JP4333115B2 - Semiconductor device manufacturing method, semiconductor device, electro-optical device, and electronic apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for manufacturing a semiconductor device including a semiconductor element such as a thin film transistor, and a semiconductor device, an electro-optical device, and an electronic apparatus manufactured using the manufacturing method.
[0002]
[Prior art]
In an electro-optical device such as a liquid crystal display device or an EL (electroluminescence) display device, pixels are switched using a thin film circuit including a semiconductor element such as a thin film transistor. In a conventional thin film transistor, an active region (channel formation region) is formed using an amorphous silicon film. A thin film transistor in which an active region is formed using a polycrystalline silicon film has also been put into practical use. By using a polycrystalline silicon film, electrical characteristics such as mobility are improved as compared with the case of using an amorphous silicon film, and the performance of the thin film transistor can be improved.
[0003]
In order to further improve the performance of the thin film transistor, a technique for forming a semiconductor film made of large crystal grains and preventing a crystal grain boundary from entering the formation region of the thin film transistor has been studied. For example, there are several techniques for forming silicon crystal grains of several μm by forming fine holes (fine holes) on a substrate and crystallizing a semiconductor film using the fine holes as a starting point for crystal growth. (Non-patent document 1 and non-patent document 2). By forming a thin film transistor using a silicon film containing large crystal grains formed using these techniques, a thin film transistor excellent in electrical characteristics such as mobility can be realized.
[0004]
[Non-Patent Document 1]
"Single Crystal Thin Film Transistors", IBM TECHNICAL DISCLOSURE BULLETIN Aug. 1993 pp257-258
[0005]
[Non-Patent Document 2]
`` Advanced Excimer-Laser Crystallization Techniques of Si Thin-Film For Location Control of Large Grain on Glass '', R.Ishihara et al., Proc.SPIE 2001, vol.4295, p.14-23
[0006]
[Problems to be solved by the invention]
In the conventional method described above, large crystal grains of about several μm can be formed, but the plane orientation of the obtained crystal grains is not controlled, and the plane orientation of each crystal grain is in a random state. It was. In order to further improve the electrical characteristics of the thin film transistor, it is desired to establish a manufacturing method capable of forming a semiconductor film by controlling the crystal plane orientation.
[0007]
Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor device, which enables a semiconductor element to be formed using a semiconductor film made of crystal grains whose surface orientation is controlled.
[0008]
Another object of the present invention is to provide a semiconductor device with good electrical characteristics.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a manufacturing method of the present invention is a manufacturing method of a semiconductor device in which a semiconductor element is formed on a substrate, and a first insulating film deposition step of depositing a first insulating film on the substrate; A crystallization promoting film deposition step of depositing a crystallization promoting film made of a metal-containing material on the first insulating film and promoting crystallization of the semiconductor film; and a second insulation depositing the second insulating film on the crystallization promoting film. A film deposition step, a micropore forming step of opening a microhole extending through the second insulating film and the crystallization promoting film to the first insulating film, and exposing the crystallization promoting film in the vicinity of the bottom of the microhole, (2) A semiconductor film deposition process for depositing a semiconductor film on the insulating film and in the micropores, and heat treatment of the substrate to crystallize the region including the vicinity of the bottom of the micropores of the semiconductor film in a solid state to contain crystal components A heat treatment step for obtaining a semiconductor film and a crystal component-containing semiconductor film in the micropores Containing semiconductor film and melt crystallization to obtain a crystalline semiconductor film by melt crystallization as a point, a.
[0010]
A crystal component-containing semiconductor film is formed by crystallizing a crystallization-promoting material made of a metal-containing substance and a semiconductor film in a solid state near the bottom of the micropore as a starting point for crystallization of the semiconductor film. Therefore, by performing melt crystallization of the semiconductor film after that, a semiconductor film (crystalline semiconductor film) in which the crystal grains are large and the plane orientation is controlled in a range centered on the fine hole is formed. Is possible. By forming a semiconductor element using a high-quality semiconductor film which can be regarded as a substantially single crystal state and whose plane orientation is controlled, it is possible to improve the performance of the semiconductor device.
[0011]
Here, in the present specification, “substantially single crystal” means not only a single crystal grain but also a state close to this, that is, the number of crystals combined is small, and the properties of the semiconductor thin film In view of the above, the case where the semiconductor thin film has properties equivalent to those of a semiconductor thin film formed from a single crystal is also included.
[0012]
Moreover, it is preferable that the manufacturing method according to the present invention further includes an element forming step of forming a semiconductor element using the crystalline semiconductor film. Here, in the present specification, the “semiconductor element” includes various transistors, diodes, resistors, inductors, capacitors, and other elements that can be manufactured by a combination of N-type and P-type semiconductors, regardless of active elements and passive elements. . In this specification, a “semiconductor device” is a device including the semiconductor element, for example, a device including an integrated circuit or the like. By using the crystalline semiconductor film according to the present invention, a semiconductor element and a semiconductor device having excellent electrical characteristics can be obtained. In the case where a light-shielding film is used as the crystallization promoting film, the light is incident on a portion of the semiconductor element constituted by the semiconductor film (for example, an active region in the case of a thin film transistor). It is also possible to prevent generation of electromotive force and dark current due to photoexcitation in the semiconductor film.
[0013]
The crystallization promoting material described above is preferably a substance containing any of nickel, iron, cobalt, platinum, and palladium. The crystallization promoting material is preferably a silicon compound (silicide). By using such a crystallization promoting material, it becomes possible to effectively control the plane orientation of the crystal grains.
[0014]
Further, it is preferable to form the second insulating film so that the ratio between the thickness of the second insulating film and the hole diameter of the fine holes is larger than 2.75. More preferably, the second insulating film is formed so that the ratio of the film thickness of the second insulating film to the hole diameter of the fine holes is larger than 5. More preferably, the second insulating film may be formed so that the ratio between the thickness of the second insulating film and the diameter of the fine holes is larger than 11. By forming micropores under the above conditions, it becomes possible to preferentially align the crystal orientation of the crystal grains appearing above the micropores in a specific direction. When crystallizing a semiconductor film, the micropores The plane orientation of the semiconductor film can be adjusted on the basis of the plane orientation of the crystal grains appearing on the upper part.
[0015]
Moreover, it is preferable that the hole diameter of a micropore shall be 45 nm or more and 190 nm or less. By forming micropores under these conditions, it is possible to more reliably obtain the action of preferentially growing one crystal nucleus in the micropore.
[0016]
The semiconductor film deposited in the above-described semiconductor film deposition step preferably has a thickness of 30 nm to 100 nm. The thickness of the semiconductor film is preferably 0.52 times or more and 0.67 times or less the hole diameter of the fine holes. By depositing the semiconductor film under such conditions, the direction of crystallization during melt crystallization is made only in a direction substantially perpendicular to the film thickness direction of the semiconductor film, and crystallization is difficult to proceed in other directions. This makes it possible to further homogenize the crystalline semiconductor film.
[0017]
Moreover, it is preferable that the semiconductor film formed in the semiconductor film forming step has silicon (silicon) as a main constituent element. As such a semiconductor film, for example, an amorphous or polycrystalline silicon film is preferably used. As a result, it is possible to form a high-quality silicon film having a substantially single crystal state and a controlled plane orientation within a range centered on the fine hole, and to form a semiconductor element using this high-quality silicon film. become.
[0018]
The heat treatment described above is preferably performed at a temperature of 300 ° C. or higher and 550 ° C. or lower. The reason why the lower limit of the heat treatment temperature is about 300 ° C. is that the semiconductor film and the compound of the crystallization promoting material are formed sufficiently and sufficiently. Moreover, the upper limit of the temperature of heat processing shall be about 550 degreeC for the following reasons. That is, when a semiconductor device used for an electro-optical device or the like is formed, an inexpensive glass substrate (for example, soda lime glass) is often used as an insulating substrate from the viewpoint of material cost. In this case, since the softening point of commonly used glass such as soda lime glass is about 550 ° C., in order to prevent the insulating substrate from being softened by heat applied during the manufacturing process, This is because the upper limit of the applied temperature needs to be about 550 ° C. corresponding to the softening point.
[0019]
Further, the processing time t (second) in the heat treatment is as follows: processing temperature T (° C.), Boltzmann constant k _B = 8.617 × 10 ⁻⁵ eV · K ⁻¹ , ε = 0.833 eV, t ₀ = 1.59. When x10 ⁻³ (seconds)
t ≧ t ₀ · exp {ε / k _B (T + 273.16)},
It is better to set so as to satisfy the relationship. This makes it possible to accurately set the heat treatment time. Here, the “processing temperature” basically indicates the substrate temperature of the substrate to be heat-treated. For industrial convenience, the temperature in a container such as a high-temperature furnace for heating the substrate is used. You may substitute. In this case, an experiment or the like is performed, and it is confirmed in advance how much time has passed since the substrate was placed in a container having an ambient temperature T (° C.), and the substrate temperature becomes substantially the same as the ambient temperature. The measurement of the processing time t (seconds) obtained by the above calculation formula may be started from the point in time when the substrate temperature becomes approximately T (° C.).
