JP2005064301A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which can widely be used for annealing of a semiconductor film or other working processing using laser beams. <P>SOLUTION: This method is performed while moving the irradiating position with the laser beams on an object to be worked by making the laser beams incident obliquely on the surface to be worked by irradiation with the laser beams. In particular, when assuming the moving direction of the irradiating position with the laser beams to be →a and the incident direction of the laser beams to be →b, their inner product is <0 or an angle made by them is >90°. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a semiconductor device including a step of annealing a semiconductor by irradiating a laser beam.

  In recent years, a technique for manufacturing a thin film transistor (hereinafter referred to as TFT) on a substrate has greatly advanced, and application development to an active matrix display device has been advanced. In particular, a TFT using a polycrystalline semiconductor film has higher field-effect mobility than a TFT using a conventional amorphous semiconductor film, and thus can operate at high speed. Therefore, it is possible to integrally form a circuit externally attached using a conventional driver IC on the same substrate as the pixel.

  Since a glass substrate used for forming a polycrystalline semiconductor film is inferior in heat resistance and easily deformed by heat, a laser annealing technique is used for crystallization of the semiconductor film.

  The characteristics of laser annealing are that the processing time can be significantly shortened compared to annealing methods using radiant heating or conduction heating, and the semiconductor substrate or semiconductor film is selectively and locally heated to make the substrate almost thermally For example, do not damage.

  The laser annealing here refers to a technique for recrystallizing a damaged layer or an amorphous layer formed on a semiconductor substrate or semiconductor film, or a technique for crystallizing an amorphous semiconductor film formed on a substrate. ing. Moreover, the technique applied to planarization and surface modification of a semiconductor substrate or a semiconductor film is also included.

  Laser oscillators used for laser annealing are roughly classified into two types, pulse oscillation and continuous oscillation, depending on the oscillation method. In recent years, it has been found that the crystal grain size formed in a semiconductor film is larger when a continuous oscillation laser oscillator is used than a pulsed laser oscillator such as an excimer laser in crystallization of a semiconductor film. (Hereinafter, this crystal is referred to as a large grain crystal). As the crystal grain size in the semiconductor film increases, the number of grain boundaries entering the TFT channel region formed using the semiconductor film decreases, so that the mobility increases, which can be used for the development of higher performance devices. Therefore, continuous wave laser oscillators are in the spotlight.

  However, even if the energy intensity distribution of the laser beam on the irradiated surface is made uniform, it is difficult to uniformly anneal the entire surface of the workpiece. In particular, when the transmitted light of the laser beam incident on the workpiece is reflected and incident on the workpiece again, there has been a problem that laser annealing is not performed uniformly due to the interference effect. Of course, it is conceivable that the optical axes of incident light and reflected light are made different so as not to be affected by interference. However, when processing is performed while converging the laser beam and scanning the entire surface of the workpiece. However, it was not possible to solve this problem simply by making the laser beam incident from an oblique direction of the substrate.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a technique that can be widely used in processing using a laser beam, including annealing of a semiconductor film.

  The present invention is performed by irradiating the laser beam obliquely with respect to the irradiated surface of the object to be processed by irradiating the laser beam and moving the irradiation position of the laser beam on the object to be processed. In particular, if the moving direction of the laser beam irradiation position is → a and the incident direction of the laser beam is → b, the inner product is less than 0 or the angle is larger than 90 degrees.

  In the above configuration, among the laser beams incident on the irradiated surface of the target object to be processed, when the transmitted light is incident on the target object again as reflected light, the laser beam is incident on the irradiated surface prior to the incident light. The beam will be irradiated. In this case, by making the incident angle of the laser beam and the moving direction of the irradiated surface as in the present invention, the incident light and the reflected light do not interfere with each other, so that uniform processing can be performed.

  In the present invention, when a semiconductor film formed on a substrate is processed with a laser beam, the semiconductor film is used as an irradiated surface, the laser beam is incident obliquely on the irradiated surface, and the position of the laser beam is relatively set. A step of performing laser annealing while moving, and assuming that the relative movement direction of the irradiated surface with respect to the laser beam is → a and the incident direction of the laser beam is → b, the inner product thereof is less than zero. It is characterized by.

