JP2004356602A - Method of manufacturing single crystal silicon thin film transistor on glass substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a single crystal silicon film transistor which sharply improves the rate of flow of a field effect carrier and solves a uniformity problem caused by differences between elements. <P>SOLUTION: In a method of manufacturing a single crystal silicon thin film for triggering a growth of an amorphous silicon thin film in the longitudinal direction by making a silicon substrate having a single trellis as a species, the amorphous silicon thin film is contacted with a single crystal silicon substrate having a pattern face to face, and an excimer laser is penetrated from a reverse side of a glass substrate, thus the amorphous silicon thin film on a front surface grows the single crystal silicon thin film in the longitudinal direction by making the pattern on the single crystal silicon substrate as a species. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of manufacturing a single-crystal silicon thin film transistor on a glass substrate, and more particularly, to a method for solving the problem that single-crystal silicon cannot be grown on an amorphous glass substrate, thereby reducing the temperature of a low-temperature poly-silicon thin film used in a display panel. The present invention relates to a silicon thin film transistor (LTPS-TFT) technique and a method of manufacturing a single crystal silicon thin film transistor on a transparent glass substrate instead of a MOS field effect transistor (SOI-MOSFETs) on a silicon insulating layer having a high price.
[0002]
[Prior art]
In the technology that has already been disclosed, low-temperature polysilicon thin-film transistors (LTPS-TFTs) manufactured on a glass substrate, whether an excimer laser (Excimer Laser) or a continuous wave laser (CW Laser), are used. Inevitably, the problem that a silicon grain boundary (Grain-Boundary) is located in the channel is unavoidable, and the silicon crystal grains in the channel have a number of different lattice directions. (LTPS-TFTs), there is a problem that there is a difference between the elements, and it is not possible to improve the carrier mobility (Mobility) which is an electric field effect, and the channel width (Channel-Width) and the channel length (Channel- When Length is small There is a chance that the channel of one low-temperature polysilicon thin film transistor (LTPS-TFT) is located on a single silicon grain so that the electrical characteristics are the same as a MOS field effect transistor (SOI-MOSFET) on a silicon insulating layer. However, due to lack of reproducibility and low output, it is practically not applicable to manufacturing.
[0003]
The above problem is that the amorphous silicon thin film (Amorphous-Silicon Thin Films) cannot be recrystallized in the horizontal direction as silicon as a seed after being completely melted by a laser. The grain-boundary and silicon grains have many different lattice directions.
[0004]
[Problems to be solved by the invention]
The main object of the present invention is to solve the problem that a silicon grain boundary (Grain-Boundary) is present in the LTPS-TFTs channel, thereby greatly improving the mobility of the field-effect carriers and improving the difference between the elements. To achieve the goal of an integrated system on a panel (System-on-Panel or System-on-Glass).
[0005]
Another object of the present invention is to simplify the production by using a silicon substrate having a single lattice direction and a pattern as a nuclide of a single crystal silicon thin film in which an amorphous silicon thin film on a glass substrate grows in a lateral direction. A MOS field effect transistor (SOI-MOSFETs) on a silicon insulating layer to be manufactured can be reused by using a single crystal silicon substrate as a nuclide, thereby significantly reducing the cost in production, manufacturing a SOI chip having a high price in terms of device characteristics, and manufacturing. Is to provide a substitute for
[0006]
[Means for Solving the Problems]
To this end, the present invention provides:
Step one, prepare a glass substrate,
Step 2, on the glass substrate, after plating a silica layer to prevent impurities from diffusing out of the glass substrate, by a chemical vapor technique, grow an amorphous silicon thin film on the surface of the glass substrate,
Step 3, another silicon substrate, patterning a single crystal silicon pattern on the silicon substrate by etching technology,
Step 4, in a state where the amorphous silicon thin film and the silicon substrate having a single crystal silicon pattern are in close contact with each other, a laser beam is irradiated from the back of the glass substrate, and the amorphous silicon thin film on the surface is adjusted according to appropriate laser parameters. Whether the whole is melted or the amorphous silicon thin film in contact in a high temperature atmosphere is recrystallized, this is a solid phase crystal (SPC) method,
Step 5. Immediately after the entire amorphous silicon thin film is melted and solidified, a recrystallization (recrystallization) phenomenon occurs. Triggering the growth of a single-crystal silicon thin film laterally on the amorphous silicon thin film being
Step 6, after separating the single crystal silicon substrate and the glass substrate, a single crystal silicon thin film transistor is manufactured on the glass substrate, thereby solving the problem that single crystal silicon does not grow on the amorphous glass substrate, This is a method of manufacturing a single crystal silicon thin film transistor on a transparent glass substrate instead of a MOS field effect transistor (SOI-MOSFETs) on a layer.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 4 are conceptual cross-sectional views of Steps 1 and 2 of the present invention in a molded state, conceptual sectional views of Step 3 of the present invention in a molded state, and conceptual sectional views of Steps 4 and 5 of the present invention in a molded state, respectively. FIG. 1 is a conceptual diagram of a molded single-crystal silicon thin film transistor of the present invention. As shown in the figure, the present invention is a method of manufacturing a single-crystal silicon thin film transistor on a glass substrate, and solves the problem that single-crystal silicon cannot be grown on an amorphous glass substrate 1 to solve the problem. This is a method of manufacturing a single crystal silicon thin film transistor on a transparent glass substrate 1 instead of a MOS field effect transistor (SOI-MOSFETs), and has the following steps.
