a laser beam from the diagonal direction of the target substrate 2, and peeling a target. The film formed on the substrate 1 using this method is deposited in the form of droplets, and as a result, there arises a problem of poor flatness. In addition, because the distance between the substrate and the target is long, selective deposition becomes impossible in principle, and it is difficult to form a desired pattern on the substrate. As a conventional example of the selective vapor deposition method, as shown in FIG. 19, a metal thin film 4 such as aluminum is formed on the quartz substrate 3 that easily transmits laser light. In addition, the semiconductor substrate 1 is disposed to face the metal thin film 4 of the quartz substrate 3. The laser thin film is transferred from the quartz substrate 3 side to the semiconductor substrate 1 provided in front of the metal thin film 4 as the target film.

As mentioned above, although it becomes possible to form a film selectively by using the method shown in FIG. 19, the problem is that the droplet-type extra film | membrane is formed on the semiconductor substrate 1, and flatness cannot be ensured. In addition, in this method, when a substance which hardly absorbs a laser such as SiO ₂ is used for the target thin film 4, the thin film 4 cannot be peeled off by laser irradiation, and film formation onto the substrate becomes impossible. There was a problem.

Therefore, it is an object of the present invention to provide a target for forming a film on a semiconductor substrate by laser irradiation.

Another object of the present invention is to provide a target for forming a film selected from a semiconductor material, a semiconductor material and an insulating material on a semiconductor substrate by laser irradiation.

Another object of the present invention is to provide a target for forming a thin film or a thick film on a semiconductor substrate by laser irradiation.

Another object of the present invention is to provide a method for forming a film on a semiconductor substrate by laser irradiation.

It is another object of the present invention to provide a method for forming a film on a semiconductor substrate without using lithography technology.

The present invention is characterized in that a target film having a structure including a material generating a gas by a laser and a target material is formed on a transparent substrate with respect to the irradiation laser, and the laser is irradiated from the transparent substrate side. With this structure, a thin film of metal or the like can be formed on the semiconductor substrate by laser irradiation of low energy, and a good pattern can be formed without scattering the target film. Further, when the laser is irradiated onto the transparent substrate with respect to the irradiation laser, only the target film of the irradiation portion can be selectively transferred onto the semiconductor substrate. Therefore, if a predetermined portion on the semiconductor substrate is determined in advance, the target film including the predetermined pattern can be transferred onto the semiconductor substrate without patterning by lithography.

The method of the present invention is suitable for forming electrode pads in the case of using a metal film, but wiring can be formed by connecting a target film formed by laser irradiation onto a semiconductor substrate. In addition, although the insulating film on a semiconductor substrate is formed in large area in many cases, using the method formed while connecting a target film as mentioned above, this invention can be applied to easy and wide area insulating film formation. When the laser beam diameter is increased, the target film can be enlarged, and a target film having an arbitrary shape can be obtained by interposing a mask between the semiconductor substrate and the laser.

According to an aspect of the present invention, there is provided a transparent substrate including first and second surfaces facing each other, a gas generating film provided on the first surface, and a target film provided on the gas generating film. The target which forms a film-forming film on the semiconductor substrate arrange | positioned facing the said target film by the laser irradiation from a 2nd surface is provided.

The target having a substance generating gas by laser irradiation formed on a transparent substrate with respect to the irradiated laser includes a film generating gas by laser irradiation formed on the transparent substrate, and a gas generated by the laser irradiation. And a target film formed on the film. By using the gas generating film, it is possible to form the film to be formed on a semiconductor substrate without scattering the film. The target formed on the transparent substrate with respect to the said irradiation laser is electroconductive particle, You may make it contain the substance which generate | occur | produces a gas by laser irradiation in the said electroconductive particle as a solvent.

When the film is formed by using a conductive paste having a solvent that easily generates gas by laser irradiation on the target substrate, it becomes possible to form a finer pattern as compared with the conventional printing method and also becomes a problem in the printing method. Defect generation such as this is also reduced. The target formed on the transparent substrate with respect to the said irradiation laser consists of the film | membrane which generate | occur | produces a gas by laser irradiation, and the film | membrane of electroconductive particle. With lower energy laser irradiation, it becomes possible to form a thicker conductive paste. The target formed on the transparent substrate with respect to the irradiation laser is formed on the film generating gas by the laser irradiation formed on the transparent substrate with respect to the irradiation laser, and formed on the film generating the gas, It may be made of a thick film. The metal bumps are provided on the pads at any place of the semiconductor substrate, and the connection can also be performed.

