JP2008047888A - Method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a crystalline silicon film capable of preventing cracks in a substrate, a base protection film and the crystalline silicon film, and to provide a manufacturing method for a semiconductor device. <P>SOLUTION: A layer containing a semiconductor layer is formed on a substrate with a coefficient of thermal expansion of more than 6×10<SP>-7</SP>/°C and no more than 38×10<SP>-7</SP>/°C, or preferably more than 6×10<SP>-7</SP>/°C and no more than 31.8×10<SP>-7</SP>/°C, and then the layer is heated. After that, laser beams are irradiated at the heated layer, and the semiconductor film is crystallized, thereby forming a crystalline semiconductor film. As for the layer containing the semiconductor film formed on the substrate, it is formed so that the total stress of the layer may be no less than -500 N/m and no more than +50 N/m, or preferably no less than -150 N/m and no more than 0 N/m after the heating mentioned above. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for manufacturing a semiconductor device having a semiconductor element over a substrate with an insulating film interposed therebetween.

As a conventional method for manufacturing a polycrystalline semiconductor used for a thin film device such as an insulated gate field effect transistor, there is a method using a laser annealing method. (For example, refer to Patent Document 1). Specifically, after forming a silicon oxide film as a base protective film on a glass substrate and forming an amorphous silicon film on the silicon oxide film, the concentration of hydrogen contained in the amorphous silicon film is changed. In order to reduce the temperature, heat annealing is performed, the amorphous silicon film is irradiated with a KrF excimer laser beam, and the amorphous silicon film is crystallized to form a polycrystalline silicon film.
JP-A-5-182923

  However, when the laser annealing method described above is used, there is a problem that if the power of the laser beam is high, the substrate, the base protective film, or the crystalline silicon film is cracked. For this reason, the yield of the semiconductor device which has a thin film device becomes low.

  In view of the above, an object of the present invention is to propose a method for manufacturing a crystalline silicon film and a method for manufacturing a semiconductor device capable of suppressing cracks in a substrate, a base protective film, or a crystalline silicon film. .

The present invention provides a substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. Then, a layer including a semiconductor film is formed and the layer is heated. Next, the heated layer is irradiated with a laser beam to crystallize the semiconductor film to form a crystalline semiconductor film. The layer including the semiconductor film formed over the substrate may have a tensile stress or a compressive stress as appropriate after the film formation. However, after the heating, the total stress of the layer including the semiconductor film (thickness direction) The layer is formed such that the stress integrated in the range of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m.

Formed on a substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. When a layer is irradiated with a laser beam, the energy of the laser beam irradiated on the layer is transmitted to the substrate surface, and the substrate surface located in the vicinity of the laser beam irradiation portion and the vicinity thereof is also heated. Immediately below the laser beam irradiation part, the laser beam energy transfer rate is high and the substrate surface is softened. Further, in the vicinity of the laser beam irradiated portion, the volume is heated and the volume is expanded, so that a compressive stress is generated. On the other hand, outside the region where the compressive stress is generated, tensile stress is generated by the reaction of the compressive stress.

When the laser beam moves, the softened substrate surface is gradually cooled, the volume contracts, and tensile stress is generated. On the other hand, in the vicinity of the irradiated portion of the laser beam, the heated substrate surface is cooled to room temperature, but compressive stress remains. Due to the difference between the tensile stress and the compressive stress, thermal strain remains on the substrate. When this thermal strain becomes larger than the breaking stress of the substrate, the substrate cracks, and the layer formed on the substrate surface also cracks. However, the heat generated on the surface of the substrate is formed by forming a layer including a semiconductor film on the substrate having a total stress after heating of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m. It is possible to reduce the distortion. As a result, cracks in the substrate or a layer formed thereon can be reduced.

As the layer including the semiconductor film formed on the substrate surface, the film thickness and the film stress satisfying the total stress after heating of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m. Forming a layer having

Here, assuming that the film stress of each layer constituting the layer including the semiconductor film contributes linearly to the total stress, assuming that the stress of each layer is σ and the film thickness of each layer is d, the total stress S is It is calculated approximately from the following formula. For this reason, even if there is a layer in which a tensile stress is generated in a layer constituting a layer including a semiconductor film, if a compressive stress is generated in another layer, the entire layer including the semiconductor film after being heated The stress can be in the range of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m.

After heating on a substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. By forming a layer having a total stress of −500 N / m or more and +50 N / m or less, preferably −150 N / m or more and 0 N / m or less, continuous oscillation or 10 MHz or more is applied to the layer formed on the substrate. When a pulsed laser beam having a frequency is irradiated, cracks can be suppressed in the substrate or the layer formed over the substrate. That is, when the layer is irradiated with a laser beam, the energy of the laser beam is transmitted to the substrate, and the coefficient of thermal expansion is greater than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably 6 × 10 ⁻ A part of the substrate that is larger than ⁷ / ° C. and 31.8 × 10 ⁻⁷ / ° C. or lower causes thermal strain as a result of heating and cooling by laser beam irradiation, and tensile stress occurs in part of the substrate surface due to the thermal strain. . However, since a layer having a compressive stress is formed on the substrate, the tensile stress on the substrate surface can be relaxed. For this reason, it can suppress that a board | substrate and a layer crack. As a result, defective products of the semiconductor device can be reduced and the yield can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes, and it is easy for those skilled in the art to change the modes and details in various ways without departing from the spirit and scope of the present invention. Understood. Therefore, the present invention is not construed as being limited to the description of this embodiment mode.

(Embodiment 1)
As shown in FIG. 1A, insulating films 101 and 102 functioning as a base protective film are formed on one surface of a substrate 100 having an insulating surface, and an amorphous semiconductor film 103 is formed over the insulating film 102. Next, the amorphous semiconductor film is heated in order to remove hydrogen from the amorphous semiconductor film. At this time, the insulating film functioning as the substrate and the base protective film is also heated. The total stress of the insulating films 101 and 102 and the amorphous semiconductor film 103 functioning as the base protective film after the heating is −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m. As described above, the insulating films 101 and 102 and the amorphous semiconductor film 103 are formed.

The substrate 100 having an insulating surface has a coefficient of thermal expansion of greater than 6 × 10 ⁻⁷ / ° C. and less than or equal to 38 × 10 ⁻⁷ / ° C., preferably greater than 6 × 10 ⁻⁷ / ° C. and 31.8 × 10 ⁻⁷ / ° C. A substrate having a temperature of ℃ or lower is used. As a typical example of a substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. , AN100 (Asahi Glass Co., Ltd.), EAGLE2000 (Corning Co., Ltd.) and the like. As the substrate 100 having an insulating surface, a substrate having a thickness of 0.5 mm to 1.2 mm can be used. Here, for example, an AN100 glass substrate having a thickness of 0.7 mm is used.

As the heat treatment after the insulating films 101 and 102 and the amorphous semiconductor film 103 are formed on one surface of the substrate, heating may be performed at a temperature at which hydrogen contained in the amorphous semiconductor film can be removed. In addition, in the heat treatment, hydrogen contained in the insulating films 101 and 102 functioning as a base protective film may be removed. By removing hydrogen contained in the amorphous semiconductor film, it is possible to avoid the release of hydrogen from the amorphous semiconductor film when the amorphous semiconductor film is irradiated with a laser beam later, The durability of the film due to laser beam irradiation can be improved. As such heating conditions, a furnace annealing furnace can be used to heat at a temperature of 500 ° C. to 550 ° C. for 1 hour to 10 hours, preferably 1 hour to 5 hours. Further, it can be heated at 550 ° C. or higher and 750 ° C. or lower, preferably 600 ° C. or higher and 650 ° C. or lower for 1 second to 10 minutes, preferably 3 minutes to 8 minutes, using a rapid thermal annealing method (RTA method).

In addition to the above heat treatment, heat treatment for crystallizing the amorphous semiconductor film may be performed. In this case, heat treatment may be performed after adding a metal element or the like that promotes crystallization to the amorphous semiconductor film. Typically, the amorphous semiconductor film is crystallized by adding a trace amount of a metal element such as nickel, palladium, germanium, iron, tin, lead, cobalt, platinum, copper, or gold, followed by heat treatment. A semiconductor film can be formed.

Here, heating is performed at 650 ° C. for 6 minutes in order to remove hydrogen contained in the amorphous semiconductor film and hydrogen contained in the insulating films 101 and 102 functioning as a base protective film.

As the insulating films 101 and 102 that function as a base protective film, compounds such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon nitride oxide film, an aluminum nitride film, an aluminum oxynitride film, and an alumina film, A compound containing hydrogen in the compound can be used.

  Note that here, a silicon oxynitride film refers to a film containing oxygen that is 1.8 to 2.3 times, preferably 1.92 to 2.16 times, that of silicon. Further, it may contain nitrogen 0.001 to 0.05 times, preferably 0.001 to 0.01 times that of silicon. Furthermore, it may contain hydrogen 0.01 to 0.3 times, preferably 0.04 to 0.24 times that of silicon. Furthermore, 0 to 0.001 times, preferably 0 to 0.003 times as much carbon as silicon may be contained. Such a film may be indicated as SiON. In addition, the silicon nitride oxide film contains 0.1 to 0.3 times, preferably 0.13 to 0.42 times oxygen, and 1 to 2 times, preferably 1.1 to 1.6 times, nitrogen of silicon. A membrane containing. Further, it may contain hydrogen 0.3 to 1.2 times, preferably 0.51 to 0.91 times that of silicon. Such a film may be referred to as SiNO.

As the amorphous semiconductor film 103, silicon, germanium, silicon germanium (Si _1-x Ge _x (0 <x <0.1)), or the like can be used.

For the insulating films 101 and 102 and the amorphous semiconductor film 103 which function as a base protective film, a plasma CVD method, a sputtering method, an evaporation method, or the like can be used as appropriate. Note that the stress of the insulating films 101 and 102 and the amorphous semiconductor film 103 that function as a base protective film before film formation, that is, before heating may be tensile stress or compressive stress.

The total stress after heating of the layer including the semiconductor film formed on the substrate is −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m.

Here, the insulating films 101 and 102 and the amorphous semiconductor film 103 are formed as layers formed over the substrate. The silicon nitride oxide film has a thickness of 0 to 100 nm, the silicon oxynitride film has a thickness of 30 to 120 nm, 30 An amorphous semiconductor film of ˜200 nm is formed.

Furthermore, the insulating film functioning as a base protective film is not limited to a structure in which two insulating films are stacked, and may be a single layer. That is, as a layer including a semiconductor film, a silicon oxynitride film with a thickness of 30 to 120 nm can be formed as a base protective film, and an amorphous semiconductor film with a thickness of 30 to 200 nm can be formed thereon. Further, instead of the silicon oxynitride film, an aluminum nitride film, an aluminum oxynitride film, or an alumina film having a thickness of 30 to 120 nm can be used. Also in this case, the total stress after heating of the insulating film and the amorphous semiconductor film is −500 N / m or more and +50 N / m or less, preferably −150 N / m or more and 0 N / m or less. That is, the product of the thickness of the insulating film after heating and the film stress is obtained by subtracting the product of the film thickness of the amorphous semiconductor film after heating and the film stress of the amorphous semiconductor film after heating from the total stress after heating. Become.

  Further, the insulating film functioning as a base protective film may have three or more layers. That is, as a layer including a semiconductor film, an aluminum nitride film of 30 to 120 nm, a silicon nitride oxide film of 0 to 100 nm, and a silicon oxynitride film of 30 to 120 nm are formed as a base protective film, and a film of 30 to 200 nm is formed thereon. An amorphous semiconductor film can also be formed. Note that the order of lamination of the base protective film at this time is a combination of an aluminum nitride film, a silicon nitride oxide film, and a silicon oxynitride film from the substrate side, or a silicon nitride oxide film, an aluminum nitride film, and a silicon oxynitride film from the substrate side. Or a combination of a silicon nitride oxide film, a silicon oxynitride film, and an aluminum nitride film from the substrate side can be used as appropriate. Further, in the above three-layer structure, an aluminum oxynitride film or an alumina film can be used instead of the aluminum nitride film. Also in this case, the total stress after heating of the insulating film and the amorphous semiconductor film is −500 N / m or more and +50 N / m or less, preferably −150 N / m or more and 0 N / m or less.

  Next, as shown in FIG. 1B, the amorphous semiconductor film 103 is irradiated with a laser beam. FIG. 1B is a schematic view of irradiation with a laser beam. The amorphous semiconductor film irradiated with the laser beam 104 is a crystalline semiconductor film 105.

  When the amorphous semiconductor film 103 is irradiated with a laser beam, the laser beam is absorbed by the amorphous semiconductor film 103 and the amorphous semiconductor film 103 is heated, and the heat is conducted to the substrate and the substrate 100 is also heated. The The temperature and stress on the substrate surface at this time will be described with reference to FIGS. FIG. 2A shows a top view of the substrate 100 in the vicinity of the region irradiated with the laser beam. Here, the laser beam is shown scanned in the direction 110 of the arrow on the substrate. The crystalline semiconductor film 105 is a region where the laser beam has already been scanned and the amorphous semiconductor film is crystallized. The amorphous semiconductor film 103 is a region of an amorphous semiconductor film that is next scanned with a laser beam. Regions 111 and 112 are regions irradiated with a laser beam.

  When the amorphous semiconductor film is irradiated with the laser beam, the laser beam irradiated to the amorphous semiconductor film is absorbed by the amorphous semiconductor film, the amorphous semiconductor film is heated, and the heat is applied to the substrate. The substrate 100 is also heated, the surface of the substrate 100 is locally heated, and a part of the surface of the substrate is softened. Further, a heated substrate region 112 is provided on both sides of the softened substrate region 111.

  Further, as shown by the temperature curve 113 of the substrate surface when the laser beam in FIG. 2B is irradiated, the temperature exceeds the softening point in the region 111 where the substrate is softened. In the heated substrate region 112, the temperature is above room temperature (RT) and below the softening point. Furthermore, the temperature of the crystalline semiconductor film 105 that has already been crystallized and the amorphous semiconductor film 103 that has not yet been irradiated with the laser beam are room temperature.

