KR20020048128A - apparatus and method for etching - Google Patents

Abstract

PURPOSE: An etching apparatus is provided to keep a constant density of an etchant by using a stirring apparatus installed in an etching tank. CONSTITUTION: An etching apparatus comprises an etching tank(110) having openings in an upper and a lower portions, a first supply pipe(131) connected to the upper portion opening for supplying a dry gas, a second supply pipe(141) connected to the lower portion opening for supplying an etchant, a third supply pipe(142) connected to the second supply pipe(141) for supplying a cleaning solution, a first exhaust pipe(132) connected to the first supply pipe(131) for exhausting the etchant and the cleaning solution, a second exhaust pipe(143) connected to the second supply pipe(141) for exhausting the dry gas, a stirring apparatus(150) installed on the lower portion opening capable of circulating so as to mix and convect a mixed solution, a stirring apparatus driving part(160) for controlling the stirring apparatus(150).

Description

Etching Apparatus and Etching Method

The present invention relates to an etching apparatus and method, and more particularly to an etching apparatus and method that proceeds in a dipping method.

In general, the etching method of the thin film is divided into dry etching method using gas plasma and wet etching method using chemical solution. Dry etching method is mainly applied to etching the insulating film. Is mainly applied to etching metal films.

In the dry etching method, the reaction gas introduced into the chamber is plasma discharged under a constant pressure, and the ions or radicals generated are reacted with the thin film, thereby etching by physical collision or chemical reaction.

Such dry etching may be divided into a plasma etching method and a reactive ion etching method according to a reaction method.

In the plasma etching method, mainly radicals of the generated reactants are used for etching by chemical reaction, and since the radicals are neutral states in which molecules are excited, they are not affected by the direction of the electric field. Therefore, the etching ratio is the same regardless of the electric field direction (isotropy) etching, the physical impact is small, there is little effect on the lower layer is advantageous for selective etching.

In contrast, reactive ion etching is mainly performed by etching ions accelerated by an electric field and colliding with a thin film. However, since an etch ratio varies depending on the direction since ions accelerate in an electric field direction, anisotropy etching is performed. Is done.

On the other hand, the wet etching method is a method of removing the thin film using a chemical solution, as described above, excellent in selectivity, good etching uniformity and productivity in large area, low cost and cleaning effect at the same time There is an advantage that can be obtained.

These wet etching methods include a dipping method and a spray method. The dipping method is a method of dipping a substrate in a chemical solution, and the spray method is a method in which a chemical solution is sprayed onto a substrate. .

When the thin film is etched by a dipping method, a batch method in which a plurality of substrates are placed in a bath and processed at a time may be used. This may allow mass production to reduce manufacturing costs.

Hereinafter, a method of etching a thin film by a dipping method will be described with reference to the accompanying drawings.

1 illustrates a conventional dipping etching apparatus.

As shown in FIG. 1, there is an etch container 10 having a plurality of substrates 20 loaded therein, and a plurality of upper and lower portions of the etch container 10 communicating with the inside of the etch container 10. Supply and discharge lines are located. The upper first supply pipe 31 is a supply path of isoprophyl alcohol, the lower second supply pipe 41 is an supply path of the etchant, and the third supply pipe 41 is connected to the second supply pipe 41. The supply pipe 42 becomes a supply path of ultra pure water (DI water; deionized water).

The first discharge pipe 32 branched from the first supply pipe 31 is positioned above the etching container 10, and the first discharge pipe 32 discharges the etching liquid and the ultrapure water. A second discharge pipe 43 connected to the second and third supply pipes 41 and 42 is positioned below the etching container 10, and the second discharge pipe 43 is introduced into the container 10 through the first supply pipe 31. It is the outlet of the injected isopropyl alcohol.

On the other hand, a fixed screw device 50 is formed in the lower portion of the inside of the etching vessel 10, that is, the portion into which the etchant and the ultrapure water are injected. To mix.

In such an etching apparatus, a plurality of substrates may be simultaneously etched and subsequently cleaned. The etching and cleaning steps will be described below.

First, as the first step, the etchant and ultrapure water are simultaneously supplied into the etching vessel 10 through the second supply pipe 41 and the third supply pipe 42. As described above, the etchant and the ultrapure water are uniformly mixed while passing through the screw device 50. At this time, only the etchant may be supplied as necessary.

Next, as a second step, the substrates 20 are immersed in the mixed solution of the etching liquid and the ultrapure water supplied inside the container 10 for a predetermined time.

