JPH0652712B2 - Semiconductor device - Google Patents

Description

The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a structure in which a semiconductor single crystal film is formed on an insulator and a transistor is formed using this single crystal film as a substrate. The present invention relates to a semiconductor device capable of forming a high-quality and large-area single crystal semiconductor layer over an insulating layer.

[Prior Art] In order to realize high speed and high density of a semiconductor device, an attempt is made to electrically separate circuit elements with a dielectric to manufacture a semiconductor integrated circuit with a small stray capacitance, and to make the circuit elements three-dimensional. Attempts have been made to manufacture so-called three-dimensional circuit elements to be laminated, and as one method therefor, there is a method of forming a semiconductor single crystal layer on an insulating layer and forming a circuit element in the semiconductor single crystal layer. As one of the methods for forming this semiconductor single crystal layer, a polycrystalline or amorphous semiconductor layer is deposited on an insulator, and the surface thereof is irradiated with an energy beam such as a laser beam or an electron beam. Heating only the semiconductor layer of
There is a method of forming a single crystal semiconductor layer by melting and recrystallizing an amorphous or polycrystalline semiconductor layer.

3A to 3C are views for showing a conventional method for manufacturing a single crystal semiconductor film on an insulator film.
FIG. 3 is a plan view of a conventional semiconductor device, FIG. 3B is a cross-sectional view taken along the line II of FIG. 3A and a laser scanning direction, and FIG. 3C is a line II-II of FIG. 3A. It is a figure which shows the cross-section along the line. The structure of a conventional semiconductor device and a method for manufacturing a single crystal semiconductor on an insulator film will be described below with reference to FIGS. 3A to 3C.

A conventional semiconductor device includes a single crystal semiconductor substrate 11 made of silicon having a {100} plane ((001) plane or its equivalent crystal plane) as a main surface, and a single crystal semiconductor substrate 11 on the main surface of the single crystal silicon substrate 11. Oxide film 12 which is an insulating film made of thick silicon dioxide having a longitudinal opening 23 in the portion, and oxide film 1
2 and the opening 23, and the polycrystalline silicon film 13 to be melted by the laser beam 15 and the polycrystalline silicon film 13 whose length direction is on the (001) plane of the silicon single crystal substrate 11. <110> direction (to be exact <1
0> direction), width about 5 μm, spacing about 10 μm
And an antireflection film 41 made of, for example, a silicon nitride film, which is periodically formed in a stripe shape. The longitudinal opening 23 provided in the oxide film 12 is provided in the <110> direction on the (001) plane of the silicon single crystal substrate 11, and in this portion, the main surface of the single crystal silicon substrate 11 is the oxide film 12. Exposed to the surface. The antireflection film 41 controls the temperature distribution in the polycrystalline silicon film 13 at the time of irradiating the laser beam 15 and realizes only one-way crystal growth (epitaxial growth using the base substrate single crystal as a seed through the opening 23). It is formed to a thickness of about 550Å by using the CVD method or the like. Laser beam 15 for melting polycrystalline silicon 13 is scanned in the direction of arrow X in FIG. 3B, that is, in the <110> direction on the (001) main surface of single crystal silicon substrate 11. Next, a method for single-crystallizing the polycrystalline silicon layer 13 will be described with reference to FIGS. 3A to 3C.

Polycrystalline silicon film 13 on elongated opening 23 and thick oxide film 12 is melted by irradiation with laser beam 15, and this melting is further spread to the surface of underlying single crystal silicon substrate 11 in elongated opening 23. As a result, when the melted portion 30 is solidified and recrystallized, epitaxial growth using the underlying single crystal silicon substrate 11 of the elongated opening 23 as a seed occurs, and the polycrystalline silicon film 13 is single crystallized. Here, the antireflection film 41 made of a stripe-shaped silicon nitride film provided on the polycrystalline silicon film 13 raises the temperature in the lateral direction with respect to the scanning direction of the laser light (direction of arrow X), and When solidifying and recrystallizing, the polycrystalline silicon film 13
The crystal growth of the melted portion 30 of the polycrystalline silicon film 13 is suppressed so that only the epitaxial growth using the underlying polycrystalline silicon substrate of the opening 23 as a seed is suppressed by suppressing the crystal growth of the miscellaneous crystal nuclei existing in the. , Its width, interval, and film thickness are set. Therefore, when the polycrystalline silicon film 13 is scanned with the laser beam 15 in the direction of the arrow X while being irradiated, the polycrystalline silicon film 13 is melted to form the melted portion 30, and from the melted portion 30, the scanning direction, that is, the arrow X.
The epitaxial growth continuously occurs in the direction, and the single crystal film 14 tracing the plane orientation of the underlying single crystal silicon substrate can be grown on the oxide film 12 as the insulating film. After irradiation with the laser beam 15, that is, after all the polycrystalline silicon film 13 is grown into the single crystal silicon film 14, the antireflection film 41 made of the silicon nitride film is removed, and the transistor is formed on the single crystallized silicon film 14. Etc. elements are created.

[Problems to be Solved by the Invention] However, in the structure of the conventional semiconductor device as described above, the longitudinal opening 23 is provided in the <110> direction on the underlying single crystal silicon substrate, and the longitudinal opening is formed. Since the laser beam 15 is scanned in the <110> (more precisely, <10>) direction perpendicular to the portion 23, the epitaxial crystal growth direction using the underlying single crystal silicon substrate 11 of the opening 20 as a seed is the laser beam 15. Scanning direction, that is, the <110> direction. However, since the crystal growth rate peculiar to this crystal plane in the <110> direction is small, if the scanning speed of the laser light is increased in consideration of the processing speed (throughput), the single crystal epitaxial growth will follow the scanning of the laser light. However, crystal defects such as stacking faults are generated, and 10
There is a problem that the epitaxial growth stops at a distance of about 0 to 200 μm, and thereafter, crystals having other crystal axes grow.

Therefore, an object of the present invention is to eliminate the above-mentioned problems, to make it possible to lengthen the single crystal growth distance even at a high laser beam scanning speed, and to achieve the same size as the large-sized base substrate on the insulating film. It is an object of the present invention to provide a semiconductor device capable of obtaining a single crystal semiconductor layer having a crystal axis.

[Means for Solving the Problems] A semiconductor device according to the present invention is formed on a polycrystalline or amorphous semiconductor (silicon) film in a stripe shape for giving a desired temperature distribution at the time of energy beam irradiation. The length direction of the antireflection film or the stripe of the reflection film is defined as the [110] direction on the main surface of the {100} plane of the underlying single crystal substrate,
An angle within a range of 20 degrees or more and 60 degrees or less is formed counterclockwise from one of the [10] direction, the [10] direction, and the [0] direction.

[Operation] Epitaxial growth occurs almost along the length direction of the stripe. The intrinsic growth rate of this crystal plane is (001)
[110] direction, [10] direction, [1
[0] direction and one direction out of the [0] direction, which is large in a direction forming an angle of 20 degrees or more and 60 degrees or less in the counterclockwise direction, a crystal is obtained even if laser light is scanned at a relatively high scanning speed. The growth can follow the scanning of the laser beam, the growth distance of the single crystal semiconductor layer formed on the insulator film can be lengthened, and a good quality semiconductor single crystal film with a large area and no crystal defects can be obtained. Obtainable.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. It should be noted that in the following description of the embodiments, the description overlapping with the description of the conventional technique will be appropriately omitted.

1A to 1C are views for explaining a process of forming a single crystal film on a semiconductor device and an insulator film according to an embodiment of the present invention, and FIG. 1A is an embodiment of the present invention. FIG. 1B is a diagram showing a planar arrangement of a semiconductor device that is
The drawing shows the cross-sectional structure along the line I-I in FIG. 1A and the scanning direction of the laser light, and FIG. 1C is the view showing the cross-sectional structure along the line II-II in FIG. 1A. 1A to 1C
In the figure, as a feature of the present invention, both the longitudinal direction of the longitudinal opening 23 and the stripe length direction of the stripe-shaped antireflection film 41 made of a silicon nitride film having a film thickness of 550Å formed by the CVD method are both <110>. Direction, or a direction that forms an angle of 33 ° with the equivalent direction, that is, <
The structure is the same as that of the conventional semiconductor device shown in FIGS. 3A to 3C except that it is provided in the 510> direction. Single crystallization of the polycrystalline silicon layer 13 is performed as follows. For example, the beam diameter of the laser beam 15 having a predetermined power density, which is a continuous wave argon laser, is adjusted to 100 μm, and the scanning speed is 10 cm in the arrow Y direction shown in FIG. 1B, that is, the <510> direction.
Irradiate while scanning at 1 / sec. When one scan of the laser beam 15 is completed, the laser beam 15 is moved by 40 μm in the direction perpendicular to the scanning direction, and then scanned again in the arrow Y direction. Next, the mechanism of single crystallization of the polycrystalline silicon layer 13 will be described in detail.

Laser light usually has a so-called Gaussian intensity distribution in which its power is high in the central part and low in the peripheral part. But,
Since the antireflection film 41 made of a silicon nitride film is patterned in a stripe shape on the polycrystalline silicon film 13, the polycrystalline silicon film 13 below the silicon nitride film 41.
Is kept higher than the temperature of the polycrystalline silicon film 13 below the region without the silicon nitride film 41. As a result, in the irradiation region of the laser beam 10, a temperature distribution having a period substantially similar to the period in which the stripes are formed is formed in the polycrystalline silicon 13 to compensate the Gaussian intensity distribution of the laser beam 15. You can That is, the antireflection film 4
A temperature distribution in which the temperature under 1 is high and the temperature in the space between the stripes is low is repeated in the polycrystalline silicon film 13. Due to the effect of the antireflection film (silicon nitride film) 41, the melted polycrystalline silicon 30 has a high temperature silicon nitride film 41 from the center of a region where the low temperature silicon nitride film 41 is not formed.
It solidifies and recrystallizes toward the area where is formed.
At this time, since the polycrystalline silicon film 13 is in contact with the substrate single crystal silicon 11 through the opening 23, the opening 23
From the base single crystal silicon substrate 11 as a seed, only epitaxial crystal growth occurs along the length direction of the stripe.
It continuously occurs toward the region where the silicon nitride film 41 is not formed. At this time, since the stripe length direction of the silicon nitride film 41 is patterned in the <510> direction in which the intrinsic crystal growth rate of the silicon crystal is high,
The single crystal epitaxial growth when the polycrystalline silicon film 13 is recrystallized can follow the scanning of the laser beam 15, so that there are few crystal defects such as stacking faults and the crystal plane thereof is the base single crystal silicon substrate 11. Same as (00
It is possible to obtain a high-quality and large-area single crystal layer having the 1) plane.

In the above embodiment, the length direction of the antireflection film stripe is set to <510 on the main surface of the single crystal silicon substrate 11.
> Direction, but other directions such as <410>, <2
Even if stripes are formed in the 10> and <100> directions, almost the same effect can be obtained. That is, the length direction of the stripe of the antireflection film forms an angle of 20 ° to 60 ° with respect to the <110> direction on the main surface of the underlying single crystal silicon substrate 11 or its equivalent direction, that is, on the main surface [ 2 in the counterclockwise direction from one of the [110] direction, the [10] direction, the [10] direction, and the [0] direction.
If the stripes are formed in a direction that forms an angle of 0 degree or more and 60 degrees or less, the epitaxial crystal growth distance from the end of the opening 23 can be significantly increased.

Here, if the <110> direction is the direction that forms the minimum angle with the orientation flat surface, the arrangement becomes practical. In a normal wafer, the orientation flat plane substantially coincides with the (110) plane. Therefore, the length direction of the stripe forms an angle within the range of 20 ° to 60 ° from the line of intersection between the orientation flat plane and the wafer main surface. May be set to.

Further, in the above embodiment, a silicon nitride film having a film thickness of 550Å is used as the antireflection film, but if the film structure is such that a desired temperature distribution is formed in the polycrystalline silicon film to be melted. Any structure may be used, for example, a two-layer structure in which a 1600Å silicon oxide film is deposited on the polycrystalline silicon film 13 by the CVD method, and a 550Å film-thickness silicon nitride film is patterned in stripes on the silicon oxide film. Similar effects can be obtained even with an insulating antireflection film having a structure. Furthermore, a polycrystalline silicon film having a stripe pattern may be provided on a silicon oxide film having a film thickness of 2000 Å formed by the CVD method. In this case, since the stripe-shaped polycrystalline silicon film absorbs laser light, the temperature of the polycrystalline silicon film 13 to be melted below the region where the stripe-shaped polycrystalline silicon film is formed is The height is lower than the area where the stripe-shaped polycrystalline silicon film is not formed. Further, a refractory metal such as a silicon oxide film and a tungsten film may be deposited on the polycrystalline silicon film to be melted, and the refractory metal may be patterned in a stripe shape. At this time, since the laser light is reflected by the refractory metal film, the function of the refractory metal is a reflection film opposite to the antireflection film.

Further, in the above embodiment, the case where a continuous wave argon laser is used, for example, is explained, but other laser light may be used, and the same effect can be obtained by using an energy beam such as an electron beam.

Further, a structure may be formed on the main surface of the underlying semiconductor substrate like a three-dimensional circuit element, and for example, the second A
As shown in FIG. 2B, after the element 30 such as a transistor is formed on the main surface of the base single crystal silicon substrate 11, the polycrystalline silicon 13 is formed through the thick insulator layer 12,
Even if the antireflection film 41 is formed, the same effect can be obtained. Here, FIG. 2A is a diagram showing an example of a configuration of a semiconductor device for realizing the above-described three-dimensional circuit element.
FIG. A is a diagram showing its plane arrangement, and FIG. 2B is a diagram showing its sectional structure. 2A and 2B, on the main surface of the base single crystal silicon substrate 11, a thick insulating film, that is, an isolation oxide film 12 'for electrically isolating circuit elements, and the operation of the MOS transistor are controlled. The first-layer circuit element 30 is formed by the gate electrode 31 and the wiring 32 for interconnecting the circuit elements and made of, for example, a refractory metal. An oxide film 12, which is a thick insulating film, is formed on the circuit element 30 of the first layer, and an opening 23 reaching the main surface of the underlying single crystal silicon substrate 11 is provided in a part of the thick oxide film 12 in a longitudinal shape. To be A polycrystalline silicon film 13 to be melted is formed on the oxide film 12 which is a thick insulating film and on the opening 23, and the length direction of the stripe on the polycrystalline silicon film 13 is, for example, the <510> direction. The antireflection film 41 set to 1 is formed in a stripe shape with a predetermined width and interval. Even in such a configuration, the polycrystalline silicon film 13 in the opening 23 is melted by using laser light, and the melting is spread to the main surface of the single crystal silicon substrate 11, so that the polycrystalline silicon film in the opening 23 is melted. 13 is epitaxially grown, the crystal plane orientation of the underlying single crystal silicon substrate 11 in the opening 23 is picked up, and the single crystal film epitaxially grown is used as a seed crystal to form a polycrystal silicon film 13 on the oxide film 12 as an insulator. Epitaxial growth can be realized by scanning with laser light, and single crystal growth can be realized over a long distance along the <510> direction where the crystal growth rate is high.

Further, in the above-described embodiment, the case where the polycrystalline silicon film is used as the semiconductor film to be melted has been described, but the same effect can be obtained even when the amorphous silicon film is used.

[Effects of the Invention] As described above, according to the present invention, a single crystal semiconductor substrate having a (001) plane or its equivalent crystal plane as a main surface, and a single crystal semiconductor substrate formed on the main surface of the substrate and at least a part thereof is formed. An insulating film having a longitudinal opening in which the main surface of the crystalline semiconductor substrate is exposed, and formed on the insulating film and the longitudinal opening.
In a semiconductor device which is a base composed of a polycrystal or amorphous semiconductor film to be melted by irradiation with energy rays, in order to give a desired temperature distribution in the polycrystal or amorphous semiconductor film at the time of irradiation with energy rays. A reflection film or an antireflection film is formed on the main surface of the underlying single crystal semiconductor substrate by [11
0] direction, [10] direction, [10] direction, and [0] direction from one direction to a counterclockwise direction in the range of 20 degrees or more and 60 degrees or less in a stripe shape having an angle within the range of 60 degrees or less. Since it is formed, a high-quality and large-area single crystal semiconductor layer can be formed over the insulator film in a short time.

[Brief description of drawings]

1A to 1C are views showing a process for forming a single crystal semiconductor layer on a semiconductor device and an insulating film according to an embodiment of the present invention, and FIG. 1A is an embodiment of the present invention. FIG. 1B is a diagram showing a planar arrangement of a semiconductor device,
The figure is a diagram showing a cross-sectional structure along the line I-I in FIG. 1A and the energy ray irradiation and scanning directions, and FIG. 1C is a diagram showing a cross-sectional structure along the line II-II in FIG. 1A. .
2A and 2B are diagrams showing the structure of a semiconductor device according to another embodiment of the present invention, FIG. 2A showing its planar arrangement, and FIG. 2B showing a line II 'in FIG. 2A. It is a figure which shows the cross-section structure along. 3A to 3C are views for showing the structure of a conventional semiconductor device and a manufacturing process for forming a single crystal semiconductor layer on an insulating film, and FIG. 3A is a plan view layout of the conventional semiconductor device. FIG.
FIG. 3B is a view showing a cross-sectional structure taken along line I-I and an energy ray irradiation scanning direction in FIG. 3A, and FIG. 3C is a view showing a cross-sectional structure taken along line II-II in FIG. 3A. is there. In the figure, 11 is a single crystal semiconductor substrate whose main surface is a (001) plane or its equivalent crystal plane, 12 is a silicon oxide film which is an insulating film, 13 is a polycrystalline or amorphous silicon film to be melted, Reference numeral 14 is a recrystallized silicon film, 23 is a longitudinal opening, 30 is a first-layer circuit element, and 41 is an antireflection film. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-59-108313 (JP, A) JP-A-58-93221 (JP, A)

Claims (13)

[Claims] 1. A substrate of a semiconductor single crystal having a crystal plane of substantially a (001) plane as a main surface, and an opening formed on the main surface of the substrate and having at least a part thereof reaching the main surface of the substrate. A first insulating layer having: and a first semiconductor layer formed on the first insulating layer and the opening, melted by irradiation of energy rays, and monocrystallized; A stripe layer having a stripe-shaped film thickness distribution in which stripes having a predetermined width and interval are periodically repeated and formed on the semiconductor layer to give a stripe-like reflectance change to the energy rays. In the semiconductor device having the following, the length direction of the stripe of the stripe layer is the [110] direction in the main surface of the substrate,
A semiconductor formed to form an angle θ within a range of 20 degrees or more and 60 degrees or less counterclockwise from one of the [10] direction, the [10] direction, and the [0] direction. apparatus. 2. The semiconductor device according to claim 1, wherein the substrate is made of silicon, and the first insulating layer is made of silicon dioxide. 3. The semiconductor device according to claim 1, wherein the stripe layer is composed of only one second insulating layer formed in a stripe shape. 4. The semiconductor device according to claim 3, wherein the second insulating layer is composed of a silicon nitride film. 5. The stripe layer includes a second insulating layer formed on the first semiconductor layer and a third insulating layer formed in the stripe shape on the second insulating layer. The semiconductor device according to claim 1, which is configured. 6. The semiconductor device according to claim 5, wherein the second insulating layer is made of silicon dioxide, and the third insulating layer is made of a silicon nitride film. 7. The stripe layer is a second insulating layer formed on the first semiconductor layer, and a non-single-crystal second semiconductor formed in a stripe shape on the second insulating layer. The semiconductor device according to claim 1 or 2, which is composed of layers. 8. The semiconductor device according to claim 7, wherein the second insulating layer is made of silicon dioxide, and the second semiconductor layer is made of polycrystalline silicon. 9. The semiconductor device according to claim 1, wherein the stripe layer includes a refractory metal layer formed in the stripe shape. 10. The semiconductor device according to claim 9, wherein the refractory metal layer is made of tungsten. 11. The semiconductor device according to claim 1, wherein the energy beam is a continuous wave laser light beam. 12. The semiconductor device according to claim 1, wherein the energy beam is an electron beam. 13. A transistor circuit element is formed between the substrate and the first insulating layer.
The semiconductor device according to the item.