  Here, the result of conducting a heat conduction simulation on the temperature rise of the substrate when a laser beam is applied to the substrate on which the laminated film of the silicon oxynitride film having a thickness of 100 nm and the silicon nitride oxide film having a thickness of 50 nm is formed. It shows in FIG. Here, the surface of the substrate kept at room temperature was instantaneously raised to the melting point of silicon (1685 K) at time t = 0, and the temperature distribution at the subsequent elapsed time t = t was calculated by the difference method.

  In FIG. 26, the horizontal axis represents the depth from the surface of the glass substrate on which a 100 nm silicon oxynitride film and a 50 nm silicon nitride oxide film are formed, and the vertical axis represents the difference method based on the heat conduction equation. The calculated temperature of each region is shown.

The melting time of the amorphous silicon film when irradiated with a continuous wave laser or a pulse laser having a repetition rate of 10 MHz or more is about 10 μsec. Becomes a high temperature, and the heat is conducted to the laminated film of the silicon oxynitride film having a thickness of 100 nm and the silicon nitride oxide film having a thickness of 50 nm and the substrate. For this reason, the solid line represents the temperature of each region at the elapsed time t = 10 μsec after irradiation with a continuous wave laser or a pulse laser having a repetition frequency of 10 MHz or more. The broken lines indicate the melting temperature of silicon (1585K) and the melting temperature of glass (1223K), respectively.

From FIG. 26, when the elapsed time after irradiation with a continuous wave laser or a pulse laser with a repetition frequency of 10 MHz or more is about 10 μs, the temperature in the region from the surface of the glass substrate to around 1 μm is above the softening point of the glass. It was a result.

In other words, when a layer including a semiconductor film is irradiated with a continuous wave laser or a pulsed laser beam having a repetition frequency of 10 MHz or more, heat is transmitted not only to the layer including the semiconductor film but also to the surface of the glass substrate. Can be seen to soften.

  Further, the stress on the substrate surface at this time is shown by a stress curve 114 in FIG. In the region 111 where the substrate is softened, the viscosity is low, no stress is generated, and the stress is zero. On the other hand, the heated regions 112 on both sides of the softened region 111 are heated at a temperature higher than room temperature and lower than the softening point, and the volume expands, so that compressive stress is generated on the substrate surface. Further, tensile stress is generated around the substrate surface where the compressive stress is generated, that is, in the crystallized crystalline semiconductor film 105 and the amorphous semiconductor film 103 which has not yet been irradiated with the laser beam.

  When the laser beam is scanned, the irradiation region of the laser beam moves, and cooling of the softened region and the heated regions on both sides of the substrate immediately below the laser beam irradiation region starts. FIG. 2D shows a top view of the substrate in the vicinity of the region irradiated with the laser beam at this time. In addition, the temperature and stress on the surface of the substrate will be described with reference to FIGS. The softened area of the substrate is solidified. The solidified region is indicated by 121 in FIG. Moreover, the heated area | region 122 is formed in the both sides. Further, as shown by the temperature curve 123 in FIG. 2E, the temperature of the substrate surface scanned with the laser beam is the room temperature (the solidified region 121 and the heated region 122 on both sides thereof are at room temperature ( RT) higher than the softening point. The stress on the substrate surface at this time is shown by a stress curve 124 in FIG. Since the temperature of the substrate becomes higher than the softening point due to laser beam irradiation and the softened region 121 is solidified and contracted by cooling, tensile stress is generated. A force that prevents contraction from the adjacent portion is applied to the portion that has started to contract, and thus compressive stress is generated.

  Further cooling brings the substrate surface to room temperature. FIG. 2G shows a top view of the substrate in the vicinity of the region irradiated with the laser beam at this time. The region solidified by cooling and the heated region are cooled to room temperature and become crystalline semiconductor films 131 and 132. The temperature and stress on the substrate surface at this time will be described with reference to FIGS. As shown by the temperature curve 133 of the substrate surface scanned with the laser beam, the temperature of the substrate surface of the solidified crystalline semiconductor film 131 and the heated region 132 on both sides thereof is the temperature curve 133 in FIG. It is room temperature (RT) as shown by. The stress on the substrate surface at this time is shown by a stress curve 134 in FIG. As the temperature of the substrate reaches room temperature, the softened region further shrinks. However, since it is prevented from shrinking from the adjacent portion, the tensile stress is further increased.

  The irradiation of the laser beam is not performed on the entire surface of the substrate at the same time, but the entire surface of the substrate is irradiated with the laser beam while being partially irradiated. For this reason, the substrate surface has a region heated by laser beam irradiation and a region not heated. Further, when the laser beam moves from the region irradiated with the laser beam, the region irradiated with the laser beam is gradually cooled to room temperature. For this reason, a tensile stress and a compressive stress are partially generated on a part of the surface of the substrate. This is called thermal distortion. The larger the coefficient of thermal expansion of the substrate, and the lower the softening point of the substrate, the greater the thermal distortion that occurs with heating, softening, and cooling, and cracks are more likely to occur. Specifically, in the region irradiated with the laser beam, a large tensile stress is generated in a direction perpendicular to the scanning direction of the laser beam or the moving direction of the substrate.

  When the thermal strain, that is, the tensile stress, on the substrate surface in the region irradiated with the laser beam becomes larger than the breaking stress of the substrate, the substrate is cracked. Once a crack occurs, the crack progresses because stress concentrates on the crack. The traveling direction is perpendicular to the stress distribution, that is, parallel to the laser beam scanning direction.

However, if a layer having a compressive stress after heating is formed on the surface of the substrate, the tensile stress on the substrate surface can be reduced. From the above, the substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. When a crystalline semiconductor film is formed by irradiating a laser beam to an amorphous semiconductor film after a layer including a semiconductor film is formed thereon and the layer including the semiconductor film is heated, the layer including the substrate and the semiconductor film It is possible to reduce the occurrence of cracks.

Here, a laser oscillator used for crystallization and an optical system for forming a beam spot will be described. As shown in FIG. 3, lasers having a wavelength that is absorbed by several tens of percent or more by the amorphous semiconductor film 103 are used as the laser oscillators 11a and 11b. Typically, a fundamental wave to a fourth harmonic can be used. Here, an LD excitation (laser diode excitation) continuous wave laser (YVO ₄ , second harmonic (wavelength 532 nm)) having a total maximum output of 20 W is prepared. The second harmonic is not particularly limited to the second harmonic, but the second harmonic is superior to higher harmonics in terms of energy efficiency.

  When the amorphous semiconductor film 103 is irradiated with the continuous wave laser, energy is continuously given to the amorphous semiconductor film 103. Therefore, once the semiconductor film is brought into a molten state, the molten state can be continued. Further, the solid-liquid interface of the semiconductor film can be moved by scanning with a continuous wave laser, and crystal grains that are long in one direction can be formed along the direction of this movement. The solid laser is used because the output stability is higher than that of a gas laser or the like and stable processing is expected. Note that not only a continuous wave laser but also a pulse laser having a repetition frequency of 10 MHz or more can be used. If a pulse laser with a high repetition frequency is used, the semiconductor film can be kept in a molten state at all times if the laser pulse interval is shorter than the time from when the semiconductor film is melted to solidification. A semiconductor film including crystal grains that are long in one direction can be formed. In the case of FIG. 3, two laser oscillators are prepared. However, one laser oscillator is sufficient if the output is sufficient.

For example, examples of the gas laser include an Ar laser, a Kr laser, and a CO ₂ laser. Examples of the solid-state laser include a YAG laser, a YLF laser, a YAlO ₃ laser, a GdVO ₄ laser, a KGW laser, a KYW laser, an alexandrite laser, a Ti: sapphire laser, a Y ₂ O ₃ laser, and a YVO ₄ laser. Further, there are ceramic lasers such as YAG laser, Y ₂ O ₃ laser, GdVO ₄ laser, and YVO ₄ laser. Examples of the metal vapor laser include a helium cadmium laser.

Further, as the laser oscillators 11a and 11b, when the laser beam is oscillated and emitted in TEM ₀₀ (single transverse mode), the linear beam spot obtained on the irradiated surface has high condensing property and the energy density is increased. This is preferable.

  The outline of laser irradiation is as follows. Laser beams 12a and 12b are respectively emitted from the laser oscillators 11a and 11b with the same energy. The laser beam 12 b emitted from the laser oscillator 11 b changes the polarization direction through the wave plate 13. The reason why the polarization direction of the laser beam 12b is changed is to synthesize two laser beams having different polarization directions by the polarizer. After passing the laser beam 12 b through the wave plate 13, it is reflected by the mirror 22, and the laser beam 12 b is incident on the polarizer 14. Then, the laser beam 12 a and the laser beam 12 b are synthesized by the polarizer 14 to obtain a laser beam 12. The wave plate 13 and the polarizer 14 are adjusted so that the light transmitted through the wave plate 13 and the polarizer 14 has an appropriate energy. In the present embodiment, the polarizer 14 is used for combining the laser beams, but other optical elements such as a polarizing beam splitter may be used.

  The laser beam 12 synthesized by the polarizer 14 is reflected by a mirror 15, and the cross-sectional shape of the laser beam is irradiated by a cylindrical lens 16 having a focal length of, for example, 150 mm and a cylindrical lens 17 having a focal length of, for example, 20 mm. In 18, it is shaped into a line. The mirror 15 may be provided according to the installation status of the optical system of the laser irradiation apparatus. The cylindrical lens 16 acts in the length direction of the beam spot formed on the irradiated surface 18, and the cylindrical lens 17 acts in the width direction. As a result, a linear beam spot having a length of about 500 μm and a width of about 20 μm is formed on the irradiated surface 18. In this embodiment, a cylindrical lens is used to form a linear shape. However, the present invention is not limited to this, and other optical elements such as a spherical lens may be used. Further, the focal length of the cylindrical lens is not limited to the above value, and can be set freely.

  Further, in this embodiment, the laser beam is shaped using the cylindrical lenses 16 and 17, but an optical system for extending the laser beam in a linear shape and a thin light beam for focusing on the irradiated surface. An optical system may be provided separately. For example, a cylindrical lens array, a diffractive optical element, an optical waveguide, or the like can be used to make the cross section of the laser beam linear. Further, if the laser medium has a rectangular shape, the cross-sectional shape of the laser beam can be made linear at the emission stage. The ceramic laser is suitable for manufacturing such a laser because the shape of the laser medium can be shaped relatively freely. Note that the cross-sectional shape of the laser beam formed in a linear shape is preferably as narrow as possible. This increases the energy density of the laser beam in the semiconductor film, so that the process time can be shortened.

  Next, a laser beam irradiation method will be described. In order to operate the irradiated surface 18 on which the amorphous semiconductor film 103 is formed at a relatively high speed, it is fixed to the suction stage 19. The suction stage 19 can be moved in the X and Y directions on a plane parallel to the irradiated surface 18 by the uniaxial robot 20 for the X axis and the uniaxial robot 21 for the Y axis. The linear beam spot is arranged so that the length direction of the linear beam spot coincides with the Y axis. Next, the irradiated surface 18 is operated along the width direction of the beam spot, that is, along the X axis, and the irradiated surface 18 is irradiated with the laser beam. Here, the scanning speed of the uniaxial robot 20 for the X axis is 35 cm / sec, and lasers are emitted from the two laser oscillators with energy of 7.0 W, respectively. The combined laser output is 14W.

By irradiation with the laser beam, a region where the semiconductor film is completely melted is formed. Crystals grow in the process of solidification, and a crystalline semiconductor film can be formed. The energy distribution of the laser beam emitted from the TEM ₀₀ mode laser oscillator is generally a Gaussian distribution. Note that the intensity of the laser beam can be made uniform by an optical system used for laser beam irradiation. For example, the intensity of the laser beam can be made uniform by using a lens array such as a cylindrical lens array or a fly-eye lens, a diffractive optical element, an optical waveguide, or the like. The scanning speed of the uniaxial robot 20 for the X axis is suitably about several tens to several hundreds cm / sec, and the operator may determine it appropriately according to the output of the laser oscillator.

  In this embodiment, a method is used in which the amorphous semiconductor film 103 that is the irradiated surface 18 is moved using the uniaxial robot 20 for the X axis and the uniaxial robot 21 for the Y axis. However, the scanning of the laser beam is not limited to this. The irradiation system is a moving type in which the irradiation surface 18 is fixed and the irradiation position of the laser beam is moved, and the irradiation surface is moved by fixing the irradiation position of the laser beam. A surface moving type or a combination of the above two methods can be used.

  As described above, since the energy distribution in the major axis direction of the beam spot formed by the optical system described above is a Gaussian distribution, small-sized crystals are formed at locations where the energy density is low at both ends. Therefore, a configuration may be adopted in which a part of the laser beam is cut off by providing a slit or the like in front of the irradiated surface 18 so that only the energy sufficient to form a large grain crystal is irradiated on the irradiated surface 18. Further, in order to use the laser beams emitted from the laser oscillators 11a and 11b more efficiently, a beam homogenizer such as a lens array or a diffractive optical element is used to uniformly distribute the energy in the length direction of the beam spot. It is good.

  Further, the Y-axis uniaxial robot 21 is moved by the width of the formed crystalline semiconductor film, and the X-axis uniaxial robot 20 is again scanned at a predetermined speed, 35 cm / sec. By repeating such a series of operations, the entire surface of the semiconductor film can be efficiently crystallized.

  Through the above steps, a crystalline semiconductor film 105 is formed by irradiating the entire amorphous semiconductor film with a laser beam as illustrated in FIG.

  After that, the crystalline semiconductor film is selectively etched to form a semiconductor film, and a semiconductor element is formed using the semiconductor film. As the semiconductor element, a thin film transistor, a nonvolatile memory element having a floating gate or a charge storage layer, a diode, a capacitor element, a resistance element, or the like can be formed. Here, a thin film transistor 150 is formed as illustrated in FIG.

In addition, a semiconductor device can be manufactured using a semiconductor element.

