JPH0710937U - Wet processing equipment for semiconductor wafers - Google Patents

Abstract

(57) [Summary] (Correction) [Objective] To provide a semiconductor wafer wet processing apparatus capable of performing uniform processing by reducing variations in processing effects among a plurality of wafers. [Structure] A plurality of semiconductor wafers 1 are loaded into a carrier 2 and immersed in a processing bath 4 containing a processing liquid 3, and each end of each of the plurality of wafers is brought into contact with at least one rotary shaft 6a. In a wet processing apparatus in which a semiconductor wafer is rotated by the rotation of a rotary shaft to perform processing, the diameters of the end portion and the central portion of the rotary shaft are set to different sizes.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor wafer wet processing apparatus.

[0002]

[Prior art]

 Since semiconductor wafers are increasingly demanded for crystal uniformity, surface cleanliness, and flatness, wet processing such as etching and cleaning has become extremely important. Therefore, in order to maintain the uniformity of the wafer in the same plane, various measures have been taken to keep the surface of the wafer in contact with the processing solution, and the device for rotating the wafer (Shokai 63-27784). ), A method of rocking a wafer (JP-A-3-231428), an apparatus combining rotation and rocking (JP-A-1-304733), and the like are known. However, in these methods and devices, even if the uniformity within the single wafer surface is maintained, if the uniformity of the flow rate and concentration of the processing liquid in the processing tank is lacking, multiple wafers can be processed simultaneously. In doing so, a uniform processing effect is not always maintained between the wafers. For this reason, stirring or bubbling of the treatment liquid is carried out for the purpose of uniformly distributing the treatment liquid in the treatment tank.

[0003]

[Problems to be solved by the device]

 Despite the above-mentioned measures, if the shape and size of the processing bath, the location of the processing liquid supply port, etc. are different, the flow velocity and concentration of the processing liquid in the processing bath will vary, and there will be multiple treatments in the same processing. There arises a problem that the processing effect is not uniform among the wafers. It is an object of the present invention to provide a semiconductor wafer wet processing apparatus capable of performing uniform processing by simultaneously processing a plurality of wafers and reducing variations in processing effects among the wafers. is there.

[0004]

[Means for Solving the Problems]

 For this reason, in the present invention, a plurality of semiconductor wafers are loaded into a carrier and immersed in a treatment layer containing a treatment liquid, and each end of each of the plurality of wafers is brought into contact with at least one rotary shaft. In the wet processing equipment that performs processing by rotating the semiconductor wafer by rotating the rotating shaft, the diameter of the rotating shaft at the end side and the center of the rotating shaft is adjusted according to the flow rate and concentration of the processing liquid. Is characterized by a different structure.

[0005]

[Action]

 In a processing tank that carries out processing for each carrier in one tank, the carrier is placed in the center of the processing tank. When the flow velocity is high or the concentration of the processing solution is high, among the wafers loaded in the carrier, the wafer loaded in the central portion side is better than the wafer loaded in the end portion of the carrier. The processing effect becomes large, and there is a difference in processing effect from the wafer loaded on the edge side. In the case of such a processing apparatus, by making the diameter of the rotating shaft for rotating the wafer smaller in the central portion than in the end portions, the wafer loaded in the central portion side is smaller than the wafer loaded in the end portion side. Since the number of rotations becomes small and the relative rotation speed decreases, the effects of the contact time with the processing solution and the concentration of the processing solution are canceled out, and the processing effect on the wafer on the edge side and the central part of the carrier is reduced. Uniformity reduces variations.

[0006]

【Example】

 1 is a longitudinal sectional view of an essential part showing an embodiment of a wet processing apparatus according to the present invention, and FIGS. 2, 3 and 4 are transverse sectional views of an essential part showing an embodiment of a wet processing apparatus according to the present invention, FIG. FIG. 4 is a horizontal cross-sectional view of a main part showing a conventional wet processing apparatus. As shown in FIG. 1, a sludge 5 having a large number of holes is provided at the bottom of the treatment tank 4 containing the treatment liquid 3 all over the bottom of the treatment tank. The processing liquid 3 is adapted to flow into the processing tank 4 from below the hole and supplied, and the overflowing processing liquid 3 is circulated and repeatedly supplied. At the center of the processing tank 4, a carrier 2 is immersed in a state in which a plurality of wafers 1 are loaded, and is loaded on a drainboard 5, and two rotary shafts 6, 6 are arranged on both lower sides thereof. Has been done.

The two rotary shafts 6, 6 are connected to a drive source (not shown) to be rotatable, and are provided so as to contact the lower end portion of the wafer 1. Then, when the carrier 2 is loaded on the drainboard 5, the two rotary shafts 6, 6 press the lower end portion of the wafer 1 so as to hold the wafer 1 slightly lifted from the groove of the carrier 2. It is arranged. Further, the two rotary shafts 6, 6 are attached at positions symmetrical with respect to a vertical line passing through the center of the wafer, and the wafer 1 is rotated by the rotation.

In the wet processing apparatus as described above, when the shape and size of the processing tank 4, the location of the supply port of the processing liquid 3 and the supply flow rate are different, the processing liquid 3 is evenly distributed in the processing tank 4. This is not always the case, and the flow velocity and concentration of the treatment liquid 3 become uneven. That is, in a device in which the diameter of the rotating shaft 6d is the same at both the end portion and the central portion as in the conventional device as shown in FIG. 5, there is a variation in the quality after processing among a plurality of wafers 1. Will occur.

For example, in the apparatus of FIG. 5, when the flow velocity of the treatment liquid 3 is high or the concentration is high in the central portion of the treatment tank 4, the diameter of the rotating shaft 6d is the same at both the end portion and the central portion. The rotation speeds of all the wafers 1 loaded in the carrier 2 are constant. Therefore, the wafer 1 loaded at the center of the carrier 2 has a greater processing effect than the wafer 1 loaded at the end portion, and a difference in processing effect from the wafer 1 loaded at the end portion side occurs. Let's do it. In such a case, that is, when the flow velocity of the treatment liquid 3 is high or the concentration is high in the central portion of the treatment tank 4, the diameter of the rotating shaft 6a is changed from the both end portions to the central portion as shown in FIG. When the wafers 1 are formed so as to become gradually smaller toward, the rotation speed of the wafer 1 loaded on the end side of the carrier 2 becomes higher than that of the wafer 1 loaded on the center side. For this reason, the effects of the concentration of the processing liquid 3 and its contact time are canceled out, and the processing effect is made uniform in any wafer 1 loaded on the rotating shaft 6a, and variations are reduced.

Contrary to the above case, when the flow velocity of the treatment liquid 3 is slow in the central portion of the treatment tank 4 or the concentration is low, the diameter of the rotating shaft 6b is set to the center from both ends as shown in FIG. It is formed so that it gradually becomes larger toward the part. Further, if the flow velocity of the treatment liquid is deviated in the lateral direction of the treatment tank, the diameter of the rotating shaft 6c is tapered so that it gradually decreases from one end to the other end as shown in FIG.

As described above, the basic configuration of the above-described embodiment is such that the diameters of the end portion and the center portion of the rotating shaft are different, so that the relative speed between the processing liquid flow rate and the wafer rotation speed is increased. The effect of the difference in the flow rate and the concentration of the processing solution is adjusted to compensate for the difference in the contact time of each wafer with the processing solution and the effect of the difference in the processing solution concentration, and the average is calculated. This is to make the processing effect uniform on the wafers loaded anywhere on the axis of motion.

[0012]

【effect】

 By performing wet processing such as etching and cleaning of semiconductor wafers with the wet processing apparatus according to the present invention, it is possible to reduce the dispersion of processing effects among multiple wafers and perform stable processing. Even if there is unevenness in the flow rate or concentration of the processing solution in the process, it is possible to manufacture a wafer of stable quality by using the rotating shaft corresponding to it.

[0013]

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a wet processing apparatus according to the present invention.

FIG. 2 is a lateral cross-sectional view of a main part showing an embodiment of the wet processing apparatus according to the present invention.

FIG. 3 is a lateral cross-sectional view of an essential part showing an embodiment of the wet processing apparatus according to the present invention.

FIG. 4 is a cross-sectional view of a main part showing an embodiment of the wet processing apparatus according to the present invention.

FIG. 5 is a lateral cross-sectional view of a main part showing a conventional wet processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 2 Carrier 3 Processing liquid 4 Processing tank 5 Slater 6 Rotation axis 6a Rotation axis 6b Rotation axis 6c Rotation axis 6d Rotation axis

Claims (4)

[Scope of utility model registration request] 1. A plurality of semiconductor wafers are loaded into a carrier and immersed in a processing layer containing a processing liquid, and each end of each of the plurality of wafers is brought into contact with at least one rotary shaft to rotate. In a wet processing apparatus that performs processing by rotating a semiconductor wafer by rotating the shaft, the diameter of the rotating shaft is different between the end portion and the central portion of the rotating shaft. Wet processing equipment. 2. The wet processing apparatus for a semiconductor wafer according to claim 1, wherein the diameter of the rotating shaft is gradually increased from both ends toward the center. 3. The wet processing apparatus for a semiconductor wafer according to claim 1, wherein the diameter of the rotating shaft is gradually reduced from both end portions toward the central portion. 4. The wet processing apparatus for a semiconductor wafer according to claim 1, wherein the diameter of the rotating shaft is tapered so as to become gradually smaller from one end to the other end.