  In the present invention, when a semiconductor film formed on a substrate is processed with a laser beam, the semiconductor film is used as an irradiated surface, the laser beam is incident obliquely on the irradiated surface, and the position of the laser beam is relatively set. It has a step of laser annealing while moving, and if the relative movement direction of the irradiated surface with respect to the laser beam is → a and the incident direction of the laser beam is → b, the angle is larger than 90 °. Yes.

  In the above-described structure of the present invention, the semiconductor film is irradiated with the laser beam processed into a laser beam having a uniform energy distribution on the irradiated surface or a rectangular shape.

  The laser beam applied to the semiconductor film may be light in a wavelength band that the semiconductor film absorbs light, and a part of the light energy may pass through the semiconductor film and reflected light may be incident again.

  The laser beam applicable in the present invention may be either continuous wave light or pulsed light.

  With the above-described configuration of the present invention, a laser beam is obliquely irradiated onto the semiconductor film on the substrate, which is the irradiated surface, and at the same time, the reflected light generated when the incident laser beam is reflected on the back surface of the substrate is incident light. The laser beam is irradiated so as to enter the irradiated surface earlier. The reflected light here refers to light that is transmitted through a part of the laser beam incident on the semiconductor film on the substrate and reflected from the back surface of the substrate, and thus the energy density of the reflected light is lower than that of the incident light. In this case, since the energy density enough to melt the semiconductor film on the substrate is already lost, even if the reflected light is incident on the semiconductor film again, the laser annealing process is hardly affected. Further, since the incident light and the reflected light of the laser beam do not interfere with each other, uniform laser annealing can be performed.

  The semiconductor device in the present invention refers to all devices that can function by utilizing semiconductor characteristics, and includes electro-optical devices such as liquid crystal display devices and light-emitting devices, and electronic devices including the electro-optical devices as components. Shall be.

  According to the present invention, the laser beam is irradiated obliquely on the irradiated surface, and the reflected light from the back surface of the substrate enters before the incident light, so that the incident light and the reflected light from the back surface of the substrate do not cause interference and are uniform. It is possible to perform processing with good characteristics.

  Further, when laser annealing is performed while scanning the laser beam irradiation surface on a semiconductor film formed on the substrate, the moving direction of the laser beam irradiation position and the laser beam incident direction are configured as the present invention. Accordingly, since the reflected light from the back surface of the substrate enters before the incident light, the incident light and the reflected light from the back surface of the substrate do not interfere with each other, and a crystalline semiconductor film with good uniformity can be obtained.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

First, in FIGS. 1 and 2, the laser oscillator 101 is preferably capable of continuous oscillation. As the type of laser, either a solid laser or a gas laser can be selected, and a plurality of laser oscillators may be used to synthesize a laser beam. For example, a laser oscillator 101 may be obtained by preparing two YVO ₄ lasers (second harmonic wave, wavelength 532 nm) with a maximum output of 10 W and combining the two using polarized light.

  1 and 2 show a configuration in which a semiconductor film 106 is incident through an optical system in which a laser beam emitted from a laser oscillator is configured using an optical lens, a mirror, or the like. The laser beam emitted from the laser oscillator 101 is shaped into a rectangular laser beam having a uniform energy distribution by the diffractive optics 102, and the length of the short side and the long side of the rectangle are adjusted by the shaping optical system 103. ing. In FIG. 1, the direction perpendicular to the paper surface is the long side direction of the rectangular beam spot. A rectangular laser beam having a uniform energy distribution is reflected by the mirror 104, condensed by the condenser lens 105, and incident on the semiconductor film 106 on the substrate 107. The incident angle θ is set to an angle at which no interference occurs. For example, if the incident angle θ is set to 3 degrees, the inner product is less than 0 when the moving direction of the irradiated surface with respect to the laser beam is → a and the incident direction is → b, that is, the angle formed by → a and → b is 90. Greater than degree.

  FIG. 3 is a diagram for explaining the scanning direction of the laser beam. Here, a rectangular laser beam 203 having a uniform energy distribution can be scanned over the entire surface of the semiconductor film 202 by the Y-axis robot 201 and the X-axis robot 204. First, the surface of the semiconductor film 202 is scanned in one direction by the Y-axis robot 201. This scanning direction is indicated as A1 in FIG. After Y1 robot 201 irradiates A1 with a laser, it passes over A1 and returns to its original position, and is the width of a region where a large grain crystal is seen (hereinafter, this region is referred to as a large grain region). The X-axis robot 204 is slid in a direction perpendicular to the scanning direction, and the next A2 is irradiated with laser. By repeating such a series of operations, the entire surface of the semiconductor film 202 can be made a large grain size region.