[0008]
Step 1, a glass substrate 1 is prepared, and the glass substrate 1 may be a transparent substrate such as quartz glass,
Step 2: After plating a glass layer on the glass substrate 1 with a silica layer for preventing impurities from diffusing out of the glass substrate, the amorphous silicon thin film 2 is grown on the surface of the glass substrate 1 by a chemical vapor technique. Also, the amorphous silicon thin film 2 to be used may be an amorphous silicon germanium (SiGe) thin film, whereby a thin film transistor of single crystal silicon or single crystal silicon germanium can be manufactured on a glass substrate. The chemical vapor technique is a technique such as plasma CVD (PECVD) or low pressure CVD (LPCVD). If the low pressure CVD (LPCVD) is used, the amorphous silicon thin film layer on the back of the glass substrate 1 is removed. Requires one step, whereby the laser is applied from the back of the glass substrate 1 to the surface. Is passed through recrystallization,
Step 3, Another silicon substrate 3, the silicon substrate 3 is a single crystal silicon substrate (Single Crystalline Silicon Substrate), and a single crystal silicon pattern 31 is patterned on the silicon substrate 3 by an etching technique; Etching technology is wet etching technology or dry etching technology,
Step 4, in a state in which the amorphous silicon thin film 2 and the silicon substrate 3 having the single-crystal silicon pattern 31 are brought into close contact with each other, a laser beam 4 is irradiated from the back of the glass substrate 1, and appropriate laser parameters are used. The entire amorphous silicon thin film 2 on the surface is melted to form a laser-triggered recrystallization (Laser-induced Crystallization). CW-Laser)
Step 5, when the entire amorphous silicon thin film 2 is melted and the silicon thin film to be formed is solidified, a recrystallization phenomenon occurs immediately. Using the pattern 31 as a nuclide, triggering the growth of a single crystal silicon thin film in the molten amorphous silicon thin film 2 in the lateral direction,
Step 6, after separating the single crystal silicon substrate 3 and the glass substrate 1, on the amorphous silicon thin film 2 of the glass substrate 1, a gate insulating layer 40 (Gate Insulator), a gate 41 (Gate), and a source 42 (Source) ) And a drain 43 (Drain), that is, a single-crystal silicon thin film transistor as shown in FIG. 4 is formed, and a single-crystal silicon thin film transistor is manufactured on a glass substrate by the above steps.
[0009]
In the present invention, the active area of the amorphous silicon thin film 2 on the glass substrate 1 is first limited, and then the amorphous silicon thin film 2 is brought into contact with the single-crystal silicon substrate 3 of the pattern 31 at the opposing position. In the transparent substrate, the active layer pattern on the glass substrate 1 is easily positioned with the single-crystal silicon substrate 3 of the pattern 31 located at the opposing position, and then irradiated with the laser 4 from behind, Then, after growing the single crystal silicon thin film in the lateral direction, the single crystal silicon substrate 3 and the glass substrate 1 are separated from each other.
