JP3210410B2 - Semiconductor device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device used for an image input / output device such as a display or a sensor, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in order to obtain a semiconductor device such as a thin film transistor, various semiconductor devices in which a single crystal silicon thin film is formed on an insulating substrate and a method for manufacturing the same have been proposed. Many semiconductor devices of this type form an amorphous or polycrystalline silicon thin film on an insulating substrate, melt the amorphous or polycrystalline silicon thin film once by various heat sources, and then cool and solidify and recrystallize. And is produced by single crystallization. As a heat source in this case, there are a laser beam, an electron beam, various lamp lights, a wire-like carbon heater, and the like.

Incidentally, the crystal orientation plane of single crystal silicon (crystal plane of silicon appearing on the substrate surface) obtained by such a conventional melt recrystallization method, when a seed crystal is used at the time of melt recrystallization, is It is determined by the orientation plane of the seed crystal. At this time, when the insulating substrate has a structure in which an insulating film is formed on a silicon wafer by a silicon oxide film or various film forming techniques, an amorphous or multi-layer film is formed on the substrate. Prior to the formation of crystalline silicon, a hole is formed in the insulating film layer on the wafer, amorphous or polycrystalline silicon is formed so as to cover the hole, and the above-described melting and recrystallization is performed from the top of the hole. Thereby, a part of the wafer can be used as a seed crystal.

On the other hand, when the insulating substrate is a so-called amorphous substrate such as quartz glass, the orientation of the recrystallized film cannot be controlled by the above-described method. Therefore, when the insulating substrate is an amorphous substrate, it is necessary to perform single crystallization by a method other than the above-described method.
Zone Melting Recrystallizatio
n, that is, the ZMR method) is known. FIG.
(A), (b) is a figure for demonstrating the outline of a ZMR method. In the ZMR method, a polycrystalline silicon film 202 is formed on a quartz glass substrate 201, and this polycrystalline silicon film 202 is formed.
After a silicon oxide film (not shown) is formed thereon as a surface protective layer, the polycrystalline silicon film 202 sandwiched between the quartz glass substrate 201 and the silicon oxide film is heated in a strip shape (as shown by a region 8). Then, by moving the region 8 which is melted in a band shape in one direction, silicon is solidified and recrystallized sequentially along the direction to obtain a single crystal silicon film. At this time, as shown in FIG. 14, there is a supercooled region in which the liquid state is maintained even after the melting point of silicon, 1412 ° C., as shown in FIG. It is said that the solid-liquid interface is formed by a collection of facets (small crystal planes) of the (111) plane, which is the slowest growing silicon crystal plane in the supercooled region. The formation of single-crystal silicon is caused by the movement of the belt-shaped molten region 8, the movement of the supercooled region, and the facet plane composed of the (111) plane of silicon continuously growing in the supercooled region. What is done. As a method of forming the band-shaped molten region, there is a method of heating with a linear carbon heater placed close to the substrate, an RF induction heating method, or the like. The moving speed of the belt-like molten region in this ZMR method is approximately several mm / sec, and the characteristic of the ZMR method is that a state close to thermal equilibrium is realized at the solid-liquid interface for recrystallization. In the ZMR method, the insulating substrate is made of quartz glass (or SiO ₂ layer), and a thermal CV is applied to the surface protective film during recrystallization.
When the SiO ₂ formed in D is used, a recrystallized film having a (100) crystal orientation plane, that is, a single crystal silicon thin crystal orientation plane is obtained even though no seed crystal is used. Can be

[0005]

As described above, conventionally, when a seed crystal is used, the crystal orientation plane of single crystal silicon formed on an insulating substrate is determined by the crystal plane of the seed crystal. Would. Further, when the ZMR method is used, the crystal orientation plane of single crystal silicon is determined to be a (100) plane. In the ZMR method, the reason why the crystal orientation plane is obtained as the (100) plane is not clarified at all. For this reason, a single crystal having another crystal orientation plane, for example, a (111) plane, is obtained by the ZMR method. There are no guidelines for obtaining a silicon film. Therefore, when the insulating substrate is an amorphous substrate, the ZMR method is effective.
At present, there is a disadvantage that single crystal silicon having a crystal orientation plane other than the (100) plane cannot be stably obtained by the ZMR method.

