JP5268944B2 - Apparatus and method for forming metal thin film using laser - Google Patents

Description

  The present invention relates to an apparatus and method for forming a metal thin film, and in particular, when a metal pattern of a liquid crystal display device is cut, a hole is formed in an upper insulating film using a laser, and the metal thin film is interposed between these holes. The present invention relates to an apparatus for forming a metal thin film and a method thereof for connecting cutting sites to each other by forming.

  Recently, with the rapid development of technology in the semiconductor industry, liquid crystal display devices are becoming smaller, lighter and more powerful.

  A liquid crystal display (LCD) has advantages such as downsizing, weight reduction, and low power consumption, and is currently attached to many information processing devices.

  In general, this type of liquid crystal display device applies a voltage to a specific molecular arrangement of liquid crystal to convert other molecular arrangement, and the birefringence, optical rotation, and two colors of a liquid crystal cell that emits light by such molecular arrangement. It is a display device that converts changes in optical properties such as light and light scattering properties into visual changes, and uses light modulation by a liquid crystal cell.

  The liquid crystal display device includes a panel upper plate and lower plate manufacturing process, which includes a process for generating a liquid crystal cell constituting a pixel unit, an alignment film forming and rubbing process for liquid crystal alignment, and an upper plate and lower plate laminating process. Then, it is completed through a process of injecting liquid crystal between the laminated upper and lower plates.

  The liquid crystal display device completed by the above-described process has a metal pattern (for example, a data line or a common electrode line) and is electrically conductive. However, line defects such as disconnection or short circuit of such a metal pattern may occur.

  Generally, in the case of a defect due to the loss of a pattern and a point defect due to a short circuit between patterns, there are levels allowed depending on the distribution, number and type of the defect, but in the case of the line defect, even one occurs. Then, since there is no value as a product, the correction process with respect to this is very important.

  At this time, as one of the correction methods, laser CVD (Chemical Vapor Deposition) which corrects the defective part by injecting a metal gas into the local part where the defect of the glass substrate of the liquid crystal display panel has occurred and irradiating the laser there. There is a correction method used.

  FIG. 1 is a schematic diagram showing a conventional thin film forming apparatus. The thin film forming apparatus includes a gas supply unit 1 that supplies a metal material for correction as a gas, a laser 5 that is irradiated to photolyze the gas injected from the gas supply unit, and a laser that is generated from the laser. An optical unit 4 that adjusts a traveling path and a focal point of light, a chamber 7 that performs a photolytic action of a laser beam from the optical unit 4 and a gas from the gas supply unit 1, a gas supply unit 1, an optical unit 4, And a control unit 6 for controlling the laser 5 and the like.

  The thin film forming apparatus having the above-described structure corrects the line open according to the following principle.

  When the array process in the liquid crystal display device manufacturing process is completed, an array test process is performed. When an open defect of the data line is detected during the array test process, a thin film forming apparatus is used to correct this.

  First, when the substrate 8 is loaded into the equipment, the optical unit 4 moves to the defect occurrence coordinates and irradiates the laser 5. After irradiating a pulsed laser to form a contact hole exposing a predetermined surface of the metal line, a continuous wave laser is irradiated. At this time, the metal source is vapor-deposited in the disconnected data line region while supplying the source gas in which the metal gas stored in the gas supply unit 1 and the inert gas are mixed to perform optical decomposition, and the disconnected portion Are electrically connected.

  However, the conventional techniques as described above have the following problems.

  When irradiating a laser, the scanning method (method of irradiating while moving the laser) is used, so it takes a lot of time for the work process, and it is difficult to deposit a thin film if there is a foreign object between the defect occurrence areas There is a problem.

  In addition, there is a problem in that the step coverage is poor due to a thickness difference in the process of forming a thin film on an existing thin film, or a water penetration phenomenon occurs during cleaning due to a via hole.

  Further, when the thickness in the overlapping region is too thick, there is a problem that a thin film peeling phenomenon occurs due to the cohesive force of the thin film.

  In addition, there is a problem that the bonding force of the thin film is weak and the resistance is high, or the thin film is peeled off in the subsequent cleaning process.

  The present invention is intended to solve such problems, and its purpose is to process the shape of a laser beam according to the shape and size of the object to be processed and form a metal thin film in a desired path. An object of the present invention is to provide a metal thin film forming apparatus and a method of forming a metal thin film using the apparatus.

  Another object of the present invention is to provide a method of connecting a broken portion by forming a metal thin film by detouring when a foreign substance is present between defect occurrence regions.

  Another object of the present invention is to provide a metal thin film forming apparatus capable of monitoring the thin film forming process in real time.

  Another object of the present invention is to provide an apparatus and method for shortening the time required for a work process by irradiating a laser beam in a desired pattern all at once when forming a thin film.

  Another object of the present invention is to provide a device that irradiates a laser beam with uniform intensity, prevents step coverage due to a step, and forms a thin film having a constant thickness. It is to provide a method.

  Another object of the present invention is to provide an apparatus and method for preventing a via hole due to a step.

  Another object of the present invention is to increase the size of a laser beam when forming a thin film, and irradiate the beam with a uniform intensity within the region, so that the formed thin film has a uniform thickness. It is an object of the present invention to provide an apparatus and method.

  Another object of the present invention is to provide an apparatus and method for controlling the strength and time of a laser beam during thin film formation so as to prevent the thin film from peeling by adjusting the strength of the adhesive force. There is.

  To achieve the above object, the present invention provides a laser oscillator and a beam forming means for flattening a laser beam emitted from the laser oscillator and adjusting the shape and size of the irradiated beam according to the object to be processed. A chamber for forming a metal thin film on the object to be processed using a metal source gas at a predetermined interval from the object to be processed, a gas supply unit for supplying the metal source gas, and a residual gas after forming the thin film There is provided a metal thin film forming apparatus including an exhaust section for exhausting air.

  The present invention also provides a method for forming a metal thin film in which a metal pattern deposited on a substrate is cut and the first laser is irradiated to remove an insulating film on the metal pattern. Forming a first contact hole and a second contact hole where a thin film can be deposited on the metal pattern; irradiating a second laser to fill the contact hole with the metal thin film; and irradiating the second laser. And forming a metal thin film between the contact holes, thereby connecting the contact holes to each other.

It is a block diagram of the metal thin film forming apparatus which concerns on a prior art. It is a block diagram of the metal thin film forming apparatus which concerns on this invention. It is a pattern comparison diagram of the beam before and after passing through the beam forming means according to the present invention. 3 is a flowchart illustrating a step of forming a metal thin film according to the present invention. FIG. 5 is a detailed view illustrating forming a contact hole according to the present invention. FIG. 4 is a detailed view illustrating filling a contact hole with a metal thin film according to the present invention. FIG. 4 is a detailed view showing that a metal thin film is formed and connected between contact holes according to the present invention. FIG. 4 is a detailed view showing that a metal thin film formed according to the present invention is separated from surrounding conductive materials. FIG. 5 is a detailed view showing that a contact hole is formed when there is no insulating film on a metal pattern according to the present invention. FIG. 4 is a detailed view illustrating forming a metal thin film between contact holes according to the present invention. It is a figure which shows the various Example of the mask based on this invention.

  Hereinafter, embodiments and configurations of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 2 is a schematic view showing a metal thin film forming apparatus according to the present invention. As shown in the figure, a metal thin film forming apparatus according to the present invention includes laser oscillators 10a and 10b that emit laser beams, beam forming means 20 that expands and adjusts the laser beams according to the size of a defective portion, and the beam. A chamber 30 that can contain a substance capable of forming a thin film in a defective removal portion, and can adjust the path of the beam to irradiate the substrate. Optical means 12, 13, 14 and 15 for monitoring, and monitoring means 50 for monitoring in real time whether the thin film is accurately deposited at a desired site.

  The laser oscillator includes a first laser oscillator 10a and a second laser oscillator 10b. The first laser oscillator 10a generates an infrared laser, a visible light laser, or an ultraviolet laser, and the second laser oscillator 10b generates a laser or an ultraviolet laser having a shorter wavelength than the blue ultraviolet laser.