1 to 3, a detailed view of an optical path through which incident light and reflected light from the back surface of the substrate pass is shown in FIG. In the semiconductor film 106 on the substrate 107, the laser beam is incident on the point c, and part of the laser beam is transmitted and reflected on the back surface of the substrate 107, whereby reflected light is generated. The generated reflected light is incident on the point d on the semiconductor film 106 again.
What is important here is the direction in which the stage is moved. When laser annealing is performed under the condition that the moving stage is moved in the P direction, the laser beam first enters the point c, and the point c is melted by the heat of the incident light. Since the melted semiconductor film has a drastic increase in the absorption coefficient, the ratio of absorbing light increases when light is irradiated in the molten state.
Since the point c moves in the P direction by the moving stage, the reflected light from the back surface of the substrate is absorbed by the point c which is in a molten state and causes interference, and as a result, the annealing state becomes uneven. There is.

  On the other hand, when laser annealing is performed under the condition that the stage is moved in the Q direction, reflected light from the back surface of the substrate is incident on the point d first on the semiconductor film 106, but the reflected light is not as strong as the incident light. The semiconductor film is not melted. Next, the point d moves in the Q direction according to the moving stage and receives incident light. However, even if light hits an unmelted portion, the absorption coefficient is low, so the reflected light is not absorbed and interference occurs. It never happened. Therefore, the semiconductor film 106 absorbs light and does not cause interference, and the semiconductor film can be annealed uniformly.

  The first embodiment of the present invention will be described in detail with reference to FIG.

  First, the perspective view of FIG. The oscillated beam is propagated in the direction of the arrow. The laser beam is focused in the long side direction of the rectangular beam spot by a cylindrical lens 401 having a focal length of 150 mm. In the perspective view of FIG. 5A, the direction parallel to the paper surface is the long side direction of the rectangle.

  Next, the side view of FIG. 5B will be described. The oscillated beam is propagated in the direction of the arrow. The laser beam is focused in the short side direction of the long side by a cylindrical lens 402 having a focal length of 20 mm arranged at a distance of 100 mm behind the cylindrical lens 401. In the side view of FIG. 5B, the direction parallel to the paper surface is the short side direction of the rectangle. Further, the irradiated surface is arranged at a distance of 18 mm behind the cylindrical lens 402.

  In the side view of FIG. 5B, the rectangular beam is incident on the silicon film on the substrate at 10 degrees so that no interference occurs, and the moving direction of the irradiated surface with respect to the beam is changed to a, the incident direction. Is set to → b, and the inner product thereof is set to be less than 0, that is, the angle formed by → a and → b is larger than 90 °, a part of the beam incident on the silicon film on the substrate is transmitted, Reflected light is generated and reenters the silicon film. Here, when the moving stage 405 is moved in the Q direction, the re-incident reflected light enters the silicon film first, and the reflected light is not as strong as the incident light, so the silicon film is not melted. . Even if light re-enters the unmelted portion, the light absorption coefficient is low, so the silicon film does not absorb light and does not cause interference. Therefore, the silicon film can be annealed uniformly.

  In this embodiment, a method for manufacturing an active matrix substrate using the present invention will be described with reference to FIGS.

  First, as shown in FIG. 7, in this embodiment, a substrate 700 made of glass such as barium borosilicate glass represented by Corning # 7059 glass or # 1737 glass or aluminoborosilicate glass is used. Note that a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used.

Next, a base film 701 made of an insulating film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is formed over the substrate 700. In this embodiment, a two-layer structure is used as the base film 701, but a single-layer film of the insulating film or a structure in which two or more layers are stacked may be used. As the first layer of the base film 701, a silicon oxynitride film 701a formed by using a plasma CVD method and using SiH ₄ , NH ₃ , and N ₂ O as a reaction gas is formed to a thickness of 10 to 200 nm (preferably 50 to 100 nm). To do. In this embodiment, a silicon oxynitride film 701a with a thickness of 50 nm is formed. Next, as a second layer of the base film 701, a silicon oxynitride film 701 _{b formed} using SiH ₄ and N ₂ O as a reaction gas is formed with a plasma CVD method to a thickness of 50 to 200 nm (preferably 100 to 150 nm). Stacked to a thickness. In this embodiment, a silicon oxynitride film 701b with a thickness of 100 nm is formed.

