JPH0250963A - Method and apparatus for forming thin patterned film - Google Patents

Abstract

PURPOSE:To improve the use efficiency of laser light and to reduce film-manufacturing costs by regulating the distribution of the intensity of laser light to be transmitted through a mask having repeated patterns so that the intensity of the laser light in the light-transmitting part of the mask is different from that in the light-shielding part. CONSTITUTION:Laser light from a laser light source 1 is transmitted by a mask 4 having repeated patterns via a mirror 3 and patterned. Then, a substrate 11 on a substrate susceptor 12 held in a chamber 6 is irradiated with the above laser light passed via a lens 5 through a window 7. The atmosphere in the above chamber 6 is regulated so that it contains gaseous raw material from a gaseous raw material feed system 10. By the above procedure, a thin patterned film is formed on the substrate 11 or the thin film on the substrate 11 is etched selectively. In the above thin patterned film-forming method, a beam contraction unit 2 in which plural beam contractors 13 are disposed into a matrix state is disposed between the above- mentioned laser light source 1 and mask 4. By this method, the distribution of the intensity of the laser light to be transmitted through the mask 4 can be controlled so that the intensity of the laser beam is high in the vicinity of the light-transmitting part of the mask 4 and low in the light-shielding part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a thin film forming method and apparatus for forming a patterned thin film using laser light.

(Prior art) Light emitted from a high-output excimer laser or the like is patterned through a pattern-forming mask, and the mask pattern is transferred to a substrate inside a chain filled with an atmosphere containing raw materials and gas. Methods of directly depositing patterned thin films are known. This method is expected to significantly reduce the number of steps compared to the well-known methods of forming patterned thin films through the processes of batch deposition, resist processing, and etching. has been done. For example, in liquid crystal display devices, which are being researched and developed as flat panel displays, a thin film transistor about 1/100th the size of each pixel is installed for each pixel in order to determine whether each pixel displays or not. The display is constructed by repeatedly arranging these pixels in a 7-tox pattern. A-8i:H, poly-Si, etc. are used for the semiconductor of the thin film transistor, and this is made into a rectangular or rectangular pattern with a thickness of about 1000 mm, a width of several tens of pm, and a culm.
It is formed on a substrate in combination with an electrode. An example of such a method and apparatus for forming a patterned thin film is disclosed in Japanese Patent Application No. 1986-
Reported by Hiura in 56051. In this invention and the conventional patterned thin film forming method, the optical system is configured so that the intensity distribution of light on the mask is as uniform as possible on the mask. For this reason, compared to the area that needs to be deposited like the display device mentioned above,
When the non-depositing area is relatively large, most of the light emitted from the laser light source is absorbed or reflected by the light shielding part of the mask, which has the disadvantage that it is not useful for thin film deposition. As a result of this low light utilization efficiency, even if a high-output excimer laser is used as a laser light source, the area in which a pattern can be formed is as small as about 10 cm square.
It took more than two hours to form a pattern, which was a major problem in making it a practical technology. The above-mentioned problems are the same when forming a patterned thin film by irradiating patterned light on a substrate with a thin film formed on the entire surface of the substrate in a gas atmosphere that causes an etching reaction in the thin film. had become a big problem.

(Object of the Invention) An object of the present invention is to eliminate the need for conventional laser light when a process requiring a large area where these processes do not occur, as compared to the area to be deposited or etched, such as a display device. An object of the present invention is to provide an excellent method and apparatus for forming a patterned thin film, which has a much higher light utilization efficiency than a method and apparatus for forming a patterned thin film using the method and apparatus.

(Structure of the Invention) The present invention irradiates a substrate held in a chamber filled with a source gas atmosphere with patterned laser light generated by transmitting laser light through a mask consisting of a repeating pattern. In a method for forming a patterned thin film in which a patterned thin film is deposited on a substrate, the intensity distribution of the laser light transmitted through the mask is set such that the intensity distribution of the laser light is strong near the light transmitting part of the mask and weak in the light blocking part of the mask. It is characterized by forming an intensity distribution of light emitted from a light source.