Moreover, this invention can be applied to the method of etching the thin film, such as copper foil, formed on the semiconductor substrate in the predetermined pattern using the film | membrane which generate | occur | produces a gas by the said laser irradiation. The patterned thin film is used for wiring and electrodes. Aluminum, polysilicon, etc. are used for thin film material besides copper. The etching gas may be any gas as long as the material can be etched.

According to another aspect of the present invention, there is provided a method of preparing a transparent substrate including first and second surfaces facing each other, forming a gas generating film on the first surface, and forming a target film on the gas generating film. Forming a film on a semiconductor substrate which laser-irradiates the target film from the second surface, transfers the target film to the semiconductor substrate, and forms a film. A method is provided.

1 is a cross-sectional view showing a target according to an embodiment of the present invention.

2 is a schematic cross-sectional view showing a laser irradiation apparatus used in an embodiment of the present invention.

3 is a schematic cross-sectional view showing a laser irradiation apparatus used in an embodiment of the present invention.

4A to 4C are cross-sectional views illustrating a process of forming a film on a semiconductor substrate according to an embodiment of the present invention.

Fig. 5 is a plan view showing a semiconductor substrate having pads formed by embodiments of the present invention.

6A and 6B are sectional views showing a film forming process for explaining the present invention in comparison with a conventional example.

7A and 7B are cross-sectional views showing the steps of producing a film for explaining the present invention in comparison with the conventional example.

8A and 8B are sectional views showing a film forming process for explaining the present invention in comparison with a conventional example.

9 is a cross-sectional view showing a target according to an embodiment of the present invention.

10A to 10D are sectional views showing a manufacturing process for forming a conductive film on a semiconductor substrate according to the prior art.

11 is a cross-sectional view illustrating a manufacturing step of forming a film on a semiconductor substrate according to an embodiment of the present invention.

12 is a cross-sectional view illustrating a target according to an embodiment of the present invention.

13 is a cross-sectional view showing a step of forming a film on a semiconductor substrate according to the embodiment of the present invention.

14 is a cross-sectional view illustrating a target including a metal bump according to an embodiment of the present invention.

15A and 15B are cross-sectional views illustrating a manufacturing process of forming metal bumps on a semiconductor substrate according to an embodiment of the present invention.

16A and 16B are sectional views showing a manufacturing process for forming metal bumps on a semiconductor substrate according to an embodiment of the present invention.

17 is a plan view showing a wiring layer on a semiconductor substrate formed by the embodiment of the present invention.

18 is a cross-sectional view schematically showing a vapor deposition apparatus using a conventional laser.

19A and 19B are sectional views showing a process of selectively transferring a metal thin film onto a semiconductor substrate using a conventional laser.

20 is a cross-sectional view illustrating a film formation on a substrate by a target and a semiconductor laser light according to the embodiment of the present invention.

21 is a cross-sectional view showing the formation of Cu bumps on a substrate by a target and a semiconductor laser light according to an embodiment of the present invention.

Fig. 22 is a cross-sectional view showing the state in which carbon fine particles are attached to a Cu pad formed on a substrate by a target and a semiconductor laser light according to an embodiment of the present invention.

FIG. 23 is a cross-sectional view illustrating a conductive layer formed on a substrate by a semiconductor laser beam and a target including a conductive paste embedded in a mask pattern according to an embodiment of the present invention. FIG.

It is sectional drawing which shows the manufacturing process of the target using the transparent substrate which has a recessed part by the Example of this invention.

25 is a schematic view showing a manufacturing apparatus used in the present invention.

Fig. 26 is a cross-sectional view showing a gas generator supplying device and a nozzle used in the present invention.

27A and 27B are cross-sectional views illustrating a process of selectively removing a thin film using the manufacturing apparatus of FIGS. 25 and 26.

28A and 28B are cross-sectional views illustrating a process of selectively removing a thin film using the manufacturing apparatus of FIGS. 25 and 26.

<Explanation of symbols for main parts of drawing>

1, 102, 112: semiconductor substrate

2, 13: target substrate

3, 10, 108: quartz substrate

4, 12, 17, 18, 19: Target film

11, 107: gas generating film

14, 103: stage

15: target holder

16: target substrate driving device

20: conductive paste

21: metal mask

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

According to the present invention, a film which generates gas by laser irradiation (hereinafter referred to as a gas generating film) and a film formed by forming a target formed on a transparent substrate with respect to a laser or a substance which generates gas by laser irradiation The metal bumps are bonded onto a mixture of particles to form a film or a substance generating gas, and the pattern can be formed on a semiconductor substrate without scattering the target film, particles or bumps.

