JPS6319836A - Semiconductor wafer transfer system - Google Patents

Abstract

PURPOSE:To eliminate influence of deposition occuring during etching to satisfy the optimum etching condition by always changing the linear portion of semiconductor wafers transferred with the linear portion not considered and housed in the carrier. CONSTITUTION:A carrier 1 comprises a cylindrical container 2 made of synthetic resin and a rotatable piller rod 3 is provided to the aperture surface thereof. The piller surface of piller rod 3 is provided with the tapered portion 9 like the staircase 10 or provided with a V-groove and semiconductor wafers 7 to be processed are placed on such staircase region or in the V-groove 11. The semiconductor wafers 7 housed in the carrier start to the rotate by the piller rod 3 rotated by operation of motor 4, rotation difference is generated due to the difference in diameter between the rods in contact with the tapered portion 9 and thereby the linear portion of semiconductor wafer appears freely.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to an improvement in the method of transporting hand-centered wafers to semiconductor manufacturing equipment.

(Conventional technology) Recently, automation has been promoted in the semiconductor industry as in other technical fields, and on the other hand, as seen in IMD-RAM, there is a trend towards higher integration and higher functionality, and this will be accelerated. This is largely due to the fact that the limits of miniaturization, which is essential for semiconductor manufacturing technology, are becoming smaller and smaller. One of the means for miniaturization is the reactive ion etching method, whose characteristic anisotropic etching is widely applied in place of the conventionally used isotropic etching.

On the other hand, as mentioned above, automation is being promoted in the equipment that makes full use of these semiconductor process technologies and the transportation of semiconductor wafers between the equipment, and the current situation is that both the abandoned method and the batch method are used for the latter. It is. In this batch type, movement by a so-called carrier, which has been used conventionally, is common, and this will be explained with reference to FIGS. 3a and 3b.

As this carrier, as shown in FIG. 3, a cylindrical container 20 made of synthetic resin is prepared, and a rotatable columnar rod 21 is provided on the opening surface of the container, and semiconductor wafers 22 to be processed are attached to this columnar rod 21. Stop. This columnar rod 21 is connected to a motor 23 etc. via a rotating shaft 24, and when securing a semiconductor wafer 22, it is set in the same direction by abutting the orientation flat portion 25 of the semiconductor wafer 22. It is common to use a carrier.

(Problem to be solved by the invention) In this way, orientation flat (
A case will be described in which semiconductor wafers with their straight portions (hereinafter referred to as straight portions) aligned in the same direction are set in manufacturing equipment.

In the above-mentioned RIE apparatus, a cooling water passage is provided on the lower surface of a plate-shaped susceptor that functions as a lower electrode, and the semiconductor wafers to be processed are arranged in a ring shape on the upper surface to perform reactive ion etching.

The semiconductor wafers to be processed are set in this RIE apparatus with their carriers, and the wafers arranged in the same direction are gripped by a robot mechanism and transferred and placed on the susceptor, so that the straight portions are generally aligned.

When reactive ion etching is performed in this state, etching residue is deposited on the surface of the susceptor other than the semiconductor wafer to be processed, and the vicinity of the linear portion also becomes convex.

During the next process, when a semiconductor wafer to be processed is transferred to and placed on this convex susceptor, its straight portion is superimposed on this convex susceptor, creating a temperature gradient within the semiconductor wafer and causing non-uniform etching. This creates difficulties.

Moreover, in order to eliminate this convex condition, the susceptor must be repaired, and it is undeniable that the life of the susceptor will be shortened.

An object of the present invention is to provide a novel semiconductor wafer transport method that eliminates the above-mentioned difficulties.

[Structure of the invention]

(Means for solving the problem) A tapered part is provided on the columnar surface of a rotatable columnar rod that is installed in a conventionally used carrier, and multiple semiconductor wafers having a straight part that is locked in a columnar rod are arranged in a columnar rod. Due to the rotation of the rond, the position of each linear portion within the carrier gradually differs due to the difference in rotation speed caused by the difference in the contacting circumference length. The present invention employs a method in which semiconductor wafers housed in carriers are transferred to necessary manufacturing equipment using such disordered linear portion positions.

(Function) Since each semiconductor wafer transferred to a desired position by such a transfer method has a different linear part position, the susceptor of a reactive ion etching apparatus has a pattern of deposited etching residue that corresponds to the diameter of the semiconductor wafer. Leaving a semicircular shape, the next transferred semiconductor wafer is placed in contact with the surface of this susceptor without tilting, so that no temperature gradient occurs in each semiconductor wafer, and desired etching can be performed.

(Example) The present invention will be explained in detail with reference to FIGS. 1 a, b and 2 a, b, and Q. Although there are some parts that overlap with the conventional technology for convenience, new numbers will be used to explain them.

The present invention will be described by way of example utilizing a reactive ion etching device, in which FIGS. 1a and 1b are cross-sectional views and side views of the carrier structure utilized, and FIGS. 2a and 2b are side views.

C is a sectional view showing the main part thereof. A cylindrical container 2 made of synthetic resin is prepared on this carrier, and a rotatable columnar rod 3 is placed on the opening surface of the container, which is connected to a motor 4 via a rotating shaft 5, and is connected to a bearing (not shown). A mechanism 6 is attached. A plurality of semiconductor wafers 7 to be processed accommodated on this carrier are formed into equal circular shapes, and a straight portion 8 is installed in a part of the circular arc, and this columnar rod 3
There are no restrictions on the position of contact.

A tapered portion 9 is provided on the columnar surface of the columnar rod 3.

As an example, FIGS. 2a and 2b are shown. As shown in 2\, the tapered part 9 includes steps 10 and 10 as shown in a and b.
. . . Or, as shown in C, a groove is provided and a columnar rod with a tapered surface is applied. The semiconductor to be processed is placed on this step portion or groove 11.

The semiconductor wafers 7 to be processed stored in such a carrier begin to rotate by the columnar rods 3 to which rotational force is applied by the operation of the motor 4, and the number of revolutions varies depending on the diameter of the rods in contact with the tapered portions 9. This causes a difference in the positions of the straight portions of the semiconductor wafer, thereby making the straight portion positions of the semiconductor wafer disordered.

This carrier is placed in a reactive ion etching apparatus, and a semiconductor wafer to be processed, which has linear portions arranged in a disorderly manner, is transferred to a susceptor by a robot mechanism, and the linear portions are arranged in different positions in a ring shape.

It should be noted that the V-groove formation described above is designed to prevent the semiconductor wafer from flopping horizontally and to ensure smooth rotation.

〔Effect of the invention〕

In this way, in the method of the present invention, the straight parts of the semiconductor wafer stored in the carrier are disordered, so after setting it in the reactive ion etching device, it is automatically transferred to the susceptor, which is the lower electrode, and the necessary etching cycle is performed. By repeating this process, the position of the straight portion of the transferred semiconductor wafer differs each time, thereby preventing the influence of deposits caused by etching and satisfying the optimum etching conditions.

Further, although overhauling of the susceptor is necessary, the frequency can be reduced compared to the conventional method, which not only prolongs the life of the susceptor but also increases the operating rate of the device.

[Brief explanation of drawings]

Figures 1 a and b are side views of the carrier used in the present invention, C diagrams and cross-sectional views, Figures 2 a and b are cross-sectional views of the main parts thereof, △ Figures 3 a and b are side views and cross-sectional views of conventional carriers. It is. Agent Patent Attorney Inoue - Rikitsutsu 2 Figure

Claims (1)

[Claims] A plurality of semiconductor wafers in which a rotatable columnar rod is arranged on the opening surface of a cylindrical container, and the semiconductor wafers are formed into a substantially circular shape that is engaged with a tapered portion formed on the columnar surface of the columnar rod, and a straight portion is provided on a part of the arc. A method for transporting a semiconductor wafer, characterized in that the rod rotates at different rotation speeds to make the position of the straight line part indefinite, and then transferred to a predetermined position.