JP2587304Y2 - Chemical processing equipment for semiconductor wafers - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for treating chemical liquids on semiconductor wafers.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of devices has been increasing more and more, the requirements for crystal characteristics and processing characteristics of semiconductor wafers have become more stringent year by year. Needless to say, stricter requirements have been placed on the surface roughness of the chamfered portion, which is also referred to as a source of particles in the device process, than ever before.
For this reason, chemical treatments such as etching and cleaning have become extremely important. Conventionally, various devices have been devised to uniformly contact the surface of the wafer with a chemical solution in order to maintain uniformity within the same plane of the wafer, and as a device for performing processing by rotating or swinging the wafer, 3-979
26, Japanese Utility Model Laid-Open No. 3-2632, Japanese Utility Model Application Laid-Open No. 57-29140, and the like are known. These apparatuses rotate one or two rotating shafts in contact with the edge of the wafer in order to impart rotation to the wafer. Since a sufficient frictional resistance can be obtained, the wafer can be sufficiently rotated even with the above-mentioned conventional apparatus, so that the purpose of the chemical treatment has been achieved.

[0003]

However, as the degree of integration of devices has increased in recent years, the surface roughness of the chamfered portion has to be reduced in order to prevent particles, chips and chips from being generated from the edge of the wafer in the device process. Has been demanded, and a smooth finish has been required for the finishing of the chamfered portion. By the way, if the surface roughness is defined as the height difference of the unevenness of the surface, the surface roughness of the conventional product is 0.07 μ, whereas the smooth surface product is 0.03 μ and the mirror surface product is 0.07 μ.
The grade is about 1μ. When a smoothed product or a mirror-finished product having a fine surface finish of the chamfered portion is subjected to a chemical treatment such as etching or cleaning by rotating the wafer by a conventional chemical treatment method, a rotation for rotating the wafer is performed. Since the frictional resistance between the moving shaft and the chamfered portion of the wafer is smaller than that of the conventional product, slippage occurs between the wafer and the rotating shaft, and uneven rotation or stop of the wafer occurs. As a result, etching or cleaning unevenness occurs. The occurrence of defects was increasing. Further, in order to increase the frictional resistance between the rotating shaft and the wafer and to improve the rotation of the wafer, the rotating shaft is surrounded by a cover made of fluoro rubber, which causes wear of the wafer end surface. There was a problem.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a plurality of semiconductor wafers are loaded into a carrier, immersed in a processing tank containing a processing solution, and a plurality of wafers are processed. In a chemical solution processing apparatus in which each end is brought into contact with a rotation axis and a semiconductor wafer is rotated to perform processing by rotation of the rotation axis, below the center of the wafer,
Four rotating shafts are provided on a circumference centered on the center of the wafer, and at least three of the rotating shafts are in constant contact with the wafer end of a semiconductor wafer having one orientation flat. It is characterized by doing.

[0005]

With the semiconductor wafer chemical processing apparatus of the present invention, if a chemical processing for etching or cleaning of a wafer is performed, the semiconductor wafer is processed by four or more rotating shafts in comparison with the conventional one or two rotating shafts.
Since the rotation is given by the rotation axis of the book, a rotation force of 2 to 4 times is given to the wafer. The orientation flat is 1
In a wafer owned by at least three wafers, at least three rotating shafts are constantly in contact with the edge of the wafer, so that the wafer can be smoothly rotated, and therefore, the chemical solution processing can be uniformly performed on the wafer surface. . Furthermore, for this reason, the acid-resistant fluoro rubber cover surrounding the rotating shaft for increasing the friction becomes unnecessary, and in addition, the number of rotating shafts having the same circular contacts as the wafer described above is increased. A more dispersed load is directly applied to the rotating shaft made of resin, and smooth rotation of the wafer is ensured, so that wear of the wafer caused by friction between the rotating shaft and the wafer is greatly reduced and improved. be able to.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a main part showing a chemical processing state of a semiconductor wafer in a chemical processing apparatus according to the present invention, and FIGS. 2, 3, 4 and 5 are wafer end parts during wafer chemical processing, in particular, orientation flats 4 and 4. It is a front view which shows the positional relationship with the rotating shaft of a book. As shown in FIG. 1, a saw blade 2 having a large number of holes 21 at the bottom of the processing tank 1 is provided on the entire bottom of the processing tank 1. This corresponds to an inflow port of a chemical solution provided to supplement the chemical solution overflowing the processing tank 1. Further, the processing tank 1 has a space in which the carrier 4 can be loaded on the die 2 without being interfered with the wafer 3 loaded in the carrier 4. Furthermore, four resin-made rotating shafts 5
Are mounted horizontally so as to rotate the wafer responsively via a drive source. When actually mounting the wafer, the wafer end 31 is slightly lifted from the groove bottom of the carrier 4 so as to be in contact with the wafer end 31 other than the orientation flat 32 at the same time. The rotating shaft 5 is symmetrically arranged so as not to contact the carrier 4 as shown in FIG. In the actual working process, the plurality of wafers 3 slightly lifted from the groove bottom of the loaded carrier 4 in the above-described chemical processing apparatus containing the chemical 6, and the wafer end 31 was in contact with the rotating shaft 5. In state. When the four rotating shafts 5 rotate in the same direction from this state, the wafer 3 starts rotating in the direction opposite to the rotating shaft 5. In the rotation operation of the wafer, the rotating shaft 5 that is in contact with the wafer end 31 other than the orientation flat portion 32 applies a rotating force to the wafer 3, and at the position where the orientation flat portion 32 contacts the rotating shaft 5, As shown in FIGS. 2, 3, 4, and 5, three of the four rotating shafts 5 are always in contact with the wafer. Orientation flat part 3
Since the length of the wafer 2 is about 12% of the entire length of the wafer, the rotation of the wafer 3 is hardly affected. Helping.

[0007]

[Effect] When the chemical processing apparatus for etching or cleaning a semiconductor wafer is performed by the chemical processing apparatus of the present invention, the wafer can be smoothly rotated even if the processing finish of the wafer chamfer is a smooth or mirror-finished product. , Etching unevenness or cleaning unevenness due to poor rotation is eliminated, and the defect which was 3% in the case of the smooth surfaced product and 10% in the case of the mirror surfaced product was reduced to almost 0%. In addition, since the dispersion of the wafer load and the contact of the wafer are made of the resinous rotation axis, the abrasion of the end face of the wafer, which has conventionally been twice as large as the one-sided etching allowance, has been greatly improved.

[0008]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing a chemical liquid processing state of a semiconductor wafer in a chemical liquid processing apparatus according to the present invention.

FIG. 2 is a front view illustrating a positional relationship between an end portion of a wafer during a chemical liquid processing of the wafer, particularly, an orientation flat portion and four rotation axes.

FIG. 3 is a front view showing a positional relationship between an end portion of the wafer during the chemical liquid processing of the wafer, in particular, an orientation flat portion and four rotation axes.

FIG. 4 is a front view illustrating a positional relationship between an end portion of a wafer during a chemical liquid processing of the wafer, particularly, an orientation flat portion and four rotation axes.

FIG. 5 is a front view showing a positional relationship between an edge portion of the wafer during the chemical liquid processing of the wafer, in particular, an orientation flat portion and four rotation axes.

[Description of Signs] 1 Processing tank 2 Slender 21 Hole 3 Wafer 31 Wafer end 32 Ori-Fla 4 Carrier 5 Rotating shaft 6 Chemical solution

Claims (1)

(57) [Scope of request for utility model registration] A plurality of semiconductor wafers are loaded into a carrier, immersed in a processing tank containing a processing solution, and respective ends of the plurality of wafers are brought into contact with a rotating shaft. In a chemical solution processing apparatus that performs processing by rotating a semiconductor wafer, four rotation axes are provided on a circumference around the center of the wafer below the center of the wafer, and at least three of the rotation axes are provided. The rotation axis of the
A chemical processing apparatus for semiconductor wafers, wherein the apparatus is always in contact with the edge of the semiconductor wafer owned by the operator.