In general, when a semiconductor device such as a thin film transistor is manufactured based on a semiconductor device, the characteristics of the semiconductor device are determined by the crystal orientation plane of single crystal silicon of the semiconductor device used to manufacture the semiconductor device. Therefore, it is desirable that the crystal orientation plane of single crystal silicon can be selected according to the type, characteristics, and the like of the semiconductor device to be manufactured. However, at this time, when a semiconductor device is to be formed using the ZMR method, There is a problem that it is difficult to appropriately select the crystal orientation plane according to the semiconductor device.

According to the present invention, even when a single-crystal silicon thin film is formed on an insulating substrate by a zone melting recrystallization method (ZMR method), the crystal orientation plane of the single-crystal silicon thin film can be easily selected. Still another object of the present invention is to provide a semiconductor device having a structure suitable for manufacturing various semiconductor devices by which silicon films having different orientations can be obtained in the same substrate, and a method for manufacturing the same.

[0008]

Means for Solving the Problems The inventor of the present application has made the above Z
The present inventors completed the present invention by examining the crystal orientation plane of the recrystallized film by the MR method from a viewpoint different from the conventional one. That is, the inventor of the present application completed the present invention,
In the process of forming single crystal silicon by the ZMR method, the interaction at the interface between the substrate and the molten silicon, particularly the interaction between silicon atoms in the substrate and the molten silicon, was also considered to be important.

Quartz glass, which is often used as an insulating substrate, has a so-called amorphous structure in which the arrangement of silicon atoms and oxygen atoms has no regularity, unlike single crystal silicon. However, even in such an amorphous structure, it is known that the arrangement of atoms is regular if the distance between atoms is extremely short. Thus, the features of the amorphous structure can be expressed. Specifically, the feature of the amorphous structure can be represented by using a radial distribution function (hereinafter referred to as RDF) in which a certain atom is defined as an origin and the existence probability of surrounding atoms is represented as a function of distance. Note that the radial distribution function can be obtained by X-ray diffraction, neutron diffraction, electron diffraction, or the like.

FIG. 1A is a diagram showing the radial distribution function of amorphous SiO _2, ie, quartz glass. according to this,
Quartz glass is around 3mm (exactly 3.10mm)
The Si—Si interaction is recognized, and the coordination number (the number of Si atoms surrounding the Si atom serving as the origin at a distance of 3.10 °) is considered to be “4”. That is, the amorphous S
In iO ₂ , four Si atoms exist around an arbitrary Si atom at an interval of 3 °. FIG. 1B is a diagram two-dimensionally expressing this state in consideration of the bonding of SiO _{2. In} the figure, black circles indicate Si atoms, and white circles indicate O atoms. Referring to FIG. 1B,
There are three Si atoms (black circles) on the circumference of a circle (shown by a broken line) with a radius of 3 ° centered on the Si atoms (black circles). That is, when silicon on a quartz glass substrate is band-melted by the ZMR method, about three silicon atoms are placed on a circumference having a radius of about 3 mm around the interface between the quartz glass substrate and the molten silicon. It is considered that Si atoms are present.

On the other hand, the relative positional relationship of Si atoms in single crystal silicon is as shown in FIGS. 2A and 2B when the crystal orientation plane is the (100) plane.
In the case of the 11) plane, it is as shown in FIGS. 3 (a) and 3 (b). 2 (b) and 3 (b), circles (shown by broken lines) with a radius of 3 ° centered on Si atoms are drawn.
As can be seen from FIGS. 2A and 2B, when the crystal orientation plane of the single crystal silicon is the (100) plane, four Si atoms are present near the circumference having a radius of 3 °. (A),
As can be seen from (b), when the crystal orientation plane of the single crystal silicon is the (111) plane, there are six Si atoms near the circumference having a radius of 3 °.

In the process of forming single crystal silicon by the ZMR method, when it is considered that Si atoms mutually interact strongly at the interface between the substrate and the silicon crystal on the substrate, the side of the silicon crystal plane is centered on the Si atoms. If there are four,
That is, the case where the (100) plane is oriented is advantageous in terms of interfacial energy. This is consistent with the conventionally known result, that is, the fact that when silicon is single-crystallized on SiO ₂ by the ZMR method, a (100) plane orientation can be obtained.

Considering the (111) plane orientation based on such a model, as shown in FIGS. 3 (a) and 3 (b), the (111) plane of the single crystal silicon has a center on Si atoms. There are six Si atoms. In this state, if the state of silicon on the surface on the substrate side is changed so that the interaction at the interface between the substrate and the (111) -oriented single-crystal silicon is reduced in energy, the (111) -oriented single crystal The inventor of the present application has conceived that silicon can be stably obtained by the ZMR method. The present invention has been made based on the above technical idea.