First, the first embodiment will be described with reference to FIGS. 1 to 8.

1 shows a target used in this embodiment. On the synthetic quartz substrate 10 that transmits laser light, a film (gas generating film) 11 that generates gas by laser irradiation is formed. As this gas generating film 11, a nitrocellulose film (powder) is used, for example. In addition, the target film 12 is formed on the gas generating film 11. As the target film 12, gold, aluminum, copper, silicon, silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ) is used, for example. As the gas generating film, gas generating agents such as tetrazole and the like are used.

Next, the outline of the laser irradiation apparatus will be described with reference to FIGS. 2 and 3. In this embodiment, the light for observation can be incident on the semiconductor substrate 1 coaxially with the laser irradiation axis. The observation mark formed on the semiconductor substrate 1 can be observed using this observation light, and alignment of the semiconductor substrate 1 and a laser irradiation axis can be performed (FIG. 2). After the completion of the alignment, the target substrate 13 is provided on the semiconductor substrate 1 mounted on the stage 14 by using the target substrate drive device 16. As shown in FIG. 1, the target substrate 13 includes a quartz substrate 10 that transmits laser light, a gas generating film 11 and a target film 12 formed thereon, and the target substrate 13. Is provided so as to irradiate laser from the quartz substrate 10 side, and the film is formed onto the semiconductor substrate 1 provided in front of the target film 12 by laser irradiation. The observation light used here is detected by the CCD camera, and its position is corrected by the monitor. The target substrate driving device 16 includes a target holder 15 holding the target substrate 13, and the target substrate 13 may be disposed on the semiconductor substrate 1 by the movement of the target holder 15. (FIG. 3).

Next, the film formation process by laser irradiation is demonstrated with reference to FIG. 4 which is sectional drawing which expanded area A of FIG. When a laser is irradiated from the back surface of the quartz substrate 10 opposite to the semiconductor substrate 1 (FIG. 4A), a target film is selectively formed on the semiconductor substrate 1 (FIG. 4B). By repeating laser irradiation while scanning the target substrate 13 and the semiconductor substrate 1, formation of the thin film pattern on the semiconductor substrate 1 becomes possible (FIG. 4C).

5 is a plan view of the semiconductor substrate 1. A pad electrode 121 made of aluminum or the like formed by the method shown in FIG. 4 is formed on the semiconductor substrate 1 in a predetermined pattern.

It is known that the nitrocellulose used as the gas generating film in this embodiment absorbs light having a wavelength of about 300 nm or less. In this embodiment, therefore, the KrF excimer laser having a wavelength of 248 nm or the Nd: YAG fourth harmonic having a wavelength of 266 nm is used as the irradiation laser whose wavelength is about 300 nm or less.

As described above, in this embodiment, nitrocellulose was used as the gas generating film and a laser having a wavelength of 300 nm or less was used as the irradiation laser. However, any film can absorb a laser beam having the wavelength and generate gas. It goes without saying that the present invention can be applied to the back side.

In order to explain the film forming effect in this embodiment, a case where a gas generating film is used and a case where a target is directly formed on a quartz substrate without using the gas generating film are compared with reference to FIGS. 6, 7 and 8.

FIG. 6 shows the result when the target film 17 of metal or semiconductor is formed on the quartz substrate 10. Specifically, gold, aluminum, copper, or silicon was used. FIG. 6A shows a case where a gas generating film is not used as it is, and FIG. 6B shows an implementation result when the gas generating film 11 is used. As shown in Fig. 6A, when the gas generating film is not used, the target film is scattered on the semiconductor substrate 1 and becomes droplet-shaped, so that the flatness is very poor. On the other hand, as shown in Fig. 6B, in the case of using the gas generating film 11, it can be seen that no fly products are formed and the flatness is good.

FIG. 7 shows the result when a silicon oxide film (SiO ₂ film) that transmits without absorbing a laser is formed on the quartz substrate 10 as the target film 18. 7A shows the case where no gas generating film is used, and FIG. 7B shows the result when the gas generating film is used. As shown in FIG. 7A, when the gas generating film is not formed, the laser light passes through the quartz substrate 10 and the target film 18, and the laser light is directly irradiated onto the semiconductor substrate. Receive. On the other hand, when the gas generating film 11 is formed under the target film 18 made of SiO ₂ , the gas generating film 11 absorbs the laser light, so that the laser does not reach the semiconductor substrate 1. Therefore, damage to the laser irradiation to the semiconductor substrate 1 is suppressed. In addition, the target film 18 is formed on the semiconductor substrate 1 by gasifying the gas generating film 11 which absorbed laser energy.