[0020]
In addition, it is preferable that the semiconductor film be melt-crystallized by laser irradiation. This makes it possible to efficiently perform melt crystallization. Various lasers such as an excimer laser, a solid-state laser, and a gas laser can be considered.
[0021]
The melt crystallization is preferably performed under the condition that the semiconductor film in the region other than the micropores is melted over the entire film thickness direction. Further, the melt crystallization is more preferably performed under the condition that the crystal component-containing semiconductor film in the micropores does not melt over the entire thickness direction. By satisfying such a condition, it becomes possible to perform melt crystallization of the semiconductor film better.
[0022]
The present invention is also a semiconductor device manufactured using the manufacturing method described above. Specifically, a semiconductor device according to the present invention is a semiconductor device including a semiconductor element formed on an insulating substrate, the first insulating film deposited on the insulating substrate, and the first insulating film on the first insulating film. The deposited crystallization promoting film made of a metal-containing material, the second insulating film deposited on the crystallization promoting film, the second insulating film and the crystallization promoting film are penetrated to reach the first insulating film. A fine hole formed so that the crystallization promoting film is exposed in the vicinity of the bottom, and a crystallized semiconductor film that is deposited on the second insulating film by filling the fine hole and is melt-crystallized starting from the fine hole; , Including. The crystalline semiconductor film desirably has a size corresponding to at least a region where a semiconductor element is formed.
[0023]
The above-described semiconductor device according to the present invention is particularly suitable for use in an electro-optical device. Specifically, an electro-optical device having good performance is provided by arranging the semiconductor device according to the present invention in a desired arrangement state (for example, in a matrix) and using the driving device for driving pixels as an electro-optical device. Can be obtained. By using such an electro-optical device, it is possible to configure a high-quality electronic device.
[0024]
Here, in the present specification, the “electro-optical device” refers to a general device including the semiconductor device according to the present invention and including an electro-optical element that emits light by electrical action or changes the state of light from the outside. Includes both those that emit light themselves and those that control the transmission of light from the outside. For example, as an electro-optical element, a liquid crystal element, an electrophoretic element having a dispersion medium in which electrophoretic particles are dispersed, an EL (electroluminescence) element, and an electroluminescent element that emits light by applying electrons generated by applying an electric field to a light emitting plate. A display device provided.
[0025]
In this specification, the “electronic device” means a general device having a certain function including the semiconductor device according to the present invention, and includes, for example, an electro-optical device and a memory. The configuration is not particularly limited, but for example, a mobile phone, a video camera, a personal computer, a head mounted display, a rear or front projector, a fax machine with a display function, a finder for a digital camera, a portable TV, a DSP device. , PDAs (portable information terminals), electronic notebooks, IC cards, electronic bulletin boards, advertising displays, and the like.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
1 and 2 are diagrams illustrating a method for manufacturing a semiconductor device according to an embodiment.
[0028]
(First insulating film deposition step)
As shown in FIG. 1A, a silicon oxide film 11 as a first insulating film is deposited on a substrate 10 made of an insulating material such as glass. The silicon oxide film 11 can be formed by a physical vapor deposition method such as a plasma chemical vapor deposition method (PECVD method), a low pressure chemical vapor deposition method (LPCVD method), or a sputtering method. For example, in this embodiment, the silicon oxide film 11 having a thickness of about 100 nm is deposited by PECVD. In addition, the insulating material which comprises the board | substrate 10 is not limited to glass.
[0029]
(Crystallization promotion film forming process)
As shown in FIG. 1B, a nickel film 12 is deposited on the silicon oxide film 11 as a crystallization promoting film made of a metal-containing material and having a property of promoting crystallization of the semiconductor film. The nickel film 12 can be formed by PECVD, LPCVD, sputtering, or the like. Further, as the metal-containing substance, a substance containing any of cobalt, platinum, palladium, and tungsten, or a silicon compound (silicide) may be used.
[0030]
When a light-shielding film is used as the crystallization promoting film like the nickel film in the present embodiment, the semiconductor film portion of the semiconductor element formed on the upper side (for example, an active region in the case of a thin film transistor) Etc.) can be blocked by the crystallization promoting film to prevent the electromotive force and dark current from being generated by photoexcitation in the semiconductor film.