  Note that in this embodiment, a separation film may be provided between the insulating film 101 and the substrate 100, and a semiconductor element formed over the insulating film 101 may be separated from the substrate 100 after the process is completed. After that, a thin and lightweight semiconductor device can be manufactured by attaching a semiconductor element to a flexible substrate.

Here, the stress measurement method used in this specification will be described below. The stress shown in this specification is measured using Tencor FLX-2320 (manufactured by KLA Tencor). Tencor FLX-2320 measures the change in radius of curvature of a substrate having a stressed thin film. The stress of the thin film is obtained using Equation 2.

  In Equation 2, E / (1-v) represents the biaxial elastic modulus of the substrate, E represents the Young's modulus of the substrate, and v represents the Poisson's ratio of the substrate. 25, h represents the thickness (m) of the substrate 600, t represents the thickness (m) of the thin film 601, R represents the radius of curvature (m) of the substrate 600, and σ represents the substrate. The stress (Pa) of the thin film 601 formed on 600 is shown.

  Note that the AN100 substrate used as the substrate in this specification has a Poisson's ratio of 0.22 and a Young's modulus of 77 GPa, so that the biaxial elastic modulus is 98.7 GPa, and the EAGLE 2000 substrate has a Poisson's ratio of 0.23 and a Young's modulus of 70. Since it is 9 GPa, the biaxial elastic modulus is 92.07 GPa.

  In general, the stress includes a tensile stress and a compressive stress. As shown in FIG. 25B, when the thin film 601 is to be contracted with respect to the substrate 600, the substrate 600 is pulled in a direction to prevent it. Therefore, the substrate 600 is deformed with the thin film 601 inside. The stress generated when the thin film 601 is contracted in this way is called tensile stress. On the other hand, as shown in FIG. 25C, when the thin film 601 is about to expand, the substrate 600 is compressed inside the thin film 601. The stress generated when the thin film 601 tries to expand in this way is called a compressive stress. In general, tensile stress is often indicated by + (plus), and compressive stress is often indicated by-(minus).

(Embodiment 2)
In this embodiment, a liquid crystal display device which is an example of a semiconductor device will be described with reference to FIGS.

Figure 4 (A), the same thermal expansion coefficient 6 × ^{10 -7} / ℃ greater than 38 × ^{10 -7} / ℃ or less as in Embodiment 1, preferably greater than 6 × ^{10 -7} / ℃ An insulating film 101 is formed over the substrate 100 at 31.8 × 10 ⁻⁷ / ° C. or lower, and an amorphous semiconductor film 103 is formed over the insulating film 101. Here, AN100 having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.7 cm is used as the substrate 100. As the insulating film 101, a silicon nitride film containing oxygen having a thickness of 40 to 60 nm and a silicon oxide film containing nitrogen having a thickness of 80 to 120 nm are formed by a plasma CVD method. Further, an amorphous semiconductor film with a thickness of 20 to 80 nm is formed as the amorphous semiconductor film 103 by a plasma CVD method.

Next, the substrate 100 is heated. Here, heating for removing hydrogen from the amorphous semiconductor film formed over the substrate 100 is performed. In addition to the heating, heating for crystallizing the amorphous semiconductor film may be performed. By heating the substrate 100, the total stress of the layers on the substrate becomes −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m. Even if such a layer is irradiated with the laser beam 104 later, cracks in the substrate or a layer on the substrate can be reduced. Here, the substrate 100 is heated at 500 ° C. for 1 hour and then heated at 550 ° C. for 4 hours.

Next, as shown in FIG. 4B, the amorphous semiconductor film 103 is irradiated with a laser beam 104. At this time, the laser beam 104 selects energy capable of melting the amorphous semiconductor film 103. In addition, the wavelength of the laser beam 104 that can be absorbed by the amorphous semiconductor film 103 is selected. As a result, the crystalline semiconductor film 105 can be formed over the insulating film 101. Here, the second harmonic (wavelength 532 nm) of YVO ₄ is used as the laser beam 104.

Next, as illustrated in FIG. 4C, the crystalline semiconductor film 105 is selectively etched to form semiconductor films 201 to 203. Here, as a method for etching the crystalline semiconductor film 105, dry etching, wet etching, or the like can be used. Here, after a resist is applied over the crystalline semiconductor film 105, exposure and development are performed to form a resist mask. Next, the crystalline semiconductor film 105 is selectively etched using a resist mask by a dry etching method in which the flow rate ratio of SF ₆ : O ₂ is 4:15. Thereafter, the resist mask is removed.

  Next, as illustrated in FIG. 4D, the gate insulating film 204 is formed over the semiconductor films 201 to 203. The gate insulating film is formed with a single layer or a stacked structure of silicon nitride, silicon nitride containing oxygen, silicon oxide, silicon oxide containing nitrogen, or the like. Here, silicon oxide containing nitrogen with a thickness of 115 nm is formed by a plasma CVD method.

  Next, gate electrodes 205 to 208 are formed. The gate electrodes 205 to 208 can be formed using a polycrystalline semiconductor to which a metal or one conductivity type impurity is added. In the case of using a metal, tungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), aluminum (Al), or the like can be used. Alternatively, a metal nitride obtained by nitriding a metal can be used. Or it is good also as a structure which laminated | stacked the 1st layer which consists of the said metal nitride, and the 2nd layer which consists of the said metal. Alternatively, a paste containing fine particles can be discharged onto the gate insulating film using a droplet discharge method, and dried and baked. Further, a paste containing fine particles can be printed on the gate insulating film by a printing method, and dried and baked. As typical examples of the fine particles, fine particles mainly containing any of gold, copper, an alloy of gold and silver, an alloy of gold and copper, an alloy of silver and copper, and an alloy of gold, silver, and copper may be used. Here, a tantalum nitride film having a thickness of 30 nm and a tungsten film having a thickness of 370 nm are formed over the gate insulating film 204 by a sputtering method, and then a tantalum nitride film and tungsten using a resist mask formed by a photolithography process. The film is selectively etched to form gate electrodes 205 to 208 having a shape in which the end portion of the tantalum nitride film protrudes outside the end portion of the tungsten film.

  Next, an impurity element imparting n-type conductivity and an impurity element imparting p-type conductivity are added to the semiconductor films 201 to 203 using the gate electrodes 205 to 208 as masks, respectively, so that source and drain regions 209 to 214 and a high concentration are added. Impurity regions 215 are formed. Further, low-concentration impurity regions 216 to 223 overlapping with part of the gate electrodes 205 to 208 are formed. Here, boron which is an impurity element imparting p-type conductivity is doped into the source and drain regions 209, 210, 213 to 215, and the low-concentration impurity regions 216, 217, and 220 to 223. Further, the source and drain regions 211 and 212 and the low-concentration impurity regions 218 and 219 are doped with phosphorus which is an impurity element imparting n-type conductivity.

  Thereafter, heat treatment is performed to activate the impurity element added to the semiconductor film. Here, heating is performed at 550 ° C. for 4 hours in a nitrogen atmosphere. Through the above steps, thin film transistors 225 to 227 are formed. Note that p-channel thin film transistors are formed as the thin film transistors 225 and 227, and n-channel thin film transistors are formed as the thin film transistors 226. The p-channel thin film transistor 225 and the n-channel thin film transistor 226 form a driver circuit. The p-channel thin film transistor 227 functions as an element that applies a voltage to the pixel electrode.

  Next, as shown in FIG. 5A, a first interlayer insulating film for insulating the gate electrodes and wirings of the thin film transistors 225 to 227 is formed. Here, a silicon oxide film 231, a silicon nitride film 232, and a silicon oxide film 233 are stacked as the first interlayer insulating film. In addition, wirings 234 to 239 and connection terminals 240 connected to the source region and the drain region of the thin film transistors 225 to 227 are formed over the silicon oxide film 233 which is a part of the first interlayer insulating film. Here, the Ti film 100 nm, the Al film 333 nm, and the Ti film 100 nm are continuously formed by sputtering, and then selectively etched using a resist mask formed by a photolithography process, so that the wirings 234 to 239 and the connection terminals 240 are formed. Form. Thereafter, the resist mask is removed.

Next, a second interlayer insulating film 241 is formed over the first interlayer insulating film, the wirings 234 to 239, and the connection terminal 240. As the second interlayer insulating film 241, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film can be used. If these insulating films are formed of a single layer or two or more layers, Good. As a method for forming the inorganic insulating film, a sputtering method, an LPCVD method, a plasma CVD method, or the like may be used. Here, after a silicon nitride film containing oxygen having a thickness of 100 nm to 150 nm is formed by a plasma CVD method, the silicon nitride film containing oxygen is selectively etched using a resist mask formed by a photolithography process. In addition, a contact hole reaching the wiring 239 of the thin film transistor 227 and the connection terminal 240 is formed, and a second interlayer insulating film 241 is formed. Thereafter, the resist mask is removed.

  By forming the second interlayer insulating film 241 as in this embodiment mode, exposure of TFTs and wirings in the driver circuit portion can be prevented and the TFTs can be protected from contaminants.

  Next, a first pixel electrode 242 connected to the wiring 239 of the thin film transistor 227 and a conductive film 244 connected to the connection terminal 240 are formed. In the case where the liquid crystal display device is a light-transmitting liquid crystal display device, the first pixel electrode 242 is formed using a light-transmitting conductive film. In the case where the liquid crystal display device is a reflective liquid crystal display device, the first pixel electrode 242 is formed using a conductive film having reflectivity. Here, the first pixel electrode 242 and the conductive film 244 are selectively etched using a resist mask formed by a photolithography process after an ITO film containing 125 nm-thick silicon oxide is formed by a sputtering method. Form.

  Next, an insulating film 243 that functions as an alignment film is formed. The insulating film 243 can be formed by rubbing after a polymer compound film such as polyimide or polyvinyl alcohol is formed by a printing method, a roll coating method, or the like. Moreover, SiO can be formed by vapor deposition with respect to the substrate. Further, it can be formed by irradiating a photoreactive polymer compound with polarized UV light and polymerizing the photoreactive polymer compound. Here, a polymer compound film such as polyimide or polyvinyl alcohol is printed by printing, baked and then rubbed.

  Next, as illustrated in FIG. 5B, the second pixel electrode 253 is formed over the counter substrate 251, and the insulating film 254 that functions as an alignment film is formed over the second pixel electrode 253. Note that a colored film 252 may be provided between the counter substrate 251 and the second pixel electrode 253.

  As the counter substrate 251, a material similar to that of the substrate 100 can be selected as appropriate. Further, the second pixel electrode 253 can be formed by a method similar to that of the first pixel electrode 242. The insulating film 254 functioning as an alignment film can be formed in a manner similar to that of the insulating film 243. The colored film 252 is a film necessary for color display. In the case of the RGB system, a colored film in which dyes and pigments corresponding to red, green, and blue colors are dispersed is associated with each pixel. Form.

  Next, the substrate 100 and the counter substrate 251 are attached to each other with a sealant 257. In addition, a liquid crystal layer 255 is formed between the substrate 100 and the counter substrate 251. The liquid crystal layer 255 can be formed by injecting a liquid crystal material into a region surrounded by the insulating films 243 and 254 functioning as alignment films and the sealant 257 by a vacuum injection method using a capillary phenomenon. . In addition, a sealing material 257 is formed on one surface of the counter substrate 251, a liquid crystal material is dropped on a region surrounded by the sealing material, and then the counter substrate 251 and the substrate 100 are pressure-bonded with the sealing material under reduced pressure. 255 can be formed.

  As the sealant 257, a thermosetting epoxy resin, a UV curable acrylic resin, thermoplastic nylon, polyester, or the like can be formed using a dispenser method, a printing method, a thermocompression bonding method, or the like. Note that the distance between the substrate 100 and the counter substrate 251 can be maintained by spraying a filler over the sealant 257. Here, the sealant 257 is formed using a thermosetting epoxy resin.

  Further, a spacer 256 may be provided between the insulating films 243 and 254 functioning as alignment films in order to maintain a distance between the substrate 100 and the counter substrate 251. The spacer can be formed by applying an organic resin and etching the organic resin into a desired shape, typically a columnar shape or a cylindrical shape. Further, a bead spacer may be used as the spacer. Here, a bead spacer is used as the spacer 256.

  Although not illustrated, a polarizing plate is provided on one or both of the substrate 100 and the counter substrate 251.

  Next, as shown in FIG. 5C, in the terminal portion 263, a connection terminal connected to the gate wiring and the source wiring of the thin film transistor (in FIG. 5C, connected to the source wiring or the drain wiring). Connection terminal 240 is shown). An FPC (flexible printed wiring) 262 serving as an external input terminal is connected to the connection terminal 240 through the conductive film 244 and the anisotropic conductive film 261. The connection terminal 240 receives a video signal and a clock signal through the conductive film 244 and the anisotropic conductive film 261.

  In the driver circuit portion 264, a circuit for driving pixels such as a source driver and a gate driver is formed. Here, an n-channel thin film transistor 226 and a p-channel thin film transistor 225 are provided. Note that the n-channel thin film transistor 226 and the p-channel thin film transistor 225 form a CMOS circuit.

  A plurality of pixels are formed in the pixel portion 265, and a liquid crystal element 258 is formed in each pixel. The liquid crystal element 258 is a portion where the first pixel electrode 242, the second pixel electrode 253, and the liquid crystal layer 255 filled therebetween overlap. The first pixel electrode 242 included in the liquid crystal element 258 is electrically connected to the thin film transistor 227.

  Through the above process, a liquid crystal display device can be manufactured. In the liquid crystal display device described in this embodiment, cracks can be reduced in a substrate or a layer over the substrate in a manufacturing process. Thus, a liquid crystal display device can be manufactured with high yield.

(Embodiment 3)
In this embodiment, a manufacturing process of a light-emitting device having a light-emitting element which is an example of a semiconductor device will be described.

  As shown in FIG. 6A, thin film transistors 225 to 227 are formed over the substrate 100 with the insulating film 101 interposed therebetween, in the same process as in Embodiment Mode 2. Further, a silicon oxide film 231, a silicon nitride film 232, and a silicon oxide film 233 are stacked as a first interlayer insulating film that insulates the gate electrodes and wirings of the thin film transistors 225 to 227. In addition, wirings 308 to 313 and connection terminals 314 connected to the semiconductor films of the thin film transistors 225 to 227 are formed over part of the silicon oxide film 233 of the first interlayer insulating film.

  Next, a second interlayer insulating film 315 is formed over the first interlayer insulating film, the wirings 308 to 313, and the connection terminal 314. Next, a first electrode 316 connected to the wiring 313 of the thin film transistor 227 and a conductive film 320 connected to the connection terminal 314 are formed. The first electrode 316 and the conductive film 320 are formed by depositing ITO containing 125 nm thick silicon oxide by a sputtering method and then selectively etching the resist using a resist mask formed by a photolithography process.

  By forming the second interlayer insulating film 315 as in this embodiment mode, exposure of TFTs and wirings in the driver circuit portion can be prevented and the TFTs can be protected from contaminants.

  Next, an organic insulating film 317 that covers an end portion of the first electrode 316 is formed. Here, after applying and baking photosensitive polyimide, exposure and development are performed so that the driver circuit, the first electrode 316 in the pixel region, and the second interlayer insulating film 315 in the peripheral portion of the pixel region are exposed. Then, an organic insulating film 317 is formed.

  Next, a layer 318 containing a light-emitting substance is formed over the first electrode 316 and part of the organic insulating film 317 by an evaporation method. The layer 318 containing a light-emitting substance is formed using a light-emitting organic compound or a light-emitting inorganic compound. Alternatively, the layer 318 containing a light-emitting substance may be formed using a light-emitting organic compound and a light-emitting inorganic compound. The layer 318 containing a light-emitting substance is formed using a red light-emitting light-emitting substance, a blue light-emitting light-emitting substance, and a green light-emitting light-emitting substance, respectively. Pixels and green light-emitting pixels can be formed.

Here, as a layer containing a red light-emitting substance, DNTPD is 50 nm, NPB is 10 nm, bis [2,3-bis (4-fluorophenyl) quinoxalinato] iridium (acetylacetonato) (abbreviation: Ir (Fdpq ) ₂ (acac)) is added to 30 nm, Alq ₃ to 60 nm, and LiF to 1 nm.

The layer containing a green light-emitting luminescent material, a 50 nm, 10 nm and NPB, coumarin 545T (C545T) 40 nm of Alq ₃ that is added to form 60nm of Alq _3, and LiF was 1nm laminated DNTPD .

Further, as a layer containing a blue light-emitting substance, DNTPD is added to 50 nm, NPB is added to 10 nm, 2,5,8,11-tetra (tert-butyl) perylene (abbreviation: TBP) is added, and 9- [ It is formed by stacking 4- (N-carbazolyl)] phenyl-10-phenylanthracene (abbreviation: CzPA :) at 30 nm, Alq ₃ at 60 nm, and LiF at 1 nm.

  Furthermore, in addition to the red light emitting pixel, the blue light emitting pixel, and the green light emitting pixel, a white light emitting light emitting material is used to form a layer containing a light emitting material, thereby producing a white Alternatively, a light-emitting pixel may be formed. By providing white light-emitting pixels, power consumption can be reduced.

  Next, a second electrode 319 is formed over the layer 318 containing a light-emitting substance and the organic insulating film 317. Here, an Al film having a thickness of 200 nm is formed by an evaporation method. As a result, the light-emitting element 321 is formed by the first electrode 316, the layer 318 containing a light-emitting substance, and the second electrode 319.

  Here, the structure of the light-emitting element 321 will be described.

  By forming a layer having a light emitting function using an organic compound (hereinafter, referred to as a light emitting layer 343) in the layer 318 containing a light emitting substance, the light emitting element 321 functions as an organic EL element.

Examples of the light-emitting organic compound include 9,10-di (2-naphthyl) anthracene (abbreviation: DNA) and 2-tert-butyl-9,10-di (2-naphthyl) anthracene (abbreviation: t-BuDNA). ), 4,4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), coumarin 30, coumarin 6, coumarin 545, coumarin 545T, perylene, rubrene, periflanthene, 2,5,8,11-tetra (Tert-butyl) perylene (abbreviation: TBP), 9,10-diphenylanthracene (abbreviation: DPA), 5,12-diphenyltetracene, 4- (dicyanomethylene) -2-methyl-6- [p- (dimethylamino) ) Styryl] -4H-pyran (abbreviation: DCM1), 4- (dicyanomethylene) -2-methyl-6- [2- Loridin-9-yl) ethenyl] -4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) styryl] -4H-pyran (abbreviation: BisDCM) and the like. Can be mentioned. In addition, bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ² ′] (picolinato) iridium (abbreviation: FIrpic), bis {2- [3 ′, 5′-bis (trifluoromethyl) ) Phenyl] pyridinato-N, C ² ′} (picolinato) iridium (abbreviation: Ir (CF ₃ ppy) ₂ (pic)), tris (2-phenylpyridinato-N, C ² ′) iridium (abbreviation: Ir (Ppy) ₃ ), (acetylacetonato) bis (2-phenylpyridinato-N, C ² ′) iridium (abbreviation: Ir (ppy) ₂ (acac)), (acetylacetonato) bis [2- ( 2'-thienyl) pyridinato -N, ^{C 3} '] iridium _{(abbreviation: Ir (thp) 2 (acac} )), ( acetylacetonato) bis (2-phenylquinolinato--N, ^{C 2')} iridium _{(Abbreviation: Ir (pq) 2 (acac} )), ( acetylacetonato) bis [2- (2'-benzothienyl) pyridinato -N, ^{C 3} '] iridium (abbreviation: _Ir (btp) 2 (acac)) A compound capable of emitting phosphorescence, such as, can also be used.

  In addition, as illustrated in FIG. 7A, a hole injection layer 341 formed of a hole injection material, a hole transport layer 342 formed of a hole transport material, and light emission are formed over the first electrode 316. A light-emitting layer 343 formed of an organic compound, an electron transport layer 344 formed of an electron-transport material, a layer 318 containing a light-emitting substance formed of an electron injection layer 345 formed of an electron-inject material, and a first layer 318 The light emitting element 321 may be formed using the second electrode 319.

The hole transporting material includes phthalocyanine (abbreviation: H ₂ Pc), copper phthalocyanine (abbreviation: CuPc), vanadyl phthalocyanine (abbreviation: VOPc), and 4,4 ′, 4 ″ -tris (N, N-diphenyl). Amino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 1,3,5 -Tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m-MTDAB), N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl -4,4'-diamine (abbreviation: TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4,4'-bis {N- [ 4-di (m-tolyl) amino Phenyl-N-phenylamino} biphenyl (abbreviation: DNTPD), 4,4′-bis [N- (4-biphenylyl) -N-phenylamino] biphenyl (abbreviation: BBPB), 4,4 ′, 4 ″- Examples include tri (N-carbazolyl) triphenylamine (abbreviation: TCTA), but are not limited thereto. Among the compounds described above, aromatic amine compounds typified by TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD, BBPB, TCTA, and the like easily generate holes and are a compound group suitable as an organic compound. It is. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher.

  As the hole injecting material, there is a material obtained by chemically doping a conductive polymer compound in addition to the above hole transporting material. Polyethylenedioxythiophene (abbreviation: PEDOT) doped with polystyrene sulfonic acid (abbreviation: PSS). ) And polyaniline (abbreviation: PAni) can also be used. In addition, an inorganic semiconductor thin film such as molybdenum oxide, vanadium oxide, or nickel oxide, or an ultrathin film of an inorganic insulator such as aluminum oxide is also effective.

Here, the electron transporting materials are tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [h]. -Quinolinato) Beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), etc., a material comprising a metal complex having a quinoline skeleton or a benzoquinoline skeleton Can be used. In addition, bis [2- (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) A material such as a metal complex having an oxazole-based or thiazole-based ligand such as ₂ ) can also be used. In addition to metal complexes, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (P-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5- ( 4-biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2, 4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), and the like can be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher.

  As the electron injection material, in addition to the above-described electron transporting materials, alkali metal halides such as lithium fluoride and cesium fluoride, alkaline earth halides such as calcium fluoride, and alkali metal oxides such as lithium oxide. Insulator-like thin films such as objects are often used. Alkali metal complexes such as lithium acetylacetonate (abbreviation: Li (acac)) and 8-quinolinolato-lithium (abbreviation: Liq) are also effective. Furthermore, the material which mixed the electron transport material mentioned above and metals with small work functions, such as Mg, Li, and Cs by co-evaporation etc. can also be used.

  In addition, as illustrated in FIG. 7B, the first electrode 316, a hole-transporting layer 346 formed using a light-emitting organic compound and an inorganic compound having an electron-accepting property with respect to the light-emitting organic compound, light emission Layer 343 formed of a light-emitting organic compound, a layer containing a light-emitting substance formed by a light-emitting organic compound and an electron transport layer 347 formed of an inorganic compound having an electron donating property to the light-emitting organic compound The light-emitting element 321 may be formed using the third electrode 319 and the second electrode 319.

  The hole-transport layer 346 formed using a light-emitting organic compound and an inorganic compound having an electron-accepting property with respect to the light-emitting organic compound appropriately uses the above-described hole-transport organic compound as the organic compound. Form. The inorganic compound may be anything as long as it can easily receive electrons from an organic compound, and various metal oxides or metal nitrides can be used. Any one of Groups 4 to 12 of the periodic table can be used. These transition metal oxides are preferable because they easily exhibit electron accepting properties. Specific examples include titanium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, and zinc oxide. Among the metal oxides described above, any of the transition metal oxides in Groups 4 to 8 of the periodic table has a high electron accepting property and is a preferred group. Vanadium oxide, molybdenum oxide, tungsten oxide, and rhenium oxide are particularly preferable because they can be vacuum-deposited and are easy to handle.

  The electron-transport layer 347 formed using a light-emitting organic compound and an inorganic compound having an electron-donating property with respect to the light-emitting organic compound is formed using the above-described electron-transport organic compound as appropriate as the organic compound. Further, the inorganic compound may be anything as long as it easily gives an electron to the organic compound, and various metal oxides or metal nitrides are possible, but alkali metal oxides, alkaline earth metal oxides, Rare earth metal oxides, alkali metal nitrides, alkaline earth metal nitrides, and rare earth metal nitrides are preferred because they easily exhibit electron donating properties. Specific examples include lithium oxide, strontium oxide, barium oxide, erbium oxide, lithium nitride, magnesium nitride, calcium nitride, yttrium nitride, and lanthanum nitride. In particular, lithium oxide, barium oxide, lithium nitride, magnesium nitride, and calcium nitride are preferable because they can be vacuum-deposited and are easy to handle.

  Since the electron transport layer 347 or the hole transport layer 346 formed of a light-emitting organic compound and an inorganic compound has excellent electron injection / transport characteristics, both the first electrode 316 and the second electrode 319 have almost work. Various materials can be used without being restricted by the function. In addition, the driving voltage can be reduced.

  In addition, the light-emitting element 321 functions as an inorganic EL element by including a layer having a light-emitting function using an inorganic compound (hereinafter referred to as a light-emitting layer 349) as the layer 318 containing a light-emitting substance. Inorganic EL elements are classified into a dispersion-type inorganic EL element and a thin-film inorganic EL element depending on the element structure. The former has a layer containing a light emitting material in which particles of the light emitting material are dispersed in a binder, and the latter has a layer containing a light emitting material made of a thin film of the light emitting material. The common point is that electrons accelerated by an electric field are required. Note that the obtained light emission mechanism includes donor-acceptor recombination light emission using a donor level and an acceptor level, and localized light emission using inner-shell electron transition of a metal ion. In many cases, dispersion-type inorganic EL emits donor-acceptor recombination light emission, and thin-film inorganic EL element emits localized light emission. The structure of the inorganic EL element is shown below.

  A light-emitting material that can be used in this embodiment mode includes a base material and an impurity element that serves as a light-emission center. By changing the impurity element to be contained, light emission of various colors can be obtained. As a method for manufacturing the light-emitting material, various methods such as a solid phase method and a liquid phase method (coprecipitation method) can be used. Also, spray pyrolysis method, metathesis method, precursor thermal decomposition method, reverse micelle method, method combining these methods with high temperature firing, liquid phase method such as freeze-drying method, etc. can be used.

  The solid phase method is a method in which a base material and an impurity element or a compound thereof are weighed, mixed in a mortar, heated and fired in an electric furnace, reacted, and the base material contains the impurity element. The firing temperature is preferably 700 to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state. Although firing at a relatively high temperature is required, it is a simple method, so it has high productivity and is suitable for mass production.

  The liquid phase method (coprecipitation method) is a method in which a base material or a compound thereof and an impurity element or a compound thereof are reacted in a solution, dried, and then fired. The particles of the luminescent material are uniformly distributed, and the reaction can proceed even at a low firing temperature with a small particle size.

  As a base material used for a light-emitting material of an inorganic EL element, sulfide, oxide, or nitride can be used. Examples of sulfides that can be used include zinc sulfide, cadmium sulfide, calcium sulfide, yttrium sulfide, gallium sulfide, strontium sulfide, and barium sulfide. As the oxide, for example, zinc oxide, yttrium oxide, or the like can be used. As the nitride, for example, aluminum nitride, gallium nitride, indium nitride, or the like can be used. Furthermore, zinc selenide, zinc telluride, and the like can also be used, and may be a ternary mixed crystal such as calcium sulfide-gallium sulfide, strontium sulfide-gallium, barium sulfide-gallium.

  As emission centers of localized emission, manganese (Mn), copper (Cu), samarium (Sm), terbium (Tb), erbium (Er), thulium (Tm), europium (Eu), cerium (Ce), praseodymium (Pr) or the like can be used. Note that a halogen element such as fluorine (F) or chlorine (Cl) may be added as charge compensation.

  On the other hand, a light-emitting material containing a first impurity element that forms a donor level and a second impurity element that forms an acceptor level can be used as the emission center of donor-acceptor recombination light emission. As the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum (Al), or the like can be used. For example, copper (Cu), silver (Ag), or the like can be used as the second impurity element.

