KR101044415B1 - Manufacturing method for thin film of poly-crystalline silicon - Google Patents

Abstract

PURPOSE: A method for manufacturing a multi-crystalline silicon thin film is provided to improve the efficiency of manufacturing processes by precisely controlling the amount of metal catalyst. CONSTITUTION: A first silicon layer is formed on an insulating substrate by stacking an amorphous silicon layer(S1). A silicon oxide film is formed on the first silicon layer(S2). A metal layer is formed on the silicon oxide film(S3). A metal oxide film is formed on the surface of the metal layer by thermally treating the metal layer(S4). A second silicon layer is formed by stacking an amorphous layer on the metal oxide film(S5). A third silicon layer is formed on the metal silicon oxide layer(S6). Crystalline silicon is generated from the third silicon layer(S8).

Description

Manufacturing method for thin film of Poly-Crystalline Silicon}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a polycrystalline silicon thin film for use in a solar cell, and more particularly, to a method for effectively producing a polycrystalline silicon thin film of an amorphous silicon thin film by metal induction crystallization.

In general, most problems arising in the production of poly-silicon (poly-Si) are due to the use of glass substrates that are vulnerable at high temperatures, and the process temperature cannot be raised sufficiently to the temperature at which the amorphous silicon (a-Si) thin film is crystallized.

The process requiring high temperature heat treatment in the production of poly-Si is a crystallization heat treatment (Crystallization) that converts the amorphous silicon (a-Si) thin film to a crystalline silicon thin film and an activation heat treatment (Dopant) that is electrically activated after doping Activation).

At present, a variety of processes (LTPS: Low Temperature poly-Si) have been proposed for forming a polycrystalline silicon thin film in a short time at a low temperature that the glass substrate allows. Representative methods for forming a polycrystalline silicon thin film include solid phase crystallization (SPC), excimer laser annealing (ELA), and metal induced crystallization (MIC).

Solid Phase Crystallization (SPC) is the most direct and long used method of obtaining polycrystalline silicon (poly-Si) thin films from amorphous silicon (a-Si). SPC is a method of obtaining a polycrystalline silicon thin film having a grain size of about several micro by heat-treating the amorphous silicon thin film at a temperature of 600 ℃ or more for several tens of hours. The polycrystalline silicon thin film obtained by this method has a disadvantage in that it is difficult to use a glass substrate because of high defect density in crystal grains and a high heat treatment temperature, and a long process time due to long heat treatment.

Excimer Laser Annealing (ELA) is a method of instantaneously irradiating an excimer laser to a amorphous silicon thin film for nanoseconds to melt and recrystallize the amorphous silicon thin film without damaging the glass substrate.

However, ELA is known to have significant problems in mass production processes. ELA has a very non-uniform grain structure of polycrystalline silicon (poly-Si) thin film according to the laser irradiation amount. ELA has a problem that it is difficult to manufacture a uniform crystalline silicon thin film because of the narrow process range. In addition, the surface of the polycrystalline silicon thin film is rough, which adversely affects the characteristics of the device. This problem is more serious in the application of organic light emitting diodes (OLEDs) in which the uniformity of thin film transistors (TFTs) is important.

To overcome this problem, the proposed method is Metal Induced Crystallization (MIC). MIC is a method of inducing crystallization of silicon by applying a metal catalyst to amorphous silicon by sputtering or spin coating, followed by heat treatment at low temperature. As the metal catalyst, various metals such as nickel (Ni), copper (Cu), aluminum (Al), and palladium (Pd) may be used. In general, nickel (Ni) is used as a metal catalyst in MIC, in which reaction control is easy and large grains are obtained. MIC can be crystallized at a lower temperature of less than 450 ° C., but there are significant problems in the actual production process. This problem is that a significant amount of metal diffused in the active region in the TFT causes typical metal contamination, increasing leakage current, one of the TFT characteristics.

The development of low temperature poly-silicon (LTPS) has been carried out for the purpose of application to liquid crystal display devices, but recently, active matrix organic light emitting diodes (AMOLED) and thin film polycrystalline silicon solar cells In addition, the need for development is increasing.

Inexpensive, high-productivity poly-Si fabrication methods will compete with amorphous silicon thin-film transistor liquid crystal displays (a-Si TFT LCDs) in the display family with many active organic light-emitting diodes (AMOLEDs) in the market. It is important in that it is. The method of manufacturing polycrystalline silicon is also important in that active organic light emitting diodes (AMOLEDs) will compete with crystalline wafer forms in solar cells. Therefore, the production cost and market competitiveness of the product are stable and polycrystalline at a low price compared to the amorphous silicon thin film transistor liquid crystal display (a-Si TFT LCD) and the crystalline wafer type solar cell in which the production technology has reached a stabilization stage. It depends on whether you can make silicon.

1 schematically shows a manufacturing process for obtaining a polycrystalline silicon thin film from amorphous silicon by a metal induction crystallization method. Referring to FIG. 1, in the conventional process, a buffer layer 2 made of silicon oxide (SiO ₂ ) is formed on a substrate 1 such as glass, and an amorphous silicon layer 3 is formed on the buffer layer 2 by plasma chemical vapor deposition (PECVD). After forming by Plasma Enhanced Chemical Vapor Deposition, sputtering and coating a metal such as nickel (Ni) on the amorphous silicon layer (3) and then heat-treated by RTA (Rapid Thermal Annealing) at about 700 ℃ The crystalline silicon 4 is formed from the silicon layer 3. However, according to the conventional method, since it is difficult to precisely control the amount of the metal applied to the upper portion of the amorphous silicon layer 3, there is an inconvenience that it is necessary to remove the excessively applied metal. This process not only increases manufacturing costs but also adversely affects the quality of the crystallized silicon.

An object of the present invention is to solve the above problems, in the method of manufacturing a polycrystalline silicon thin film using the metal induction crystallization method, precisely control the amount of catalyst metal and enable crystallization at low temperature By providing an efficient method for producing a polycrystalline silicon thin film.

In order to achieve the above object, a method of manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention includes: forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;

The first silicon layer is heat-treated and the first silicon layer is coated. Forming a silicon oxide film;

A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;

A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;

Forming a second silicon layer by laminating an amorphous silicon layer on the metal oxide film;

A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;

Forming a third silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer; And

And a crystallization step of heat-treating the crystalline silicon in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst.

The heat treatment temperature in the silicon oxide film forming step and the metal oxide film forming step is 100 ℃ to 1000 ℃,

The heat treatment temperature of the crystallization step is preferably 300 ℃ to 1000 ℃.

The metal layer has a thickness of 5 kPa to 1500 kPa,

The thickness of the silicon oxide film and the metal oxide film is 1Å to 300Å,

The thickness of the first silicon layer and the thickness of the second silicon layer are 5 kPa to 1500 kPa, respectively.

The ratio of the thickness of the sum of the thickness of the metal layer and the thickness of the first silicon layer and the second silicon layer is preferably 1: 0.3 to 1:30.

A patterning step of removing a portion of the metal layer by a photolithography method after the metal layer forming step;

And forming a metal oxide film on the surface of the metal layer by heat-treating the patterned metal layer or by depositing a metal oxide film on the surface of the metal layer to form a metal oxide film.

In order to achieve the above object, a method of manufacturing a polycrystalline silicon thin film according to a second embodiment of the present invention includes: forming a first silicon layer by laminating amorphous silicon on an insulating substrate;

Forming a silicon oxide film on the surface of the first silicon layer by heat-treating the first silicon layer;

A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;

A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;

Forming a second silicon layer by laminating amorphous silicon on the metal oxide film;

A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;

A third silicon layer forming step of laminating an amorphous silicon germanium layer or an amorphous silicon carbide layer on the metal silicon oxide layer to form an amorphous silicon germanium layer or an amorphous silicon carbide layer; And

And a crystallization step of heat-treating the crystalline silicon germanium layer or the crystalline silicon carbide layer from the amorphous silicon germanium layer or the amorphous silicon carbide layer formed in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst. There is this.

