TWI418655B - Wet bench sidewall paddle agitation method and apparatus - Google Patents

Description

Wet process etching method and device for disturbing carrier edge with stirring rod

The present invention relates to a wet process etching method and apparatus, and more particularly to a wet process etching method and apparatus for disturbing the edge of a carrier with a stir bar.

Generally, when wet etching is performed, first, the reactant utilizes a diffusion effect through a thin diffusion boundary layer to reach the surface of the film to be etched. These reactants then chemically react with the molecules on the surface of the film and produce various reaction products. These reaction products on the surface of the film will also use the diffusion effect to reach the solution by diffusing the boundary layer, and the subsequent solution is discharged. In order to increase the diffusion effect, a magnet is used to drive the stir bar at the bottom of the etching tank to stir the etching liquid, but only the lower etching liquid can be stirred. For the etching of a large area of glass or wafer, the groove of the carrier cannot be reached (Slot). ), and form a dead end. U.S. Patent No. 6,054,162 to Jellrey C. Calio et al. teaches a method and apparatus for agitating an etchant by ejecting bubbles at the bottom of the etched tank to agitate the etchant but still not agitate to the groove of the carrier. It also formed a dead end.

Therefore, there is a need for a method and apparatus for agitating an etchant that provides a uniform etchant distribution across the glass/wafer surface within the Cassette.

In view of this need, the present invention provides a method and apparatus for agitating an etchant that can solve the above disadvantages.

SUMMARY OF THE INVENTION The object of the present invention is to provide a wet process etching apparatus for disturbing the edge of a carrier with a stir bar, which uses a stir bar to reciprocally stir to generate minute vibrations, thereby improving etching uniformity and improving yield.

A second object of the present invention is to provide a wet process etching method for disturbing the edge of a carrier with a stir bar to eliminate the dead field of the flow field at the groove of the carrier, improve the etching uniformity, and improve the yield.

In order to achieve the above and other objects, the first aspect of the present invention teaches a wet process etching apparatus that disturbs the edge of a carrier with a stir bar, and uses a reciprocating stirring design of the stir bar to cause micro-vibration of the glass/wafer. It can make a uniform etchant distribution on each glass/wafer surface in the Cassette, especially at the fixed glass/wafer slot, which is the dead spot where the etching solution is the least likely to spread. The reciprocating agitation of the stir bar can improve the etching uniformity of the glass/wafer, including: a wet process etching bath with an etchant and a carrier, and a groove for the carrier to be embedded with the glass/wafer to be etched; Two sets of stir bar are placed on both sides of the vehicle, driven by the connecting rod, one set forward and one set back and forth to reciprocate; two connecting rods, one for forward and one backward for etching Exercise to drive the two sets of stir bars separately.

Another aspect of the present invention teaches a wet process etching method for disturbing the edge of a carrier with a stir bar, which uses a stir bar reciprocating agitation to generate water waves in different directions to push both sides of the workpiece so that one side is forward and the back is pressed against the concave Slots that cause micro-vibration of the glass/wafer to provide uniform etchant distribution across the glass/wafer surface in the Cassette, especially in fixed glass/wafer grooves (Slot) is the dead angle that the etching liquid is most difficult to diffuse. By adjusting the stirring frequency and the shape, number and position of the stirring rod, the flow field dead angle at the groove of the carrier can be eliminated, and the thickness of the diffusion boundary layer can be effectively reduced, thereby improving Glass/wafer etch uniformity, including: placing the glass/wafer in the recess of the carrier; placing the glass/wafer carrier in a wet process etching bath with an etchant; Two sets of connecting rods on both sides are used to drive the two sets of stirring rods; the stirring frequency and the shape, number and position of the stirring rods are adjusted to eliminate the flow field dead angle at the groove of the carrier to improve the etching uniformity of the glass/wafer.

The above and other objects and advantages of the present invention will be more fully understood from the description and appended claims appended claims.

Please refer to FIG. 1 , which shows a schematic diagram of the diffusion boundary layer of wet etching. In the wet etching, the reactants first pass through a thin diffusion boundary layer to reach the surface of the film to be etched by the diffusion effect. These reactants then chemically react with the molecules on the surface of the film and produce various reaction products. These reaction products on the surface of the film will also use the diffusion effect to reach the solution by diffusing the boundary layer, and the subsequent solution is discharged. According to the fluid mass transfer formula, the device uses the Paddle stirring method to increase the value of W (vibration frequency or angular frequency) to reduce the diffusion boundary layer thickness (δ), thereby increasing the diffusion rate and the final etching rate. Where D is the diffusion constant and V is the Kinetic Viscosity.

Diffusion layer thickness δ=1.61D ^1/3 V ^1/6 (w) ^1/2

Figure 2 is a schematic illustration of a wet process etching apparatus for disturbing the edges of a carrier with a stir bar in accordance with an embodiment of the present invention. The wet process etching apparatus 200 for disturbing the edge of the carrier with a stir bar has an etching liquid (not shown) in the wet process etching bath 202, and the carrier 208 is placed in the middle, and the groove 212 of the carrier can be placed on the glass/crystal to be etched. Circle 210, the two sets of stir bars 206, 207 are placed on either side of the carrier 208, driven by the links 204, 205, one set forward and one set back and forth agitated. Figure 3 shows a side view of a set of stir bars in accordance with an embodiment of the present invention. The stir bar 206, 207 may be one, or a plurality of groups, for example, 2 to 5, but not too much, otherwise the stroke is insufficient and the disturbing power path is too small. The stirring frequency is 5 to 20 times per minute. The links 204, 205 are driven by a motor or pneumatically.

Figure 3 is a schematic illustration of the formation of water waves at the edges of the carrier by a stir bar in accordance with an embodiment of the present invention. The recess 212 of the carrier places the glass/wafer 210 to be etched. The glass/wafer 210 to be etched is placed, and the stir bar 206 pushes the etchant forward to form a water wave 402. Pushing the right side of the glass/wafer 210 forward causes the etchant to reach the surface of the glass/wafer 210 within the recess 212. Conversely. The stir bar 207 pushes the etching liquid backward to form a water wave 403. Pushing the left side of the glass/wafer 210 rearward causes the etchant to reach the surface of the glass/wafer 210 within the recess 212. Therefore, the thickness of the diffusion boundary layer is effectively reduced, and the etching liquid enters a dead angle which is least likely to diffuse into the groove. In turn, the etch uniformity of the glass/wafer is improved. Figure 4 shows a schematic diagram of the reverse disturbance of the stir bar. The stir bar 206 is changed to the rear and the stir bar 207 is changed to the forward direction, so that the disturbance is repeated to improve the etching uniformity of the glass/wafer.

The features and spirit of the present invention are more clearly described in the detailed description of the preferred embodiments of the present invention, and are not intended to limit the scope of the invention. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the invention as claimed.

200. . . Wet process etching device for disturbing the edge of the carrier with a stir bar

202. . . Wet process etching bath

204. . . link

206. . . Stir bar

207. . . Stir bar

208. . . vehicle

210. . . Glass/wafer

212. . . Carrier groove

402. . . Forward water wave

403. . . Backward water wave

Figure 1 shows a schematic diagram of the diffusion boundary layer of wet etching.

Figure 2 is a schematic illustration of a wet process etching apparatus for disturbing the edges of a carrier with a stir bar in accordance with an embodiment of the present invention.

Figure 3 is a schematic illustration of the formation of water waves at the edges of the carrier by a stir bar in accordance with an embodiment of the present invention.

Figure 4 shows a schematic diagram of the reverse disturbance of the stir bar.

200. . . Wet process etching device for disturbing the edge of the carrier with a stir bar

202. . . Wet process etching bath

204. . . link

206. . . Stir bar

207. . . Stir bar

208. . . vehicle

Claims (7)

A wet process etching device that disturbs the edge of the carrier with a stir bar, and uses a reciprocating stirring design of the stir bar to cause micro-vibration of the glass/wafer to make each glass/wafer in the Cassette The surface can obtain a uniform etchant distribution, especially at the fixed glass/wafer groove, which is the dead zone where the etchant is least likely to diffuse, and the reciprocating agitation of the stir bar can improve the etch of the glass/wafer. Uniformity, at least: a wet process etching bath with an etchant and a carrier, the groove of the carrier is provided with a glass/wafer to be etched; two sets of stir bars are placed on both sides of the carrier, The connecting rod drives, one set forwards and one set backwards reciprocatingly; two connecting rods, when etched, one forward and one backward reciprocate to drive the two sets of stirring rods respectively. A wet process etching method for disturbing the edge of a carrier with a stir bar, using a stir bar reciprocating agitation to generate water waves in different directions to push both sides of the workpiece so that one side is forward and the back is pressed against the groove to make the glass/wafer Micro-vibration produces uniform etchant distribution on each glass/wafer surface in the Cassette, especially at the fixed glass/wafer Slot. The liquid is most difficult to diffuse to reach the dead angle. By adjusting the stirring frequency and the shape, number and position of the stir bar, the flow field dead angle at the groove of the carrier can be eliminated, the thickness of the diffusion boundary layer can be effectively reduced, and the etching of the glass/wafer can be improved. The degree includes at least: placing the glass/wafer in the groove of the carrier; placing the glass/wafer carrier in the wet process etching bath with the etching liquid; and making the two sides of the carrier The connecting rod drives two sets of stir bar; adjust the stirring frequency and the shape, quantity and position of the stir bar to meet the flow field requirements of different processes to eliminate the dead angle of the flow field at the groove of the carrier to improve the etching of the glass/wafer Evenness. The method or apparatus of claim 1 or 2, wherein the two sets of stir bars are one on each side. The method or apparatus of claim 1 or 2, wherein the two sets of stir bars are 2 to 5 on each side, and the shape and number of the stir bar can be modified to meet the flow field requirements of different processes. The method or apparatus of claim 1 or 2, wherein the stirring frequency is 5 to 20 times per minute. The method or apparatus of claim 1 or 2 wherein the link is driven by a motor. A method or apparatus of claim 1 or 2 wherein the link is pneumatically driven.