FIG. 4 is a diagram showing a configuration example of a semiconductor device of the present invention to be subjected to a single crystallization process by the ZMR method.
Referring to FIG. 4, the semiconductor device comprises a substrate 1 and a first
Silicon concentration modulation layer 2, silicon layer 3 to be monocrystallized by the ZMR method, and second silicon concentration modulation layer 4
And a surface protective layer 5. Here, as the substrate 1, a substrate whose surface layer is formed of an insulating material, for example, silicon oxide is used. Specifically, quartz glass can be used for the substrate 1 as a single material. Alternatively, a material in which a silicon oxide film is formed on a metal, a semiconductor, a ceramic, or the like by an appropriate method can be used. For example, SiO ₂ formed on a silicon wafer by thermal oxidation, or Fe, C
Metal materials such as u and Al, ceramic materials such as alumina and zirconia, and various physical,
The surface layer of the substrate 1 can be formed by forming SiO ₂ by a chemical film forming method or the like. When a single piece of quartz glass is used as the substrate 1, its thickness is selected from the requirements of the mechanical strength of the substrate. Usually 0.3mm ~
It is 5.0 mm, preferably 0.5 mm to 2.0 mm. In addition, SiO ₂ is used as an insulating layer on a material other than quartz glass.
When a layer is formed and used as an insulating substrate, its S
The thickness of the iO ₂ layer is set in consideration of the step of forming the first silicon concentration modulation layer 2. Usually, it is selected within a range of about 1 μm to 10 μm.

The first silicon concentration modulation layer 2 is provided for controlling the crystal orientation of a single crystal silicon layer formed thereon by the ZMR method. In the case where the plane is to be formed to be, for example, a (100) plane or a (111) plane, the interaction of Si atoms at the interface between the concentration modulation layer 2 and the single crystal silicon layer depends on each case. It is formed to be large. More specifically, (10)
The concentration of Si atoms on the 0) plane is 6.78 × 10 ¹⁸ /
cm ² , and the concentration of Si atoms on the (111) plane is 7.83 × 10 ¹⁸ atoms / cm ² , so that the first silicon concentration modulation layer 2 6.78 × 10 ¹⁸ / cm ²
The silicon concentration of about 1.83 × 10 ¹⁸ / cm ^{2 is used} as one guide when single crystal silicon is to be formed in the (100) orientation. Is done. However, it is not necessary for the entire first silicon concentration modulation layer 2 to have the above-described silicon concentration value, and it is sufficient that a necessary amount of Si atoms exist only at the interface in contact with the silicon layer 3.

Accordingly, there is no particular limitation on the amount of Si atoms inside the surface other than the surface in contact with the silicon layer 3. However, in order to reduce the distortion caused by providing the first silicon concentration modulation layer 2, 1 silicon concentration modulation layer 2
It is desirable that the amount of Si atoms contained therein gradually decreases toward the substrate 1 side.

Various methods are conceivable for forming the first silicon concentration modulation layer 2 on the surface of the insulating substrate 1 such as quartz glass (or SiO ₂ layer). For example, the first silicon concentration modulation layer 2 can be formed on the surface of the substrate 1 by a so-called ion implantation method in which silicon ions are accelerated at high speed in a vacuum by the effect of an electric field and collide with the substrate 1. This method depends on the ion current density and the implantation time,
There is an advantage that the injection amount of silicon into the first silicon concentration modulation layer 2 can be controlled with high accuracy. Alternatively, a first silicon concentration modulation layer 2 is formed on the surface of the substrate 1 by forming a material containing Si atoms on the surface of the substrate 1 and then performing a heat treatment to thermally diffuse the Si atoms into the substrate 1. can do. The first silicon concentration modulation layer 2
As described above, the crystal orientation of the single crystal silicon formed thereon by the ZMR method is set to the (100) plane or (1).
11) Since it is provided to control the surface,
When the same crystal orientation is required over the entire area on the substrate 1, the silicon layer is formed to have a uniform silicon concentration over the entire area on the substrate 1. On the other hand, if the orientation is different depending on the location on one substrate, such as a certain portion having a (100) orientation and another portion having a (111) orientation, the first
The silicon concentration modulation layer 2 is also formed with a different silicon concentration value for each location on the substrate according to its orientation.