  Next, a semiconductor film 702 is formed over the base film. As the semiconductor film 702, a semiconductor film having an amorphous structure is formed by a known means (sputtering method, LPCVD method, plasma CVD method, or the like) to 25 to 200 nm, preferably 25 to 80 nm (typically 30 to 60 nm). The thickness is formed. There is no limitation on the material of the semiconductor film, but it is preferably formed of silicon or a silicon germanium (SiGe) alloy. In this embodiment, a 55 nm amorphous silicon film is formed by plasma CVD.

Subsequently, the semiconductor film is crystallized. Laser crystallization is applied to the crystallization of the semiconductor film. Laser crystallization is performed by applying a continuous wave laser and applying the present invention. For example, a laser beam using a YAG laser, a YVO ₄ laser, a YLF laser, a YAlO ₃ laser, an alexandride laser, a Ti: sapphire laser, or the like as a light source is processed into a linear beam using an optical system, as shown in FIG. The semiconductor film is irradiated by a simple method. At this time, the reflected light from the substrate surface and the reflected light from the back surface of the substrate are incident at an angle of 5 degrees with respect to the irradiated surface. In this embodiment, after heating the substrate in a nitrogen atmosphere at a temperature of 500 ° C. for 1 hour, the semiconductor film is crystallized by the laser annealing method shown in FIG. 6 to obtain a crystalline silicon film having large crystal grains. Form. At this time, a YVO ₄ laser is used as a laser oscillator, a laser beam modulated to a second harmonic by a non-linear optical element is processed into a linear beam having a length of 400 μm and a width of 15 μm by an optical system, and irradiated to a semiconductor film . The stage is moved in the direction of the arrow. In the case of using a continuous wave laser, the energy density is required to be approximately 0.01 MW / cm ^{2 to} 100 MW / cm ² (preferably 0.1 MW / cm ^{2 to} 10 MW / cm ² ). The stage is preferably moved at a speed of about 0.5 cm / s to 2000 cm / s to irradiate the laser.

  The crystalline semiconductor film thus obtained is patterned into a desired shape to form semiconductor layers 802 to 806. Then, semiconductor layers 802 to 806 are formed by patterning the crystalline silicon film using a photolithography method. After forming the semiconductor layers 802 to 806, a small amount of impurity element (boron or phosphorus) may be doped in order to control the threshold value of the TFT.

  Next, a gate insulating film 807 covering the semiconductor layers 802 to 806 is formed. The gate insulating film 807 is formed of an insulating film containing silicon with a thickness of 40 to 150 nm by a plasma CVD method or a sputtering method. In this embodiment, a silicon oxynitride film is formed with a thickness of 110 nm by plasma CVD. Needless to say, the gate insulating film is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure.

Alternatively, a silicon oxide film may be formed using a reaction gas in which TEOS (Tetraethyl Ortho Silicate) and O ₂ are mixed by a plasma CVD method.

  Next, as illustrated in FIG. 7B, a first conductive film 808 with a thickness of 20 to 100 nm and a second conductive film 809 with a thickness of 100 to 400 nm are stacked over the gate insulating film 807. In this embodiment, a first conductive film 808 made of a TaN film with a thickness of 30 nm and a second conductive film 809 made of a W film with a thickness of 370 nm are stacked. The TaN film is formed by sputtering, and is sputtered in a nitrogen-containing atmosphere using a Ta target. The W film is formed by sputtering using a W target.

  In this embodiment, the first conductive film 808 is TaN, and the second conductive film 809 is W. However, the present invention is not limited to this. From Ta, W, Ti, Mo, Al, Cu, Cr, and Nd. You may form with the selected element or the alloy material or compound material which has the said element as a main component. Alternatively, a semiconductor film typified by a crystalline silicon film doped with an impurity element such as phosphorus may be used. Further, an AgPdCu alloy may be used. In addition, the first conductive film is formed using a tantalum (Ta) film, the second conductive film is formed using a W film, the first conductive film is formed using a titanium nitride (TiN) film, and the second conductive film is formed. The first conductive film is formed of a tantalum nitride (TaN) film, the second conductive film is formed of an Al film, and the first conductive film is formed of a tantalum nitride (TaN) film. The second conductive film may be a combination of Cu films.

Next, resist masks 810 to 815 are formed by photolithography, and a first etching process for forming electrodes and wirings is performed. The first etching process is performed under the first and second etching conditions. In this embodiment, ICP (Inductively Coupled Plasma) etching method is used as the first etching condition, CF ₄ , Cl ₂ and O ₂ are used as etching gases, and each gas flow rate is 25 sccm, Etching is performed by generating plasma by generating 500 W RF (13.56 MHz) power to the coil-type electrode at a pressure of 1 Pa at 25 sccm and 10 sccm. 150 W RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. The W film is etched under the first etching condition so that the end portion of the first conductive layer is tapered.

Thereafter, the resist masks 810 to 815 are not removed, but the second etching conditions are changed, CF ₄ and Cl ₂ are used as etching gases, the respective gas flow rates are 30 sccm and 30 sccm, and the pressure is 1 Pa. 500 W RF (13.56 MHz) power is applied to the coil-type electrode to generate plasma, and etching is performed for about 30 seconds. 20 W RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. Under the second etching condition in which CF ₄ and Cl ₂ are mixed, the W film and the TaN film are etched to the same extent. Note that in order to perform etching without leaving a residue on the gate insulating film, it is preferable to increase the etching time at a rate of about 10 to 20%.

  In the first etching process, the shape of the mask made of resist is made suitable, and the end portions of the first conductive layer and the second conductive layer are tapered due to the effect of the bias voltage applied to the substrate side. It becomes. The angle of the taper portion is 15 degrees to 45 degrees. Thus, the first shape conductive layers 817 to 822 (first conductive layers 817 a to 822 a and second conductive layers 817 b to 822 b) composed of the first conductive layer and the second conductive layer by the first etching treatment. Form. Reference numeral 816 denotes a gate insulating film, and a region which is not covered with the first shape conductive layers 817 to 822 is etched and thinned by about 20 to 50 nm.

Then, a first doping process is performed without removing the resist mask, and an impurity element imparting n-type conductivity is added to the semiconductor layer (FIG. 8A). The doping process may be performed by ion doping or ion implantation. The conditions of the ion doping method are a dose amount of 1 × 10 ¹³ / cm ^{2 to} 5 × 10 ¹⁵ / cm ² and an acceleration voltage of 60 to 100 keV. In this embodiment, the dose is set to 1.5 × 10 ¹⁵ / cm ² and the acceleration voltage is set to 80 keV. As an impurity element imparting n-type, an element belonging to Group 15, typically phosphorus (P) or arsenic (As), is used here, but phosphorus (P) is used. In this case, the conductive layers 817 to 821 serve as a mask for the impurity element imparting n-type, and the first high-concentration impurity regions 706 to 710 are formed in a self-aligning manner. An impurity element imparting n-type conductivity is added to the first high-concentration impurity regions 706 to 710 in a concentration range of 1 × 10 ²⁰ / cm ³ to 1 × 10 ²¹ / cm ³ .

Next, a second etching process is performed without removing the resist mask. Here, CF ₄ , Cl _2, and O ₂ are used as the etching gas, and the W film is selectively etched. At this time, second conductive layers 828b to 833b are formed by a second etching process. On the other hand, the first conductive layers 817a to 822a are hardly etched, and the second shape conductive layers 828 to 833 are formed.

Next, a second doping process is performed as shown in FIG. 8B without removing the resist mask. In this case, an impurity element imparting n-type conductivity is introduced at a high acceleration voltage of 70 to 120 keV with a lower dose than in the first doping treatment. In this embodiment, the dose is set to 1.5 × 10 ¹⁴ / cm ² and the acceleration voltage is set to 90 keV. The second doping process uses the second shape conductive layers 828 to 833 as a mask, an impurity element is also introduced into the semiconductor layer below the second conductive layers 828b to 833b, and a second high concentration impurity is newly added. Regions 823a to 827a and low concentration impurity regions 823b to 827b are formed.

Next, after removing the resist mask, new resist masks 834a and 834b are formed, and a third etching process is performed as shown in FIG. 8C. SF ₆ and Cl ₂ are used as the etching gas, the gas flow rate is 90 sccm, 10 sccm, and 500 W of RF (13.56 MHz) power is applied to the coil-type electrode at a pressure of 1.3 Pa to generate plasma. Etching is performed for about 30 seconds. 10 W RF (13.56 MHz) power is applied to the substrate side (sample stage), and a negative self-bias voltage is applied substantially. Thus, the third etching process forms the third shape conductive layers 835 to 838 by etching the Ta channel film of the p-channel TFT and the TFT (pixel TFT) of the pixel portion.