  The beam forming means 20 includes beam shapers 21 a and 21 b and a beam slit 22. The beam slit 22 adjusts the size and shape of the beam, and can be adjusted to various sizes and shapes according to the process. When adjusting the beam size, use the X and Y axis motors to adjust the beam size by adjusting a total of four blades, two for each axis, and when adjusting the beam shape. A necessary mask pattern can be selected according to the process procedure and adjusted to a desired shape.

  The beam shapers 21a and 21b include a beam expander that expands the size of the laser beam emitted from the laser oscillator 10 and a homogenizer that makes the energy distribution of the laser uniform. The initial beam oscillated from the laser oscillator has a small Gaussian shape and the energy is concentrated in the center, but such a beam is unsuitable for irradiating a wide area all at once. Therefore, after expanding the beam using the beam forming means 20, it is flattened and expanded to such a size that the processed portion can be irradiated all at once.

  The beam slit 22 functions to divide the beam expanded and flattened by the beam shaper 21 in accordance with the size of the defective portion.

  FIG. 3 is a diagram showing the shape of the beam that has passed through the beam forming means. FIG. 3A is a diagram comparing the beam before and after passing through the beam shapers 21a and 21b. The right graph in FIG. 3A is a graph before passing and has a Gaussian distribution. The left graph in FIG. 3A is a graph showing the energy distribution of the beam after passing through the beam shapers 21a and 21b, and it can be confirmed that the energy distribution has a uniform flat shape. FIG. 3B shows a usage example of the beam slit 22. The size of the slit can be adjusted according to the part to be irradiated, that is, the size of the object to be processed. The size can be adjusted by moving the blade 31 up, down, left and right.

  A mask is selected according to a process procedure, and the mask can form various patterns according to a pattern to be processed. FIG. 11 shows various embodiments of the mask. Detailed description thereof will be described later.

  The monitoring unit 50 includes a CCD camera 51 that displays a process process, and a focus adjustment unit 52 that automatically adjusts the focus of the laser irradiated on the substrate 40.

  Next, a process of forming a metal thin film with the above-described configuration will be briefly described.

The laser beam oscillated from the first laser oscillator 10a perforates the insulating film on the metal pattern. The insulating film can be an insulating film such as SiNx or SiO ₂ . The same applies when an organic film, a metal film, a residual layer (hereinafter referred to as “insulating film”), or the like is used instead of the insulating film. Only when such an insulating film or the like is present, the insulating film or the like may be removed. When there is no insulating film or the like, such a process can be omitted. However, even if the metal pattern insulating film is not deposited, the metal thin film may not be formed due to metal oxidation or the like. Therefore, it is preferable to irradiate the metal pattern with the laser to remove the oxide film.

  After forming a contact hole and injecting a mixed gas of a metal gas and an inert gas into the chamber, the contact hole is filled with a metal thin film by irradiating a second laser. After filling the contact holes, a thin metal film is deposited between the contact holes to connect the disconnected metal patterns.

  FIG. 4 is a flowchart illustrating a method of connecting the disconnected metal patterns using the above-described apparatus.

  First, in order to form a thin film, two contact holes are formed on the disconnected metal pattern (S40), metal gas is injected into the contact holes to completely fill the contact holes (S41), and the two contacts A metal thin film is formed between the holes, and these contact holes are connected to each other (S42). By such a procedure, the metal thin film is formed, and the disconnected portions can be connected. When the conductive material (ITO / IZO) film is present around the thin film region after the thin film is formed, the thin film is separated from the peripheral conductive material by irradiating with a laser for the purpose of insulation (S43).

  Next, the procedure of FIG. 4 will be described in detail with reference to FIGS. FIG. 5 shows a process of forming the contact hole 44 using the infrared, visible light, or ultraviolet laser 10 irradiated from the first laser oscillator.

  As shown in the drawing, a metal pattern 41 is vapor-deposited on a glass substrate 40, and an insulating film 42 and the like are vapor-deposited thereon.