Next, as a third step, ultrapure water is supplied through the third supply pipe 42 to discharge the etching liquid diluted in the ultrapure water inside the container 10 to the first discharge pipe 32. That is, the etching liquid diluted with ultrapure water is discharged by pushing from the bottom to the top.

Subsequently, as a fourth step, the substrates 20 are dried by supplying approximately isopropyl alcohol into the container 10 through the first supply pipe 31.

However, when etching using such an etching apparatus, the substrate is immersed in an etchant diluted about 10 minutes or more, and over time, the etchant having a large specific gravity sinks to the lower portion of the vessel 10, and thus the upper portion of the vessel 10. The mixing concentration of the etchant and the ultrapure water is low, and the mixing concentration of the lower portion of the container 10 is high. Therefore, the uniformity of the mixed state of the etchant and the ultrapure water is poor.

Such a difference in concentration affects the substrate 21 inside the etching vessel 10, so that the etching states of the upper portion a and the lower portion b of the substrate 21 are different as illustrated in FIG. 2. That is, the upper portion a of the substrate 21 is under etched, and the lower portion b is overetched.

In addition, bubbles may be generated when the etching solution and the ultrapure water are introduced, and since the etching solution and the ultrapure water injected into the container 10 are maintained without flow, when the bubble 22 is positioned on the thin film surface of the substrate 21, bubbles are generated. 22 interferes with etching. Therefore, a problem arises in which this portion is not etched.

The present invention has been made to solve the above-mentioned conventional problems, an object of the present invention to provide an etching apparatus and an etching method which is uniformly etched.

1 is a view showing a conventional dipping etching apparatus.

2 illustrates a substrate etched by a conventional dipping method.

3 is a view showing a dipping etching apparatus according to the present invention.

4 and 5 show an example of a stirring device according to the invention.

<Description of the symbols for the main parts of the drawings>

110: etching vessel 120: substrate

131: first supply pipe 132: first discharge pipe

141: second supply pipe 142: third supply pipe

143: second discharge pipe 150: stirring device

160: stirring device drive unit

An etching apparatus according to the present invention for achieving the above object is an etching container having an opening in the upper and lower, a first supply pipe connected to the upper opening and supplying dry gas, connected to the lower opening and the etching liquid A second supply pipe for supplying, and a third supply pipe for supplying a cleaning liquid, a first supply pipe for supplying a cleaning liquid, and a first discharge pipe for discharging the etching liquid and the cleaning liquid, and a connection of the second supply pipe. And a second discharge pipe for discharging the dry gas, a stirring device rotatable in the lower opening, and a stirring device driving unit for controlling the stirring device.

Here, the stirring device may be made of any one of a screw shape and a propeller shape.

In addition, the drying gas may be isopropyl alcohol, and the cleaning liquid may be ultrapure water.

In the etching method according to the present invention, a plurality of substrates are placed inside an etching vessel having a rotatable stirring device, and an etching solution is injected into the etching vessel so that the plurality of substrates are locked. Subsequently, the etching apparatus is rotated to convex the etching solution, and etching is performed on a plurality of substrates, and then the etching solution is discharged. Next, the cleaning solution is injected into the etching container to clean the inside of the etching container and the plurality of substrates, and the cleaning solution is discharged.

As described above, in the present invention, a rotatable stirring device is installed inside the etching container to convex the mixed etching solution inside the etching container, thereby maintaining a constant concentration of the etching solution, and removing bubbles or moving to the surface of the etching solution. To prevent bad etching.

Hereinafter, an etching apparatus and an etching method according to the present invention will be described in detail with reference to the accompanying drawings.

3 illustrates a dipping etching apparatus according to the present invention.

As shown in FIG. 3, an etching container having openings 111 and 112 respectively opened and closed by valves (not shown) at an upper portion and a lower portion thereof, and an etch container including a space enclosed by the openings 111 and 112. There is 110. Upper and lower portions of the etching vessel 110 are provided with a plurality of supply pipes and discharge tubes communicating with the inside of the etching vessel 110 through the openings 111 and 112.

A first supply pipe 131 connected to the upper opening 111 and serving as an isopropyl alcohol supply path, and a first discharge pipe branched from the first supply pipe 131 and discharging the etchant and the cleaning liquid, is disposed on the etching container 110. 132 is located.

Here, the isopropyl alcohol has a melting point of about 80 ° C. and a gaseous state at 125 ° C.