The silicon layer 3 to be monocrystallized by the ZMR method is formed of polycrystalline silicon or amorphous silicon. This silicon layer 3 is generally formed by a plasma CVD method, a thermal CVD method, a photo CVD method,
It is formed by various film forming methods such as LPCVD method, MOCVD method, sputtering method, vacuum evaporation method, ion beam cluster film forming method, etc., when it is judged necessary in the process of zone melting recrystallization by ZMR method. May be processed into an arbitrary shape using a normal photolithography technique. Specifically, it is processed into a shape such as a stripe shape, an island shape, or a continuous island shape as shown in FIG. 5, FIG. 6, and FIG. The movement of the silicon melt can be restricted, and the stability of single crystal growth can be improved.

The second silicon concentration modulation layer 4 is provided for controlling the crystal orientation of the single crystal silicon layer formed thereunder, similarly to the first silicon concentration modulation layer 2, The crystalline silicon layer has a crystal orientation plane of, for example, (1)
When it is intended to form the (00) plane or the (111) plane, the interaction of Si atoms at the interface between the concentration modulation layer 4 and the single crystal silicon layer is increased depending on the case. Is formed.

[0020] As a method of forming the second silicon concentration modulation layer 4, after forming the SiO ₂ thin film on the silicon layer 3, SiO ₂ and silicon ions by ion implantation
There is a method of modulating the concentration of silicon ions in the silicon thin film to a desired value by injecting it into a thin film, or modulating the concentration of silicon by a thermal diffusion method.

The surface protective layer 5 is provided to prevent the evaporation of the molten silicon in the ZMR method or to prevent the movement of the melt inside the silicon layer processed as described above. It is formed of a high material. Suitable materials include SiO ₂ , SiO,
There are Si ₃ N ₄ and SiN, and these can be used alone or in combination of two or more to deposit on the second silicon concentration modulation layer 4 to form the surface protection layer 5. The surface protective layer 5 may be formed by plasma CVD, thermal CVD, or the like.
And various film forming methods such as a photo-CVD method, an optical CVD method, an LPCVD method, an MOCVD method, a sputtering method, a vacuum evaporation method, and an ion beam cluster film forming method. The thin film is optimized and formed within a range of about 0.5 μm to 5.0 μm, and preferably, 1.0 μm to 2.0 μm.

The silicon layer 3 of the semiconductor device having the above-described structure shown in FIG. 4 is melted by a known ZMR method.
By recrystallizing and changing to a single crystal silicon layer,
A semiconductor device according to the present invention can be obtained. In the ZMR method, as a method of forming a band-shaped heat melting region, heating with a linear carbon heater placed close to the substrate, high-frequency heating using a carbon susceptor,
Halogen lamp heating, laser heating, electron beam heating and the like are used.

FIG. 8 is a diagram showing a configuration example of the semiconductor device of the present invention as a result of zone melting and recrystallization of the silicon layer 3 of the semiconductor device shown in FIG. 4 by the ZMR method. Referring to FIG. 8, the silicon layer 3 of the semiconductor device shown in FIG.
As a result of the zone melting and recrystallization by the method, a single crystal silicon layer 13 is obtained. At this time, even if the ZMR method is used, the first
Silicon concentration modulation layer 2 and second silicon concentration modulation layer 4
Is provided, the crystal orientation plane of the single crystal silicon layer 13 is set to (1) in accordance with the state of silicon.
It can be stably obtained on an alignment plane other than the (00) plane. In the semiconductor device shown in FIG. 4, for example, at the interface in contact with the silicon layer 3, the density of Si atoms in the first silicon concentration modulation layer 2 and the second silicon concentration modulation layer 4 is 6.78 × 10 ¹⁸ / cm. If the thickness is about ^two , a single crystal silicon layer 13 having a (100) crystal orientation plane can be stably obtained, and the first silicon concentration modulation layer 2. The density of Si atoms in the second silicon concentration modulation layer 4 is 7.83 × 10
^{If the} number is about ¹⁸ / cm ² , the single crystal silicon layer 13
As a result, those having a (111) crystal orientation plane can be stably obtained. Therefore, in the semiconductor device shown in FIG. 8, the single crystal silicon layer 13 is formed of quartz glass (or S
Even when an amorphous substrate such as an iO ₂ layer) is used and is manufactured by the ZMR method, it is possible to stably obtain a crystal orientation plane other than the (100) plane, and control to a desired crystal orientation plane. It is formed well.