8 shows the result when a silicon nitride film (Si ₃ N ₄ film) was formed on the quartz substrate 10 as the target film 19. 8A shows the case where no gas generating film is used, and FIG. 8B shows the result when the gas generating film is used. As shown in FIG. 8A, when the laser is irradiated to the target film 19 without using the gas generating film, it can be seen that Si ₃ N ₄ scatters in the form of particles on the semiconductor substrate 1. This scattering phenomenon is caused by the fact that the thermal diffusion length of Si ₃ N ₄ is significantly shorter than that of the metal film or the semiconductor film, regardless of whether the Si ₃ N ₄ film absorbs the laser light. As a result, it is considered that large distortion occurs inside the Si ₃ N ₄ film. On the other hand, when the gas generating film 11 is used, the target film can be formed without scattering the Si ₃ N ₄ film.

In this embodiment, the gas absorbing the laser is formed on the substrate that easily transmits the laser, and the target film is formed on the substrate, and the optical properties such as the laser transmittance and the absorption of the target film or the metal, semiconductor, insulator, etc. A good pattern can be formed on a semiconductor substrate without depending on the difference of materials.

Next, a second embodiment will be described with reference to FIGS. 9 to 13.

9 and 12 are cross-sectional views of the target substrate, FIG. 10 is a cross-sectional view illustrating a process by a conventional method, and FIGS. 11 and 13 are cross-sectional views of a process according to this embodiment. In the first embodiment, a method of forming a film for generating gas by laser irradiation on a transparent substrate with respect to the irradiation laser and forming a target film thereon has been described. In this embodiment, a method of forming a target film using a target coated with a conductive paste containing a solution gasified by laser irradiation on a transparent substrate with respect to the irradiation laser will be described.

9 is a sectional view of the target substrate 13 used in this embodiment. In other words, the target substrate 13 is composed of a synthetic quartz substrate 10 that easily transmits an irradiation laser and a conductive paste layer 20 coated on the quartz substrate 10. The conductive paste used in this example is composed of a mixture of metal fine particles such as gold, a resin such as epoxy, and a solvent such as propylene glycol monomethyl ether. Since the boiling point of this solvent is 120 degreeC, it can gasify easily by the low energy laser irradiation.

The boiling point of the solvent is 100 ° C to 200 ° C, and the present invention can be applied when a solvent which is gasified by laser irradiation of low energy is used.

The target substrate 13 shown in FIG. 9 is provided on the target holder 15 of the laser irradiation apparatus shown in FIG. 2 and FIG. 3 so that laser irradiation may be performed from the quartz substrate 10 side. As in the first embodiment, after the semiconductor substrate 1 is aligned with the laser irradiation axis, the target substrate 13 is inserted into the upper portion of the semiconductor substrate 1, and the laser is scanned while scanning the target substrate 13 and the semiconductor substrate 1. By irradiating, pattern formation of the target film obtained from the electrically conductive paste on the semiconductor substrate 1 is performed (FIG. 11).

Conventionally, the so-called printing method is used for pattern formation of an electrically conductive paste, and the film formation of this Example is compared with this conventional method below.

Fig. 10 shows the conventional printing method, respectively, and Fig. 11 shows the film formation shape in the case where the pattern of the conductive paste is formed on the semiconductor substrate by this example. In the conventional printing method, a mask 21 made of metal or the like is first provided on the semiconductor substrate 1 (Fig. 10A). Next, a pattern is formed by applying the conductive paste 20 using the skid 22 from the upper portion of the semiconductor substrate 1 on which the mask 21 is disposed (FIGS. 10B and 10C). Finally, the metal mask 21 is removed and a conductive paste pattern is formed on the semiconductor substrate 1.

However, the minimum dimension limit of the pattern formed by the printing method is only about 10 mu m, and there is a problem that voids are formed inside the conductive paste to be applied.

On the other hand, as shown in FIG. 11, the minimum dimension of the pattern formed in this Example is about 3 micrometers, and it turns out that the target film which has a finer pattern can be formed compared with the printing method. Moreover, the void formation inside the electrically conductive paste observed by the printing method can also be fully suppressed.