  The metal patterns 41 are preferably connected, but if they are disconnected, they must be connected. Since the insulating film 42 or the like is deposited on the metal pattern 41, it cannot be immediately connected, and the insulating film 42 or the like must be perforated.

  Two holes 44 must be formed for connection, but the first hole may be formed by irradiating the laser 10 while moving, and then the second hole may be formed. Alternatively, two holes may be formed simultaneously by maintaining the intensity of the laser beam uniform, increasing the beam size, and irradiating the beam through a mask. Such a scheme is possible because the beam size can be increased by the beam forming means discussed from FIG.

  At this time, the output of the laser is adjusted so that the metal pattern 41 is adhered to the wall of the hole while melting during the hole formation. That is, instead of removing only the insulating film 42 when forming the holes, holes are also formed in the metal pattern 41.

  FIG. 5A is a cross-sectional view, and FIG. 5B is a top view. Referring to FIG. 5B, the conductive material 43 widely distributed around the two contact holes 44, the disconnection portion 45 between the contact holes, and the metal pattern 41 is shown.

  FIG. 6 is a diagram showing that a metal thin film is deposited on the contact hole 44 and the contact hole is filled with the metal thin film.

  After injecting a metal source gas (a mixed gas of a metal gas and an inert gas) into the chamber with an optical window, the metal 13 is filled in the holes 44 by irradiating a laser using a second laser oscillator.

  As shown in the figure, the metal source gas injected into the chamber is filled into the hole while being irradiated with the laser 11. At this time, a blue laser or an ultraviolet laser can be used as the laser.

  The metal part melted in the step of generating the hole and the metal part adsorbed on the surface of the hole 44 is completely filled with a thin film using a laser so as to cover it. Thus, the adhesion reliability is improved, and the resistance between the metal pattern 41 and the metal thin film 46 is reduced.

  In FIG. 6B, it can be confirmed that the metal thin film 46 is formed in the hole.

  FIG. 7 shows a process of depositing a thin film between the contact holes 44 to connect the contact holes to each other.

  In the same manner as when the metal thin film 46 is filled in the hole 44, the two contact holes are connected to each other by irradiating the blue laser or the ultraviolet laser 12 to form a metal thin film between the contact holes 44.

  At this time, depending on the defective part, it may be directly connected or may be bypassed. In particular, when there is a foreign substance in the defective part, it is preferable to bypass and connect. At this time, similarly to the above procedure, the laser is irradiated while moving (scanning method), or the intensity of the laser beam is kept uniform, the beam size is increased and the optical device is fixed. It is also possible to irradiate with a laser (block shot method) and pass through the mask. FIG. 7A shows that a thin film was deposited while irradiating a laser by a scanning method, and FIGS. 7B and 7C show that a thin film was deposited using a mask.

  When the detour connection is performed using the scanning method, as shown in FIG. 7A, an overlapping region 47 is generated in the bent portion. Since the same part is irradiated with the laser twice, there is a problem that a thin film is formed thicker than the other part and a step is generated. However, if vapor deposition is performed using a mask, such a superposition problem can be solved and the time required for the work process can be shortened. Of course, even when directly connecting, it is advantageous to adjust the size of the irradiated laser beam by using a slit or a mask so that the process time can be shortened.

  By the procedure described above, the formation of the metal thin film is completed, and the disconnected metal pattern 41 is connected.

  After the thin film is formed, if there is a conductive material around the thin film region, the conductive material and the metal thin film must be insulated from each other.

  FIG. 8 is a diagram showing insulation between the metal thin film and the conductive material. FIG. 8A shows a case of irradiating a laser by a scan method, and FIG. 8B shows a case of irradiating a laser by a block shot method.

  That is, after the thin film deposition is completed, the conductive material is cut by irradiating the periphery of the thin film using an infrared laser, a visible light laser, or an ultraviolet laser 11. In the drawing, a cross-sectional portion 48 where the metal thin film 46 and the conductive material 43 are separated from each other by cutting can be seen.

Applying a method of irradiating through the mask by maintaining the intensity of the laser beam uniformly, increasing the size of the beam even when irradiating the laser beam for the purpose of insulating the metal thin film and the conductive material. be able to.

FIG. 9 and FIG. 10 are diagrams illustrating connecting broken metal patterns when there is no insulating film as another embodiment of the present invention. FIG. 10A shows a case of irradiating a laser by a scanning method, and FIG. 10B shows a case of irradiating a laser by a block shot method.

  Even if there is no insulating film or the like, the metal pattern 41 is oxidized. Therefore, it is not preferable to immediately deposit a thin film on the metal pattern 41 for connection. Therefore, a certain region of the metal pattern 41 is cut out using the infrared laser 11 or the like to form a contact hole.

  After the metal pattern 41 is cut out, a metal source gas is injected into the chamber, and the contact holes are filled by irradiating a blue laser or an ultraviolet laser 12 to connect the contact holes to each other.

  As described above, the laser irradiation method may use the scanning method. The intensity of the laser beam is maintained uniformly, the beam size is increased, and irradiation is performed through a mask patterned in a desired shape. You may use the method to do.

  FIG. 11 is an embodiment showing various shapes of the mask pattern according to the present invention. FIG. 11A shows a mask used when forming a contact hole or filling a contact hole with a metal thin film, FIG. 11B shows a mask pattern for bypassing and connecting the contact holes, FIG. 11C shows a mask pattern for directly connecting the contact holes.

  FIG. 11D shows an example of a mask pattern for separating the metal thin film from the surrounding conductive material. FIG. 11E shows an example of a mask pattern in the case of irradiating a wide area with a laser such as forming a nitride film on a metal thin film.

  As described above, the shape of the mask pattern can be changed and selected in various ways depending on the process procedure, such as forming holes or connecting the holes together. Even when the holes are connected to each other, the shape of the mask pattern can be selected depending on whether the holes are connected in series or bypassed.

  With the above-described configuration, according to the present invention, a contact hole can be generated by one laser irradiation and a metal thin film can be formed, so that the time required for connecting short-circuited metal patterns can be shortened.

  In addition, according to the present invention, the short-circuit portion can be connected even if there is a foreign substance in the defective portion by connecting the contact holes by bypassing each other. In addition, it is possible to prevent the thin film superposition phenomenon that may occur during the bypass connection.

  In addition, according to the present invention, not only the insulating film is removed when the contact hole is generated, but also the metal pattern is melted together and the metal adsorbed on the surface of the hole is completely covered with the metal thin film. By using this, the adhesion reliability can be improved and the resistance between the metal thin films on which the metal patterns are formed can be reduced.

  Further, according to the present invention, it is possible to prevent the occurrence of a step and prevent the occurrence of step coverage or a via hole.

  Further, according to the present invention, the beam output can be maintained uniformly using the beam forming means and processed into various shapes according to the irradiation target.

  In addition, according to the present invention, even when an insulating film or the like is not formed on the metal pattern, the adhesion force is improved during metal thin film deposition by removing the oxide film formed on the metal pattern. Can do.

Claims (22)

