Polishing device of semiconductor wafer

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an apparatus for polishing a semiconductor wafer in the process of producing a semiconductor apparatus.

【0002】

[Conventional technology]

With the recent increase in the integration of semiconductor devices and the miniaturization of devices, the number of layers of wiring is being increased. Due to the miniaturization of this element and the multi-layered wiring, the depth of focus cannot be obtained during exposure during photolithography due to the element pattern, interlayer insulating film, and steps caused by the wiring pattern, resulting in poor resolution and wiring short circuit or disconnection. Such problems are likely to occur. Therefore, for the purpose of preventing the occurrence of this defect, a method of removing and flattening the unevenness on the semiconductor substrate generated in the lamination process by polishing in order to reduce the step is attracting attention. As a polishing device for performing this polishing, there are a single-head type polishing device for polishing one wafer at a time with one polishing head and a multi-head type polishing device for polishing a plurality of wafers at the same time with a plurality of heads.

【0003】

[Problems to be Solved by the Invention]

However, although the single-head type polishing apparatus is excellent in reproducibility and uniformity of polishing in and between wafer surfaces, there is a problem that the throughput is low. Further, although the multi-head type polishing apparatus can process a plurality of wafers at the same time, the throughput is high, but since each head is fixed, the polishing table is unevenly worn, and the inside and between the wafer surfaces are uneven. There was a problem that the reproducibility and uniformity of the wafer were poor.

【0004】

In view of such problems of the prior art, a main object of the present invention is to provide a polishing apparatus capable of polishing a semiconductor wafer with high throughput and good reproducibility and uniformity.

【0005】

[Means for solving problems]

According to the present invention, the above-mentioned object is a plurality of heads each holding a semiconductor wafer, a plurality of arms capable of moving the heads so as to change at least their radial positions on a rotating polishing table, and the above-mentioned purpose. This is achieved by providing a semiconductor wafer polishing apparatus, which comprises means for driving and controlling the arms so as not to interfere with each other.

【0006】

BEST MODE FOR CARRYING OUT THE INVENTION

A plurality of heads, each holding a semiconductor wafer, are held in each arm, and each head is polished while swinging or sliding, for example, so that its radial position changes at least on the polishing table so that the arms do not interfere with each other. By doing so, the semiconductor wafers held by the heads can be uniformly slided against the polished surface of the polishing table, and many semiconductor wafers can be polished at one time.

【0007】

[Example]

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

【0008】

FIG. 1 is a schematic plan view showing a schematic configuration of a semiconductor wafer polishing apparatus based on the present invention. This polishing device holds a polishing table 1 that rotates as shown by an arrow in the figure and a semiconductor wafer (not shown) having an uneven surface, and four polishing heads that can rotate this as shown by an arrow in the figure. 2, the arm 3 that supports these polishing heads 2 at the free end, the actuator 4 provided at the base end of the arm 3 so as to swing as shown by the arrow in the figure, and the actuator 4 are driven and controlled. It has a control unit 5.

【0009】

To actually polish the surface of the semiconductor wafer, first, the semiconductor wafer is held on the polishing head 2, and the polishing table 1 is rotated at a speed of 10 to 250 rpm while dropping a polishing liquid (not shown) onto the surface of the polishing table 1. Also, each polishing head 2 is also rotated at a speed of 10 to 250 rpm. Next, the semiconductor wafer held by each polishing head 2 is brought into sliding contact with the surface of the polishing table 1. At this time, the pressure applied to each polishing head 2 is 0 to 1 kgf / cm.²Adjust to. Then, the four arms 3 are swung, and each semiconductor wafer is evenly slidably contacted with the surface of the polishing table 1 for polishing.

【0010】

By doing so, the wear of the polishing table 1 can be made uniform, and the uniformity in the wafer surface and between the surfaces is as good as about 6%. In addition, the throughput was four times higher than that when the single-head type polishing device was used.

【0011】

In this embodiment, the number of arms is set to 4, but the number is not limited to this, and it goes without saying that an appropriate number may be set as long as they do not interfere with each other.

【0012】

[Effect of the invention]

As is clear from the above description, according to the semiconductor wafer polishing apparatus according to the present invention, a plurality of heads each holding the semiconductor wafer are held by the arms, and each head is polished so that the arms do not interfere with each other. By polishing while swinging or sliding, for example, so that the position in the radial direction changes at least on the table, the semiconductor wafer held by each head is uniformly slided against the polished surface of the polishing table, and many at once. Since the semiconductor wafer can be polished, it is possible to polish the semiconductor wafer with high throughput and good reproducibility and uniformity.

[Simple explanation of drawings]

[Figure 1]

The schematic plan view which shows the schematic structure of the polishing apparatus of a semiconductor wafer based on this invention.

[Explanation of symbols]

1 Polishing table 2 Polishing head 3 arm 4 actuator 5 Control unit