[0031]
(Second insulating film deposition process)
Next, as shown in FIG. 1C, a silicon oxide film 13 as a second insulating film is deposited on the nickel film 12. The silicon oxide film 13 can be formed by PECVD, LPCVD, sputtering, or the like.
[0032]
(Micropore formation process)
Next, as shown in FIG. 1 (d), the silicon oxide film 13 (second insulating film) and the nickel film 12 (crystallization promoting film) penetrate through the silicon oxide film 11 (first insulating film). The hole 14 is opened, and the nickel film 12 is exposed on the side wall near the bottom of the fine hole 14. The fine holes 14 are for playing a role of preferentially growing only one crystal nucleus. In the following description, this fine hole is referred to as a “grain filter”. The grain filter 14 is formed, for example, by forming a photoresist film (not shown) having an opening that exposes the formation position of the grain filter 14 on the silicon oxide film 13, and using the photoresist film as a mask. It can be formed by performing ion etching and then removing the photoresist film on the silicon oxide film 13. The grain filter 14 is preferably formed in a cylindrical shape, but may have a shape other than the cylindrical shape (for example, a cone shape, a prism shape, a pyramid shape, etc.).
[0033]
Here, the pore diameter of the grain filter 14 is preferably 45 nm to 190 nm. Further, the hole diameter of the grain filter 14 may be formed to be 1.5 to 1.9 times the film thickness of a semiconductor film (a silicon film in the present embodiment) to be formed on the silicon oxide film 13 later. Is preferred. For example, in this embodiment, the film thickness of the silicon film is 50 nm, and the hole diameter of the grain filter 14 is 75 nm (= 50 nm × 1.5). In the present embodiment, the thickness of the silicon oxide film 13 is 825 nm. The reason why the dimensions of the silicon oxide film 13 and the grain filter 14 are set to such values will be described later.
[0034]
(Semiconductor film deposition process)
Next, as shown in FIG. 2A, a semiconductor film containing silicon (silicon) as a main constituent element is formed on the silicon oxide film 13 and in the grain filter 14. In this embodiment, an amorphous (or polycrystalline) silicon film 16 is formed as a semiconductor film. The silicon film 16 is preferably formed to a thickness of about 30 nm to 100 nm by a film forming method such as LPCVD.
[0035]
From another viewpoint, it is desirable that the thickness of the silicon film 16 deposited in this step is 0.52 to 0.67 times the pore diameter of the grain filter 14. For example, when the hole diameter of the grain filter 14 is set to 75 nm as described above, the thickness of the silicon film 16 is preferably in the range of about 39 nm to 50 nm.
[0036]
(Heat treatment process)
Next, as shown in FIG. 2B, the substrate 10 is subjected to a heat treatment, and the region including the vicinity of the bottom of the grain filter 14 of the silicon film 16 is crystallized in a solid phase, so that a crystal component-containing semiconductor is obtained. A film (compound NiSi ₂ of silicon and nickel in this example) is obtained. As will be described in detail later, at least the semiconductor film in the grain filter (fine hole) 14 is crystallized by this heat treatment process so that the direction perpendicular to the semiconductor film becomes <111>. This heat treatment is preferably performed at a temperature of about 300 ° C to 550 ° C. The reason why the lower limit of the temperature of the heat treatment is about 300 ° C. is to form the crystal component-containing semiconductor film as necessary and sufficient. Moreover, the upper limit of the temperature of heat processing shall be about 550 degreeC for the following reasons. That is, from the viewpoint of material cost and the like, an inexpensive glass substrate (for example, soda lime glass) is often used as the substrate 10. In this case, since the glass used generally has a softening point of about 550 ° C., the upper limit of the temperature applied to the substrate 10 is softened in order to prevent the substrate 10 from being softened by heat applied during manufacture. This is because the temperature needs to be lower than about 550 ° C. corresponding to the point. For the reasons described above, in the present embodiment, a range of 300 ° C. to 550 ° C. is employed as a suitable temperature when performing the heat treatment.
[0037]
In addition, with regard to the relationship between the treatment temperature and the treatment time during heat treatment, suitable conditions have been found by detailed examination by the inventors of the present application. Below, the suitable conditions of heat processing are demonstrated. The treatment time t (second) for the heat treatment is as follows: treatment temperature T (° C.), Boltzmann constant k _B = 8.617 × 10 ⁻⁵ eV · K ⁻¹ , ε = 0.833 eV, t ₀ = 1.59. When x10 ⁻³ (seconds)
t ≧ t ₀ · exp {ε / k _B (T + 273.16)} (1),
It is better to set so as to satisfy the relationship.