In the above example, the single crystal silicon layer 13
Is controlled to two types of orientation planes of the (100) plane and the (111) plane. However, by changing the density of Si atoms in the silicon concentration modulation layer or the like, any desired orientation plane other than the above two types can be controlled. Can also be controlled.

In the above example, the first and second silicon concentration modulation layers 2 and 4 have a predetermined Si atom concentration at the interface with the silicon layer 3 (or the single crystal silicon layer 13). The thickness is not particularly limited. Further, the second silicon concentration modulation layer 4
Is provided, the crystal orientation plane of the single crystal silicon layer 13 can be more stably and surely controlled. However, the second silicon concentration modulation layer 4 may not necessarily be provided as necessary. good.

FIG. 9 is a diagram showing another configuration example of a semiconductor device to be subjected to a single crystallization process by the ZMR method. In FIG. 9, the same parts as those in FIG. 4 are denoted by the same reference numerals. With reference to FIG. 9, this semiconductor device includes a substrate 1
, A first silicon concentration modulation layer 22, a silicon layer 23 to be monocrystallized by the ZMR method, a second silicon concentration modulation layer 24, and the surface protection layer 5. Incidentally, in the semiconductor device of FIG. 9, the first silicon concentration modulation layer 22 is formed by the same method as that of the first silicon concentration modulation layer 2 of FIG. The density of Si atoms in the two parts 2
2a and 22b are different from each other. Also, the second silicon concentration modulation layer 24 is formed in the same manner as the second silicon concentration modulation layer 4 in FIG. 4, but at this time, the density of Si atoms at the interface with the silicon layer 23 is reduced. The two portions 24a and 24b corresponding to the portions 22a and 22b of one silicon concentration modulation layer 22 are different from each other. More specifically, the portions 22a and 24a of the first and second silicon concentration modulation layers 22 and 24 have a Si atom density of, for example, 6.78 × 10 ¹⁸ atoms / cm ² at the interface with the silicon layer 23. And the first and second silicon concentration modulation layers 22 and 2
The portions 22b and 24b of No. 4 have an Si atom density of, for example, 7.83 × 10 ¹⁸ atoms / cm ² at the interface with the silicon layer 23.

FIG. 10 shows the silicon layer 2 of the semiconductor device of FIG.
3 is a diagram showing a configuration example of a semiconductor device as a result of zone melting and recrystallization of No. 3 by a ZMR method. Referring to FIG.
The silicon layer 23 in the semiconductor device shown in FIG.
It becomes 3. At this time, the first and second silicon concentration modulation layers 2
The Si atom density of the portions 22a and 24a of 2, 24 is 6.7.
Since these are 8 × 10 ¹⁸ pieces / cm ² , these portions 22a,
Portion 33a of single crystal silicon layer 33 corresponding to 24a
Is formed such that the crystal orientation plane is a (100) plane. On the other hand, the Si atom density of the portions 22b and 24b of the first and second silicon concentration modulation layers 22 and 24 is 7.83 × 10 ¹⁸ /
Since it is cm ² , the portion 33b of the single crystal silicon layer 33 corresponding to these portions 22b and 24b has a crystal orientation plane formed as a (111) plane. As described above, in the semiconductor device of FIG.
Above are formed as portions 33a and 33b having different orientations.

In the above example, two different orientation planes,
That is, the single-crystal silicon layer 33 is formed to have two parts having the (100) plane and the (111) plane.
The silicon concentration modulation layer is further finely divided, and S
By making the density of i atoms different, the single crystal silicon layer 33 can be easily formed on the same substrate 1 as having two or more portions having different orientations.

In the above example, the first and second silicon concentration modulation layers 22 and 24 are provided at predetermined interfaces at the interface with the silicon layer 23 (or the single crystal silicon layer 33).
It is sufficient that the atomic concentration is secured, and there is no particular limitation on the thickness. Further, by providing the second silicon concentration modulation layer 24, the single crystal silicon layer 33 is formed.
Although the crystal orientation plane of each of the portions 33a and 33b can be more stably and surely controlled, the second silicon concentration modulation layer 24 may not necessarily be provided as necessary.