In order to achieve the above object, a method of manufacturing a polycrystalline silicon thin film according to a third embodiment of the present invention includes: forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;

The first silicon layer is heat-treated and the first silicon layer is coated. Forming a silicon oxide film;

A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;

A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;

A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer to form a metal silicon oxide layer;

Forming a second silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer;

And a crystallization step of heat treating the crystalline silicon in the second silicon layer using the metal particles of the metal silicon oxide layer as a catalyst.

In order to achieve the above object, a method of manufacturing a polycrystalline silicon thin film according to a fourth embodiment of the present invention includes: forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;

Forming a first metal oxide layer by depositing a metal oxide layer on the first silicon layer;

A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;

Forming a metal oxide film on the surface of the metal layer by heat-treating the metal layer or forming a metal oxide film by depositing a metal oxide film on the surface of the metal layer;

Forming a second silicon layer by laminating an amorphous silicon layer on the second metal oxide film;

A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;

Forming a third silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer; And

And a crystallization step of heat-treating the crystalline silicon in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst.

Method for producing a polycrystalline silicon thin film according to the present invention has the advantage that it can be crystallized at a lower temperature than the conventional manufacturing method. In addition, the method for producing a polycrystalline silicon thin film according to the present invention can produce an effective polycrystalline silicon crystallized thin film by precisely controlling the amount of the metal catalyst diffused into the amorphous silicon layer and the nucleus of silicon crystallization in the amorphous silicon layer. It works.

1 is a view for explaining a conventional method for producing a polycrystalline silicon thin film by a metal induction crystallization method.
2 is a view showing a manufacturing process according to a first embodiment of the present invention.
3 is a cross-sectional view after the first silicon layer forming step illustrated in FIG. 2.
4 is a cross-sectional view after the silicon oxide film forming step illustrated in FIG. 2.
5 is a view showing a cross section after the metal layer forming step shown in FIG.
FIG. 6 is a cross-sectional view after the metal oxide film forming step illustrated in FIG. 2.
FIG. 7 is a view illustrating a cross section after the second silicon layer forming step illustrated in FIG. 2.
8 is a view showing a cross section after the silicide heat treatment step shown in FIG.
FIG. 9 is a cross-sectional view after the third silicon layer forming step illustrated in FIG. 2.
10 is a view showing a cross section after the crystallization step shown in FIG.
11 is a photograph of the surface of amorphous silicon as viewed under an optical microscope.
FIG. 12 is a graph analyzing the wave number of the amorphous silicon illustrated in FIG. 11.
13 is a photograph of the surface of a crystalline silicon wafer as seen under an optical microscope.
FIG. 14 is a graph analyzing the wave number of the silicon wafer illustrated in FIG. 13.
15 is a photograph of a surface of a polycrystalline silicon thin film manufactured by a conventional metal induction crystallization method viewed with an optical microscope.
FIG. 16 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 15.
17 is a photograph of the surface of the polycrystalline silicon thin film prepared according to the present invention under an optical microscope.
FIG. 18 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 17.
19 is a view showing a manufacturing process according to a third embodiment of the present invention.
20 is a view showing a manufacturing process according to a fourth embodiment of the present invention.
FIG. 21 is a view illustrating a cross section after the second silicon layer forming step illustrated in FIG. 20.