A laser oscillator,
Beam forming means for flattening the laser beam emitted from the laser oscillator and adjusting the shape and size of the irradiated beam according to the object to be processed;
A chamber for forming a metal thin film on the object to be processed using a metal source gas at a predetermined interval from the object to be processed;
A metal thin film forming apparatus comprising: a gas supply unit that supplies the metal source gas; and an exhaust unit that exhausts residual gas after thin film formation,
The laser oscillator includes: a first laser oscillator for forming a hole by removing an insulating film, an organic film, a metal film, or a residual layer of a workpiece; a metal thin film is formed inside the hole; And a second laser oscillator for forming a metal thin film that connects the two to each other,
Metal thin film forming equipment . 2. The metal thin film forming apparatus according to claim 1 , wherein the first laser oscillator generates a pulse wave laser, and the second laser oscillator generates a continuous wave laser. 3. The metal thin film forming apparatus according to claim 2 , wherein the first laser oscillator and the second laser oscillator include a beam intensity adjusting device for controlling the intensity of laser energy. The first laser oscillator is characterized by generating an infrared laser, a visible light laser or ultraviolet laser, a metal thin film forming apparatus according to claim 1. 2. The metal thin film forming apparatus according to claim 1 , wherein the second laser oscillator generates a laser having a wavelength shorter than a wavelength length of blue ultraviolet light. 2. The metal thin film forming apparatus according to claim 1 , wherein the first laser oscillator and the second laser oscillator are formed on the same optical axis.   2. The metal thin film according to claim 1, wherein the beam forming unit includes a beam shaper for converting the energy distribution of the laser beam into a flat top format, and a beam slit for adjusting the size and shape of the laser beam. Forming equipment. 8. The metal thin film forming apparatus according to claim 7 , wherein the beam slit includes four blades for adjusting the beam size and a plurality of mask patterns for adjusting the beam shape. The metal thin film forming apparatus according to claim 7 , wherein the beam shaper includes a beam expander that expands a beam size and a homogenizer that makes a beam energy distribution uniform. Characterized in that it further comprises a monitoring device for sensing the process condition in real time, the metal thin film forming apparatus according to any one of claims 1-9. 11. The metal thin film forming apparatus according to claim 10 , wherein the monitoring device includes a focus adjustment unit that automatically adjusts a laser focus and a CCD (Charge Coupled Device) camera. When the metal pattern deposited on the substrate is cut, in the metal thin film forming method for connecting the cut metal pattern,
Irradiating a first laser to remove an insulating film on the metal pattern, and forming a first contact hole and a second contact hole in which a thin film can be deposited on the metal pattern;
Irradiating a second laser to fill the contact hole with a metal thin film; and
A method of forming a metal thin film, comprising: irradiating the second laser to form a metal thin film between the contact holes, thereby connecting the contact holes to each other. Wherein the first laser is an infrared laser, a one of a visible light laser and ultraviolet laser, and said second laser is a laser of shorter wavelength than the wavelength of blue UV, according to claim 12 Metal thin film forming method. The step of forming the contact hole is characterized in that a metal pattern is melted and adhered to the wall of the contact hole when the contact hole is formed by adjusting a laser output. 12. The metal thin film forming method according to 12 . The step of forming the contact hole or the step of filling the contact hole with a metal thin film is performed by sequentially irradiating a laser or simultaneously using a mask pattern to form the contact hole or to the contact hole. The metal thin film forming method according to claim 12 , wherein the metal thin film is filled. The method of forming a metal thin film according to claim 12 , wherein in the step of connecting the contact holes, the first and second contact holes are directly connected or detoured. In the step of connecting the contact holes, the contact holes are masked by irradiating the laser while moving, or maintaining the intensity of the laser to be uniform, and increasing the beam size to pass through the mask. The metal thin film forming method according to claim 12 , wherein the metal thin film is connected along the pattern. If there is a conductive material around the thin film formed region, further comprising the step of cutting the conductive material by irradiating a first laser, in any one of claims 12 to 17 The metal thin film formation method of description. In the cutting step, the conductive material is cut along the mask pattern by irradiating the laser with a method in which the intensity of the laser is kept uniform, the beam size is increased and the mask is passed. The method for forming a metal thin film according to claim 18 , wherein the metal thin film is formed. When the metal pattern deposited on the substrate is cut, in the metal thin film forming method for connecting the cut metal pattern,
Irradiating the first laser to remove the oxide film at the site where the metal pattern is to be connected;
Irradiating a second laser to form a hole in the oxide film removal portion, and filling the formed hole with a metal thin film;
Forming a metal thin film between the holes filled with the metal thin film by irradiation of the second laser, thereby connecting the holes to each other. 21. The method of forming a metal thin film according to claim 20 , wherein in forming and connecting the metal thin film, the oxide film removal portions are directly connected to each other or are bypassed. In the step of irradiating the laser, the laser is radiated while moving, or the intensity of the laser is kept uniform, the beam size is increased, and the laser irradiates along the mask pattern through the mask. The metal thin film forming method according to claim 20 , wherein the metal thin film forming method is performed.

Images