  Next, after removing the resist mask, the gate insulating film 816 is selectively removed and insulated using the second shape conductive layers 828 and 830 and the second shape conductive layers 835 to 838 as masks. Layers 839-844 are formed. (Fig. 9 (A))

Next, resist masks 845a to 845c are newly formed, and a third doping process is performed. By this third doping treatment, impurity regions 846 and 847 are formed in which an impurity element imparting a conductivity type opposite to the one conductivity type is added to the semiconductor layer that becomes the active layer of the p-channel TFT. The second conductive layers 835a and 838a are used as masks against the impurity element, and an impurity element imparting p-type is added to form an impurity region in a self-aligning manner. In this embodiment, the impurity regions 846 and 847 are formed by an ion doping method using diborane (B ₂ H ₆ ) (FIG. 9B). In the third doping process, the semiconductor layer forming the n-channel TFT is covered with resist masks 845a to 845c. In the first doping process and the second doping process, phosphorus is added to the impurity regions 846 and 847 at different concentrations, respectively, and the concentration of the impurity element imparting p-type in each of the regions is 2 ×. By performing the doping treatment so as to be 10 ²⁰ / cm ^{3 to} 2 × 10 ²¹ / cm ³ , there is no problem because it functions as the source region and the drain region of the p-channel TFT. In this embodiment, since a part of the semiconductor layer serving as an active layer of the p-channel TFT is exposed, there is an advantage that an impurity element (boron) can be easily added.

  Next, the resist masks 845a to 845c are removed, and a first interlayer insulating film 861 is formed. The first interlayer insulating film 861 is formed of an insulating film containing silicon with a thickness of 100 nm to 200 nm by using a plasma CVD method or a sputtering method. In this embodiment, a silicon oxynitride film with a thickness of 150 nm is formed by a plasma CVD method. Needless to say, the first interlayer insulating film 861 is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure.

Next, activation treatment is performed using the laser annealing method of the present invention (FIG. 9C). The laser is preferably irradiated with a laser beam such as a solid-state laser (YVO ₄ laser, etc.), a gas laser, a metal laser, or the like. And if it irradiates using this invention, interference by reflected light will not occur.

  Further, heat treatment may be performed before the first interlayer insulating film is formed. However, when the wiring material used is weak against heat, it is activated after an interlayer insulating film (insulating film containing silicon as a main component, for example, a silicon nitride film) is formed to protect the wiring as in this embodiment. It is preferable to perform the conversion treatment.

  Further, a heat treatment at 410 ° C. is performed to hydrogenate the semiconductor layer. This step is a step of terminating dangling bonds in the semiconductor layer with hydrogen contained in the interlayer insulating film. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed.

  Next, a second interlayer insulating film 862 made of an inorganic insulating film material or an organic insulating material is formed over the first interlayer insulating film 861. For example, an interlayer insulating film made of a polymer compound is formed by a coating method. Further, a thermosetting or photo-curable organic resin material is applied, and acrylic, polyimide, polyamide, polyimide amide, aramid, or the like can be applied. In addition, as a low dielectric constant film having a dielectric constant smaller than 3.8, a fluorine-added silicon oxide film, organic SOG (Spin on Glass), HSQ (inorganic hydrogenated siloxy acid), HOSP (organic siloxy acid polymer) It is also possible to apply a porous chamber SOG or the like.

  In the driver circuit 906, wirings 863 to 867 that are electrically connected to the impurity regions are formed. Note that these wirings are formed by patterning a laminated film of a Ti film having a thickness of 50 nm and an alloy film (alloy film of Al and Ti) having a thickness of 500 nm.

  In the pixel portion 907, a pixel electrode 870, a gate wiring 869, and a connection electrode 868 are formed (FIG. 10). With the connection electrode 868, the source wiring is electrically connected to the pixel TFT. In addition, the gate wiring 869 is electrically connected to the gate electrode of the pixel TFT. The pixel electrode 870 is preferably formed using a highly reflective material such as a film containing Al or Ag as a main component or a stacked film thereof.

