JP2000093906A - Apparatus for producing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To circulate, filter, or replace a chemical liquid in a tank efficiently in a short time and to keep the purity and clarity of a cleaning liquid uniform by forming protruding openings in a proper number of places in the side wall of a cleaning tank in an apparatus for cleaning the surface of an object to be cleaned while the object is being immersed in liquid being allowed to over flow. SOLUTION: A protruding opening 101 for generating the convection of liquid to a tank lower part, a protruding opening 102 for generating convection to an overflow part 104, and a protruding opening 103 for leading the flow of a chemical liquid surface to a discharge opening 114 are formed. A cleaning liquid introduced from the opening 102 is made to flow convectively in a straight line toward the opposite surface 112 of a tank. The surface 112 is tapered toward the overflow part 104 in a tank upper part, and the liquid which collided is made to flow along an upper part wall surface 112. Moreover, the liquid introduced from the opening 101 is made to collide with an opposite surface 113, made to flow along a tank wall 113 reversely tapered toward a tank bottom part, and discharged from a discharge opening 105(b), In this way, the convection of the liquid in a cleaning tank is changed, and the liquid is treated uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor cleaning apparatus for immersing an object to be cleaned in a liquid and performing a cleaning or etching process while circulating, filtering or overflowing.

[0002]

2. Description of the Related Art Conventionally, as an apparatus structure of a cleaning apparatus using this type of wet cleaning method, a pump 304 (a) circulates and filters 305 from an arbitrary location on the bottom of the apparatus as shown in FIG. 3 (b), the filtrate or unused high-purity chemical is supplied by the pump 304 (a), and the chemical overflowed from 306 in FIG.
A method has been used in which the chemical solution recovered from the sample No. 02 is circulated by a filter pump 304 (a) and filtered by a filter 305 (a).

[0003]

Generally, in this type of wet cleaning in which an object to be cleaned is entirely immersed in a liquid, the amount of fine particles present in the cleaning liquid and the cleanliness of the object to be cleaned after the cleaning are reduced. Has a strong correlation, and the higher the cleanliness of the cleaning liquid, the higher the cleanliness of the object to be cleaned. This is because this cleaning method is based on the physical or scientific action of the cleaning solution.
On the one hand, it is caused by dissociation and release and washing, and the phenomenon that the once released fine particles are reattached by approaching or contacting the object to be washed again and again. Therefore, it is necessary that the fine particles once released from the object to be cleaned are immediately discharged from the tank, and take the opportunity to approach or come into contact with the object to be cleaned again. Also, in etching, the temperature, which is an important control factor, is made uniform in each part of the chamber, and the chemical reactants after etching are effectively diluted, so that fresh chemical solution can be used one after another. It was necessary to supply

However, in the conventional semiconductor manufacturing apparatus shown in FIG. 3, the direction of convection of the liquid is not only directed to the overflow surface, but is complicated by the reflection of the liquid flow colliding with the contact surface between the liquid and the atmosphere or the tank wall. By interfering with
There is a disadvantage that a place where the liquid stays or the flow is extremely slow and a place where the flow is extremely active coexist in the tank.

[0005] That is, there is a point at which contaminants and particles generated by etching and cleaning processes in the tank are delayed in the retention or replacement with the supplied fresh chemical solution. As a result, in the case of filtration and circulation, the effect of the filter provided in the circulation system as shown in 305 (a) of FIG. 3 is not sufficiently utilized, and the liquid in the tank is replaced with a fresh chemical in a short time. Had to spend a long time in order to.

[0006] In addition, it is very inefficient to perform cleaning or etching at intervals of replacing the liquid with a fresh chemical supplied from the filter 305 (a). It was inconvenient. Further, since the chemical solution is collected or discharged only from the overflow section 306, it has no chemical reactivity with the chemical solution used in the tank, and has a higher specific gravity than the cleaning chemical solution existing as a mixture, such as IPA. Most of the water and other metals, or most of the reaction products generated by the etching action, settle at the bottom of the tank,
The phenomenon in which the unnecessary material stays at the bottom of the tank also occurs due to the influence of the convection.

On the other hand, a substance having a lower specific gravity than the chemical used as the cleaning liquid floats on the upper part of the tank, and is eventually recovered in the outer tank 302 by the flow of the liquid at the time of overflow 306. Thereby, in particular, heavy particles and impurities settled at the bottom of the tank, in combination with the non-uniform convection in the tank, almost do not proceed with replacement with a fresh chemical solution, and often stagnate in the tank. Was. Due to these two phenomena, it is impossible for the particles and impurities in the tank to circulate and filter in a short time even though the new liquid is continuously supplied and the circulation and filtration are performed. there were. The object of the present invention is to improve these disadvantages, efficiently in a short time, circulate, filter or replace the chemical in the tank,
By making the purity and cleanliness of the cleaning solution or etching solution uniform in each part of the bath, increasing the cleanliness in a short time, and further reducing the variation in the temperature inside the bath, To achieve a high cleaning effect, and to minimize variations in the amount of etching depending on the site.

[0008]

In order to achieve the above object, a semiconductor manufacturing apparatus according to the present invention is provided at an arbitrary position on a side wall of a cleaning tank in order to prevent liquid from remaining in a cleaning tank or an etching tank. In addition, providing a spout for supplying filtration, circulation or new liquid to one or more places, and facing the spout,
By arbitrarily tilting it so as not to be perpendicular to the projection angle, the convection of the liquid in the washing tank overflows,
The method is characterized in that a liquid is sucked or a flow of the liquid is created toward a recovery port. In addition, the liquid suction port of the tank is provided at any one or more locations on the overflow portion and the bottom or lower portion of the tank.

[0009]

According to the semiconductor manufacturing apparatus of the present invention described above, by changing the convection of the liquid in the cleaning tank, a clean chemical liquid newly supplied by filtration, circulation, etc. It is possible to efficiently replace the contaminated chemical solution in the treatment tank in a short time, and to efficiently discharge the fine particles in the tank out of the cleaning tank.

[0010] Further, by using two discharge ports, a liquid discharge port and an overflow, provided at the bottom or lower part of the tank, fine particles having a characteristic of floating or sinking due to a difference in specific gravity with the cleaning liquid can be obtained. Can be captured selectively. As a result, the probability of fine particles re-adhering to the object to be cleaned during cleaning, which is caused by the particles dissociated and released from the object to be cleaned due to cleaning remaining in the tank for a long time, can be extremely reduced. The surface can be obtained. In addition, in the case of etching, the etching solution containing the component dissolved by the etching action is prevented from staying for a long time in the vicinity where the etching reaction has occurred, and the concentration distribution of each portion of the etching solution is always kept constant,
In addition, it has a feature that the liquid temperature variation in the tank can be made extremely small, and the etching can be made uniform.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of a semiconductor manufacturing apparatus according to the present invention will be described with reference to the drawings. FIG. 1 schematically shows a cross-sectional structure of a semiconductor manufacturing apparatus according to the present invention. In FIG. 1, reference numerals 101, 102, and 103 denote a pipe for feeding the cleaning liquid after filtration and circulation into the tank, and a protrusion. Here, 101 is a projecting port for creating a convection of the liquid to the lower part of the tank, 102 is a projecting port for guiding the flow of the solution on the surface of the chemical solution to the discharge port 114 for creating a convection to the overflow section, and 103 is a projecting port. is there. In most cases, the cleaning liquid guided from this projecting port 102 macroscopically linearly convects toward the facing surface 112 of the bath. The facing surface 112 is tapered toward the upper overflow portion 104 of the bath. Therefore, the colliding liquid flows along almost the 112 wall surfaces, and eventually reaches the overflow surface and is discharged. The liquid guided from the projecting port 101 collides with the facing surface 113, flows along the tank wall 113 having an inverse taper toward the tank bottom, and is discharged from the discharge port 105 (b). On the other hand, the liquid in the stagnation area formed below the protrusion 101 is positively discharged from the discharge port 105 (a). What is needed here is that the taper provided on the wall facing the outlets 101, 102 must be the overflow 104 or the bottom outlet 1
05 (b).

In addition, 105 (a) is provided at a position where the flow direction of the liquid surface is directed to the discharge port 104 in order to supplement a portion which is likely to cause stagnation. The highly contaminated chemical solution efficiently captured and replaced by the convection control in the solution as described above
A method may be adopted in which the fine particles are removed by the method described above and the guide is again led to the projecting opening. Further, by opening the valve 109 (f) and closing the valve 109, all the used chemical liquid is discharged, and the pump 110 (b) the valve 109 (c) 109
(G) may be opened and a method of always supplying a new liquid may be adopted. Further, the normally open valve 109
The flow rates of the outlets 101, 102, and 103 may be arbitrarily controlled by arbitrarily adjusting the degree of opening of each of the valves (a), 109 (b), and 109 (g). Further, the valves 109 (d), 109
By adjusting the degree of opening in (e), the convection velocity of the entire tank or the flow velocity balance at the bottom of the tank may be controlled. Next, a second embodiment of the present invention will be described with reference to FIG. 201
(A), 201 (b), 201 (c), 201 (d),
201 (e), 201 (f), 201 (g), 201
(H), the chemical solution pumped up by the pump 205 or the valve 201 (i) is opened and the filter 2 is opened.
This is a flow control valve for supplying into the cleaning tank via 06 (a) or 206 (b). With this flow control valve, the cleaning liquid supplied into the tank moves linearly macroscopically in the tank.

In the same manner as in the first embodiment, the cleaning liquid that has collided is collected by the overflow recovery section 203 because the projection 207 has a structure 207 that expands toward the tank opening. Fine particles having a specific gravity higher than that of the cleaning liquid are opposed to this flow and settle at the bottom of the tank. Therefore, a flow for collecting the chemical at the bottom of the tank from the suction port 202 is formed for the purpose of collecting such heavy fine particles. In order to arbitrarily change the convection inside the tank, a combination in which the valve opening / closing degrees of 201 (a) to 201 (h) and 201 (k) are arbitrarily changed may be made. The chemical in the tank is drained by opening the valve 201 (j) and closing the valve 201 (k), and the valve 201 (i) is opened and the filter 206 (b) is interposed. May be supplied, or 201 (j) may be closed and 201
Close (I), pump 205, filter 206 (a)
And circulation may be performed.

[0014]

According to the semiconductor manufacturing apparatus of the present invention described above, in a wet cleaning method in which an object to be cleaned is completely immersed in a chemical solution, the shape of the inner wall of the cleaning tank can be changed and the liquid outlet, discharge or discharge can be performed. Since the convection of the liquid in the cleaning tank can be controlled only by optimizing the position and number of the suction ports, the liquid and fine particles due to the manner of convection of the liquid in the cleaning tank do not stagnate, and a reasonably short period of time does not occur. Can be discharged or replaced with a new solution. Also, fine particles with a higher specific gravity than the cleaning liquid, condensed at the top of the liquid, and conversely, collected at the top of the liquid, and particles that flew down to the surface of the cleaning tank from outside air, are collected at the bottom of the tank without yielding to the convection of the liquid in the tank. Since the fluid flows efficiently toward the mouth, a clean washing liquid state can be created in a short time. As a result, the chance of the fine particles once removed in the cleaning liquid again encountering or approaching the object to be cleaned is greatly reduced, and the re-adhesion of the fine particles to the object to be cleaned is reduced. High cleaning effect can be obtained. In addition, since the time required to obtain the necessary replacement and cleaning degree can be reduced, the amount of the cleaning liquid used can be reduced, and high-precision cleaning can be performed in a short time.

Furthermore, in etching applications, it is possible to minimize the temperature variation in the bath, which is an important control factor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the semiconductor manufacturing apparatus of the present invention.

FIG. 3 is a sectional view showing an embodiment of a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

101, 102, 103, 109 (a), 109
(B), 109 (c), 109 (e), 109 (f),
109 (g) 201 (a), 201 (b), 201
(C), 201 (d), 201 (e), 201 (f),
201 (g), 201 (h), 201 (i), 201
(J), 201 (k), 303 (a), 303 (b)
To supply or waste liquid chemicals or cleaning liquids in the tank,
Piping and valves 106, 204, 306 Marks indicating the flow of the chemical or cleaning liquid 104, 203, 302 Overflow liquid recovery lines 105 (a), 105 (b), 202 Chemical or cleaning liquid recovery ports 108, 206 (a), 206 ( b), 305 (b) Filter for removing fine particles 110 (a), 110 (b), 205, 304 (a),
304 (b) Circulation pump for circulation or recovery of chemical or cleaning liquid

Claims (3)

[Claims] In a wet cleaning or wet etching apparatus for cleaning the surface of an object to be cleaned while immersing the object to be cleaned in a liquid and causing it to overflow, one or more arbitrary one or more of the side walls of the cleaning tank are provided. A semiconductor manufacturing apparatus characterized in that a protrusion is provided at a location. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the side wall of the surface facing the mounting surface of the projection is arbitrarily inclined so as not to be perpendicular to the projection angle of the liquid. 3. In the semiconductor manufacturing apparatus, recovering the cleaning liquid supplied into the tank by overflowing;
A semiconductor manufacturing apparatus characterized in that a suction port for performing waste liquid or circulation is provided at one or a plurality of arbitrary locations on a tank bottom.