JP2005228938A - Method and device for drying substrate having amorphous silicon film treated with hydrofluoric acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device, by which a substrate having an amorphous silicon film treated with a hydrofluoric acid can be dried, without producing watermarks on the substrate. <P>SOLUTION: After the substrate 1, having the amorphous silicon film treated with the hydrofluoric acid, is treated with a treating liquid selected from among a group of alcohol, an aqueous solution of alcohol, and ozone water by using a treating liquid shower 3 in a drying chamber 4, the surface of the substrate 1 is made to have a hydrophilic nature, and the substrate 1 is subject to air-knife drying with an air-knife 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drying method and a drying apparatus that do not generate water spots on the entire surface of a substrate with an amorphous silicon film that has been treated with hydrofluoric acid in a thin film transistor manufacturing process.

  In a thin film transistor manufacturing process, there is a process of removing an amorphous silicon oxide film before laser irradiation in a low temperature polysilicon process. Usually, treatment with hydrofluoric acid or the like is performed to remove the oxide film, but the amorphous silicon film treated with hydrofluoric acid exhibits strong water repellency. In such a water-repellent substrate, after rinsing, the rinse liquid partially remains on the surface of the substrate. When air knife drying is performed in this state, draining becomes uneven and a watermark (water stain) is generated. there were.

  As a technique for solving the above-mentioned problem, there is a method of covering a substrate surface with a rinsing liquid until just before air knife drying by providing a shower called a slit-shaped rinsing liquid shower and applying a rinsing liquid (for example, Patent Document 1 and 2).

  However, in the drying method, pure water is used as the rinsing liquid. Therefore, in a state where a very strong water-repellent film is present, such as a substrate obtained by hydrofluoric acid processing of an amorphous silicon film, the pure water is supplied immediately after showering. Even if air knife drying is used in this state, the generation of watermarks cannot be suppressed.

  Further, when the distance between the rinse shower and the air knife is reduced, there is a problem that the rinse liquid that has flowed on the substrate flows to the air knife portion and it is difficult to uniformly drain the substrate surface.

JP-A-8-236498 JP 2003-124182 A

  An object of the present invention is to provide a drying method and a drying apparatus that do not generate a watermark on a substrate with an amorphous silicon film treated with hydrofluoric acid.

  The present invention hydrophilizes the surface of a substrate with an amorphous silicon film and treats the substrate from which the oxide film has been removed with a treatment liquid selected from the group consisting of alcohol, an aqueous solution of alcohol and ozone water to make the surface hydrophilic. And a drying method comprising a step of air knife drying a hydrophilically treated substrate.

  Further, the present invention provides a substrate having an amorphous silicon film treated with hydrofluoric acid, and the substrate from which the oxide film has been removed is treated with a treatment liquid selected from the group consisting of alcohol, an aqueous solution of alcohol and ozone water, and the surface is treated. The present invention relates to a drying apparatus comprising a means for hydrophilizing and a means for air-knife drying a hydrophilically treated substrate.

  According to the present invention, as a method for drying a hydrofluoric acid-treated substrate with an amorphous silicon film, the surface of the substrate with an amorphous silicon film is changed to hydrophilic by alcohol, an aqueous solution thereof or an ozone water shower, and the substrate is treated with these treatment liquids. By performing air knife drying in a state where the surface is uniformly covered, it is possible to dry without generating a watermark on the entire surface of the substrate, and the yield of the product can be improved.

  The present invention will be described below with reference to FIG. FIG. 1 is a schematic side view of a drying apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a substrate with an amorphous silicon film, 2 is an air knife, 3 is a treatment liquid shower, 4 is a drying chamber, 5 is a transport roller, 6 is a washing chamber, 7 is a washing shower, 8 is a substrate traveling direction, 10 Is a hydrofluoric acid treatment tank, and 11 is an unloader.

  In the hydrofluoric acid treatment tank 10, hydrofluoric acid treatment is performed on the surface of the substrate 1 with an amorphous silicon film transported from the loader by the transport roller 5 to remove the oxide film. You may process with BHF (buffered hydrofluoric acid) instead of hydrofluoric acid.

  Next, the hydrofluoric acid-treated substrate 1 with the amorphous silicon film is transported to the washing chamber 6 by the transport roller 5, and the substrate is showered with pure water by the washing shower 7 provided in the washing chamber 6. Rinse away the etchant.

  Next, the substrate 1 with the amorphous silicon film is transported to the drying chamber 4 by the transport roller 5. The drying chamber 4 is provided with a treatment liquid shower 3 and an air knife 2, and after the substrate is conveyed so that the treatment liquid is applied to the entire surface of the substrate by the treatment liquid shower 3, the air knife 2 drains the liquid. The flow rate of the processing liquid is adjusted so as to uniformly cover the surface of the substrate up to the portion where the air from the air knife 2 is blown.

  An example of the structure of the treatment liquid shower 3 is shown in FIGS. In FIG. 2, 9 is a processing liquid, 12 is a slit, and 13 is a nozzle. In the processing liquid shower of FIG. 2, the processing liquid 9 is applied in a waterfall shape from the slit 12 so that the processing liquid is showered on the entire surface of the substrate. In the treatment liquid shower of FIG. 3, the treatment liquid 9 is applied from the nozzle 13.

  Alcohol or ozone water is used as the treatment liquid.

  Although it does not specifically limit as alcohol, Lower alcohols, such as methanol, ethanol, isopropyl alcohol, and butanol, are used preferably. Of these, isopropyl alcohol is preferred because it has a great effect of preventing the generation of watermarks during drying of the air knife and can be easily mixed with water.

  Moreover, the aqueous solution of alcohol (a mixed solution of alcohol and pure water) can also be used. The aqueous solution of alcohol has an advantage that, when the air knife is dried, there is no ignition from the apparatus due to air charging during the air knife treatment.

  In order to prevent ignition of alcohol due to air charging during air knife processing, a mixed solution of alcohol and pure water may be used as the processing solution. In the mixed solution of alcohol and pure water, it is preferable to mix 0.3 or more of pure water with respect to alcohol 1 by volume ratio, and it is particularly preferable to mix alcohol and pure water at a volume ratio of 1: 1.

  When ozone water is used as the treatment liquid, the ozone concentration is preferably 10 to 20 mg / L.

  Air knife drying requires a smaller apparatus than spin drying, and can be installed directly in the substrate transfer line, so there is no need to prepare a separate robot for loading and unloading. In this way, since it does not take up space and is efficient, it has recently been used as a drying means after washing in a horizontal transfer type substrate processing apparatus.

  In the present embodiment, a pair of air knives 2 are provided above and below the conveyance line of the substrate 1 with an amorphous silicon film. The upper air knife 2 is for removing the processing liquid on the upper surface of the substrate 1 with an amorphous silicon film by blowing air in a thin film shape so as to reach the entire upper surface of the substrate 1 with an amorphous silicon film. The lower air knife 2 is for removing the processing liquid on the lower surface of the substrate 1 with an amorphous silicon film by blowing air in a thin film shape so as to reach the entire lower surface of the substrate 1 with an amorphous silicon film.

  Further, the air knife is installed so that the air blowing direction is inclined to the upstream side in the transport direction when viewed from the side. In addition, when viewed from above, the air is blown from the inside to the outside of the substrate 1 with the amorphous silicon film, not perpendicular to the substrate 1 with the amorphous silicon film. By adopting such a structure, the treatment liquid can be efficiently removed.

  As air used for air knife drying, high-pressure air or high-pressure inert gas is used.

  The distance between the treatment liquid shower 3 and the air knife 2 depends on the flow rate of the treatment liquid flowing out from the treatment liquid shower 3, but it is preferable to leave a distance of one substrate or more than one substrate. By doing so, the processing liquid is not scattered and does not affect the air knife portion.

  The substrate 1 with the amorphous silicon film dried in the drying chamber 4 is transferred to the unloader 11.

  In the washing chamber 6, the amorphous silicon film treated with hydrofluoric acid is water-repellent, so that the substrate surface is in a state of repelling water. The surface of the silicon film becomes hydrophilic, and a uniform treatment liquid film can be formed on the substrate surface. In this state, by performing air knife drying, the processing liquid covering the entire surface of the substrate can be easily drained, and the substrate can be dried without generating a watermark on the entire surface.

  Even if the substrate surface is hydrophilized using the treatment liquid, if spin drying is used as a drying method, a watermark is generated around the substrate due to bounce of mist from the spin cup. It is difficult not to generate a watermark.

It is a schematic side view of the drying device in one embodiment of the present invention. It is an example of the structure of the process liquid shower used for this invention. It is an example of the structure of the process liquid shower used for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate with an amorphous silicon film 2 Air knife 3 Treatment liquid shower 4 Drying chamber 5 Transport roller 6 Flushing chamber 7 Flushing shower 8 Substrate traveling direction 9 Treatment solution 10 Hydrofluoric acid treatment tank 11 Unloader 12 Slit 13 Nozzle

Claims (4)

Treating the surface of the substrate with an amorphous silicon film with hydrofluoric acid, removing the oxide film, treating the substrate with a treatment liquid selected from the group consisting of alcohol, an aqueous solution of alcohol and ozone water, and hydrophilizing the surface; and A drying method comprising a step of air knife drying a hydrophilically treated substrate. The drying method according to claim 1, wherein in the step of hydrophilizing the surface, the treatment liquid is applied to the entire surface of the substrate with the amorphous silicon film by a shower having a slit shape or a nozzle shape. The drying method according to claim 1 or 2, wherein in the step of hydrophilizing the surface, the treatment liquid is applied to the entire surface of the substrate with an amorphous silicon film during conveyance of the substrate with an amorphous silicon film. Hydrofluoric acid treatment of the surface of the substrate with the amorphous silicon film, the substrate from which the oxide film has been removed is treated with a treatment liquid selected from the group consisting of alcohol, an alcohol aqueous solution and ozone water, and the surface is hydrophilized; and A drying apparatus comprising means for drying a hydrophilically treated substrate with an air knife.

Images