[0010]
Among them, the limited function of the single crystal silicon pattern 31 is only the nuclide that grows the single crystal silicon thin film. According to the current silicon process technology, the single crystal silicon pattern 31 can be made very small. Since the contact area between the silicon substrate 3 and the glass substrate 1 is very small, the silicon substrate 3 and the glass substrate 1 after recrystallization can be easily separated by increasing the number of simple vacuum equipments. The flatness on the silicon substrate 3 pattern 31 after being separated can be reused if flattened by, for example, a chemical mechanical polishing (CMP) facility, and the process cost does not increase much.
[0011]
From the above detailed description, it can be understood that a skilled person who is familiar with the present technology can clearly achieve the above object by the present invention.
[0012]
The above description is merely a preferred embodiment of the present invention, and does not limit the scope of the present invention. In addition, equivalent modifications and changes may be made in accordance with the claims and the description of the present invention. Included in the claims of the invention.
[Brief description of the drawings]
FIG. 1 is a conceptual sectional view of a molded state of Steps 1 and 2 of the present invention.
FIG. 2 is a conceptual sectional view of a molding state of Step 3 of the present invention.
FIG. 3 is a conceptual sectional view of a molding state of steps 4 and 5 of the present invention.
FIG. 4 is a conceptual diagram of a molded single-crystal silicon thin film transistor of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Amorphous silicon thin film 3 Silicon substrate 31 Single crystal silicon pattern 4 Laser light 40 Gate insulating layer 41 Gate 42 Source 43 Drain

Claims (9)

Step one, prepare a glass substrate,
Step 2, on the glass substrate, after plating a silica layer to prevent impurities from diffusing out of the glass substrate, by a chemical vapor technique, grow an amorphous silicon thin film on the surface of the glass substrate,
Step 3, another silicon substrate, patterning a single crystal silicon pattern on the silicon substrate by etching technology,
Step 4, in a state where the amorphous silicon thin film and the silicon substrate having a single crystal silicon pattern are in close contact with each other, a laser beam is irradiated from the back of the glass substrate, and the amorphous silicon thin film on the surface is adjusted according to appropriate laser parameters. The whole is melted,
Step 5. After the entire amorphous silicon thin film is melted and solidified, a recrystallization (recrystallization) phenomenon occurs immediately. Triggering the growth of a single-crystal silicon thin film laterally on the amorphous silicon thin film being
Step 6, a method of manufacturing a single crystal silicon thin film transistor on a transparent glass substrate, comprising separating a single crystal silicon substrate and a glass substrate, thereby manufacturing a single crystal silicon thin film transistor on a glass substrate . The method for manufacturing a single crystal silicon thin film transistor on a transparent glass substrate according to claim 1, wherein the glass substrate may be a transparent substrate such as quartz. 2. The method for manufacturing a single crystal silicon thin film transistor on a transparent glass substrate according to claim 1, wherein the amorphous silicon thin film used may be an amorphous silicon germanium (SiGe) thin film. The method for manufacturing a single crystal silicon thin film transistor on a transparent glass substrate according to claim 1, wherein the chemical vapor technique is a technique such as plasma CVD (PECVD) or low pressure CVD (LPCVD). When the low-pressure CVD (LPCVD) is used, another step of removing the amorphous silicon thin film layer on the back of the glass substrate allows the laser to pass from the back to the surface of the glass substrate 1 to recrystallize. The method for manufacturing a single crystal silicon thin film transistor on a transparent glass substrate according to claim 4. 2. The method of claim 1, wherein the silicon substrate is a single-crystal silicon substrate having a unidirectional crystal. 2. The method for manufacturing a single crystal silicon thin film transistor on a transparent glass substrate according to claim 1, wherein said etching technique is wet or dry. 2. The single crystal silicon thin film transistor on a transparent glass substrate according to claim 1, wherein in step 4, the laser beam 4 used is an excimer laser (Excimer-Laser) and a continuous wave laser (CW-Laser). How to manufacture. 2. The method according to claim 1, wherein in the step (4), the amorphous silicon thin film in contact with the amorphous silicon thin film and the silicon substrate having the single-crystal silicon pattern in a high-temperature atmosphere is recrystallized in a state of being in close contact with each other. A method for producing a single crystal silicon thin film transistor on the transparent glass substrate according to the above.

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