  As described above, the CMOS circuit including the n-channel TFT 901 and the p-channel TFT 902, the driver circuit 906 having the n-channel TFT 903, and the pixel portion 907 having the pixel TFT 904 and the storage capacitor 905 are formed over the same substrate. can do. Thus, the active matrix substrate is completed.

  An n-channel TFT 901 of the driver circuit 906 includes a channel formation region 823c, a low-concentration impurity region 823b (GOLD region) overlapping with the first conductive layer 828a which forms part of the gate electrode, and a high function as a source region or a drain region. A concentration impurity region 823a is provided. The p-channel TFT 902, which is connected to the n-channel TFT 901 and the electrode 866 to form a CMOS circuit, functions as a channel formation region 846d, impurity regions 846b and 846c formed outside the gate electrode, and a source or drain region. A high concentration impurity region 846a is provided. In addition, the n-channel TFT 903 includes a channel formation region 825c, a low-concentration impurity region 825b (GOLD region) that overlaps with the first conductive layer 830a that forms part of the gate electrode, and a high-concentration function that functions as a source region or a drain region. An impurity region 825a is provided.

  The pixel TFT 904 in the pixel portion includes a channel formation region 826c, a low concentration impurity region 826b (LDD region) formed outside the gate electrode, and a high concentration impurity region 826a functioning as a source region or a drain region. In addition, an impurity element imparting p-type conductivity is added to each of the semiconductor layers 847a and 847b functioning as one electrode of the storage capacitor 905. The storage capacitor 905 is formed using an insulating film 844 as a dielectric, an electrode (a stack of 838a and 838b), and semiconductor layers 847a to 847c.

  FIG. 11 is a top view of the pixel portion of the active matrix substrate manufactured in this embodiment. In addition, the same code | symbol is used for the part corresponding to FIGS. A chain line AA ′ in FIG. 10 corresponds to a cross-sectional view taken along the chain line AA ′ in FIG. Also, the chain line BB ′ in FIG. 10 is the same as FIG. 11 HYPERLINK “http://www8.ipdl.jpo.go.jp/Tokujitu/tjitemdrw.ipdl? =; /// & N0001 = 152 & N0552 = 9 & N0553 = 000031 "\ t" tjitemdrw "corresponds to the cross-sectional view taken along the chain line BB '.

  In the active matrix substrate manufactured as described above, TFTs can be formed using a crystal with good uniformity by using the present invention, so that variation in TFT characteristics is reduced, and a circuit with a wide operation margin is provided. Can be driven. In particular, since the variation such as the threshold voltage is reduced, driving at a low voltage can be facilitated.

  FIG. 12 is a diagram illustrating a configuration of a liquid crystal display panel manufactured using the active matrix substrate of this embodiment. A spacer 972 formed of an organic resin material and an alignment film 967 formed of a resin material such as polyimide are provided over an active matrix substrate including a driving circuit 906 and a pixel portion 907. The counter substrate 969 is provided with a counter electrode 976 and an alignment film 974 formed of a transparent conductive material such as ITO. These substrates are fixed with a sealant 968 at a predetermined interval. A liquid crystal material 975 is sealed between the substrates.

FIG. 13 illustrates a light-emitting device manufactured using the active matrix substrate of this example. The active matrix substrate is provided with a driver circuit 906 including an n-channel TFT 901 and a p-channel TFT 902, and a pixel portion 907. The structure of the pixel portion 907 is different from that of the active matrix substrate described with reference to FIG. 10, and has a pixel circuit in which at least two TFTs are provided in one pixel. That is, a switching TFT 1003 and a current control TFT 1004 that controls a current supplied to the light emitting element 1115 are provided.
The light-emitting element includes an EL layer 1113 including one or both of an inorganic or organic material capable of controlling light emission by an electric field between the first electrode 1110 and the second electrode 1114. The EL layer 1113 has a structure in which one layer or a plurality of layers are stacked. The first electrode 1110 and the second electrode 1114 can be distinguished by calling one of them an anode and the other a cathode depending on the polarity of an applied voltage. The anode is formed of a material having a high work function (preferably a material of 4 eV or more), and a conductive material containing indium oxide such as ITO is typically used. The cathode material is formed of a material having a low work function (preferably a material of 4 eV or less) and has an electrode structure in which a layer containing an alkali metal, an alkaline earth metal, or the like is in contact with the EL layer 113. At this time, when the first electrode 1110 is an anode, the current control TFT 1004 connected to the first electrode 1110 is preferably a p-channel TFT.
The second electrode 1114 is preferably formed using a gas barrier silicon nitride film, a silicon nitride oxide film, a carbon nitride film, an aluminum nitride film, or another insulating film containing nitrogen that hardly transmits water vapor, oxygen, or the like. . The sealing substrate 1118 is fixed to the active matrix substrate with an adhesive resin layer 1117, and a light-emitting device is formed in such a manner as to prevent intrusion of outside air. In the case where light from the light-emitting element 1115 is emitted to the sealing substrate side 1118 side, the adhesive resin layer 1117 and the sealing substrate 1118 may be formed using a light-transmitting material.