A second supply pipe 141 and a third supply pipe 142 connected to the lower opening 112 are positioned below the etching container 110, and the second supply pipe 141 is a supply path for the etching liquid and the third supply pipe 142. ) Becomes a supply path of the cleaning liquid. Here, the cleaning liquid mainly uses ultrapure water, and the ultrapure water not only cleans the inside of the etching vessel 110 and the substrate 120 after etching, but is also injected with the etching solution to dilute the etching solution.

In addition, a second discharge pipe 143 connected to the second and third supply pipes 141 and 142 is positioned below the etching container 110, and the second discharge pipe 143 is an outlet of isopropyl alcohol.

In the etching vessel 110, a plurality of substrates 120 are loaded by a device such as a cassette (not shown), which may be loaded up to 40 sheets depending on the process environment. .

A rotatable stirring device 150 is disposed at a lower portion of the etching vessel 110, that is, a portion of the lower opening 112 into which the etching liquid and the ultrapure water are injected, and the stirring device 150 drives the stirring device 150. Is connected to the external stirring device driver 160 for.

4 and 5 show a stirring device according to the present invention, respectively, as shown, the stirring device may be made of a screw shape, or may be made of a propeller shape.

Such a stirring device is to be uniformly mixed when the etching liquid and the ultrapure water is injected into the container, and by the convection of the mixed liquid rotated by the stirring device drive unit during etching, it serves to maintain the uniformity of the mixture. In addition, bubbles generated when the etchant and the ultrapure water are injected may be located on the substrate to cause an etching failure. Convection of the mixed solution removes the bubbles or moves the bubbles to the mixed solution surface, thereby preventing the etching defect caused by the bubbles.

The etching process using such an etching apparatus is as follows.

First, the etchant and the ultrapure water are supplied through the second supply pipe 141 and the third supply pipe 142, respectively, and the mixed solution is injected into the etching vessel 110 loaded with the substrate 120. Here, the mixed solution is more uniformly mixed through the stirring device 150.

Next, after the mixed solution is filled in the etching vessel 110 so that the substrate 120 is sufficiently immersed, the substrate 120 is etched for a predetermined time. At this time, when the etching proceeds, the stirring apparatus 150 is rotated to convex the mixed liquid, thereby maintaining the concentration of the mixed liquid uniformly and removing bubbles.

Next, the ultrapure water is injected into the etching vessel 110 through the third supply pipe 142 to push out the mixed solution of the etchant and the ultrapure water. Therefore, the mixed liquid is discharged through the first discharge pipe 132, and the inside of the etching container 110 is filled with ultrapure water. Subsequently, the inside of the etching vessel 110 and the substrate 120 are cleaned with filled ultrapure water.

Next, the ultrapure water inside the etching vessel 110 is removed, and the substrate 120 is dried by supplying isopropyl alcohol at about 125 ° C. into the vessel 110 through the first supply pipe 131.

The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit of the present invention.

The present invention is a dipping method of etching apparatus, by installing a rotatable stirring device inside the etching vessel by convection of the mixed etching solution in the inside of the etching vessel, to maintain the concentration of the etching solution constant, remove the bubbles generated during the etching solution injection or etching solution Move to the surface to prevent etching failure.

Claims (5)

An etching container having an opening at an upper portion and a lower portion thereof; A first supply pipe connected to the upper opening and supplying a dry gas; A second supply pipe connected to the lower opening and supplying an etchant; A third supply pipe connected to the second supply pipe and supplying a cleaning liquid; A first discharge pipe connected to the first supply pipe and configured to discharge the etching solution and the cleaning solution; A second discharge pipe connected to the second supply pipe and configured to discharge the dry gas; A rotatable stirring device positioned in said lower opening; Stirring device drive unit for controlling the agitating device Etching apparatus comprising a. The method of claim 1, The stirring device is an etching device consisting of any one of a screw shape and a propeller shape. The method of claim 1, The dry gas is an etching apparatus is isopropyl alcohol. The method of claim 1, The cleaning liquid is an ultra pure water etching apparatus. Placing a plurality of substrates inside the etching vessel having a rotatable stirring device; Injecting an etchant into the etching vessel to lock the plurality of substrates; Rotating the stirring device to convection the etchant and etching the plurality of substrates; Discharging the etchant after the etching; Injecting a cleaning solution into the etching vessel to clean the inside of the etching vessel and the plurality of substrates; Discharging the injected cleaning liquid Etching method comprising a.