JPH03188621A - Method and device for forming film - Google Patents

Abstract

PURPOSE:To collectively form a clear pattern and a thin film covering the pattern in a vacuum process by forming a thin film pattern on a substrate by irradiating the substrate with light in the atmosphere of a gaseous starting material while applying a mask tightly onto the substrate and collectively forming the pattern and thin film after considerably separating the mask from the substrate. CONSTITUTION:When a switch 8 is turned on, a pattern mask 3 made of Ni and suspended from a CVD chamber 9 is applied in tight or approximately tight state onto a quartz substrate 5 by springs 4 through a coil 7. When the substrate 5 is irradiated with a laser beam from an ArF laser 1 under such condition, a gas from a gas supplying system 10, is decomposed and becomes a gaseous starting material and a state where the substrate is irradiated with the laser beam in the atmosphere of the gaseous starting material is produced, resulting in a thin film pattern formed on the substrate 5. When the switch 8 is turned off, the mask 3 is considerably separated from the substrate 5 and, when the laser beam irradiation is restarted similarly, the entire surface of the substrate 5 is irradiated with the light of the beam diffracted by the mask 3 and collective film formation takes place. Therefore, a clear pattern and a thin film covering the pattern can be formed collectively in a vacuum process.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to film formation.

[Conventional technology]

When creating a structure in which a patterned thin film is uniformly covered with a thin film of a different material, up until now, two steps have been used: an earlier batch deposition, photolithography, and etching process, and a later batch deposition process. manufacturing process was required. This method requires many steps, and the resist coating and stripping operations often damage the device. As a shortened version of this method, a patterned thin film is directly formed on the substrate by laser beam pattern transfer in a source gas atmosphere.
A method has been proposed in which the material on the rear side is deposited all at once (
For example, Hiura et al., 1988 Autumn Academic Conference Proceedings of the Japan Society of Applied Physics, p. 534). However, when film formation by photochemical decomposition of a raw material gas is used in the first step of this method, it is unavoidable that vapor phase reaction products accumulate around the pattern, which tends to make the pattern unclear. As a method to improve this drawback, Kuninaka et al. proposed a method of forming a film by photochemical reaction with a patterned mask placed on a substrate at the 1986 Spring Conference of the Japan Society of Applied Physics, Proceedings 49.
Reported on page 1. In this method, compared to pattern transfer, accumulation around the pattern can be reduced. However, if the mask and substrate are kept in close contact with each other, it is not possible to form a film on the entire surface of the substrate in the subsequent step, so take the substrate out of the reaction vessel, remove the pattern mask from the substrate, and then return the substrate to the reaction vessel to form a film all at once. It is necessary to perform a membrane.

For this reason, for example, T F T (Thin Film
The latter method cannot be applied to applications where successive film formation is required in the same reaction vessel to maintain the cleanliness of the interface, such as the formation of semiconductor layers and gate insulating films during the formation of transistors. It was causing problems.

[Problems to be Solved by the Invention] As described above, the conventional film forming apparatus cannot form a clear pattern and a thin film covering the pattern by a vacuum-through process.

An object of the present invention is to solve the problems of the conventional apparatus and form a thin film.

[Means to solve the problem]

In order to solve the above-mentioned problems of the prior art, the present invention provides a film forming method that uses light, in which a patterned mask is closely attached to a substrate or a pair of images in close proximity is formed on a substrate in an atmosphere of a source gas that is decomposed by the light. After irradiating light and forming a patterned thin film, the patterned mask is separated from the substrate by a large distance,
We adopted a film formation method characterized by batch film formation.

In order to solve the problems of the prior art described above, the present invention also provides a mechanism for mounting a substrate, a mechanism for bringing a pattern mask held above the substrate into close contact with or releasing it from the substrate, and a mechanism for attaching a pattern mask to or from the substrate. A reaction vessel having a window capable of light irradiation, a gas supply system for supplying a first raw material gas for forming a patterned thin film and a second raw material gas for batch film formation to the reaction vessel. and an optical system for irradiating the substrate through the window with light emitted from a light source having an emission wavelength that is equal to the decomposition/absorption wavelength of the first source gas and the second source gas. We took the method of using a film-forming apparatus that

[Effect]

In the proximity method, in which a pattern mask is placed close to the top of a substrate and light is irradiated, the influence of diffraction increases as the distance between the pattern mask and the substrate increases. Therefore, the exposure area extends to the periphery of the desired pattern formation portion. Therefore, when the mask is in close contact with the substrate or sufficiently close to it,
By dividing the irradiation into two cases, ie, when they are separated by a large distance, both pattern irradiation and patternless batch irradiation can be performed continuously. In the present invention, the patterned thin film and the covering thin film are vacuum-penetrated by performing this close contact or close contact state and the widely separated state under light irradiation in the atmosphere of the raw material gas for film formation. This is to obtain the effect of forming.