14A and 14B are diagrams illustrating the entire light-emitting device, in which FIG. 14A is a top view thereof and FIG. 14B is a cross-sectional view thereof. An active matrix substrate in which the driver circuit 906 and the pixel portion 907 are formed and the light emitting element 1115 is provided is fixed to the sealing substrate 1118 with an adhesive resin layer 1117. Since the interlayer insulating film 862 formed in the driver circuit 906 and the pixel portion 907 may be formed of, for example, a hygroscopic organic resin material, its end face is covered with a gas barrier protective film 1116, and A sealing material 1302 is formed in the peripheral portion of the substrate so that the region sandwiched between the two substrates is separated from the outside air. Further, in order to further strengthen the airtightness with the outside air and increase the mechanical strength, the second sealing material 1303 may be filled in the bonded end surfaces of the two substrates. An external signal input terminal 1304 is connected to the flexible printed wiring 1305 using an anisotropic conductive material.
The light emitting device manufactured as described above can form a TFT using a crystal with good uniformity by using the present invention. Therefore, variation in TFT characteristics is reduced, and a circuit with a wide operation margin can be formed. Can be driven. In particular, since the variation such as the threshold voltage is reduced, driving at a low voltage can be facilitated.

The figure explaining embodiment of this invention. The figure explaining embodiment of this invention. The figure explaining the Example of this invention. The figure explaining the Example of this invention. The figure explaining the Example of this invention. The figure which shows an example of the laser annealing method of this invention. Sectional drawing which shows the manufacturing process of TFT of a pixel TFT and a driver circuit. Sectional drawing which shows the manufacturing process of TFT of a pixel TFT and a driver circuit. Sectional drawing which shows the manufacturing process of TFT of a pixel TFT and a driver circuit. Sectional drawing which shows the manufacturing process of TFT of a pixel TFT and a driver circuit. FIG. 6 is a top view illustrating a configuration of a pixel TFT. Sectional drawing which shows the manufacturing process of an active matrix liquid crystal display device FIG. 6 is a cross-sectional structure diagram of a driver circuit and a pixel portion of a light emitting device. 2A is a top view of a light-emitting device, and FIG.

Claims (6)

A step of forming a semiconductor film on a substrate; a step of performing laser annealing while using the semiconductor film as a surface to be irradiated, causing a laser beam to be incident obliquely with respect to the surface to be irradiated, and relatively moving the position of the laser beam; The inner product is less than 0 when the relative moving direction of the irradiated surface with respect to the laser beam is → a and the incident direction of the laser beam is → b. Manufacturing method. A step of forming a semiconductor film on a substrate; a step of performing laser annealing while using the semiconductor film as a surface to be irradiated, causing a laser beam to be incident obliquely with respect to the surface to be irradiated, and relatively moving the position of the laser beam; When the relative moving direction of the irradiated surface with respect to the laser beam is → a and the incident direction of the laser beam is → b, the angle is larger than 90 degrees. A method for manufacturing a semiconductor device. 3. The method for manufacturing a semiconductor device according to claim 1, wherein in the laser annealing step, the semiconductor film is irradiated with the laser beam processed into a laser beam having a uniform energy distribution on a surface to be irradiated. . 4. The method for manufacturing a semiconductor device according to claim 1, wherein in the laser annealing step, the laser beam is processed into a rectangular shape on a surface to be irradiated, and the semiconductor film is irradiated. . 5. The method for manufacturing a semiconductor device according to claim 1, wherein part of the laser beam is transmitted through the semiconductor film. 6. The method for manufacturing a semiconductor device according to claim 1, wherein the laser beam is oscillated from a continuous wave laser irradiator.

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