[0038]
FIG. 3 is a graph (graph) showing the relationship between the treatment temperature T (° C.) and the treatment time t (seconds) during the heat treatment based on the above equation (1). For example, when the processing temperature is 300 ° C., it is understood that the processing time may be 12206 seconds (about 3 hours 23 minutes) or more. Similarly, when the processing temperature is 400 ° C., it is understood that the processing time may be 1158 seconds (about 19 minutes) or more. It can be seen that when the processing temperature is 500 ° C., the processing time may be 202 seconds or longer. It can be seen that when the treatment temperature is 550 ° C., the treatment time may be 99 seconds or more. From the viewpoint of productivity and the like, it is practical to set the processing time to 30000 seconds (about 8 hours) or less. From such a point of view, it is preferable to set the heat treatment time t within a range shown by hatching in FIG.
[0039]
FIG. 4 is a diagram for explaining the shape of the grain filter 14 suitable for performing crystallization as described above. The grain filter 14 is preferably formed such that the ratio h / r of the film thickness h of the silicon oxide film (second insulating film) 13 and the hole diameter r of the grain filter 14 is larger than 2.75. That is, if the angle seen from the nickel film (crystallization promoting film) 12 toward the side wall of the grain filter 14 with respect to the central axis (z axis shown) of the grain filter 14 is φ, h / r> 2.75. In this case, the angle φ is smaller than 20 °. When solid phase crystallization of silicon is advanced with a crystallization promoting substance such as nickel (Ni), the crystal grows linearly, and the growth direction becomes <111>. Accordingly, in the grain filter 14, the crystal orientation of the silicon crystal grains is such that the {111} plane is directed in the z-axis direction. Further, the {111} plane and the {331} plane close thereto have an angle of about 22 °. Therefore, by forming the grain filter 14 so that φ <20 ° when h / r> 2.75, the {331} plane having an angle of about 22 ° with the {111} plane is the grain filter. It grows toward the 14 side walls. As a result, the {111} plane appears preferentially in the silicon crystal grains on the upper part of the grain filter 14, and the plane orientation is determined based on this {111} plane when the silicon film is melt-crystallized later. Can be arranged.
[0040]
Further, when the grain filter 14 is formed with h / r> 5, the above-described angle φ becomes smaller than 11 °, and the deviation of the plane orientation of the silicon crystal grains formed with the grain filter 14 substantially at the center is reduced. Further suppression is possible. Specifically, according to the inventors of the present application, it has been confirmed that the deviation of the plane orientation between the plurality of silicon crystal grains formed based on the plurality of grain filters 14 is 10 ° or less on average. ing.
[0041]
Further, when the grain filter 14 is formed with h / r> 11, the above-mentioned angle φ is smaller than 5 °, and the deviation of the plane orientation of the silicon crystal grains formed with the grain filter 14 substantially at the center is further increased. Further suppression is possible. Specifically, according to the inventors of the present application, it has been confirmed that the deviation of the plane orientation between the plurality of silicon crystal grains formed based on the plurality of grain filters 14 is 5 ° or less on average. ing. Based on such examination results, in this embodiment, the film thickness h of the silicon oxide film 13 in the grain filter 14 is set to 825 nm, which is 11 times the hole diameter r (= 75 nm).
[0042]
(Melt crystallization process)
Next, as shown in FIG. 2C, the silicon film 16 is irradiated with a laser to melt and crystallize the silicon film 16 with the crystal component-containing semiconductor film in the grain filter 14 as a starting point. A semiconductor film is formed. As a result, as shown in FIG. 2D, a crystalline semiconductor film centered on the grain filter 14, specifically, a substantially single crystal silicon film 18 made of large crystal grains is formed. During the melt crystallization, the silicon and nickel compound formed in the grain filter 14 has the effect of adjusting the crystal plane orientation, whereby the plane orientation of the silicon film 18 is substantially controlled in a specific direction. Is possible.
[0043]
The laser irradiation described above is preferably performed using, for example, an XeCl pulse excimer laser having a wavelength of 308 nm and a pulse width of 100 ns to 300 ns so that the energy density is about 0.4 to 1.5 J / cm ² . By performing laser irradiation under such conditions, most of the irradiated laser is absorbed near the surface of the silicon film 16. This is because the absorption coefficient of amorphous silicon at the wavelength (308 nm) of the XeCl pulse excimer laser is relatively large at 0.139 nm ⁻¹ . By appropriately selecting the laser irradiation conditions in this manner, the crystal component-containing semiconductor film in the grain filter 14 is not completely melted over the entire film thickness direction, and is always in a certain unmelted state. While the portion remains, the silicon film 16 in the region other than the grain filter 14 is completely melted over the entire film thickness direction. As a result, the crystal growth of the silicon after laser irradiation starts first near the bottom of the grain filter 14 and proceeds to the vicinity of the surface of the silicon film 16, that is, the substantially completely melted portion. At the bottom of the grain filter 14, crystal grains with {111} faces appear. Thus, using the crystal whose direction perpendicular to the semiconductor film is <111> as a seed, crystal growth proceeds in the substantially completely melted portion of the silicon film 16.
[0044]
(Element formation process)
By performing melt crystallization of the silicon film 16 as described above, it is possible to form the silicon film 18 that is substantially in a single crystal state and whose plane orientation is controlled, with the grain filter 14 being substantially at the center. By using the silicon film 18 thus obtained, a high-performance semiconductor element (for example, a thin film transistor or a thin film diode) can be formed.
[0045]
Next, taking a thin film transistor as an example, a process for forming a semiconductor element using the crystalline semiconductor film (silicon film 18) according to the present invention will be described. By using the crystalline semiconductor film according to the present invention for an active region of a thin film transistor, a high-performance thin film transistor with low off-state current and high mobility can be formed.
[0046]
FIG. 5 is a diagram illustrating a thin film transistor forming process. First, as shown in FIG. 5A, the silicon film 18 is patterned, and a portion unnecessary for forming a thin film transistor is removed and shaped.
[0047]
Next, as shown in FIG. 5B, a silicon oxide film 20 is formed on the upper surfaces of the silicon oxide film 13 and the silicon film 18 by a film forming method such as an electron cyclotron resonance PECVD method (ECR-PECVD method) or a PECVD method. To do. This silicon oxide film 20 functions as a gate insulating film of the thin film transistor.
[0048]
Next, as shown in FIG. 5C, a gate electrode 22 and a gate wiring film (not shown) are formed by patterning after forming a conductive thin film such as tantalum or aluminum by a film forming method such as sputtering. Form. Then, a source region 24, a drain region 25, and an active region 26 are formed in the silicon film 18 by performing so-called self-aligned ion implantation by implanting an impurity element serving as a donor or acceptor using the gate electrode 22 as a mask. For example, in this embodiment, phosphorus (P) is implanted as an impurity element, and then an XeCl excimer laser is adjusted to an energy density of about 400 mJ / cm ² to irradiate the element to activate the impurity element. Form. Note that the impurity element may be activated by performing heat treatment at a temperature of about 250 ° C. to 400 ° C. instead of laser irradiation.
[0049]
Next, as shown in FIG. 5D, a silicon oxide film 28 having a thickness of about 500 nm is formed on the upper surfaces of the silicon oxide film 20 and the gate electrode 22 by a film forming method such as a PECVD method. Next, contact holes that penetrate each of the silicon oxide films 20 and 28 to reach the source region 24 and the drain region 25 are formed, and aluminum, tungsten, or the like is formed in these contact holes by a film forming method such as sputtering. The source electrode 30 and the drain electrode 32 are formed by embedding and patterning the conductor. As a result, as shown in FIG. 5D, the nickel film 12 made of a metal-containing substance and serving as a crystallization promoting film for promoting the crystallization of the semiconductor film is disposed in the vicinity of the bottom of the grain filter 14, and the grain filter A thin film transistor T in which an active region 26 and the like are formed using a silicon film 18 formed by melt crystallization from 14 is obtained.
[0050]
As described above, in the present embodiment, crystallization promotion made of a metal-containing material is formed on the side wall in the vicinity of the bottom of the grain filter 14 as a starting point when the amorphous (or polycrystalline) silicon film 16 is melt-crystallized. The nickel film 12 as a film is exposed, and the silicon film 16 in the grain filter 14 is crystallized in a solid state to form a crystal component-containing semiconductor film having a plane orientation of {111}. . As a result, when the silicon film 16 is melt-crystallized, a substantially single-crystal silicon film 18 (crystalline semiconductor film) whose crystal grains are large and whose plane orientation is controlled is within a range substantially centered on the grain filter 14. ) Can be formed. Since the thin film transistor T is formed using the high-quality silicon film 18 having a large crystal grain size and a controlled surface orientation, it is possible to improve the performance of the thin film transistor. Such a thin film transistor according to the present embodiment is suitable for use in various devices such as an electro-optical device. Next, specific examples of the display device (electro-optical device) and the electronic apparatus according to the invention will be described.