  When a light-emitting material for donor-acceptor recombination light emission is synthesized using a solid-phase method, the base material, the first impurity element or compound thereof, and the second impurity element or compound thereof are weighed, respectively, After mixing, heating and baking are performed in an electric furnace. As the base material, the above-described base material can be used, and as the first impurity element or a compound thereof, for example, fluorine (F), chlorine (Cl), aluminum sulfide, or the like can be used. In addition, as the second impurity element or a compound thereof, for example, copper (Cu), silver (Ag), copper sulfide, silver sulfide, or the like can be used. The firing temperature is preferably 700 to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state.

  In addition, as an impurity element in the case of using a solid phase reaction, a compound including a first impurity element and a second impurity element may be used in combination. In this case, since the impurity element is easily diffused and the solid-phase reaction easily proceeds, a uniform light emitting material can be obtained. Further, since no extra impurity element is contained, a light-emitting material with high purity can be obtained. As the compound constituted by the first impurity element and the second impurity element, for example, copper chloride, silver chloride, or the like can be used.

  Note that the concentration of these impurity elements may be 0.01 to 10 atom% with respect to the base material, and is preferably in the range of 0.05 to 5 atom%.

  FIG. 7C illustrates a cross section of an inorganic EL element in which a layer 318 containing a light-emitting substance includes a first insulating layer 348, a light-emitting layer 349, and a second insulating layer 350.

  In the case of a thin-film inorganic EL, the light emitting layer 349 is a layer containing the above light emitting material, and is a physical vapor deposition method (such as a resistance heating vapor deposition method, a vacuum vapor deposition method such as an electron beam vapor deposition (EB vapor deposition) method, or a sputtering method ( PVD), metal organic chemical vapor deposition (CVD), chemical vapor deposition (CVD) such as hydride transport low pressure CVD, atomic layer epitaxy (ALE), or the like.

  The first insulating layer 348 and the second insulating layer 350 are not particularly limited, but are preferably highly insulating and have a dense film quality, and more preferably have a high dielectric constant. For example, silicon oxide, yttrium oxide, aluminum oxide, hafnium oxide, tantalum oxide, barium titanate, strontium titanate, lead titanate, silicon nitride, zirconium oxide, etc., or a mixed film or a laminate of two or more of them may be used. it can. The first insulating layer 348 and the second insulating layer 350 can be formed by sputtering, vapor deposition, CVD, or the like. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm. Note that the light-emitting element of this embodiment mode does not necessarily require hot electrons, and thus can be formed into a thin film and has an advantage that a driving voltage can be reduced. The film thickness is preferably 500 nm or less, more preferably 100 nm or less.

  Note that although not illustrated, a buffer layer may be provided between the light-emitting layer 349 and the insulating layers 348 and 350 or between the light-emitting layer 349 and the electrodes 316 and 319. This buffer layer has a role of facilitating carrier injection and suppressing mixing of both layers. The buffer layer is not particularly limited, but for example, zinc sulfide, selenium sulfide, cadmium sulfide, strontium sulfide, barium sulfide, copper sulfide, lithium fluoride, calcium fluoride, fluorine, which are the base materials of the light emitting layer, are used. Barium fluoride, magnesium fluoride, or the like can be used.

  Further, as illustrated in FIG. 7D, the layer 318 containing a light-emitting substance may be formed of a light-emitting layer 349 and a first insulating layer 348. In this case, FIG. 7D illustrates a mode in which the first insulating layer 348 is provided between the second electrode 319 and the light-emitting layer 349. Note that the first insulating layer 348 may be provided between the first electrode 316 and the light-emitting layer 349.

  Further, the layer 318 containing a light-emitting substance may be formed using only the light-emitting layer 349. That is, the light-emitting element 321 may be formed using the first electrode 316, the light-emitting layer 349, and the second electrode 319.

  In the case of a dispersion type inorganic EL, a particulate luminescent material is dispersed in a binder to form a layer containing a film-like luminescent substance. When particles having a desired size cannot be obtained sufficiently by the method for manufacturing a light emitting material, the particles may be processed into particles by pulverization or the like in a mortar or the like. The binder is a substance for fixing a granular light emitting material in a dispersed state and holding it in a shape as a layer containing a light emitting substance. The light emitting material is uniformly dispersed and fixed in the layer containing the light emitting substance by the binder.

  In the case of a dispersion-type inorganic EL, a method for forming a layer containing a light-emitting substance includes a droplet discharge method that can selectively form a layer containing a light-emitting substance, a printing method (such as screen printing or offset printing), and a spin coating method. An application method, a dipping method, a dispenser method, or the like can also be used. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm. In the layer including a light-emitting material and a light-emitting substance including a binder, the ratio of the light-emitting material may be 50 wt% or more and 80 wt% or less.

  7E includes a first electrode 316, a layer 318 containing a light-emitting substance, and a second electrode 319, and the layer 318 containing a light-emitting substance emits light in which a light-emitting material 352 is dispersed in a binder 351. A layer and an insulating layer 348. Note that although the insulating layer 348 is in contact with the second electrode 319 in FIG. 7E, the insulating layer 348 may be in contact with the first electrode 316. The element may include an insulating layer in contact with each of the first electrode 316 and the second electrode 319. Further, the element does not need to have an insulating layer in contact with the first electrode 316 and the second electrode 319.

  As a binder that can be used in this embodiment mode, an organic material or an inorganic material can be used. Further, a mixed material of an organic material and an inorganic material may be used. As the organic insulating material, a polymer having a relatively high dielectric constant such as a cyanoethyl cellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride can be used. Alternatively, a heat-resistant polymer material such as aromatic polyamide, polybenzimidazole, or a siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aryl group) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, phenol resins, novolac resins, acrylic resins, melamine resins, urethane resins, and oxazole resins (polybenzoxazole) may be used. Moreover, a photocuring type etc. can be used. The dielectric constant can be adjusted by appropriately mixing fine particles having a high dielectric constant such as barium titanate or strontium titanate with these resins.

  Inorganic materials used for the binder include silicon oxide, silicon nitride, silicon containing oxygen and nitrogen, aluminum nitride, aluminum or aluminum oxide containing oxygen and nitrogen, titanium oxide, barium titanate, strontium titanate, lead titanate , Potassium niobate, lead niobate, tantalum oxide, barium tantalate, lithium tantalate, yttrium oxide, zirconium oxide, zinc sulfide, and other materials including inorganic materials. By including an inorganic material having a high dielectric constant in the organic material (by addition or the like), the dielectric constant of the layer containing the light emitting material including the light emitting material and the binder can be further controlled, and the dielectric constant can be further increased. Can do.

  In the manufacturing process, the light-emitting material is dispersed in a solution containing a binder, but as a solvent of the solution containing the binder that can be used in this embodiment mode, a method of forming a light-emitting layer by dissolving the binder material (various wet types A solvent capable of producing a solution having a viscosity suitable for the process) and a desired film thickness may be appropriately selected. For example, when a siloxane resin is used as a binder, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (also referred to as PGMEA), 3-methoxy-3-methyl-1-butanol (also referred to as MMB) can be used. Etc. can be used.

  Inorganic EL light-emitting elements can emit light by applying a voltage between a pair of electrodes sandwiching a layer containing a light-emitting substance, but can operate in either DC driving or AC driving.

  Next, as illustrated in FIG. 6B, a protective film 322 is formed over the second electrode 319. The protective film 322 is for preventing moisture, oxygen, and the like from entering the light emitting element 321 and the protective film 322. The protective film 322 uses a thin film formation method such as a plasma CVD method or a sputtering method, and includes silicon nitride, silicon oxide, silicon nitride oxide, silicon oxynitride, aluminum oxynitride, or aluminum oxide, diamond-like carbon (DLC), and nitrogen content It is preferable to use carbon or another insulating material.

  Further, the sealing substrate 324 is bonded to the second interlayer insulating film 315 formed over the substrate 100 with the sealing material 323, thereby emitting light to the space 325 surrounded by the substrate 100, the sealing substrate 324, and the sealing material 323. The element 321 is provided. Note that the space 325 is filled with a filler and may be filled with a sealant 323 in addition to an inert gas (such as nitrogen or argon).

  Note that an epoxy-based resin is preferably used for the sealant 323. Moreover, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition to a glass substrate or a quartz substrate, a plastic substrate made of FRP (Fiberglass-Reinforced Plastics), PVF (polyvinyl fluoride), polyester film, polyester, acrylic, or the like can be used as a material for the sealing substrate 324.

  Next, as illustrated in FIG. 6C, the FPC 327 is attached to the conductive film 320 in contact with the connection terminal 314 using the anisotropic conductive film 326 as in Embodiment 3.

  Through the above steps, a semiconductor device having an active matrix light-emitting element can be formed.

  Here, in this embodiment mode, an equivalent circuit diagram of a pixel in the case of full color display is shown in FIG. In FIG. 8, a thin film transistor 331 surrounded by a broken line corresponds to a thin film transistor for switching the driving thin film transistor 227 in FIG. 6A, and a thin film transistor 332 surrounded by a broken line corresponds to the thin film transistor 227 for driving a light emitting element. Yes. Note that as the light-emitting element, a mode using an organic EL element (hereinafter referred to as an OLED) in which a layer containing a light-emitting substance is formed using a layer containing a light-emitting organic compound will be described.

  In the pixel displaying red, an OLED 334R that emits red light is connected to the drain region of the thin film transistor 332, and an anode-side power line 337R is provided in the source region. The OLED 334R is provided with a cathode side power supply line 333. The switching thin film transistor 331 is connected to the gate wiring 336, and the gate electrode of the driving thin film transistor 332 is connected to the drain region of the switching thin film transistor 331. Note that the drain region of the switching thin film transistor 331 is connected to the capacitor 338 connected to the anode power supply line 337R.

In the pixel displaying green, an OLED 334G that emits green light is connected to the drain region of the driving thin film transistor 332, and an anode-side power line 337G is provided in the source region. The OLED 334G is provided with a cathode side power supply line 333, the switching thin film transistor 331 is connected to the gate wiring 336, and the gate electrode of the driving thin film transistor 332 is connected to the drain region of the switching thin film transistor 331. Is done. Note that the drain region of the switching thin film transistor 331 is connected to the capacitor 338 connected to the anode power supply line 337G.

In the pixel displaying blue, an OLED 334B that emits blue light is connected to the drain region of the driving thin film transistor 332, and an anode-side power line 337B is provided in the source region. The OLED 334B is provided with a cathode side power supply line 333, the switching thin film transistor 331 is connected to the gate wiring 336, and the gate electrode of the driving thin film transistor 332 is connected to the drain region of the switching thin film transistor 331. Is done. Note that the drain region of the switching thin film transistor 331 is connected to the capacitor 338 connected to the anode-side power supply line 337B.

Different voltages are applied to the pixels of different colors depending on the material of the layer containing the light-emitting substance.

Here, the source wiring 335 and the anode side power supply lines 337R, 337G, and 337B are formed in parallel. It may be formed. Further, the driving thin film transistor 332 may have a multi-gate electrode structure.

In the light emitting device, a driving method for screen display is not particularly limited, and for example, a dot sequential driving method, a line sequential driving method, a surface sequential driving method, or the like may be used. Typically, a line sequential driving method is used, and a time-division gray scale driving method or an area gray scale driving method may be used as appropriate. The video signal input to the source line of the light-emitting device may be an analog signal or a digital signal, and a drive circuit or the like may be designed in accordance with the video signal as appropriate.

Further, in a light emitting device in which a video signal is digital, there are a video signal input to a pixel having a constant voltage (CV) and a constant current (CC). A video signal having a constant voltage (CV) includes a signal having a constant voltage applied to the light emitting element (CVCV) and a signal having a constant current applied to the light emitting element (CVCC). . In addition, when the video signal has a constant current (CC), the signal voltage applied to the light emitting element is constant (CCCV), and the signal applied to the light emitting element has a constant current (CCCC). There is.

  In the light emitting device, a protection circuit (such as a protection diode) for preventing electrostatic breakdown may be provided.

  Through the above process, a light-emitting device having an active matrix light-emitting element can be manufactured. In the light-emitting device described in this embodiment, cracks can be reduced in a substrate or a layer over the substrate in a manufacturing process. Therefore, a light-emitting device can be manufactured with high yield.

(Embodiment 4)
In this embodiment, a manufacturing process of a semiconductor device capable of transmitting data without contact will be described with reference to FIGS. A structure of the semiconductor device will be described with reference to FIG. The use of the semiconductor device described in this embodiment will be described with reference to FIGS.

  As shown in FIG. 9A, a separation film 402 is formed over a substrate 401. Next, an insulating film 403 is formed over the separation film 402 and a thin film transistor 404 is formed over the insulating film 403. Next, an interlayer insulating film 405 that insulates a conductive film included in the thin film transistor 404 is formed, and a source electrode and a drain electrode 406 connected to the semiconductor film of the thin film transistor 404 are formed. Next, an insulating film 407 is formed to cover the thin film transistor 404, the interlayer insulating film 405, and the source and drain electrodes 406, and a conductive film 408 connected to the source or drain electrode 406 through the insulating film 407 is formed.

  As the substrate 401, a substrate similar to the substrate 100 can be used. Alternatively, a metal substrate or a stainless steel substrate with an insulating film formed on one surface thereof, a heat-resistant plastic substrate that can withstand the processing temperature in this step, a ceramic substrate, or the like can be used. Here, a glass substrate is used as the substrate 401.

  The release film 402 is formed of tungsten (W), molybdenum (Mo), titanium (Ti), tantalum (Ta), niobium (Nb), nickel (Ni), sputtering, plasma CVD, coating, printing, or the like. An element selected from cobalt (Co), zirconium (Zr), zinc (Zn), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), silicon (Si), Alternatively, a layer formed of an alloy material containing an element as a main component or a compound material containing an element as a main component is formed as a single layer or a stacked layer. The crystal structure of the release film containing silicon may be any of amorphous, microcrystalline, and polycrystalline.

In the case where the separation film 402 has a single-layer structure, a layer containing tungsten, molybdenum, or a mixture of tungsten and molybdenum is preferably formed. Or a layer containing tungsten oxide or a layer containing oxynitride, a layer containing molybdenum oxide or a layer containing oxynitride, or a layer containing an oxide of a mixture of tungsten and molybdenum or oxynitride Form a layer. Note that the mixture of tungsten and molybdenum corresponds to, for example, an alloy of tungsten and molybdenum.

  In the case where the separation film 402 has a stacked structure, it is preferable that a layer containing tungsten, molybdenum, or a mixture of tungsten and molybdenum be formed as a first layer, and an oxide of tungsten, molybdenum, or a mixture of tungsten and molybdenum be formed as a second layer. A layer containing nitride, a layer containing nitride, a layer containing oxynitride, or a layer containing nitride oxide is formed.

In the case where a stacked structure of a layer containing tungsten and a layer containing tungsten oxide is formed as the separation film 402, a layer containing tungsten is formed, and an insulating layer formed using an oxide is formed thereover. The fact that a layer containing an oxide of tungsten is formed at the interface between the tungsten layer and the insulating layer may be utilized. Furthermore, the surface of the layer containing tungsten is subjected to thermal oxidation treatment, oxygen plasma treatment, N ₂ O plasma treatment, treatment with a solution having strong oxidizing power such as ozone water, treatment with water to which hydrogen is added, and the like. Alternatively, a layer containing an oxide of tungsten may be formed. This also applies to the case where a layer containing tungsten nitride, a layer containing oxynitride, or a layer containing nitride oxide is formed. After forming a layer containing tungsten, a silicon nitride layer, an oxide layer is formed thereon. A silicon nitride layer or a silicon nitride oxide layer is preferably formed.

The oxide of tungsten is represented by WOx. x is in the range of 2 ≦ x ≦ 3, when x is 2 (WO ₂ ), when x is 2.5 (W ₂ O ₅ ), when x is 2.75 (W ₄ O ₁₁₎ ), And x is 3 (WO ₃ ).

  Here, a tungsten film having a thickness of 20 to 100 nm, preferably 40 to 80 nm, is formed by a sputtering method.

  Note that although the peeling film 402 is formed so as to be in contact with the substrate 401 according to the above steps, the present invention is not limited to this step. An insulating film serving as a base may be formed so as to be in contact with the substrate 401, and the peeling film 402 may be provided so as to be in contact with the insulating film.

The insulating film 403 can be formed in a manner similar to that of the insulating film 101. Here, plasma is generated while flowing N ₂ O gas to form a tungsten oxide film on the surface of the separation film 402, and then a silicon oxide film containing nitrogen is formed by a plasma CVD method.

  The thin film transistor 404 can be formed in a manner similar to that of the thin film transistors 225 to 227 described in Embodiment 2. The source and drain electrodes 406 can be formed in a manner similar to the wirings 234 to 239 described in Embodiment 2.

  The interlayer insulating film 405 and the insulating film 407 can be formed by applying and baking polyimide, acrylic, or siloxane polymer. Alternatively, a single layer or a stacked layer may be formed using an inorganic compound by a sputtering method, a plasma CVD method, a coating method, a printing method, or the like. Typical examples of the inorganic compound include silicon oxide, silicon nitride, and silicon oxynitride.

  Next, as illustrated in FIG. 9B, a conductive film 411 is formed over the conductive film 408. Here, a composition having gold particles is printed by a printing method, heated at 200 ° C. for 30 minutes, and the composition is baked to form the conductive film 411.

  Next, as illustrated in FIG. 9C, an insulating film 412 which covers end portions of the insulating film 407 and the conductive film 411 is formed. Here, the insulating film 412 which covers end portions of the insulating film 407 and the conductive film 411 is formed using an epoxy resin. After applying the epoxy resin composition by spin coating and heating at 160 ° C. for 30 minutes, the insulating film covering the conductive film 411 is removed to expose the conductive film 411 and have a thickness of 1 to 20 μm. An insulating film 412 having a thickness of 5 to 10 μm is preferably formed. Here, a stacked body from the insulating film 403 to the insulating film 412 is referred to as an element formation layer 410.

  Next, as illustrated in FIG. 9D, the insulating films 403, 405, and 407, and the insulating film 412 are irradiated with a laser beam 413 in order to easily perform the subsequent peeling step, so that FIG. An opening 414 as shown in FIG. Next, an adhesive member 415 is attached to the insulating film 412. As the laser beam with which the opening 414 is formed, a laser beam having a wavelength absorbed by the insulating films 403, 405, and 407 or the insulating film 412 is preferable. Typically, irradiation is performed by appropriately selecting a laser beam in an ultraviolet region, a visible region, or an infrared region.

As a laser oscillator capable of oscillating such a laser beam, an excimer laser oscillator such as ArF, KrF, or XeCl, or the same one as the laser oscillators 11a and 11b described in Embodiment 1 can be used as appropriate. In the solid-state laser oscillator, it is preferable to appropriately apply the fundamental wave to the fifth harmonic. As a result, the insulating films 403, 405, 407, and 412 absorb the laser beam and melt to form openings.

Note that throughput can be improved by eliminating the step of irradiating the insulating films 403, 405, 407, and 412 with a laser beam.

  Next, as illustrated in FIG. 10A, in the metal oxide film formed at the interface between the separation film 402 and the insulating film 403, the substrate 401 having the separation film and the part 421 of the element formation layer are physically attached. Peel off. Physical means refers to mechanical means or mechanical means, and means to change some mechanical energy (mechanical energy). The physical means is typically applying mechanical force (for example, a process of peeling with a human hand or a grip jig, or a process of separating while rotating the roller with the roller as a fulcrum).

  In this embodiment, a method is used in which a metal oxide film is formed between the peeling film and the insulating film, and a part 421 of the element formation layer is peeled off by physical means in the metal oxide film. Absent. A light-transmitting substrate is used as the substrate, an amorphous silicon layer containing hydrogen is used as the peeling film, and an amorphous semiconductor film is irradiated with a laser beam from the substrate side after the step of FIG. A method can be used in which hydrogen contained in is vaporized and separated between the substrate and the separation film.

  Further, after the step of FIG. 9E, a method of mechanically polishing and removing the substrate or a method of removing the substrate using a solution that dissolves the substrate such as HF can be used. In this case, it is not necessary to use a release film.

In FIG. 9E, before bonding the adhesive member 415 to the insulating film 412, a halogen fluoride gas such as NF ₃ , BrF ₃ , or ClF ₃ is introduced into the opening 414, and the release film is made of halogen fluoride. After etching and removing with gas, a method in which an adhesive member 415 is attached to the insulating film 412 and a part 421 of the element formation layer is peeled from the substrate can be used.

In FIG. 9E, before adhering the adhesive member 415 to the insulating film 412, a halogen fluoride gas such as NF ₃ , BrF ₃ , or ClF ₃ is introduced into the opening 414, and a part of the separation film is formed. After etching and removing with halogen fluoride gas, an adhesive member 415 is attached to the insulating film 412, and a part 421 of the element formation layer is peeled off from the substrate by physical means.

  Next, as illustrated in FIG. 10B, a flexible substrate 422 is attached to the insulating film 403 of the part 421 of the element formation layer. Next, the adhesive member 415 is peeled off from the part 421 of the element formation layer. Here, as the flexible substrate 422, a film formed of polyaniline by a casting method is used.

  Next, as illustrated in FIG. 10C, the flexible substrate 422 is attached to the UV sheet 431 of the dicing frame 432. Since the UV sheet 431 has adhesiveness, the flexible substrate 422 is fixed on the UV sheet 431. After that, the conductive film 411 may be irradiated with a laser beam to improve adhesion between the conductive film 411 and the conductive film 408.

  Next, as illustrated in FIG. 10D, the connection terminal 433 is formed over the conductive film 411. By forming the connection terminal 433, alignment and adhesion with a conductive film which functions as an antenna later can be easily performed.

Next, as illustrated in FIG. 11A, a part 421 of the element formation layer is divided. Here, the part 421 of the element formation layer and the flexible substrate 422 are irradiated with a laser beam 434, so that the part 421 of the element formation layer is divided into a plurality of portions as illustrated in FIG. As the laser beam 434, a laser beam described in the laser beam 413 can be selected as appropriate and applied. Here, it is preferable to select a laser beam that can be absorbed by the insulating films 403, 405, and 407, the insulating film 412, and the flexible substrate 422. Note that, here, a part of the element formation layer is divided into a plurality of parts by using a laser cut method, but a dicing method, a scribing method, or the like can be appropriately used instead of this method. As a result, the divided element formation layers are denoted as thin film integrated circuits 442a and 442b.

  Next, as illustrated in FIG. 11C, the UV sheet of the dicing frame 432 is irradiated with UV light to reduce the adhesive strength of the UV sheet 431, and then the UV sheet 431 is supported by the expander frame 444. . At this time, the width of the groove 441 formed between the thin film integrated circuits 442a and 442b can be increased by supporting the expander frame 444 while extending the UV sheet 431. Note that the enlarged groove 446 is preferably matched with the size of the antenna substrate to be bonded to the thin film integrated circuits 442a and 442b later.

  Next, as shown in FIG. 12A, a flexible substrate 456 having conductive films 452a and 452b functioning as antennas and thin film integrated circuits 442a and 442b are used with anisotropic conductive adhesives 455a and 455b. And paste them together. Note that the flexible substrate 456 including the conductive films 452a and 452b functioning as antennas is provided with openings so that parts of the conductive films 452a and 452b are exposed. Therefore, the conductive films 452a and 452b functioning as antennas and the connection terminals of the thin film integrated circuits 442a and 442b are connected to the conductive particles 454a and 454b included in the anisotropic conductive adhesives 455a and 455b. , Paste together while aligning.

  Here, the conductive film 452a functioning as an antenna and the thin film integrated circuit 442a are connected by the conductive particles 454a in the anisotropic conductive adhesive 455a, and the conductive film 452b functioning as an antenna and the thin film integrated circuit 442b are They are connected by conductive particles 454b in the anisotropic conductive adhesive 455b.

  Next, as illustrated in FIG. 12B, the flexible substrate 456 and the insulating film 453 are separated in a region where the conductive films 452a and 452b functioning as antennas and the thin film integrated circuits 442a and 442b are not formed. Here, the insulating film 453 and the flexible substrate 456 are divided by a laser cut method in which a laser beam 461 is irradiated.

  Through the above steps, as illustrated in FIG. 12C, semiconductor devices 462a and 462b that can transmit data without contact can be manufactured.

  Note that in FIG. 12A, a flexible substrate 456 including conductive films 452a and 452b functioning as antennas and thin film integrated circuits 442a and 442b are attached to each other with anisotropic conductive adhesives 455a and 455b. After that, a flexible substrate 463 is provided so as to seal the flexible substrate 456 and the thin film integrated circuits 442a and 442b. As shown in FIG. 12B, conductive films 452a and 452b functioning as antennas and thin films A semiconductor device 464 as illustrated in FIG. 12D may be manufactured by irradiation with a laser beam 461 in a region where the integrated circuits 442a and 442b are not formed. In this case, since the thin film integrated circuit is sealed by the divided flexible substrates 456 and 463, deterioration of the thin film integrated circuit can be suppressed.

  Through the above process, a thin and lightweight semiconductor device can be manufactured with high yield. The semiconductor device of this embodiment can reduce occurrence of cracks in a substrate or a layer over the substrate in a manufacturing process. Thus, a semiconductor device can be manufactured with high yield.

  Next, a structure of the semiconductor device capable of transmitting data without contact will be described with reference to FIG.

The semiconductor device of this embodiment is roughly composed of an antenna unit 2001, a power supply unit 2002, and a logic unit 2003.

The antenna unit 2001 includes an antenna 2011 for receiving external signals and transmitting data. As a signal transmission method in the semiconductor device, an electromagnetic coupling method, an electromagnetic induction method, a microwave method, or the like can be used. The transmission method may be appropriately selected by the practitioner in consideration of the intended use, and an optimal antenna may be provided according to the transmission method.

The power supply unit 2002 includes a rectifier circuit 2021 that generates power based on a signal received from the outside via the antenna 2011, and a storage capacitor 2022 that stores the generated power.

The logic unit 2003 includes a demodulation circuit 2031 that demodulates the received signal, a clock generation / correction circuit 2032 that generates a clock signal, each code recognition and determination circuit 2033, and a signal for reading data from the memory based on the received signal. It has a memory controller 2034 to be created, a modulation circuit 2035 for putting the encoded signal on the received signal, an encoding circuit 2037 for encoding the read data, and a mask ROM 2038 for holding the data. Note that the modulation circuit 2035 includes a modulation resistor 2036.

The codes recognized and determined by each code recognition and determination circuit 2033 are a frame end signal (EOF, end of frame), a frame start signal (SOF, start of frame), a flag, a command code, a mask length (mask length), and a mask. For example, a value (mask value). Each code recognition and determination circuit 2033 also includes a cyclic redundancy check (CRC) function for identifying a transmission error.

  Next, an application of the semiconductor device capable of transmitting data without contact will be described with reference to FIGS. The semiconductor device capable of transmitting data without contact is widely used. For example, banknotes, coins, securities, bearer bonds, certificate documents (driver's license, resident's card, etc., see FIG. 14A). ), Packaging containers (wrapping paper, bottles, etc., see FIG. 14C), recording media (DVD software, videotapes, etc., see FIG. 14B), vehicles (bicycles, etc., FIG. 14D) See), personal items (such as bags and glasses), foods, plants, animals, clothing, daily necessities, electronic goods, etc. and luggage tags (see FIGS. 14E and 14F) It can be used by being provided on an article such as. Electronic devices refer to liquid crystal display devices, EL display devices, television devices (also simply referred to as televisions, television receivers, television receivers), mobile phones, and the like.

The semiconductor device 9210 of this embodiment is fixed to an article by mounting on a printed board, sticking to a surface, embedding, or the like. For example, a book is embedded in paper, and a package made of an organic resin is embedded in the organic resin, and is fixed to each article. Since the semiconductor device 9210 of the present embodiment realizes a small size, a thin shape, and a light weight, the design of the article itself is not impaired even after being fixed to the article. In addition, by providing the semiconductor device 9210 of this embodiment on banknotes, coins, securities, bearer bonds, certificates, etc., an authentication function can be provided, and if this authentication function is used, forgery is prevented. be able to. In addition, by providing the semiconductor device of this embodiment in packaging containers, recording media, personal items, foods, clothing, daily necessities, electronic devices, etc., it is possible to improve the efficiency of systems such as inspection systems. it can.

(Embodiment 5)
As electronic devices including the semiconductor device described in any of the above embodiments, a television device (also simply referred to as a television or a television receiver), a camera such as a digital camera or a digital video camera, or a mobile phone device (simply a mobile phone or a mobile phone) (Also called a telephone), portable information terminals such as PDAs, portable game machines, computer monitors, computers, sound reproduction apparatuses such as car audio, and image reproduction apparatuses equipped with recording media such as home game machines. . A specific example thereof will be described with reference to FIG.

  A portable information terminal illustrated in FIG. 15A includes a main body 9201, a display portion 9202, and the like. By applying what is described in the above embodiment to the display portion 9202, a portable information terminal capable of high-definition display can be provided at low cost.

  A digital video camera shown in FIG. 15B includes a display portion 9701, a display portion 9702, and the like. By applying the display portion 9701 to the display portion described above, a digital video camera capable of high-definition display can be provided at low cost.

  A portable terminal illustrated in FIG. 15C includes a main body 9101, a display portion 9102, and the like. By applying what is described in the above embodiment to the display portion 9102, a highly reliable portable terminal can be provided at low cost.

  A portable television device illustrated in FIG. 15D includes a main body 9301, a display portion 9302, and the like. By applying what is described in the above embodiment to the display portion 9302, a portable television device capable of high-definition display can be provided at low cost. Such a television device can be widely applied from a small one mounted on a portable terminal such as a cellular phone to a medium-sized one that can be carried and a large one (for example, 40 inches or more). .

  A portable computer shown in FIG. 15E includes a main body 9401, a display portion 9402, and the like. By using the display portion 9402 which is described in the above embodiment, a portable computer capable of high-quality display can be provided at low cost.

  A television device illustrated in FIG. 15F includes a main body 9501, a display portion 9502, and the like. By applying the display portion 9502 to the above embodiment, a television device capable of high-definition display can be provided at low cost.

  Here, a configuration of the television device will be described with reference to FIG.

  FIG. 16 is a block diagram illustrating a main configuration of a television device. A tuner 9511 receives a video signal and an audio signal. The video signal includes a video detection circuit 9512, a video signal processing circuit 9513 that converts the signal output from the video signal into a color signal corresponding to each color of red, green, and blue, and converts the video signal into the input specifications of the driver IC. Is processed by a control circuit 9514. The control circuit 9514 outputs signals to the scan line driver circuit 9516 and the signal line driver circuit 9517 of the display panel 9515, respectively. In the case of digital driving, a signal dividing circuit 9518 may be provided on the signal line side so that an input digital signal is divided into m pieces and supplied.

  Of the signals received by the tuner 9511, the audio signal is sent to the audio detection circuit 9521, and the output is supplied to the speaker 9523 through the audio signal processing circuit 9522. The control circuit 9524 receives control information on the receiving station (reception frequency) and volume from the input unit 9525 and sends a signal to the tuner 9511 and the audio signal processing circuit 9522.

  This television device includes the display panel 9515, whereby low power consumption of the television device can be achieved. In addition, a television device capable of high-definition display can be manufactured.

  Note that the present invention is not limited to a television receiver, and is applicable to various uses as a display medium of a particularly large area such as a monitor of a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

  Next, a cellular phone will be described with reference to FIG. 17 as one embodiment of an electronic device on which the semiconductor device of the present invention is mounted. The cellular phone includes housings 2700 and 2706, a display panel 2701, a housing 2702, a printed wiring board 2703, operation buttons 2704, and a battery 2705 (see FIG. 17). A display panel 2701 is incorporated in a housing 2702 so as to be detachable. The housing 2702 is fitted on a printed wiring board 2703. The shape and size of the housing 2702 are changed as appropriate in accordance with an electronic device into which the display panel 2701 is incorporated. A plurality of packaged semiconductor devices are mounted on the printed wiring board 2703, and the semiconductor device of the present invention can be used as one of them. The plurality of semiconductor devices mounted on the printed wiring board 2703 have any one function of a controller, a central processing unit (CPU), a memory, a power supply circuit, a sound processing circuit, a transmission / reception circuit, and the like.

A printed wiring board 2703 is connected to the display panel 2701 through a connection film 2708. The display panel 2701, the housing 2702, and the printed wiring board 2703 are housed in the housings 2700 and 2706 together with the operation buttons 2704 and the battery 2705. A pixel region 2709 included in the display panel 2701 is arranged so that it can be seen from an opening window provided in the housing 2700.

In the display panel 2701, a pixel portion and some peripheral driver circuits (a driver circuit having a low operating frequency among the plurality of driver circuits) are integrally formed using a TFT over a substrate, and some peripheral driver circuits (a plurality of driver circuits) are formed. A driving circuit having a high operating frequency among the circuits) may be formed over the IC chip. The IC chip may be mounted on the display panel 2701 by COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate using TAB (Tape Automated Bonding) or a printed board. Note that FIG. 18A illustrates an example of a structure of a display panel in which some peripheral driver circuits are integrally formed with a pixel portion over a substrate and an IC chip on which other peripheral driver circuits are formed is mounted with COG or the like. 18A includes a substrate 3900, a signal line driver circuit 3901, a pixel portion 3902, a scan line driver circuit 3903, a scan line driver circuit 3904, an FPC 3905, an IC chip 3906, an IC chip 3907, and a sealing substrate. 3908 and a sealant 3909. With such a structure, the power consumption of the display device can be reduced, and the usage time by one charge of the mobile phone can be extended. In addition, the cost of the mobile phone can be reduced.

In order to further reduce power consumption, a pixel portion is formed on a substrate using TFTs as shown in FIG. 18B, and all peripheral driver circuits are formed on an IC chip. You may mount in a display panel by COG (Chip On Glass). Note that the display panel in FIG. 18B includes a substrate 3910, a signal line driver circuit 3911, a pixel portion 3912, a scan line driver circuit 3913, a scan line driver circuit 3914, an FPC 3915, an IC chip 3916, an IC chip 3917, and a sealing substrate. 3918 and a sealant 3919 are provided.

As described above, the semiconductor device of the present invention is characterized in that it is small, thin, and lightweight, and the limited space inside the housings 2700 and 2706 of the electronic device can be effectively used due to the above characteristics. . In addition, cost reduction is possible and an electronic device including a highly reliable semiconductor device can be manufactured.

  In this embodiment, the total stress (calculated value) and cracks after the substrate that is prone to crack when irradiated with a laser beam and the layer including the semiconductor film formed on the substrate are heated. The presence or absence of occurrence is shown.

  First, after a layer including a semiconductor film is formed over a substrate and a layer including the semiconductor film is irradiated with a laser beam, generation of cracks and the type of the substrate will be described with reference to FIGS.

  A layer including a semiconductor film was formed over the substrates 1 to 3. Here, as a layer including a semiconductor film, a silicon nitride oxide film with a thickness of 50 nm, a silicon oxynitride film with a thickness of 100 nm, and an amorphous silicon film with a thickness of 66 nm are sequentially formed by a plasma CVD method. .

  Here, EAGLE 2000 (manufactured by Corning) having a thickness of 0.7 mm is used as the substrate 1, AN100 (manufactured by Asahi Glass) having a thickness of 0.7 mm is used as the substrate 2, and a thickness of 0.7 mm is used as the substrate 3. AQ (quartz) substrate (Asahi Glass Co., Ltd.) was used.

Here, the thermal expansion coefficient of each substrate is shown in Table 1 and FIG.

  Table 2 shows deposition conditions of the silicon nitride oxide film, the silicon oxynitride film, and the amorphous silicon film.

Next, the substrates 1 to 3 were heated in a furnace at 500 ° C. for 1 hour, and then heated at 550 ° C. for 4 hours.

Next, the laser beam was irradiated to the substrates 1 to 3. The laser beam irradiation conditions at this time were such that the second harmonic of Nd: YVO ₄ was used as the laser oscillator, the scan speed was 35 cm / sec, the power was 18 W, and the number of scans was 10.

  Table 3 shows the presence or absence of cracks in the substrates 1 to 3 and the average number of cracks. At this time, as the average number of cracks, the average number of cracks per scan was shown at the substrate end and 1 cm inside from the substrate end.

図１９、表１、及び表３より、熱膨張率が６×１０^−７／℃より大きく３８×１０^−７／℃以下、好ましくは６×１０^−７／℃より大きく３１．８×１０^−７／℃以下の基板においては、半導体膜を含む層を形成し加熱した後レーザビームを照射すると、基板乃至半導体膜を含む層にクラックが生じることが分かった。

19, Table 1 and Table 3, the coefficient of thermal expansion is greater than 6 × 10 ⁻⁷ / ° C. and less than or equal to 38 × 10 ⁻⁷ / ° C., preferably greater than 6 × 10 ⁻⁷ / ° C. and 31.8 × 10 ^{− It} was found that in a substrate of ⁷ / ° C. or lower, a layer including a semiconductor film was formed and heated and then irradiated with a laser beam, and then a crack was generated in the substrate or the layer including the semiconductor film.

Next, in a substrate having a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. The conditions of the layer including the semiconductor film in which the substrate or the layer including the semiconductor film was not cracked even when the layer including the semiconductor film was formed and heated and then irradiated with the laser beam were examined. The results are shown below with reference to FIGS.

In FIG. 21, after using AN100 (Asahi Glass Co., Ltd.) having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm as a substrate, a layer including a semiconductor film is formed on the substrate and heated. Whether or not a crack occurs in the substrate or the layer including the semiconductor film when irradiated with the laser beam, and the total stress of the layer including the semiconductor film calculated from the film stress of the film constituting the layer including the semiconductor film and the film thickness The relationship is shown.

In FIG. 21, sample 1 has the structure 510 in FIG. 20A. A silicon nitride oxide film 502 with a thickness of 140 nm, a silicon oxynitride film 503 with a thickness of 100 nm as a layer including a semiconductor film over a substrate 501, Then, an amorphous silicon film 504 having a thickness of 66 nm was sequentially formed by a plasma CVD method.

Samples 2 to 9 each have a structure 520 in FIG. 20B, and include a silicon nitride oxide film 512 with a thickness of 50 nm, a silicon oxynitride film 503 with a thickness of 100 nm as a layer including a semiconductor film over a substrate 501, and Amorphous silicon films 504 having a thickness of 66 nm were sequentially formed by plasma CVD.

The sample 10 has a structure 530 in FIG. 20C, and a 100-nm-thick silicon oxynitride film 503 and a 66-nm-thick amorphous silicon film 504 are formed on the substrate 501 as layers including a semiconductor film, respectively. Films were formed in order by the CVD method.

Table 4 shows the film forming conditions of Samples 1 to 10.

  In addition, film stress after each film forming the layers including the semiconductor films of Sample 1 to Sample 10 on the silicon substrate, film stress after heat treatment at 650 ° C. for 6 minutes, film stress after film formation, A value obtained by calculating the total stress of the layer including the semiconductor film from the film thickness, a value calculated by calculating the total stress of the layer including the semiconductor film formed on the substrate from the film stress after heating at 650 ° C. for 6 minutes and the film thickness. As shown in FIG. Further, a value obtained by calculating the total stress of the layer including the semiconductor film from the film stress and the film thickness after forming each film constituting the layer including the semiconductor film of Sample 1 to Sample 10 on the silicon substrate is shown in FIG. This is indicated by a triangle mark. Further, the black circles in FIG. 21 show values obtained by calculating the total stress of the layer including the semiconductor film formed on the substrate from the film stress and the film thickness after heating Samples 1 to 10 at 650 ° C. for 6 minutes. The total stress S of the layer including the semiconductor film was calculated using the above formula 1.

  The change in the total stress of the layer including the semiconductor film after heating as shown in Table 5 is mainly caused by the film formation conditions and the film density of the silicon nitride oxide films 502 and 512. When the silicon nitride oxide films 502 and 512 are formed under a condition such that the silicon nitride oxide films 502 and 512 are dense, the film stress of the silicon nitride oxide films 502 and 512 after heating tends to be compressive stress. In addition, since the film stress of silicon oxynitride and amorphous silicon film does not change so much before and after heating, the film stress of the silicon nitride oxide film becomes compressive stress, so that the total stress of the layer including the semiconductor film after heating is , Less than 0 N / m, preferably -16 N / m or less, resulting in compressive stress.

  As shown in FIG. 21, in Samples 1 to 7, cracks occurred in the layers including the substrate and the semiconductor film. On the other hand, in Samples 8 to 10, no crack was generated in the layer including the substrate or the semiconductor film.

From FIG. 21 and Table 5, the total stress after heating is less than 0 N / m on an AN100 (Asahi Glass Co., Ltd.) substrate having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm, preferably It can be seen that by forming a layer including a semiconductor film of −16 N / m or less, no crack is generated in the substrate or the layer including the semiconductor film even when the layer including the semiconductor film is irradiated with a laser beam.

  In addition, when the total stress after heating of the layer including the semiconductor film formed on the substrate is less than −150 N / m, and further −500 N / m, there is a problem that the layer including the semiconductor film is peeled from the substrate. For this reason, the total stress that does not peel off after heating the layer including the semiconductor film formed on the substrate is −500 N / m or more, preferably −150 N / m or more.

Next, when using EAGLE 2000 (manufactured by Corning) having a thermal expansion coefficient of 31.8 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm as the substrate, a semiconductor laser beam formed on the substrate was irradiated. FIG. 22 shows the relationship between the presence or absence of occurrence of cracks in the substrate or the layer including the semiconductor film and the total stress calculated from the film stress and the film thickness of the film constituting the layer including the semiconductor film.

The sample 11 has a structure 510 in FIG. 20A and includes a silicon nitride oxide film 502 with a thickness of 140 nm, a silicon oxynitride film 503 with a thickness of 100 nm, and a thickness of 66 nm as a layer including a semiconductor film over a substrate 501. Amorphous silicon films 504 were sequentially formed by plasma CVD.

Samples 12 to 15 have the structure 520 in FIG. 20B, and include a silicon nitride oxide film 512 with a thickness of 50 nm, a silicon oxynitride film 503 with a thickness of 100 nm, and a layer including a semiconductor film over a substrate 501. Amorphous silicon films 504 having a thickness of 66 nm were sequentially formed by plasma CVD.

The sample 16 has the structure 530 in FIG. 20C, and a 100-nm-thick silicon oxynitride film 503 and a 66-nm-thick amorphous silicon film 504 are formed on the substrate 501 as layers including a semiconductor film. Films were formed in order by the CVD method.

The film formation conditions for Samples 11 to 16 are shown in Table 4 above.

  Further, film stress after each film forming the layers including the semiconductor films of Sample 11 to Sample 16 on the silicon substrate, film stress after heat treatment at 650 ° C. for 6 minutes, film stress after film formation, and A value obtained by calculating the total stress of the layer including the semiconductor film from the film thickness, a value calculated by calculating the total stress of the layer including the semiconductor film formed on the substrate from the film stress after heating at 650 ° C. for 6 minutes and the film thickness. It is shown in FIG. Furthermore, the values obtained by calculating the total stress of the layer including the semiconductor film from the film stress and the film thickness after each film of each sample is formed on the silicon substrate are indicated by triangles in FIG. Further, the black circles in FIG. 22 show values obtained by calculating the total stress of the layer including the semiconductor film formed on the substrate from the film stress and the film thickness after heating the samples 11 to 16 at 650 ° C. for 6 minutes.

  The change in the total stress of the layer including the semiconductor film after heating as shown in Table 6 is mainly caused by the film formation conditions and the film density of the silicon nitride oxide films 502 and 512. When the silicon nitride oxide films 502 and 512 are formed under conditions such as a low film formation rate and high temperature, for example, a dense film is formed. As a result, the total stress value at which the layer including the semiconductor film does not peel after heating is less than +50 N / m, preferably +28 N / m or less.

As shown in FIG. 22, in Sample 11 and Sample 12, cracks occurred in the layer including the substrate or the semiconductor film. On the other hand, in Samples 13 to 16, no crack was generated in the layer including the substrate or the semiconductor film.

According to FIG. 22 and Table 6, the total stress after heating is less than +50 N / m on an EAGLE 2000 (made by Corning) substrate having a thermal expansion coefficient of 31.8 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm, preferably It can be seen that by forming a layer including a semiconductor film of +28 N / m or less, no crack is generated in the layer including the substrate or the semiconductor film even when the layer including the semiconductor film is irradiated with a laser beam.

  In addition, when the total stress after heating of the layer including the semiconductor film formed on the substrate is less than −150 N / m, and further −500 N / m, there is a problem that the layer including the semiconductor film is peeled from the substrate. For this reason, it is desirable that the total stress after heating of the layer including the semiconductor film formed on the substrate is −500 N / m or more, preferably −150 N / m or more.

On an AN100 (Asahi Glass Co., Ltd.) substrate having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm, the total stress after heating is −500 N / m or more and less than 0 N / m, preferably −150 N After the formation of the layer including the semiconductor film of / m to -16 N / m, the number of cracks generated in the layer including the substrate or the semiconductor film can be reduced by irradiating the layer with a laser beam.

Further, on the EAGLE 2000 (manufactured by Corning) substrate having a coefficient of thermal expansion of 31.8 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm, the total stress after heating is −500 N / m or more and less than +50 N / m, preferably When a layer including a semiconductor film of −150 N / m or more and +28 N / m or less is formed, cracks are not generated in the substrate or the layer including the semiconductor film even when the layer including the semiconductor film is irradiated with a laser beam. I understand.

From the above, it has a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. In the substrate, a layer including a semiconductor film having a total stress after heating of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m is formed, and then the layer is irradiated with a laser beam. Accordingly, the number of cracks generated in the layer including the substrate or the semiconductor film can be reduced.

  In this embodiment, the stress (experimental value) after the layer including the amorphous semiconductor film formed on the substrate is heated and the number of cracks generated when the amorphous semiconductor film is irradiated with the laser beam. Is shown using FIG.

A layer including an amorphous semiconductor film was formed over the substrate. Here, an AN100 substrate having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.7 mm was used as the substrate.

  In Sample 21-1 to Sample 21-3, a silicon nitride oxide film having a thickness of 50 nm, a silicon oxynitride film having a thickness of 100 nm, and an amorphous silicon film having a thickness of 66 nm are sequentially formed as a layer including a semiconductor film over a substrate. Filmed.

  In Samples 22-1 to 22-3, a silicon nitride oxide film having a thickness of 50 nm, a silicon oxynitride film having a thickness of 100 nm, and an amorphous silicon film having a thickness of 66 nm are sequentially formed as a layer including a semiconductor film over a substrate. Filmed.

  In Samples 23-1 to 23-3, a silicon oxynitride film having a thickness of 100 nm and an amorphous silicon film having a thickness of 66 nm were sequentially formed as a layer including a semiconductor film over a substrate.

  Table 7 shows the film formation conditions of the films constituting the layers including the semiconductor films of Sample 21-1 to Sample 21-3, Sample 22-1 to Sample 22-3, and Sample 23-1 to Sample 23-3. .

  Next, Sample 21-1 to Sample 21-3 were heated in a furnace at 500 ° C. for 1 hour, and then heated at 550 ° C. for 4 hours to dehydrogenate the amorphous semiconductor film.

  Next, FIG. 24 shows the number of cracks after irradiating the sample 21-1, the sample 22-1, and the sample 23-1 with the laser beam. At this time, the numbers of cracks at the upper end of the substrate, the center of the substrate, the lower end of the substrate, 1 cm inside from the upper end of the substrate, and 1 cm inside from the lower end of the substrate are shown.

The irradiation conditions of the laser beam at this time are the second harmonic of Nd: YVO ₄ , the scanning speed is 35 cm / sec, and the power is 18 W.

  From FIG. 23, in Sample 21-1 to Sample 21-3, the total stress of the layer including the semiconductor film after heating is tensile stress. Since the total stress of sample 21-1 is a tensile stress greater than 100, it is not plotted in FIG. In Sample 22-1 to Sample 22-3, the total stress of the layer including the semiconductor film after heating is approximately zero. Samples 23-1 to 23-3 have a compressive stress in which the total stress after heating is lower than zero.

  In this embodiment, an AN100 substrate is used as the substrate. Sample 21-1 to Sample 21-3 use the same film formation conditions as Sample 2 in Example 1, and Sample 22-1 to Sample 22-3 have the same film formation as Sample 3 in Example 1. The sample 23-1 to the sample 23-3 use the same film forming conditions as the sample 10 of the first embodiment.

  Sample 2, sample 3 and sample 10 of Example 1 are the product of film stress and film thickness when each film of a layer including a semiconductor film formed on a substrate is formed on a different silicon substrate and heated. The total stress of the layer including the semiconductor film is calculated from the sum of the above. On the other hand, in each sample of this example, an AN100 substrate is used as the substrate. The AN100 substrate is slightly compressed by heating at 550 ° C. For this reason, in the sample of Example 2, as compared with the corresponding sample of Example 1, the total stress of the layer formed on the substrate is also slightly shifted to the compressive stress side.

  FIG. 24 shows that the total stress of the sample 22-1, that is, the layer including the semiconductor film after heating is approximately 0, compared with the sample 21-1, that is, the sample in which the total stress of the layer including the semiconductor film after heating is tensile stress. It can be seen that the number of cracks is reduced in the sample.

  Further, the total stress of the sample 23-1, that is, the layer including the semiconductor film after heating, is approximately zero as compared with the sample 22-1 that is, the sample whose layer including the semiconductor film after heating is approximately zero. It can be seen that the number of cracks is reduced in the sample having a lower compressive stress.

  That is, when the total stress after heating the layer including the amorphous silicon film formed on the substrate is 0 N / m or less, cracks in the substrate can be reduced. Moreover, it turns out that it is possible to suppress generation | occurrence | production of a crack in the center of a board | substrate. That is, when the total stress after heating the layer including the amorphous silicon film formed on the substrate is 50 N / m or less, preferably 0 N / m or less, the generation of cracks at the center of the substrate can be suppressed. .

  In FIG. 24, the number of cracks in the upper and lower ends of the substrate is larger than the number of cracks in the region 1 cm inside from the central portion of the substrate and the upper or lower end of the substrate. This is because cracks tend to progress.

From the above, it has a coefficient of thermal expansion of more than 6 × 10 ⁻⁷ / ° C. and not more than 38 × 10 ⁻⁷ / ° C., preferably more than 6 × 10 ⁻⁷ / ° C. and not more than 31.8 × 10 ⁻⁷ / ° C. In the substrate, a layer including a semiconductor film having a total stress after heating of −500 N / m to +50 N / m, preferably −150 N / m to 0 N / m is formed, and then the layer is irradiated with a laser beam. Accordingly, the number of cracks generated in the layer including the substrate or the semiconductor film can be reduced. Furthermore, it is possible to suppress the occurrence of cracks at the center of the substrate.

8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. It is a figure explaining the top view of a board | substrate when a semiconductor film is irradiated with a laser beam, the temperature distribution of a board | substrate, and the stress of the board | substrate surface. It is a figure which shows the outline | summary of the laser irradiation apparatus applicable to this invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. It is sectional drawing explaining the structure of the light emitting element which can be applied to this invention. It is a figure explaining the equivalent circuit of the light emitting element which can be applied to this invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. 8A to 8D are cross-sectional views illustrating a method for manufacturing a semiconductor device of the present invention. It is a figure explaining the structure of the semiconductor device of this invention. It is a figure explaining the use of the semiconductor device of this invention. FIG. 11 illustrates an electronic device using a semiconductor device of the present invention. FIG. 11 illustrates a structure of an electronic device using a semiconductor device of the invention. FIG. 11 is a development view illustrating an electronic device using the semiconductor device of the present invention. It is a top view illustrating a semiconductor device of the present invention. It is a figure explaining the thermal expansion coefficient of the board | substrate used in the Example. It is sectional drawing explaining the structure of the layer containing the semiconductor film on the board | substrate used in the Example. It is a figure explaining the total stress calculated from the film | membrane stress of a single film. It is a figure explaining the total stress calculated from the film | membrane stress of a single film. It is a figure explaining the total stress of the layer containing the semiconductor film formed on the board | substrate. It is a figure explaining generation | occurrence | production of the crack when a laser beam is irradiated to the layer containing the semiconductor film formed on the board | substrate. It is a figure explaining the calculation method of stress, and stress. It is a figure explaining the simulation result of the temperature of a board | substrate.

Claims (6)

On a glass substrate having a coefficient of thermal expansion of greater than 6 × 10 ⁻⁷ / ° C. and not greater than 38 × 10 ⁻⁷ / ° C., a layer including a semiconductor film having a total stress after heating of −500 N / m to +50 N / m is formed. And
A method for manufacturing a semiconductor device, comprising: heating a layer including the semiconductor film; and irradiating the heated layer including the semiconductor film with a laser beam having a continuous oscillation or a repetition frequency of 10 MHz or more. Forming a layer including a semiconductor film on a glass substrate having a coefficient of thermal expansion of greater than 6 × 10 ⁻⁷ / ° C. and not greater than 38 × 10 ⁻⁷ / ° C .;
The layer including the semiconductor film is heated, and after the total stress of the heated layer including the semiconductor film is set to −500 N / m or more and +50 N / m or less, the layer including the heated semiconductor film continuously oscillates or repeats. A method for manufacturing a semiconductor device, wherein a laser beam having a frequency of 10 MHz or more is irradiated. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the layer including the semiconductor film is formed by sequentially stacking a silicon nitride oxide film, a silicon oxynitride film, and an amorphous semiconductor film over the substrate. Method. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the layer including the semiconductor film is formed by sequentially stacking a silicon oxynitride film and an amorphous semiconductor film over the substrate. A silicon nitride oxide film having a thermal expansion coefficient of 38 × 10 ⁻⁷ / ° C. and a thickness of 0.5 mm to 1.2 mm, a silicon nitride oxide film having a thickness of 40 nm to 60 nm, and a silicon oxynitride having a thickness of 80 nm to 120 nm A film and an amorphous semiconductor film having a thickness of 50 nm to 80 nm are sequentially formed by a plasma CVD method, heated at 500 ° C. to 650 ° C., and the silicon nitride oxide film having a thickness of 40 nm to 60 nm. After the total stress of the silicon oxynitride film having a thickness of 80 nm to 120 nm and the amorphous semiconductor film having a thickness of 50 nm to 80 nm is set to −500 N / m to −16 N / m, the continuous oscillation or repetition frequency is 10 MHz or more. A method for manufacturing a semiconductor device, characterized by irradiating a laser beam. A glass substrate having a thermal expansion coefficient of 31.8 × 10 ⁻⁷ / ° C. and a thickness of 0.5 mm to 1.2 mm, a silicon nitride oxide film having a thickness of 40 nm to 60 nm, and an oxidation of 80 nm to 120 nm A silicon nitride film and an amorphous semiconductor film having a thickness of 50 nm to 80 nm are sequentially formed by a plasma CVD method, heated at 500 ° C. to 650 ° C., and the silicon nitride oxide film having a thickness of 40 nm to 60 nm; After the total stress of the silicon oxynitride film having a thickness of 80 nm to 120 nm and the amorphous semiconductor film having a thickness of 50 nm to 80 nm is set to −500 N / m to +28 N / m, continuous oscillation or repetition frequency is 10 MHz or more. A method for manufacturing a semiconductor device, characterized by irradiating a laser beam.

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