Another aspect of the present invention is to apply patterned laser light generated by transmitting laser light through a mask having a repeated pattern onto a thin film on a substrate held in a chamber filled with an atmosphere containing an etching gas. irradiate it to
In a method for forming a patterned thin film in which the thin film is selectively etched to form a patterned thin film, the intensity distribution of the laser light transmitted through the mask is strong in the vicinity of the light transmitting part of the mask and weak in the light blocking part of the mask. A further aspect of the present invention is characterized in that the intensity distribution of the light emitted from the laser light source is changed so that the intensity distribution of the light emitted from the laser light source is changed so that an exposure optical system consisting of a mask having a repeated pattern, a lens that introduces the laser light transmitted through the mask into the chamber through a window and transfers the mask pattern onto the substrate; In a patterned thin film forming apparatus comprising a moving mechanism that guides the irradiation position to a predetermined position on the substrate, a source gas supply system that supplies the reactive source gas, and an exhaust unit that processes exhaust gas, the laser light source and the mask are connected to each other. It is characterized in that a beam reduction unit configured by arranging a plurality of beam reduction units in a 7-trinox shape at intervals equal to the period of the repeating pattern of the mask is arranged between them.

(Operation/Principle of the Invention) In the present invention, by making a difference in the irradiation intensity between the light-transmitting part and the light-blocking part of the mask part for pattern transfer, the light emitted from the laser light source can be effectively used for CVD reactions and etching reactions. It is characterized by its effect on

As a means for producing the above-mentioned intensity distribution, a beam condenser, which is a beam diameter converting means for a directional laser beam, is used. When it is necessary to deposit semiconductor thin films in the form of a matrix, such as in the production of display devices, this beam condenser is arranged in a matrix between the laser light source and the mask, and the beam condenser is arranged in a matrix between the laser light source and the mask. The irradiation distribution can be made stronger in the light transmitting portion of the mask. In principle, if the magnification of the beam condenser is N, the light intensity at the light transmitting portion of the mask increases to NXN times the intensity at the laser light source output end. In other words, in the case of a display device, etc., if the area of the semiconductor part is about 1/00th of the area of the pixel, increasing the magnification of the beam condenser by 5 times, the magnification of the beam condenser will be 25 times that of the conventional method, and 8 If you double it, the light intensity will be 64 times stronger.
It becomes possible to irradiate laser light onto the substrate. As a result, when depositing on an area of the same area,
The time required for deposition can be significantly shortened. Furthermore, if the intensity of irradiation onto the substrate is kept the same, the area of the region that can be irradiated each time can be significantly increased.

Needless to say, when etching a thin film into a pattern, increasing the amount of light transmitted through the mask pattern described above can shorten the time required to etch a given thickness, and if the irradiation intensity is kept the same, it can be etched in one go. The area for etching can be made much wider.

(Example) The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic diagram of a method and apparatus for forming a patterned thin film, which is an embodiment of the invention of the present application.

This figure shows the application of the present invention to the deposition of a-3i:H used in thin film transistors for liquid crystal displays. In the figure, the emitted laser light from a laser light source 1 composed of an ArF excimer laser is transmitted through a plurality of beam condensers 13 smaller than the emitted pattern from the laser light source 1, which are arranged at the same intervals as the mask pattern arrangement of the mask 4. The beam passes through the beam reduction unit 2 arranged in a matrix, is reflected by a mirror 3, and is irradiated onto a mask 4.

The laser beam transmitted through the mask 4 is configured to be irradiated onto the substrate 11 placed on the substrate support 12 through the lens 5 and the window 7 provided in the chamber 6. The optical system described above is an exposure optical system that transfers the pattern of the mask 4 onto the substrate 6 in a 5:1 ratio. The raw material gas supply system 10 that supplies CVD raw material gas to the chamber 6 is made of Si
N2 gas containing 5% 2H6 gas is supplied. The exhaust unit 8 exhausts the air in the chamber before CVD and
It consists of a vacuum pump to keep the pressure at D time below atmospheric pressure and an adsorption trap to detoxify the exhausted gas. The XY steller 9 supporting the chamber 6 is used to align the irradiation position of the laser beam onto the substrate 11.

FIG. 2 is a diagram showing the intensity distribution of the laser beam at the positions of the beam condenser 13, which is a basic unit in the beam condensation unit 2, which is a feature of the present invention, and the mask 4. a- onto the board
The thickness of the 3i:H deposit is 10×10 μm, and the pixel size is 100×1100p. Since the transfer ratio of the mask pattern is 5:1, the mask pattern has a rectangular shape of the light transmitting part of 50 x 50 pm, and this part is arranged in a matrix with repeats of 50011 m vertically and horizontally. . Each beam reducer 13, which is the basic unit of the beam reduction unit 2, is composed of two convex lenses, the beam reduction ratio is 1/8, and the repetition interval of the beam reducer 13 is 500p, which is the same as the mask pattern.
It is designed to be m. As shown in FIG. 2, the laser beam emitted from the laser light source 1 is converted into a plurality of narrow laser beams corresponding to the number of transparent parts of the mask 4 in the beam reduction unit 2, and the center of each narrow beam is centered on the mask 4. It is placed in the center of the transparent part. By using the beam reduction unit 2, the light intensity of the light transmitting portion on the mask 4 became 60 times stronger than when the beam reduction unit I-2 was not used.

Next, the operation of the present invention will be explained step by step. First, set the substrate 11 on the substrate support stand 12 of the chamber 6, and
The Y stage 9 is moved to adjust the irradiation position of the laser beam onto the substrate 11. The exhaust unit 8 is operated to exhaust the air inside the chamber 6. Next, raw material gas supply system 1
0 to 512H6 gas is flowed into the chamber 6, and at the same time, the inside of the chamber 6 is depressurized to a pressure of 10 Torr by the exhaust unit 6. In this state, laser light sources 1 to 19
The substrate 11 is irradiated with 3 nm ultraviolet light to decompose Si2H6 gas caused by a photochemical reaction, and a 10×10 pm film is deposited on the substrate.
An a-8i:H film with a size of is deposited in a matrix with a period of 100 x 1100p. When one deposition is completed, the laser light source 1 is stopped, the XY stage 9 is moved to set the substrate 11 at the next irradiation position, and the second deposition is performed. After repeating the above steps and completing deposition on the entire substrate 11, the supply of CVD raw material gas from the raw material gas supply unit 10 is stopped, and the residual gas in the chamber 6 is exhausted by the exhaust unit 8, replacing the inside with air. After that, the substrate 6 is taken out and the series of processes is completed.

When the beam reduction unit 2 of the conventional method is not used, it takes 2 hours to obtain a predetermined film thickness when the laser beam irradiation area on the substrate is 10 cm square; When the invention was applied, the time required to obtain a predetermined film thickness was 2 minutes, significantly shortening the deposition time when the output conditions of the laser light source and the irradiation area on the substrate were the same. Moreover, as a result, it was found that the time for processing -substrates can be greatly reduced, and the load per substrate placed on the laser light source 1 is also reduced at the same time, leading to a significant reduction in manufacturing costs.

In the example described above, the configuration of the unit beam reducer of the beam reduction unit 2 has been described using two convex lenses, but it is of course possible to use a beam reducer that combines a convex lens and a concave lens. Of course, it is also possible to deposit a plurality of thin films in succession, and in that case, if the irradiation pattern is the same, the raw material gas supply system 10
All you have to do is change the CVD raw material gas. At this time,
If it is necessary to vary the irradiation pattern, CVD
It is also possible to perform deposition by switching either or both of the beam reduction unit 2 and the mask 4 at the same time as switching the source gas. Furthermore, after patterning and forming a thin film to be deposited in substantially the same manner as the process of depositing multiple thin films described above, the raw material gas atmosphere is used as the raw material gas for doping this thin film, and the material is placed on the substrate rather than the laser light source. By irradiating the thin film with an intense laser beam that causes a temperature rise of several hundred degrees Celsius, it is possible to dope the entire or part of the patterned thin film with impurities.

5i02. It is possible to form various thin films such as W and AI, and various lasers such as not only excimer laser but also visible light and ultraviolet laser can be used.

In the embodiments described above, the case was mainly described in which a patterned thin film was directly formed on the substrate, but the raw material gas supplied from the raw material gas supply system 10 shown in FIG. 1 was applied to the thin film on the substrate by light irradiation. By using a gas that causes an etching reaction, the time required for etching a predetermined thickness can be shortened or the area that can be processed at one time can be greatly increased due to the increase in light utilization efficiency according to the present invention.

An example of an embodiment of the present invention that utilizes the etching action is an example in which a ZeC1 excimer laser is used as a light source, chlorine gas is used as a raw material gas, and poly-Si is used as a thin film material on a substrate.

The etching gas is not limited to chlorine gas, but various gases such as NF3 may be used, and the material to be etched may also be Si or 510.
Since 2 is a group, it can also be applied to III-V group compound semiconductors.

(Effects of the Invention) As described above, according to the present invention, compared to the conventional method and apparatus for forming a patterned thin film using laser light, the efficiency of light utilization is significantly improved, and as a result, the process time can be significantly reduced. , and without significantly reducing the burden on the light source.
Overall, there is an advantage that manufacturing costs can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the features of the optical system of the present invention. 1 Laser light source 2 Beam reduction unit 3, mirror 4, mask 5, lens 6, CVD chamber 7 window 8, exhaust unit 9, X-Y stage 10, source gas supply unit 11, substrate 12, etc.・Substrate support stand 13...Beam reducer

Claims (3)

[Claims] (1) Patterned laser light, which is generated by transmitting laser light through a mask with a repeated pattern, is irradiated onto a substrate held in a chamber filled with an atmosphere containing source gas, and In a method for forming a patterned thin film in which a patterned thin film is deposited, the intensity distribution of the laser light transmitted through the mask is adjusted so that the intensity distribution of the laser light transmitted through the mask is strong near the light transmitting part of the mask and weak in the light shielding part of the mask. A patterned thin film forming method characterized by changing the intensity distribution. (2) A thin film on a substrate held in a chamber filled with an etching gas is irradiated with patterned laser light, which is generated by transmitting laser light through a mask with a repeated pattern. In a method for forming a patterned thin film in which a thin film is selectively etched to form a patterned thin film, the intensity distribution of a laser beam transmitted through the mask is made such that the intensity distribution of the laser light is strong near the light transmitting part of the mask and weak in the light blocking part of the mask. A patterned thin film forming method characterized by changing the intensity distribution of light emitted from a laser light source. (3) a substrate support installed in a chamber to be filled with an atmosphere containing a reactive raw material gas, and a laser light source;
A mask comprising a repeating pattern, and a laser beam transmitted through the mask is introduced into the chamber through a window,
an exposure optical system consisting of a lens that transfers the mask pattern onto the substrate; a movement mechanism that guides the irradiation position of the laser beam to a predetermined position on the substrate; a source gas supply system that supplies the reactive source gas; and an exhaust system. A patterned thin film forming apparatus consisting of an exhaust unit that processes gas, in which a plurality of beam condensers are arranged in a matrix between the laser light source and the mask at intervals equal to the period of the repeating pattern of the mask. A patterned thin film forming apparatus characterized by arranging a beam reduction unit.