[0051]
FIG. 6 is a diagram illustrating an electro-optical device according to an embodiment of the invention. As shown in FIG. 6, the electro-optical device 100 is configured by arranging a pixel region 112 in a display region 111. The pixel region 112 uses a thin film transistor that drives an organic EL light emitting element. A thin film transistor manufactured by the manufacturing method of the above-described embodiment is used. A light emission control line (Vgp) and a write control line are supplied from the driver area 115 to each pixel area. A current line (Idata) and a power supply line (Vdd) are supplied from the driver area 116 to each pixel area. By controlling the writing control line and the constant current line Idata, current programming is performed for each pixel region, and light emission is controlled by controlling the light emission control line Vgp. Note that the thin film transistor according to the present invention can also be used for the driver regions 115 and 116.
[0052]
FIG. 7 is a diagram illustrating an example of an electronic apparatus to which the electro-optical device according to the invention can be applied. FIG. 7A shows an application example to a mobile phone. The mobile phone 230 includes an antenna unit 231, an audio output unit 232, an audio input unit 233, an operation unit 234, and the electro-optical device 100 according to the invention. ing. As described above, the electro-optical device according to the invention can be used as a display unit. FIG. 7B shows an application example to a video camera. The video camera 240 includes an image receiving unit 241, an operation unit 242, an audio input unit 243, and the electro-optical device 100 according to the invention. As described above, the electro-optical device according to the invention can be used as a finder or a display unit. FIG. 7C shows an application example to a portable personal computer (so-called PDA). The computer 250 includes a camera unit 251, an operation unit 252, and the electro-optical device 100 according to the present invention. As described above, the electro-optical device according to the invention can be used as a display unit.
[0053]
FIG. 7D shows an application example to a head-mounted display. The head-mounted display 260 includes a band 261, an optical system storage unit 262, and the electro-optical device 100 according to the present invention. As described above, the electro-optical device according to the present invention can be used as an image display source. FIG. 7E shows an application example to a rear projector. The projector 270 includes a housing 271, a light source 272, a composite optical system 273, mirrors 274 and 275, a screen 276, and the electro-optical device according to the invention. 100. As described above, the electro-optical device according to the present invention can be used as an image display source. FIG. 7F shows an application example to a front type projector. The projector 280 includes an optical system 281 and the electro-optical device 100 according to the present invention in a housing 282, and can display an image on a screen 283. Yes. As described above, the electro-optical device according to the present invention can be used as an image display source.
[0054]
Further, the electro-optical device 100 according to the present invention is not limited to the above-described example, and can be applied to any electronic apparatus to which an active type or passive matrix type liquid crystal display device or organic EL display device can be applied. For example, in addition to this, it can also be used for a fax machine with a display function, a finder for a digital camera, a portable TV, an electronic notebook, an electric bulletin board, a display for advertisements, etc.
[0055]
In addition, this invention is not limited to the content of embodiment mentioned above, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the thin film transistor has been described as a specific example of the semiconductor element. However, the scope of application of the present invention is not limited to this, and the present invention is applied to various semiconductor elements such as a thin film diode. It is possible to apply.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment.
FIG. 2 is a diagram illustrating a method for manufacturing the semiconductor device of one embodiment.
FIG. 3 is a diagram showing a relationship between a processing temperature and a processing time during heat treatment.
FIG. 4 is a diagram illustrating a preferred shape of a grain filter.
FIGS. 5A and 5B are diagrams illustrating a process for forming a thin film transistor. FIGS.
FIG. 6 is a diagram illustrating an electro-optical device according to an embodiment.
FIG. 7 is a diagram illustrating an example of an electronic apparatus to which the electro-optical device can be applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 11 ... Silicon oxide film (1st insulating film), 12 ... Nickel film (crystallization promotion film), 13 ... Silicon oxide film (2nd insulating film), 14 ... Grain filter (micropore), 16 ... Amorphous silicon film (semiconductor film), 18 ... Substantially single crystal silicon film (crystalline semiconductor film), 100 ... Electro-optical device, T ... Thin film transistor

Claims (20)

A method of manufacturing a semiconductor device in which a semiconductor element is formed on a substrate,
A first insulating film deposition step of depositing a first insulating film on the substrate;
A crystallization promoting film deposition step of depositing a crystallization promoting film made of a metal-containing material on the first insulating film to promote crystallization of the semiconductor film;
A second insulating film deposition step of depositing a second insulating film on the crystallization promoting film;
Forming a microhole penetrating the second insulating film and the crystallization promoting film to reach the first insulating film, and exposing the crystallization promoting film in the vicinity of the bottom of the microhole;
A semiconductor film deposition step of depositing a semiconductor film on the second insulating film and in the fine holes;
A heat treatment step of performing a heat treatment on the substrate to obtain a crystal component-containing semiconductor film by crystallizing a region including the vicinity of the bottom of the micropore in the semiconductor film in a solid state;
And a melt crystallization step of obtaining a crystalline semiconductor film by melt crystallization of the semiconductor film starting from the crystal component-containing semiconductor film in the micropore. The method for manufacturing a semiconductor device according to claim 1, further comprising an element forming step of forming a semiconductor element using the crystalline semiconductor film. The method for manufacturing a semiconductor device according to claim 1, wherein the metal-containing substance is a substance containing any one of nickel, cobalt, platinum, palladium, and tungsten. The method for manufacturing a semiconductor device according to claim 1, wherein the metal-containing substance is a silicon compound (silicide). 5. The method of manufacturing a semiconductor device according to claim 1, wherein a ratio of a film thickness of the second insulating film to a hole diameter of the fine hole is larger than 2.75. 5. The method of manufacturing a semiconductor device according to claim 1, wherein a ratio of a film thickness of the second insulating film to a hole diameter of the fine hole is larger than 5. 5. 5. The method of manufacturing a semiconductor device according to claim 1, wherein a ratio of a film thickness of the second insulating film to a hole diameter of the fine hole is larger than 11. 6. The method for manufacturing a semiconductor device according to claim 1, wherein a hole diameter of the fine hole is not less than 45 nm and not more than 190 nm. 9. The method of manufacturing a semiconductor device according to claim 1, wherein a film thickness of the semiconductor film deposited in the semiconductor film deposition step is not less than 30 nm and not more than 100 nm. 10. The method of manufacturing a semiconductor device according to claim 1, wherein a thickness of the semiconductor film deposited in the semiconductor deposition step is not less than 0.52 times and not more than 0.67 times the diameter of the micropore. 11. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor film deposited in the semiconductor film deposition step contains silicon as a main constituent element. The method for manufacturing a semiconductor device according to claim 1, wherein the heat treatment is performed at 300 ° C. or more and 550 ° C. or less. The heat treatment time t (seconds) is as follows: treatment temperature T (° C.), Boltzmann constant k _B = 8.617 × 10 ⁻⁵ eV · K ⁻¹ , ε = 0.833 eV, t ₀ = 1.59 × 10. ^-3 (seconds)
t ≧ t ₀ · exp {ε / k _B (T + 273.16)},
The method for manufacturing a semiconductor device according to claim 1, wherein the method is set so as to satisfy the relationship. The method for manufacturing a semiconductor device according to claim 1, wherein the melt crystallization is performed by laser irradiation. The method of manufacturing a semiconductor device according to claim 1, wherein the melt crystallization is performed under a condition that the semiconductor film in a region other than the fine hole is melted over the entire film thickness direction. The method of manufacturing a semiconductor device according to claim 15, wherein the melt crystallization is performed under a condition that the crystal component-containing semiconductor film in the fine hole is not melted over the entire film thickness direction. A semiconductor device including a semiconductor element formed on an insulating substrate,
A first insulating film deposited on the insulating substrate;
A crystallization promoting film made of a metal-containing material and deposited on the first insulating film;
A second insulating film deposited on the crystallization promoting film;
A fine hole formed so as to penetrate the second insulating film and the crystallization promoting film to reach the first insulating film and to expose the crystallization promoting film in the vicinity of the bottom thereof;
A semiconductor device comprising: a crystallized semiconductor film embedded in the fine hole and deposited on the second insulating film, and melt-crystallized from the fine hole as a starting point. The semiconductor device according to claim 17, wherein the crystalline semiconductor film has a size corresponding to at least a formation region of the semiconductor element. An electro-optical device comprising a semiconductor device manufactured by the manufacturing method according to claim 1. An electronic apparatus comprising the electro-optical device according to claim 19.

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