A semiconductor device such as a thin film transistor can be formed based on the semiconductor device shown in FIGS. At this time, in the semiconductor device shown in FIGS. 8 and 10, the single-crystal silicon layer 13 and the
Since the crystal orientation plane of 33 can be selected to any desired one,
According to the present invention, a semiconductor device having a crystal orientation plane according to the characteristics of a semiconductor device to be formed can be provided. Further, in the semiconductor device of FIG. 10, since a single crystal silicon layer 33 having different crystal orientation planes is formed on the same substrate, a semiconductor device having higher performance characteristics can be easily formed using this semiconductor device. It is possible to do. In the semiconductor device shown in FIGS. 8 and 10, the surface protective layer 5 may be removed as needed in the step of forming the semiconductor device.

[0031]

An embodiment of the present invention will be described below with reference to FIG. In FIG. 11, the thickness of the substrate 41 is 1.6 mm.
Was used. After the substrate 41 was washed by an ordinary method, a first silicon concentration modulation layer 42 was formed on the surface of the substrate 41 by ion implantation. Next, a polycrystalline silicon thin film was formed as a silicon layer to be single-crystallized by ZMR using low pressure chemical vapor deposition (LPCVD) using silane gas (SiH ₄ ) as a raw material. Its film thickness was 3500 °. Thereafter, the polycrystalline silicon thin film was formed into a stripe-shaped silicon layer 43 having a width of 100 μm by photolithography.
The stripe interval was processed to 10 μm.

Next, a second silicon concentration modulation layer 44 was formed on the striped polycrystalline silicon thin film 43 by the following procedure. That is, first, silane (SiH ₄ )
Pressure chemical vapor deposition (L) using the thermal decomposition of oxygen and oxygen (O ₂ )
PCVD method) to form a 2000 ₂ SiO ₂ layer,
Silicon ions are implanted into this layer by ion implantation,
The second silicon concentration modulation layer 44 was used. At this time, the conditions for forming the SiO ₂ film were such that the silane / oxygen gas ratio was 2/5.
(At 25 ° C., 1 atm), the film forming pressure was 0.2 Torr, and the film forming temperature was 430 ° C.

Next, the second silicon concentration modulation layer 44
A surface protective layer was formed on the substrate by the following procedure. That is,
First, as in the case of forming the second silicon concentration modulation layer, first, an SiO ₂ layer is formed by low pressure chemical vapor deposition (LPCVD) using thermal decomposition of silane (SiH ₄ ) and oxygen (O ₂ ). (First surface protective layer) 45 was formed into a film having a thickness of 1.6 μm. The film forming conditions were as follows: a silane / oxygen gas ratio of 2/5 (25 ° C., 1 atm conversion), a film forming pressure of 0.2 Torr, and a film forming temperature of 430 ° C. Under these conditions, a silicon oxide film substantially recognized as SiO ₂ by infrared spectroscopy or the like could be formed. Next, an Si ₃ N ₄ layer (second surface protection layer) 46 was formed on the SiO ₂ layer by a high frequency sputtering method for 2000 times.
Å A film was formed. The film formation was performed using a sintered target of SiN as a target material, in a mixture of Ar and N ₂ gas at a mixing ratio of 1: 1 at a pressure of 5 × 10 ³ Torr and a high-frequency power density of 3 W / cm ² . Under these conditions, a silicon nitride film substantially recognized as Si ₃ N ₄ by infrared spectroscopy or the like was obtained. After the semiconductor device 102 was formed as described above, the stripe-shaped silicon layer 43 of the semiconductor device 102 was single-crystallized by using the ZMR method. FIG. 12 shows ZM
FIG. 2 is a schematic view of a melt recrystallization apparatus that performs single crystallization by the R method. In FIG. 12, reference numeral 101 denotes a sample stage in which a heater is incorporated, which can be moved at an arbitrary speed in the y direction by a bolt screw 110 and a motor 109. Reference numeral 103 denotes a semiconductor device formed according to the above-described procedure, that is, a carbon rod-shaped heater for applying heat to melt the silicon layer 43 of the sample 102, and is disposed on the sample 102 at an equal distance from the sample surface. I have. The shape of the carbon rod heater 103 is adjusted so that the temperature of the molten silicon portion falls within a temperature range of ± 0.5 ° C. when the silicon layer 43 on the substrate 41 of the sample 102 is melted by the heating. It has been processed. Also,
Reference numeral 104 denotes a non-contact thermometer, which is arranged so that the temperature of the molten silicon portion formed on the sample 102 can be detected. A temperature signal is output from the thermometer 104, and the temperature signal is transmitted to a heater temperature control circuit 106 via a temperature detection circuit 105. The heater temperature control circuit 106 The heater power supply 107 of the rod-shaped heater 103 is controlled so that the temperature of the molten silicon portion is kept constant within a range of ± 0.5 ° C. through melting and recrystallization. Using the apparatus having such a configuration as shown in FIG. 12, the sample 102 was subjected to a recrystallization treatment. At this time, the sample 10 was placed such that the stripe of the stripe-shaped silicon layer 43 was orthogonal to the carbon rod heater.
2 is placed on the sample stage 101 and the motor 109
, The zone melting recrystallization was performed from one end of the sample 102 to the other end. The conditions for recrystallization are as follows: substrate heating temperature 9
The temperature was 00 ° C., the moving speed of the sample was 0.1 mm / sec, and the temperature of the molten silicon portion was 1425 ° C.