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

2 is a view showing a manufacturing process according to a first embodiment of the present invention. 3 is a cross-sectional view after the first silicon layer forming step illustrated in FIG. 2. 4 is a cross-sectional view after the silicon oxide film forming step illustrated in FIG. 2. 5 is a view showing a cross section after the metal layer forming step shown in FIG. FIG. 6 is a cross-sectional view after the metal oxide film forming step illustrated in FIG. 2. FIG. 7 is a view illustrating a cross section after the second silicon layer forming step illustrated in FIG. 2. 8 is a view showing a cross section after the silicide heat treatment step shown in FIG. FIG. 9 is a cross-sectional view after the third silicon layer forming step illustrated in FIG. 2. 10 is a view showing a cross section after the crystallization step shown in FIG. 11 is a photograph of the surface of amorphous silicon as viewed under an optical microscope. FIG. 12 is a graph analyzing the wave number of the amorphous silicon illustrated in FIG. 11. 13 is a photograph of the surface of a crystalline silicon wafer as seen under an optical microscope. FIG. 14 is a graph analyzing the wave number of the silicon wafer illustrated in FIG. 13. 15 is a photograph of a surface of a polycrystalline silicon thin film manufactured by a conventional metal induction crystallization method viewed with an optical microscope. FIG. 16 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 15. 17 is a photograph of the surface of the polycrystalline silicon thin film prepared according to the present invention under an optical microscope. FIG. 18 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 17.

2 to 18, a method of manufacturing a polycrystalline silicon thin film according to a first embodiment of the present invention includes a first silicon layer forming step S1, a silicon oxide film forming step S2, and a metal layer forming step S3. ), A metal oxide film forming step S4, a second silicon layer forming step S5, a silicide heat treatment step S6, a third silicon layer forming step S7, and a crystallization step S8. have.

In the first silicon layer forming step (S1), an amorphous silicon layer is laminated on the insulating substrate 10 such as glass to form the first silicon layer 30. The substrate 10 includes a buffer layer 20 made of a material such as silicon nitride (SiN) or silicon oxide (SiO ₂ ). The buffer layer 20 is provided to serve as an insulation function. In addition, in the buffer layer 20, impurities are diffused from the substrate 10 to the first silicon layer 30 or the second silicon layer 50 in the silicide heat treatment step S6 or the crystallization step S8, which will be described later. It is provided to prevent impurities from being contaminated in the first silicon layer 30 or the second silicon layer 50. In the first silicon layer forming step (S1), an amorphous first silicon layer 30 is formed on the buffer layer 20 by using a known means such as plasma chemical vapor deposition. It is preferable that the thickness of the said 1st silicon layer 30 is 5 kPa-1500 kPa. In the case where the thickness of the first silicon layer 30 is less than 5 mm, the thickness of the first silicon layer 30 is so thin that process reproducibility deteriorates and the uniformity of the first silicon layer 30 when deposited in a large area. There is a problem of poor uniformity. On the other hand, when the thickness of the first silicon layer 30 exceeds 1500Å, the first silicon layer 30 is not required to form the metal silicon oxide layer 55 in combination with the metal layer 40 described later. There is a problem that chemical bonds are produced.

In the silicon oxide film forming step (S2), the first silicon layer 30 is heat-treated to form a silicon oxide film 35 on the surface of the first silicon layer 30. The heat treatment temperature in the silicon oxide film forming step (S2) is preferably 100 ℃ to 1000 ℃. When the heat treatment temperature in the silicon oxide film forming step S2 is less than 100 ° C., there is a problem in that the silicon oxide film 35 is not formed well. On the other hand, when the heat treatment temperature of the silicon oxide film forming step S2 exceeds 1000 ° C., the substrate 10 made of glass deforms or breaks due to thermal shock. The heat treatment method of the silicon oxide film forming step S2 may be a high temperature furnace, a metal heat treatment (RTA), an ultraviolet (UV) heating method, or the like. The thickness of the silicon oxide film 35 is preferably 1 kPa to 300 kPa. The thickness of the silicon oxide film 35 is 1Å If less, there is a problem in process reproducibility because it is too thin. When the thickness of the silicon oxide film 35 is greater than 300 GPa, there is a problem that it is difficult for the silicon particles of the first silicon layer 30 to penetrate into the metal layer 40 described later.

In the metal layer forming step (S3), the metal layer 40 is formed by stacking the metal layer 40 on the silicon oxide film 35. As the metal layer 40, a metal such as nickel (Ni) may be used. The metal layer 40 may be performed by known methods such as sputtering or plasma chemical vapor deposition (PECVD). It is preferable that the thickness of the said metal layer 40 is 5 kPa-1500 kPa. If the thickness of the metal layer 40 is less than 5Å, the thickness of the metal layer 40 is so thin that the process reproducibility deteriorates, and the problem of deterioration in uniformity of the metal layer 40 when deposited in a large area. have. On the other hand, when the thickness of the metal layer 40 exceeds 1500 kPa, too much metal penetrates into the second silicon layer 50, which will be described later, so that the problem of metal contamination occurs, the polycrystal formed in the crystallization step (S8) described later. There is a problem of degrading the characteristics of a device containing silicon. After the metal layer forming step S3, a patterning step of removing a portion of the metal layer 30 by a photolithography method may be performed. If necessary, the patterning step can be omitted. The patterning step is to uniformly distribute the growth nucleus of the crystalline silicon.

In the metal oxide film forming step (S4), the metal layer 40 is heat-treated to form a metal oxide film 45 on the surface of the metal layer 40. The metal oxide layer 45 may be formed by depositing a metal oxide layer 45 on the surface of the metal layer 40. It is preferable that the thickness of the said metal oxide film 45 is 1 kPa-300 kPa. If the thickness of the metal oxide film 45 is less than 1 GPa, there is a problem in process reproducibility because it is too thin. When the thickness of the metal oxide film 45 is greater than 300 GPa, it is difficult to penetrate the metal particles of the metal layer 40 into the second silicon layer 50 described later. When the metal oxide film 45 is formed by heat treatment, the heat treatment temperature is preferably 100 ° C to 1000 ° C. When the heat treatment temperature in the metal oxide film forming step S4 is less than 100 ° C., the metal oxide film 45 may not be well formed. When the heat treatment temperature in the metal oxide film forming step S4 exceeds 1000 ° C., the substrate 10 made of glass may deform or break due to thermal shock. The heat treatment method of the metal oxide film forming step S4 may be a high temperature furnace, a metal heat treatment (RTA), an ultraviolet (UV) heating method, or the like.

In the second silicon layer forming step S5, an amorphous silicon layer is stacked on the metal oxide layer 45 to form a second silicon layer 50. It is preferable that the thickness of the second silicon layer 50 is 5 kPa to 1500 kPa. When the thickness of the second silicon layer 50 is less than 5 mm, the thickness of the second silicon layer 50 is so thin that process reproducibility deteriorates and the uniformity of the second silicon layer 50 when deposited in a large area. There is a problem of poor uniformity. On the other hand, when the thickness of the second silicon layer 50 exceeds 1500Å, the second silicon layer 50 is not necessary to form the metal silicon oxide layer 55 in combination with the metal layer 40 described later. There is a problem that chemical bonds are produced. Since the method of forming the second silicon layer 50 in the second silicon layer forming step S5 is substantially the same as the method of the first silicon layer forming step S1, a detailed description thereof will be omitted.

The ratio of the thickness of the thickness of the metal layer 40 to the thickness of the first silicon layer 30 and the second silicon layer 50 is preferably 1: 0.3 to 1:30. When the ratio of the sum of the thickness of the metal layer 40 and the thickness of the first silicon layer 30 and the second silicon layer 50 is out of the above range, the metal silicon oxide layer in the silicide heat treatment step (S6) described later. There is a problem that chemical bonds are generated that are not necessary to form (55). In other words, a chemical bond of a composition other than the metal silicon oxide composition required for the metal inductive bond is formed to interfere with inductive crystallization.

In the silicide heat treatment step (S6), a catalyst metal atom is transferred from the metal layer 40 to the first silicon layer 30 and the second silicon layer 50 to form a metal silicon oxide layer 55. The heat treatment performed in the silicide heat treatment step S6 may be performed by a high temperature furnace, rapid heat treatment (RTA), ultraviolet (UV) heating, or the like. The metal silicon oxide layer 55 formed in the silicide heat treatment step S6 serves as a nucleus for crystallizing amorphous silicon (a-Si) in the crystallization step S8 described later.

In the third silicon layer forming step (S7), an amorphous silicon layer is stacked on the metal silicon oxide layer 55 to form a third silicon layer 60. The method of forming the third silicon layer 60 may be performed using a method such as a known plasma chemical vapor deposition method.

In the crystallization step S8, heat treatment is performed such that crystalline silicon 70 is generated in the third silicon layer 60 using the metal particles of the metal silicon oxide layer 55 as a catalyst. The heat treatment in the crystallization step (S8) is carried out using RTA (Rapid Thermal Annealing) equipment. The heat treatment temperature of the crystallization step (S8) is preferably 300 ℃ to 1000 ℃. When the heat treatment temperature of the crystallization step (S8) is less than 300 ℃ there is a problem that the crystallization is low because the temperature is low to crystallize. When the heat treatment temperature of the crystallization step S8 exceeds 1000 ° C., the substrate 10 may be deformed or damaged due to thermal shock.

In order to analyze the crystallization state of the polycrystalline silicon thin film manufactured by such a manufacturing method, the size of the crystal grains was observed by using an optical microscope and Raman Spectroscopy, and the wave number having the maximum intensity was analyzed.

11 is a photograph of the surface of amorphous silicon as viewed under an optical microscope. FIG. 12 is a graph analyzing the wave number of the amorphous silicon illustrated in FIG. 11. 13 is a photograph of the surface of a crystalline silicon wafer as seen under an optical microscope. FIG. 14 is a graph analyzing the wave number of the silicon wafer illustrated in FIG. 13. 15 is a photograph of a surface of a polycrystalline silicon thin film manufactured by a conventional metal induction crystallization method viewed with an optical microscope. FIG. 16 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 15. 17 is a photograph of the surface of the polycrystalline silicon thin film prepared according to the present invention under an optical microscope. FIG. 18 is a graph analyzing the wave number of the polycrystalline silicon thin film illustrated in FIG. 17. 13, 15, and 17 are magnified 1000 times.

11 and 12, the second silicon layer 60, which is amorphous silicon, exhibits maximum intensity at a wavenumber of 480 cm ⁻¹ . In FIG. 12, the horizontal axis represents a wave number (cm ⁻¹ ) and corresponds to a frequency. A wave number is a unit of frequency that represents the number of waves in a unit distance by dividing the frequency of light by the speed of light in atomic, molecular, and nuclear spectroscopy. In other words, the frequency of a wave is represented by the Greek letter ν (nu), which is equal to the luminous flux c divided by the wavelength λ. That is, ν〓c / λ. In the visible region of the spectrum, a typical spectral line is a wavelength of 5.8 × 10 −5 cm and corresponds to a frequency of 5.17 × 10 14 kHz. However, because such a frequency has a value that is too large, it is convenient to divide the number by the speed of light to reduce the size. The frequency divided by the speed of light is ν / c, which is 1 / λ in the above equation. When the wavelength is measured in m, 1 / λ represents the number of waves found within 1m. The wavenumber is usually measured in units of 1 / m, i.e. m ^{- 1} and 1 / cm, i.e. cm- ¹ .

In FIG. 12, the vertical axis represents a sum of wave numbers measured per unit time and corresponds to intensity (CPS, Count Per Second). The units of the horizontal axis and the vertical axis of FIGS. 14, 16, and 18 are the same as those of FIG. 12. In contrast, silicon wafers, which are typical crystalline silicon, exhibit maximum strength at a wavenumber of 520 cm ⁻¹ as shown in FIGS. 13 and 14. 15 and 16 show surface photographs and wave number analysis graphs of a polycrystalline silicon thin film manufactured by a conventional metal induction crystallization method. Referring to FIGS. 15 and 16, the maximum strength is shown at a similar frequency compared to the crystalline silicon wafers shown in FIGS. 13 and 14. By the way, it can be seen that the optical micrograph of the surface of the silicon thin film shown in FIG. 15 is enlarged by 1000 times and the size of the crystal grain is relatively small.

Meanwhile, optical micrographs and wave number analysis graphs of the polycrystalline silicon thin film manufactured by the present invention are shown in FIGS. 17 and 18, respectively. Referring to FIG. 18, it can be seen that the wave number representing the maximum strength in the polycrystalline silicon thin film manufactured by the present invention is well represented as in the crystalline silicon wafer shown in FIG. 14. In addition, FIG. 17 is an optical micrograph of 1000 times magnification. Comparing FIG. 17 with FIG. 15, it is shown that the grains of the polycrystalline silicon thin film manufactured by the present invention are much larger than those of the polycrystalline silicon thin film manufactured by the conventional method. Able to know. From the experimental results, it can be seen that the manufacturing method of the polycrystalline silicon thin film according to the present invention is superior to the conventional manufacturing method. In addition, the manufacturing method of the polycrystalline silicon thin film according to the present invention has the advantage that it can be crystallized at a lower temperature than the conventional manufacturing method. In the method for producing a polycrystalline silicon thin film according to the present invention, by precisely controlling the amount of the catalyst metal in advance by disposing the catalyst metal, which is a nucleus of the reaction that is transformed from amorphous silicon into crystalline silicon, under the amorphous silicon layer, it is then diffused into the amorphous silicon layer. By doing so, there is an advantage of preventing the inflow of impurities and lowering the activation energy.

On the other hand, the second embodiment according to the present invention is to replace the amorphous silicon laminated in the third silicon layer with amorphous silicon germanium (SiGe) or amorphous silicon carbide (SiC) compared to the first embodiment described above. Since the second embodiment is almost the same process as the first embodiment, a detailed description will be referred to the first embodiment.

Meanwhile, a third embodiment according to the present invention will be described with reference to FIG. 19. 19 is a view showing a manufacturing process according to a third embodiment of the present invention.

Referring to FIG. 19, unlike the first embodiment described above, the third embodiment of the present invention may include a first silicon layer forming step (S1), a silicon oxide film forming step (S2), a metal layer forming step (S3), After the metal oxide film forming step S4, the silicide heat treatment step S9 is performed. In the third embodiment, when the silicide heat treatment step S9 is performed after the metal layer forming step S3, as shown in FIG. 6, a cross-sectional structure as shown in FIG. 8 is formed. After the second silicon layer forming step (S10) after the crystallization step (S11) shows the same cross-sectional structure as in FIGS.

Meanwhile, a fourth embodiment according to the present invention will be described with reference to FIGS. 20 and 21. 20 is a view showing a manufacturing process according to a fourth embodiment of the present invention. FIG. 21 is a view illustrating a cross section after the second silicon layer forming step illustrated in FIG. 20.

20 and 21, in the method of manufacturing the polycrystalline silicon thin film according to the fourth embodiment, the silicon oxide film forming step S2 is replaced with the first metal oxide film forming step S12 as compared with the first embodiment. . That is, in the first metal oxide film forming step S12, the first metal oxide film 36 is formed by depositing a metal oxide film such as nickel oxide (NiO) on the first silicon layer 30 in the first embodiment. The first metal oxide layer 36 may be formed by depositing nickel oxide (NiO) using a known method such as sputtering.

In the first metal oxide film forming step (S12), the silicon oxide film 35 is replaced with the first metal oxide film 36 in the first embodiment. Therefore, the cross-section after the second silicon layer forming step S15 shown in FIG. 21 can be easily understood by comparing with FIG. 7. Since the process after the second silicon layer forming step (S15) is the same as the first embodiment, a detailed description thereof will be omitted.

The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to the examples, and various forms of embodiments may be embodied without departing from the technical spirit of the present invention.

10 substrate 20 buffer layer
30 ... first silicon layer 35 ... silicon oxide film
36 First metal oxide film 40 Metal layer
45 ... (second) metal oxide film 50 ... second silicon layer
55 ... metal silicon oxide layer 60 ... third silicon layer
70 ... crystalline silicon S1 ... first silicon layer forming step
S2 ... Silicon oxide film forming step S3, S13 ... Metal layer forming step
S4 ... metal oxide film forming step S5, S15 ... second silicon layer forming step
S6, S9, S16 ... silicide heat treatment step S7, S17 ... third silicon layer forming step
S8, S11, S18 ... crystallization step S12 ... first metal oxide film forming step
S14 ... Second Metal Oxide Formation Step

Claims (7)

Forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;
The first silicon layer is heat-treated and the first silicon layer is coated. Forming a silicon oxide film;
A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;
A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;
Forming a second silicon layer by laminating an amorphous silicon layer on the metal oxide film;
A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;
Forming a third silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer; And
And a crystallization step of heat treating the crystalline silicon in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst. The method of claim 1,
The heat treatment temperature in the silicon oxide film forming step and the metal oxide film forming step is 100 ℃ to 1000 ℃,
The heat treatment temperature of the crystallization step is a method for producing a polycrystalline silicon thin film, characterized in that 300 ℃ to 1000 ℃. The method of claim 1,
The thickness of the first silicon layer and the thickness of the second silicon layer are 5 kPa to 1500 kPa, respectively.
The metal layer has a thickness of 5 kPa to 1500 kPa,
The thickness of the silicon oxide film and the metal oxide film is 1Å to 300Å,
The ratio of the thickness of the sum of the thickness of the metal layer and the thickness of the first silicon layer and the second silicon layer is 1: 0.3 to 1:30 method of producing a polycrystalline silicon thin film. The method of claim 1,
A patterning step of removing a portion of the metal layer by a photolithography method after the metal layer forming step;
Forming a metal oxide film on the surface of the metal layer by heat-treating the patterned metal layer or depositing a metal oxide film on the surface of the metal layer to form a metal oxide film. Manufacturing method. Forming a first silicon layer by laminating amorphous silicon on an insulating substrate;
Forming a silicon oxide film on the surface of the first silicon layer by heat-treating the first silicon layer;
A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;
A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;
Forming a second silicon layer by laminating amorphous silicon on the metal oxide film;
A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;
A third silicon layer forming step of laminating an amorphous silicon germanium layer or an amorphous silicon carbide layer on the metal silicon oxide layer to form an amorphous silicon germanium layer or an amorphous silicon carbide layer; And
And a crystallization step of heat treating the crystalline silicon germanium layer or the crystalline silicon carbide layer in the amorphous silicon germanium layer or the amorphous silicon carbide layer formed in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst. Method for producing a polycrystalline silicon thin film. Forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;
The first silicon layer is heat-treated and the first silicon layer is coated. Forming a silicon oxide film;
A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;
A metal oxide film forming step of forming a metal oxide film by heat-treating the metal layer to form a metal oxide film on the surface of the metal layer or by depositing a metal oxide film on the surface of the metal layer;
A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer to form a metal silicon oxide layer;
Forming a second silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer;
And a crystallization step of heat treating the crystalline silicon in the second silicon layer by using the metal particles of the metal silicon oxide layer as a catalyst. Forming a first silicon layer by laminating an amorphous silicon layer on an insulating substrate;
Forming a first metal oxide layer by depositing a metal oxide layer on the first silicon layer;
A metal layer forming step of forming a metal layer by laminating a metal layer on the silicon oxide film;
Forming a metal oxide film on the surface of the metal layer by heat-treating the metal layer or forming a metal oxide film by depositing a metal oxide film on the surface of the metal layer;
Forming a second silicon layer by laminating an amorphous silicon layer on the second metal oxide film;
A silicide heat treatment step of heat treating the catalyst metal atoms from the metal layer to the first silicon layer and the second silicon layer to form a metal silicon oxide layer;
Forming a third silicon layer by laminating an amorphous silicon layer on the metal silicon oxide layer; And
And a crystallization step of heat treating the crystalline silicon in the third silicon layer using the metal particles of the metal silicon oxide layer as a catalyst.

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