Next, referring to FIGS. 12 and 13, a method of forming a conductive paste of a thick film in FIG. 9 by laser irradiation of lower energy will be described. As shown in FIG. 12, the target substrate 13 which formed the film | membrane 11 which generate | occur | produces a gas by laser irradiation on the transparent substrate 10 with respect to an irradiation laser, and apply | coated the conductive paste 20 on the upper part To form.

After the semiconductor substrate 1 is aligned with the laser irradiation axis, the target substrate 13 is disposed above the semiconductor substrate 1, and the semiconductor substrate is subjected to laser irradiation while scanning the target substrate 13 and the semiconductor substrate 1. Pattern formation of the target film obtained from the electrically conductive paste on (1) is performed (FIG. 13).

When the gas generating film is used for the target substrate 13, the pattern of the conductive paste of a film thickness can be formed compared with the case where the gas generating film shown in FIG. 11 is not used. Therefore, when forming the conductive paste of a thick film, it is preferable to use the target substrate using the gas generating film shown in FIG.

Next, a third embodiment will be described with reference to FIGS. 14 to 16.

14 is a cross-sectional view of the target substrate, and FIG. 15 and FIG. 16 are process cross-sectional views of forming a bump. In this embodiment, a target substrate in which metal bumps such as solder and gold are formed on a gas generating film gasified by laser irradiation is used. The target substrate 13 is composed of a quartz substrate 10 that transmits laser light, a film 11 that generates gas by laser irradiation formed thereon, and metal bumps 30 such as solder or gold (Fig. 14). The target substrate 13 is installed on the target holder 15 of the laser irradiation apparatus shown in FIGS. 2 and 3 so that the laser irradiation can be performed from the quartz substrate 10 side, and the semiconductor substrate 1 is aligned with the laser irradiation axis. The target substrate 13 is inserted into the upper portion of the semiconductor substrate 1, and the metal bumps 30 are connected to the semiconductor substrate 1 by performing laser irradiation while scanning the target substrate 13 and the semiconductor substrate 1. Do it.

The metal bumps 30 used in this embodiment are solder bumps or gold bumps, and an aluminum (Al) pad 31 is formed on the semiconductor substrate 1. When the laser is irradiated from the upper part of the metal bump 30, the film generating gas by laser irradiation is gasified, and the metal bump 30 moves to the semiconductor substrate 1 side. When this film is gasified, a pressure of 100 atm or more is applied to the metal bumps 30. In addition, the temperature of the metal bump 30 at this time is anticipated to be several 100 degreeC under the influence of the heat by the gasification of the film | membrane which produces gas by laser irradiation. The pressure and heat as described above are provided to the metal bumps 30 so that the metal bumps 30 are connected to the aluminum pads 31 on the semiconductor substrate 1 (FIG. 15). In addition, when firm connection is required, the bonding strength can be strengthened by continuously irradiating a laser and irradiating a laser directly to the metal bumps 30 attached to the aluminum pad 31 (FIG. 16A). ). When sufficient bonding strength is obtained in the state of FIG. 15B, the step of FIG. 16A may be omitted.

By irradiating a laser while scanning a target substrate and a semiconductor substrate, it is possible to form the metal bump 30 on the aluminum pad 31 formed in arbitrary places on the semiconductor substrate 1 (FIG. 16B).

In the first embodiment, the pad electrode is electrically connected to the integrated circuit inside the semiconductor substrate by the method of the present invention. In the third embodiment, bumps are formed on the pad electrode. In addition, as shown in FIG. 17, wirings can be formed on a semiconductor substrate using the method of the present invention. By irradiating a laser multiple times while scanning a target substrate and a semiconductor substrate, the area | region 41, 42, 43 of predetermined magnitude | size is formed to join these at every predetermined position on the semiconductor substrate 1, and finally, the wiring ( 45). In addition, by appropriately changing the beam diameter during laser irradiation, it is possible to easily form regions 41, 42 and 43 of different sizes.

In addition, a fourth embodiment will be described with reference to FIGS. 20 to 24.

In this embodiment, a semiconductor laser of low cost and high reliability is used as the laser light source. The wavelength of the semiconductor laser used is 785 nm, and the average power is 3 watts. In this case, the laser beam can be pulsed at an arbitrary pulse width by turning ON / OFF the power supply connected to the semiconductor laser.

However, as described above, when nitrocellulose is used as the gas generating film, nitrocellulose does not absorb light having a wavelength of 300 nm or more. Therefore, even if the laser beam of the said semiconductor laser is irradiated to the gas generating film which used nitrocellulose, the gas generating film does not generate gas.

And nitrocellulose which added about 2 wt% of pigment | dyes which absorb infrared light from visible light in order to generate a gas by absorbing a laser beam to nitrocellulose is used as a gas generating film. When the irradiation area of the laser beam is 100 µm x 100 µm, when the 50-second laser beam is irradiated with 3 watts, the gas generating film to which the dye is added can be gasified and the target film can be transferred onto the substrate. That is, when using a laser of infrared light from visible light, it becomes possible to gasify a gas generating film by adding the heat absorber which absorbs the light of the wavelength to a gas generating film.

In the case of using DUV light such as Nd: YAG fourth harmonic or KrF excimer laser, it is necessary to use an expensive synthetic quartz substrate as a transparent substrate. However, when irradiating the laser of visible light or infrared light, an advantage also exists that an inexpensive glass substrate, a resin substrate, etc. can be used as a transparent substrate. The transparent here means that the gas generating film was gasified by the light transmitted through the transparent substrate, and that the transparent substrate was not directly damaged by the laser irradiated.

On the other hand, the pigment | dye added in the gas generating film | membrane arises a problem that it adheres as dust on a board | substrate without gasifying after laser irradiation.

20 to 23 show targets that solve the above problems. That is, as shown in FIG. 20, the gas generating film 11 is provided on the glass substrate or the resin substrate 10 that transmits the semiconductor laser light, and is formed on the gas generating film 11. The target film 12 is formed in the film. In addition, at least one of the said glass substrate 10 and the board | substrate 1 is scanned similarly to the said Example. In addition, the gas generating film 11 is composed of nitrocellulose, a heat absorber having a mesh shape such as carbon fibers and carbon mesh mixed in nitrocellulose.

When the semiconductor laser is irradiated to the glass substrate 10, the carbon fiber absorbs the laser light, and raises the temperature of the surrounding nitrocellulose film to gasify the nitrocellulose. A portion 51 of the target film 12 is transferred onto the substrate 1 disposed opposite to the target film 12 in a predetermined pattern by the force by gasification. At this time, the carbon fibers contained in the nitrocellulose remain on the glass substrate 10 because the respective fibers are entangled with each other, so that generation of unwanted dust is suppressed.

Cu (copper) is also used as a material for forming a low resistance wiring layer, pads, bumps and the like. However, when Cu heat-treats in air, it is known that oxidation advances and resistance increases significantly. That is, when using Cu, the process which prevents oxidation in a subsequent thermal process is needed, such as forming the insulating film used as a protective film around Cu.

FIG. 21 shows a target capable of suppressing oxidation of Cu while forming a Cu wiring layer. That is, the carbon fine particle 61 is added to nitrocellulose, and the gas generating film 11 is formed. As the target film 12, a Cu paste containing Cu particles is used, and a plastic substrate is used for the transparent substrate 10. In addition, a semiconductor laser having a wavelength of 785 nm is used as the irradiation laser. As shown in the drawing, when the transparent substrate 10 is irradiated with a laser beam, the carbon fine particles 61 absorb the laser beam and gaseous nitrocellulose is gasified, and the Cu paste is disposed as a Cu bump 62. Transferred onto the substrate 1. On the transferred paste Cu bumps 62, many carbon fine particles 61 mixed in the nitrocellulose adhere. Thereafter, heat treatment is performed in the air in order to cure the paste-type Cu bumps 62. In this case, since carbon adheres to the surface of the paste Cu bump 62, oxidation does not proceed even after heat treatment, and a low resistance Cu bump is obtained. This shows that the carbon adhering to the surface has an effect of suppressing oxidation of Cu.

On the other hand, when the Cu paste is transferred onto the substrate 1 using a fourth harmonic of YAG as an irradiation laser without adding carbon fine particles to nitrocellulose, the Cu paste is oxidized and the resistance is significantly increased. .

As mentioned above, by forming the heat absorber mixed in the film of the gas generating agent with the substance used as a surface additive, it becomes possible to add another substance to the surface with formation of a pattern.

In addition to the carbon fine particles, Fe fine particles and Cr fine particles can be added to the nitrocellulose to obtain a Cu oxidation inhibiting effect.

FIG. 22 shows the carbon on the Cu pad 72 formed on the transparent substrate 10 and exposed to the surface of the semiconductor chip 71 using the nitrocellulose film 11 to which the carbon fine particles 61 are added. The method of attaching the fine particles 61 is shown.