The crystal orientation of the single crystal silicon layer obtained when the conditions of silicon ion implantation in the first and second silicon concentration modulation layers 42 and 44 of the sample 102 are variously changed is determined by X-ray diffraction and etch pit grit method. The results evaluated by are shown in the following table. As can be seen from the following table, the first and second
By appropriately setting the conditions for implanting silicon ions into the silicon concentration modulation layers 42 and 44, (10)
A single-crystal silicon film having 0) plane orientation and (111) plane orientation was obtained.

[0035]

[Table 1]

[0036]

As described above, according to the first aspect of the present invention, the first silicon concentration modulation layer is provided between the substrate and the silicon layer to be monocrystallized. At the interface of the silicon concentration modulation layer in contact with the silicon layer, the first silicon concentration modulation layer has a predetermined silicon atom concentration necessary for controlling the crystal orientation plane when the silicon layer is single-crystallized. Therefore, when the silicon layer is single-crystallized, the crystal orientation plane of the single crystal silicon layer can be stably and reliably controlled to any desired one.

According to the second aspect of the present invention, a second silicon concentration modulation layer is further provided on the side of the silicon layer opposite to the first silicon concentration modulation layer, and the second silicon concentration modulation layer is provided. At the interface of the layer in contact with the silicon layer,
Since the second silicon concentration modulation layer is provided with a predetermined silicon atom concentration necessary for controlling the crystal orientation plane when the silicon layer is single-crystallized, when the silicon layer is single-crystallized, The crystal orientation plane of the single crystal silicon layer can be more stably and more reliably controlled by any desired one.

Further, according to the third aspect of the present invention, wherein
Item 3. In the semiconductor device according to Item 2 , since the silicon layer has a crystal orientation plane corresponding to the silicon atom concentration of the first and second silicon concentration modulation layers at the time of single crystallization, A semiconductor device having an optimal crystal orientation plane according to the characteristics of a semiconductor device to be manufactured or the like can be provided.

Further, according to the invention of claim 4, wherein
Item 3. In the semiconductor device according to Item 2 , since the first and second silicon concentration modulation layers include a plurality of portions having different silicon atom concentrations at an interface in contact with the silicon layer, the silicon layer is monocrystallized. In this case, a plurality of single crystal silicon portions having different crystal orientation planes can be easily formed on the same substrate.

According to a fifth aspect of the present invention, in the semiconductor device according to the fourth aspect, the silicon layer is formed of the first and second silicon concentration modulation layers when the single crystallization is performed. Since the crystal orientation planes are different from each other corresponding to a plurality of portions, a higher-performance semiconductor device can be formed based on this semiconductor device.

According to the invention, a step of providing a first silicon concentration modulation layer on a substrate having at least a surface layer made of silicon oxide, and a step of forming a first silicon concentration modulation layer on the first silicon concentration modulation layer Forming a layer of amorphous silicon or polycrystalline silicon, and a step of converting the layer of amorphous silicon or polycrystalline silicon into a single crystal silicon layer by a zone melting recrystallization method. A semiconductor device having a crystal orientation plane can be formed.

[Brief description of the drawings]

FIG. 1A is a diagram showing an outline of a radial distribution function of amorphous SiO ₂ , and FIG. 1B is a diagram showing a two-dimensional amorphous SiO ₂ inferred from the radial distribution function shown in FIG. It is a figure showing an expression.

FIGS. 2A and 2B are diagrams for explaining the arrangement of Si atoms on a (100) plane of a silicon crystal.

FIGS. 3A and 3B are diagrams for explaining the arrangement of Si atoms on a (111) plane of a silicon crystal.

FIG. 4 is a diagram showing a configuration example of a semiconductor device of the present invention in which a single crystallization process is performed by a ZMR method.

FIG. 5 is a plan view showing an example of a planar arrangement of a silicon layer of the present invention.

FIG. 6 is a plan view showing an example of a planar arrangement of a silicon layer of the present invention.

FIG. 7 is a plan view showing an example of a planar arrangement of a silicon layer according to the present invention.

8 is a diagram showing a configuration example of the semiconductor device of the present invention as a result of zone melting and recrystallization of the silicon layer of the semiconductor device shown in FIG. 4 by the ZMR method.

FIG. 9 is a diagram showing another configuration example of the semiconductor device of the present invention in which a single crystallization process is performed by the ZMR method.

FIG. 10 is a view showing a state in which the silicon layer of the semiconductor device shown in FIG.
FIG. 11 is a diagram showing another configuration example of the semiconductor device of the present invention as a result of zone melting and recrystallization by a method.

FIG. 11 is a configuration diagram of one embodiment of a semiconductor device of the present invention.

FIG. 12 is a schematic view of a melt recrystallization apparatus for manufacturing a semiconductor device of the present invention.

FIGS. 13A and 13B are diagrams for explaining the ZMR method.

FIG. 14 is a diagram for explaining the progress of zone melting recrystallization.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 22 First silicon concentration modulation layer 3, 23 Silicon layer 4, 24 Second silicon concentration modulation layer 5 Surface protection layer 13, 33 Single crystal silicon layer 101 Internal heater 102 Sample for melting and recrystallization 103 Bar-shaped heater 104 Thermometer 105 Temperature detection circuit 106 Heater temperature control circuit 107 Heater power supply 108 Heater power supply and temperature control circuit 109 Motor 110 Ball screw

Continuation of the front page (56) References JP-A-2-150017 (JP, A) JP-A-62-73704 (JP, A) JP-A-3-200319 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H01L 21/20

Claims (6)

(57) [Claims] 1. A substrate, a silicon layer to be single crystal by zone melting recrystallization method, provided between the substrate and the silicon layer, the single crystal by zone melting recrystallization method
A first silicon concentration modulation layer for controlling the crystal orientation of the silicon layer to be converted, and silicon at the interface of the first silicon concentration modulation layer in contact with the silicon layer.
Atomic concentration, and a predetermined silicon atomic concentration needed to control the crystal orientation surface when the silicon layer is single crystal
The semiconductor device is characterized in that it it. 2. The semiconductor device according to claim 1, further comprising: a second silicon concentration modulation layer for stabilizing a crystal orientation on a side of said silicon layer opposite to said first silicon concentration modulation layer. And silicon atoms at the interface of the second silicon concentration modulation layer in contact with the silicon layer
Concentration, a predetermined silicon atomic concentration needed to control the crystal orientation surface when the silicon layer is single crystal
Wherein a is. 3. The semiconductor device according to claim 2 , wherein said silicon layer has a crystal orientation plane corresponding to a silicon atom concentration of said first and second silicon concentration modulation layers at the time of single crystallization. A semiconductor device, comprising: The semiconductor device 4. The method of claim 2, wherein, shea
The silicon atom concentration at the interface in contact with the
Said first and / or second having a silicon atom concentration
Wherein the silicon concentration modulation layer comprises a plurality of portions. 5. The semiconductor device according to claim 4, wherein said silicon layer has a first shape when a single crystal is formed.
And / or a semiconductor device having different crystal orientation planes corresponding to the plurality of portions of the second silicon concentration modulation layer. 6. Single crystallization by a zone melting recrystallization method on a substrate having at least a surface formed of an insulating material .
Providing a first silicon concentration modulation layer for controlling the crystal orientation of the silicon layer to be formed; and forming an amorphous silicon or polycrystalline silicon layer on the first silicon concentration modulation layer. , a layer of amorphous silicon or polycrystalline silicon by zone melting recrystallization method has a step of converting the single crystal silicon layer, before
In the first silicon concentration modulation layer forming step, the silicon
Interface of the first silicon concentration modulation layer in contact with the silicon layer
Of the silicon layer is monocrystallized.
Required to control the crystal orientation plane
A method for manufacturing a semiconductor device, comprising: