JPS6083333A - Drying method - Google Patents

Abstract

PURPOSE:To reduce the adhesion of fine particles onto a substrate through a dust-free drying method heating and drying a wash frozen after rinsing washing treatment while the wash is mounted to a spinner in a drying atmosphere and turned at high speed. CONSTITUTION:A substrate completely washed is moved to an atmosphere at 0 deg.C or lower as it is left as it is entered into a frame body holding it, water adhering on the surface is frozen, and the substrate 3 is set to a spinner 2, an upper section thereof has an infrared ray lamp 1. The spinner 2 is mountd into a draft 10, to an upper section thereof the infrared ray lamp 1 for heating the substrate is fitted and to a side surface thereof a feed-hole 9 for dried air, dried nitrogen, etc. is formed. The substrate 3 is brought to a drying atmosphere at all times, the infrared ray lamp is lit synchronized with a starting switch for a motor 4 and ice 8 on the surface of the substrate 3 thaws, and thawed ice is scattered by centrifugal force while the substrate is dried rapidly.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a drying method which provides a particularly dust-free surface after washing with water.

(b) Background of the technology Currently, semiconductor components and circuit components are required to be small and large in capacity, and fine patterns are often created using thin film technology and photolithography.

In this case, thin films such as gold stripes, resistors, and insulators are produced using the vacuum evaporation method.
Thin films are made using various thin film forming methods such as sputter deposition and ion beam vapor deposition, but the thickness of the thin film in those cases is on the order of several hundred to several thousand [in]. [μ]
There are many small particles (floating) on the order of 100 degrees, but if they adhere to the thin film forming substrate, it is impossible to improve the yield of good products.The present invention is a drying method that obtains a clean surface after washing with water.
It is related to C.

((1). Conventional technology and problems Semiconductor elements, magnetic bubble memory elements, 2 elastic blood wave filters, etc. are made by using fine butter on semiconductor crystal substrates, magnetic crystal substrates, electric crystal substrates, etc., respectively. Thin film formation technology and photoetching technology> Complete removal of the drying solution is carried out, but in order to form a thin film, cleaning must be done using completely dust-free and clean water so that no particulates adhere to the dry surface. is necessary, and adhesion of fine particles may cause a decrease in yield.

A photomask substrate will be explained below as an example. A photomask is made by forming chromium (Cr) metal to a thickness of about 1000 (A) on a substrate made of transparent quartz or glass and having a thickness of about 25 [home], and then patterning it using Photo7!4 etching technology. This is an original plate used when performing projection exposure or contact exposure on the photoresist film coated on the above-mentioned semiconductor crystal substrate or induced fJt crystal substrate. Therefore, high pattern accuracy is required and there must be no scratches or contamination.

Furthermore, even if the product is in good condition, it is easily damaged during use, so its service life is relatively short and it is replaced with a new one.

Therefore, it is customary to remove the surface WLt number (μ) after the photomask becomes defective during formation or use and reuse it as a photomask.

Such substrates are subjected to ultrasonic cleaning and then dried to obtain a clean substrate surface, but in this case the presence of fine particles contained in the cleaning water poses a problem.

In other words, the final step of cleaning is performed using pure water that has been purified using an ion exchange resin after passing through a filter, so most inorganic ions such as anions and cations are removed. Then, the number of fine particles in a microsleeve with an average pore diameter of 0.2 [μm] is 20 to 1 (CC).
This subdivision, of which there are as many as 100, consists of microorganisms such as bacteria, minute dust, and fine particles of ion exchange resin.

If these fine particles adhere to the substrate surface during drying, the fine particles are thicker than the thickness of the deposited Cr film, which often causes defects.

In addition, although pure water has a small number of particles in its purified state, the sterilizers have been removed during the ion exchange process, making it easy for fungi and other microorganisms to propagate and grow. Usually, a deposit of fine particles with a particle size of 0.1 [μfn] or more is included.

If such fine particles exist on the substrate, they interfere with the adhesion of the Cr metal and tend to cause peeling, resulting in mask defects.

(d) Purpose of the Invention An object of the present invention is to provide a drying method that reduces the amount of particles attached to a substrate in a water-washed and temporarily dried state.

(e) Structure of the Invention The object of the present invention is to provide a dust-free round wire method in which the object to be washed, which has been frozen after washing with water, is mounted on a spinner in a dry atmosphere, rotated at high speed, and heated and twisted. can be achieved.

(f) It is a commonly used drying method to carry out an embodiment of the invention, and then wash it with pure water and dry it.

However, as mentioned above, a considerable number of fine particles are contained in pure water, and the number of particles tends to increase over time.

Therefore, if the substrate is dried as it is, the appearance of fine particles on the substrate surface cannot be avoided.

Therefore, the proposed method uses the principle that foreign substances are removed when water freezes and crystals develop to separate microparticles from the substrate surface.

Here, the ice crystal structure has an oxygen ion (
0-) is also formed at the apex by a hydrogen ion (H+) due to the electronegativity of AmO-1, and all H+ are shared and connected in three dimensions, and H+ is 0. - It has a crystal structure located on a line connecting each other.

When the water is cooled and becomes ice, it is rapidly cooled to form fine polycrystalline aggregates, and apart from the case where fine particles are taken into the boundaries, as the ice grows, the fine particles are excluded from the crystal lattice and crystallized. A state is obtained in which there is no foreign material inside.

In the drying method according to the present invention, the substrate is heated to a temperature below 0 [° C.], and the water adhering to the surface is crystallized to form fine particles separated from the substrate surface, and the particles are dried while maintaining this state.

The method is to place the cleaned substrate in a holding frame and move it to an atmosphere below ＼℃ (°C) to freeze the water adhering to the surface. As shown in Figure 2, a substrate 3'f: is set on a spinner 2 equipped with an infrared lamp 1 on the upper part, and (5) in the figure is a block diagram of a drying apparatus according to the present invention equipped with a spinner 2f. Figure (B) is a plan view of the spinner 2.Although the water on the surface of the substrate 30 is frozen, the amount of adhesion is very small.Therefore, it is easy to take out from the frame and also easy to attach to the spinner 2. It is.

The spinner 2 is equipped with a vacuum chuck mechanism.
The substrate 3 is held by a decompression suction mechanism in which the shaft center of the rotating shaft 5 rotates at high speed by the motor 4 and is slowed down to the surface of the sample holding table 6, and in this case, the substrate 3 is removed by the claw portion 7. A structure is in place to prevent this.

The spinner 2iL, for example, Kataya 1, has a door that can be opened and closed, through which the board 3 can be mounted, and an infrared ray rung 1 for heating the board on the top, and dry air on the side.
A draft 10 equipped with a supply hole 9 for supplying dry nitrogen (N, ), etc.
It is located inside. Then, the circuit board 3 is always kept in a dry atmosphere, and the infrared lamp turns on in synchronization with the start switch of the motor 4, and the ice 8 on the surface of the circuit board 3 melts and scatters due to centrifugal force, rapidly drying. ing.

By creating a state in which the substrate 3 after cleaning does not contain any particulates and rapidly drying it in this way, a surface state with a very small amount of adhesion of particulates can be obtained. When using such a substrate drying method, conventionally, when a dried substrate was inspected under a microscope, several fine particles with a particle size of 1000 (A) or more were always present within the field of view, but the method of the present invention is implemented. In most cases, fine particles cannot be observed.

(g) Effects of the invention The present invention has a particle size of 1000 (A) as in photomask formation.
) The presence of particles as small as 100% was made to improve the yield in substrate drying, which affects the drying process, and by implementing the present invention, the adhesion of fine particles is reduced, making it possible to improve the yield.

[Brief explanation of the drawing]

FIG. 1 is a 11ii 'Fjir diagram of the structure of the drying apparatus used to carry out the present invention, and FIG. 2 is a plan view of the spinner section, in which an ih infrared lamp, 2 a spinner, 3 a substrate, and 7 a Claw part, 8#'i ice, 9 is dry gas supply port, lO
is a draft. Mine Uta''#2 song

Claims (1)

[Claims] A dust-free drying method 0 characterized in that the object to be cleaned, which has been frozen after washing with water, is mounted on a spinner in a dry atmosphere, rotated at high speed, and heated and dried.