When the laser light is irradiated from the transparent substrate 10 side, nitrocellulose around the carbon fine particles 61 is gasified, and the carbon fine particles 61 are sprayed onto the Cu pad 72 as gas is generated. Carbon fine particles 61 adhere to the Cu pad 72. As described above, since the Cu pad 72 to which the carbon fine particles 61 are attached has improved oxidation resistance to heat treatment, subsequent heat treatment is possible.

At present, in order to suppress the oxidation of the Cu pad as described above, a metal thin film having high oxidation resistance such as Al is formed on the Cu pad. However, in order to form an Al thin film on a Cu pad, a lithography process is required, resulting in a problem that the number of steps increases.

However, as described above, by irradiating the nitrocellulose film containing the carbon fine particles with the laser light, the carbon fine particles can be attached to the Cu pad to improve the oxidation resistance. Therefore, oxidation of a Cu pad can be suppressed simply in one process.

23 shows a target having a thin film paste embedded in a mask pattern. That is, the gas generating film 11 is formed on the transparent substrate 10, and the mask 81 having a desired pattern is formed on the gas generating film 11. The transparent substrate 10 and the mask 81 are made of a resin substrate, and the gas generating film 11 and the mask 81 are fixed by an adhesive. The laser light source is a semiconductor laser, and nitrocellulose into which carbon particles are mixed is used as the gas generating film 11.

When the Cu paste 82 is embedded in the pattern of the mask 81 and irradiated with laser light from the transparent substrate 10 side, the Cu paste 82 embedded in the mask pattern on the opposing substrate 1 is disposed. Is transferred. The transfer using such a mask has an advantage that the transfer control can be performed with good accuracy, and the irradiation pitch can be made finer than the transfer using no mask.

24A to 24D show a step of producing a target using a transparent substrate having recesses. As shown in Fig. 24A, a transparent substrate 1 having a recess 91 is prepared. In order to facilitate the formation of the recess 91, a resin substrate is used as the transparent substrate 1.

As shown in Fig. 24B, the nitrocellulose to which the dye or the carbon particles are added is dissolved in a solvent such as acetone to prepare a gas generator 92, and the gas generator 92 is formed using, for example, skid. It apply | coats in the recessed part 91.

As shown in FIG. 24C, when the gas generator 92 coated in the recess 91 is dried, the gas generating film 93 is formed only at the bottom of each recess 91.

As shown in Fig. 24D, a metal paste 94 such as Cu paste is embedded in the recess 91 having the gas generating film 93 to form a target.

Thereafter, similarly to the above-described embodiment, the metal paste 94 embedded in the recess 91 is transferred onto the substrate arranged opposite to the laser substrate by the semiconductor laser from the transparent substrate 1 side. do.

25 is a schematic diagram of a semiconductor manufacturing apparatus used in the present invention. The semiconductor substrate 102 is provided on the stage 103, and can scan in the vacuum chamber 106. The nozzle 101 is filled with etching gas such as chlorine (Cl ₂ ), and it is possible to control the etching gas pressure in the nozzle 101 by adjusting the etching gas flow rate and the pump displacement. The gas generating agent supply apparatus 100 is provided on the nozzle 101, and it is possible to irradiate a laser to a gas generating agent (gas generating film 107 of FIG. 26) through the quartz window 105. FIG.

26 illustrates a cross-sectional structure of the gas generator supplying device 100 and the nozzle 101. The gas generator supply device 100 can move the gas generator by rotating the cylindrical winding device 109 in a shape in which a band-shaped gas generator (gas generator film) 107 is wound in a cylindrical shape at both ends.

27 and 28, an embodiment of the present invention using the semiconductor manufacturing apparatus of FIGS. 25 and 26 will be described. At this time, the etching gas is chlorine (Cl ₂ ). Moreover, the thin film 111 of copper is formed on the semiconductor substrate. The etching gas at this time is 200 ° C.

First, as shown in FIG. 27A, the laser is irradiated from the quartz substrate 108 side in a state where an etching gas such as chlorine is filled in the nozzle 110. When the laser is irradiated, the gas generating film 107 gasifies, and as shown in FIG. 28B, the gas is ejected from the nozzle 110 with force. At this time, not only the gas generated from the gas generating film 107 but also the chlorine gas charged into the nozzle 110 is ejected from the nozzle 110 toward the semiconductor substrate 112 in the same manner. By the etching gas ejected from the nozzle 110, the copper thin film 111 can be selectively etched as shown in FIG. 28B. The semiconductor thin film 111 on the semiconductor substrate 112 can be selectively etched in an arbitrary pattern by scanning the semiconductor substrate 112 while rotating the winding device 109 and irradiating a laser. The gas generating film uses the same material as in the previous embodiment.

According to the above configuration, by using a substance generating gas in the target of the film forming method using a laser, the film can be formed on the semiconductor substrate by laser irradiation of low energy, and the film can be formed without scattering the target. have. It is also possible to easily perform selective etching.

Claims (27)

A transparent substrate including first and second surfaces opposing each other, a gas generating film provided on the first surface, and a target film provided on the gas generating film, for laser irradiation from the second surface. Thereby forming a film on a semiconductor substrate opposed to the target film. The target of claim 1 wherein the transparent substrate is selected from quartz, glass and resin. The target according to claim 1, wherein the first surface of the transparent substrate includes a plurality of recesses, and the target film is provided in the recess via the gas generating film. The target according to claim 1, wherein the gas generating film is made of a gas generating agent such as nitrocellulose, tetrazole, or the like. The target of claim 1, wherein the gas generating film comprises a mesh heat absorber. The target of claim 5, wherein the mesh-shaped heat absorber is selected from carbon fiber and carbon mesh. The target according to claim 1, wherein the gas generating film contains carbon fine particles. The target of claim 1, wherein the target film is a metal made of gold, aluminum, copper, or the like. The target of claim 1, wherein the target layer is a semiconductor such as silicon. The target of claim 1, wherein the target layer is an insulator such as silicon oxide or silicon nitride. A transparent substrate comprising first and second surfaces facing each other, and a target film disposed on the first surface and made of a conductive paste, and facing the target film by laser irradiation from the second surface. A target is formed by forming a film on the disposed semiconductor substrate. 12. The target according to claim 11, wherein the conductive paste contains a solvent which gasifies by laser irradiation. A target comprising a transparent substrate including first and second surfaces facing each other, a gas generating film provided on the first surface, a mask pattern provided on the gas generating film, and a conductive paste embedded in the mask pattern. A film, wherein the film is formed on a semiconductor substrate facing the target film by laser irradiation from the second surface. The target according to claim 13, wherein the conductive paste contains carbon particles. The target according to claim 1, wherein the film formation formed on the semiconductor substrate is a thin film. The target according to claim 1, wherein the film formation formed on the semiconductor substrate is a thick film. The target according to claim 1, wherein the laser irradiation is performed by a laser device having a wavelength of 300 nm or less. The target according to claim 5, wherein the laser irradiation is performed by a semiconductor laser including a wavelength of 300 nm or more. Preparing a transparent substrate comprising first and second surfaces facing each other, Forming a gas generating film on the first surface; Forming a target film on the gas generating film; Arranging a semiconductor substrate opposite the target film; Laser irradiating the target film and transferring the target film to the semiconductor substrate to form a film A method for forming a film on a semiconductor substrate comprising a. The method for forming a film on a semiconductor substrate according to claim 19, wherein the gas generating film is gasified by the laser irradiation. 20. The method of claim 19, wherein the gas generating film is formed of a gas generating agent such as nitrocellulose, tetrazole, or the like. 20. The method of claim 19, wherein the target film is made of a metal, a semiconductor, and an insulator. Preparing a transparent substrate comprising first and second surfaces facing each other, Forming a target film made of a conductive paste containing a solvent gasified by laser irradiation on the first surface; Arranging a semiconductor substrate opposite the target film; Laser irradiating the target film and transferring the target film to the semiconductor substrate to form a film A method for forming a film on a semiconductor substrate comprising a. 24. The method of claim 23, wherein the film formation formed on the semiconductor substrate is a conductive thin film. The method for forming a film on a semiconductor substrate according to claim 23, wherein the film formation formed on the semiconductor substrate is a conductive thick film. Forming a film of a substance generating gas by laser irradiation on a transparent substrate with respect to the irradiated laser light, Irradiating a laser to the film of a substance generating gas by the laser irradiation selectively from the transparent substrate side, and gasifying a substance generating the gas of the irradiated portion; By gasification, the etching gas filled around the gas generating material is driven, and the etching gas is sprayed onto the semiconductor substrate provided in front of the film generating gas to selectively etch the film formation on the semiconductor substrate. Method for manufacturing a semiconductor device comprising a. 27. The method of claim 26, wherein the etching gas filled around the gas-generating material is chlorine gas and selectively etches the metal thin film formed on the semiconductor substrate by irradiating a laser.