Since the present invention does not require any photolithography, the number of manufacturing steps is reduced, and the resist stripping operation does not damage the device. In addition, there is almost no accumulation of rain around the pattern, which is difficult to avoid with the □ method of transferring pattern light.

〔Example〕

Embodiments in which the present invention is applied to the formation of a thin film transistor (TFT) matrix by laser CVD will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of an apparatus in which photochemical reactions are used for both pattern thin film formation and batch film formation. ArF
The emitted light of the laser 1 is irradiated onto the quartz substrate 5 fixed to the substrate susceptor 6 in the CVD chamber 9 through the quartz window 2 and the pattern mask 3 made of Ni, which is held at a position several mm away from the quartz substrate 5 by the spring 4. do. The Ni pattern mask has 20 μm slits cut at a pitch of 100 μm. Drain and source electrodes have already been formed on the quartz substrate 5. First, in order to form a semiconductor layer, the switch 8 is turned on, the coil 7 wound around the substrate susceptor is energized, the Ni pattern mask 3 is attracted and brought into close contact with the substrate 5, and disilane gas (S 12H6)C
Introduce it into the VD chamber. By photochemically decomposing disilane gas with laser light, amorphous snow hydrogenated silicon (
Form an a-9 inch thin film pattern. Then switch 8
The Ni pattern mask 3 is separated from the quartz substrate 5, N20 gas is introduced into the gas supply system 10 in addition to disilane gas, and these gases are subsequently photochemically decomposed to form an a-3i pattern thin film. A structure in which the matrix is covered with a 5i02 film is formed by a vacuum-through process. A spring,
There is no need to use electromagnets. As shown in FIG. 2, the pattern mask may be released from the substrate by blowing nitrogen gas from the back side of the substrate using a nozzle 11. In this case, if the pattern mask has sufficient mass, it will stick to the substrate simply by placing it on the substrate. In the case of a mask that is not sufficiently heavy, an electromagnet may be used in combination, or an inert gas may be sprayed from the top of the patterned mask. a-3i film and SiO
The interface between the two films was kept clean, and the TPT properties were good. Furthermore, damage to the device due to close contact with the pattern mask had little effect on the electrical characteristics.

〔Effect of the invention〕

As explained above, according to the present invention, patterned thin film formation and batch film formation can be performed in a vacuum-through process by combining the operation of bringing the patterned mask into close contact with or close to the substrate and the operation of separating it. can.

[Brief explanation of drawings]

FIG. 11 FIG. 2 is a diagram showing an embodiment of the present invention. 1...ArF laser, 2...quartz window, 3...Ni
pattern mask, 4... spring, 5... quartz substrate,
6... Substrate susceptor, 7... Coil, 8... Switch, 9... CVD chamber, 10... Gas supply system, 11... Nitrogen spray nozzle.

Claims (1)

[Claims] 1. In a film forming method using light, a patterned mask is closely attached to a substrate in an atmosphere of a source gas that is decomposed by the light;
Alternatively, a film forming method characterized in that after forming a patterned thin film by irradiating light in close proximity, the patterned mask is separated from the substrate to perform batch film formation. 2. In a film forming apparatus that uses light, a mechanism that allows a substrate to be mounted and a mechanism that switches a pattern mask held above the substrate into two states: a state where it is in close contact with or close to the substrate, and a state where it is widely separated. and a window capable of irradiating the substrate with light; a first raw material gas for forming a patterned thin film and a second raw material gas for batch film formation are supplied to the reaction vessel. comprising a gas supply system and an optical system for irradiating the substrate through the window with light emitted from a light source having an emission wavelength that is equal to the decomposition and absorption wavelength of the first source gas and the second source gas. A film forming apparatus featuring: