KR20010107057A - Cmp for lager diameter of silicon wafer and method using the cmp machine - Google Patents

Abstract

A large-diameter chemical mechanical polishing apparatus, which is fixed to a table using a vacuum so that the surface to be polished of the semiconductor wafer faces upward, attaches a polishing cloth called a pad used for polishing to the spindle, and a portion of the semiconductor wafer surface when the spindle is lowered. In contact with the surface, the wafer is rotated and the spindle rotates to uniformly polish the entire surface of the semiconductor wafer. At this time, the semiconductor wafer is moved back and forth according to the program so that the polishing pad (Pad) is in contact with the center of the semiconductor wafer to facilitate the polishing of the center portion. The slurry, which is a polishing liquid, is evenly spread on the polishing surface of the semiconductor wafer by the supply device inside the spindle, and the uniform polishing can be always performed by supplying new abrasive particles.

Description

Large diameter chemical mechanical polishing device and chemical mechanical polishing method using the same {CMP FOR LAGER DIAMETER OF SILICON WAFER AND METHOD USING THE CMP MACHINE}

The present invention relates to the manufacture of equipment for performing a planarization operation through chemical mechanical polishing of the semiconductor surface, and more particularly, by spraying a polishing solution called a slurry of a mixture of abrasive particles and chemicals on the surface of the semiconductor wafer, The present invention relates to an apparatus for uniformly grinding a wafer surface by contacting the abrasion with the wafer surface and then applying a pressure to rotate the wafer. In general, a chemical mechanical polishing (CMP) apparatus attaches a semiconductor wafer to a table on which a surface of a semiconductor wafer is faced downward after mounting a wafer holder called a carrier on a spindle, and then contacting the table with the polishing cloth for polishing. The surface of the semiconductor wafer is polished by spraying, rotating the table and the spindle, and applying pressure to the spindle. In the conventional polishing apparatus, as the diameter of the semiconductor wafer increases, the size of the table must increase accordingly, and the polishing liquid is not sprayed directly onto the surface of the semiconductor wafer, but the polishing liquid is applied to the table, causing a loss of polishing liquid. Mixing of the polishing liquid that is not used may result in lowering of the polishing ability, dissipation of heat generated during polishing, resulting in uneven polishing of the surface of the semiconductor wafer. In addition, various pressures must be applied to the carrier of the semiconductor wafer holder for uniform polishing of the surface of the semiconductor wafer. Therefore, the mechanical structure must be complicated and the diameter must be large, thereby increasing the size of the polishing apparatus.

The present invention, unlike the conventional chemical mechanical devices to solve the above problems, by fixing the semiconductor wafer surface to the table facing up to perform the polishing process, while simplifying the equipment required for the equipment, while reducing the size of the equipment It is an object of the present invention to effectively perform the planarization operation of the semiconductor wafer surface.

In order to achieve the above object, the present invention removes a carrier, which is a semiconductor wafer holder of a complicated structure used in a conventional chemical mechanical polishing apparatus, by fixing the semiconductor wafer surface upward using a vacuum to fix the table. A special polishing liquid supply device is designed to spray new abrasives on the surface all the time, and the polishing cloth is designed to come into contact with a part of the surface of the semiconductor wafer to increase the lifespan of the pad, which is the polishing cloth, and to quickly release heat generated during polishing and process characteristics. It is easy to install the attached device (end point detector), which has its characteristics. In addition, the twin table is equipped to process two semiconductor wafers per table module at the same time so that the semiconductor wafer processing capability is significantly higher than the existing devices. In order to proceed, each table module is rotated by 90 degrees at the same time, and finally designed to return to the origin after rotating 360 degrees. The table module is also designed to be equipped with four.

1 is a side view of a table and a spindle

2 is a front view of a semiconductor wafer in contact with a polishing cloth;

3 is a side view of the spindle and a front view of the spindle head;

4 is a front view of the table module;

Explanation of symbols for the main parts of the drawing:

1: Spindle 2: Spindle Head

3: polishing cloth 4: semiconductor wafer

5: semiconductor wafer fixture 5a: polishing liquid removal hole

6: semiconductor wafer cushion 7: vacuum hole

8: table 9: polishing cloth conditioner

DESCRIPTION OF SYMBOLS 10 Slurry supply apparatus which is an abrasive 10a: Slurry droplet which is an abrasive 10b: Slurry supply hole which is an abrasive

11: ultrapure water supply device 11a: ultrapure water drops

12: rubber knife 13: table module

14: twin table

Hereinafter, described in detail by the accompanying drawings as follows.

Figure 1 is attached by using a vacuum to the table as a side view of the table and the spindle necessary for polishing a semiconductor wafer, the surface of the semiconductor wafer side up. At this time, if the vacuum is used, the shape of the back surface of the semiconductor wafer is deformed by the vacuum, which affects the front surface of the semiconductor wafer when the vacuum is released after polishing, thereby lowering the flatness. Do not affect the degree. Attaching the semiconductor wafer to the table eliminates the need for a carrier, which is a complex wafer holder that requires existing devices, thus simplifying the structure and reducing the size of the equipment. In addition, the abrasive polishing cloth attached to the spindle can increase the life of the polishing cloth due to polishing by contacting a part of the area of the front surface of the semiconductor wafer, and can easily remove heat generated during polishing to cause the spindle head to be caused by the polishing heat. Excellent flatness can be obtained by preventing the minute deformation of the device, and the end point detector, which is a secondary device, can be equipped with a simple structure.

FIG. 2 is a front view in which the semiconductor wafer and the polishing pad are in contact with each other so that the used abrasive remaining on the surface of the semiconductor wafer can be easily removed through holes provided in the surface of the semiconductor wafer fixture. In addition, since the semiconductor wafer fixture can be equipped with a fixture having a suitable shape according to the shape of the semiconductor wafer (knitted wafer, flat wafer), the flatness of the semiconductor wafer edge side can be improved.

FIG. 3 is a side view of the spindle and a front view of the spindle head. When polishing the surface of the semiconductor wafer, flatness can be improved through smooth and balanced supply of slurry and ultrapure water, which are abrasives.

The abrasive slurry and ultrapure water are supplied to different parts by a rubber knife mounted inside the spindle. The slurry, which is an abrasive, is supplied to the surface of the semiconductor wafer through the holes drilled in the spindle head and the polishing cloth. The abrasive, which was not supplied due to the rotational movement of the spindle head, is recovered by an internally mounted rubber knife. In addition, the ultrapure water supply device installed on the opposite side of the abrasive supply position supplies ultrapure water for post-polishing cleaning and cleans the inside of the spindle head with the abrasive, so that unnecessary abrasives can be discharged out of the table through holes in the spindle head and pads. Configured. In addition, the polishing heat generated during the polishing process may deform the spindle head finely, leading to a decrease in flatness. Therefore, in order to solve this problem, the ultrapure water is supplied only to the spindle during the polishing process, and thus the fine deformation of the spindle can be prevented by removing the heat of polishing, thereby obtaining excellent flatness of the semiconductor wafer.

FIG. 4 is a front view of the table module, which has two work tables for each table module to increase workability, and each table module rotates by 90 degrees for the next process after the work is completed. Designed to return to its original position through degree rotation. This minimizes the robotic arm required to move the semiconductor wafer under work, increasing the efficiency of the equipment and reducing its size.

As described above, according to the present invention, by mounting the semiconductor wafer face upward, the present invention can simply design the structure of the chemical mechanical polishing equipment and process a large diameter semiconductor wafer to the size of the existing equipment, The effective supply of (Pad) and slurry, which is an abrasive, can reduce these raw materials and improve polishing flatness.

Claims (8)

Polishing liquid supply device for uniformly supplying the polishing liquid to the front surface of the semiconductor wafer through the hole drilled in the polishing cloth, A semiconductor wafer to be polished, Abrasive pads, Drive device (spindle) of spindle head with abrasive cloth, A vacuum pump for holding a vacuum, which is a means for fixing a semiconductor wafer to be polished to a table, which is a polishing workbench, Twin table, which is a workbench for grinding work, A fixing part for fixing the semiconductor wafer to prevent polishing non-uniformity of the flat zone of the semiconductor wafer to be polished; A chemical mechanical polishing apparatus comprising a buffer layer for reducing the influence of warpage of a semiconductor wafer to be polished. The chemical mechanical polishing apparatus according to claim 1, wherein the polishing liquid supplying device divides the polishing semiconductor wafer spindle head into two parts to supply polishing liquid and ultrapure water. 3. The chemical mechanical polishing apparatus of claim 2, wherein the polishing liquid supply device further comprises a rubber knife necessary to maintain the functions of the polishing liquid and the ultrapure water, and to minimize internal cleanliness and usage of the polishing liquid. . The chemical mechanical polishing apparatus according to claim 1, wherein the twin table is characterized by a dual operation for simultaneously progressing two polishing objects, and further comprising a rotating unit capable of moving 90 degrees to the next process after the operation. A first step of fixing the semiconductor wafer to be polished by vacuum using the chemical mechanical polishing apparatus of claim 1, A second step in which the polishing cloth is placed on the semiconductor wafer to be polished, A third step of simultaneously supplying the polishing liquid and the ultrapure water by the polishing liquid supplying device, And a fourth step of driving the driving device to polish the semiconductor wafer to be polished. 6. The chemical mechanical polishing method according to claim 5, wherein the first step is characterized by simplifying the process by eliminating the need for a carrier, which is a holder of the semiconductor wafer to be polished. 6. The chemical mechanical polishing method according to claim 5, wherein the third step is characterized by optimizing the effect of using the polishing liquid and ultrapure water using a rubber knife. The method of claim 5, wherein the fourth step is capable of simultaneously polishing two polishing objects using a twin table, and partially polishing the semiconductor wafer to be polished to quickly release the heat of polishing generated during polishing. Chemical mechanical polishing method comprising the step of having.