KR19990016402A - CMP equipment with sensors to detect wafers - Google Patents

Abstract

The present invention relates to a CMP apparatus having a sensor for detecting a wafer, wherein an optical sensor is mounted on a cleaner between a head cap loading unloading (HCLU) and each platen, thereby providing a wafer on a rubber plate of a head during a polishing process of the CMP apparatus. Can be detected. Therefore, it is possible to prevent the tearing of the rubber sheet generated when the head approaches the platen without polishing and contamination of the pads of each platen, thus improving the life and work efficiency of the CMP equipment. There is an advantage to prevent the economic loss of the replacement of these.

Description

CPM equipment with sensors to detect wafers

The present invention relates to a CMP apparatus having a sensor for detecting a wafer, and more particularly, to tearing of a rubber sheet when the head approaches the platen and polishes while the wafer is not in the rubber plate of the head during the polishing process of the CMP apparatus. And a sensor that can prevent contamination of the pads of each platen.

In recent years, semiconductor devices have become more directly and large in capacity, and accordingly, circuit patterns formed in the active region of the semiconductor chip are becoming more fine. The miniaturization of these circuit patterns is highly dependent on the semiconductor manufacturing process technology. In semiconductors, individual devices are formed on top of a wafer through fabrication (FAB) processes such as oxidation, etching, and diffusion. Since semiconductor devices are repeated many times, the surface of the wafer is uneven surface. Is formed. As a result, such surface asperities deteriorate the characteristics of the semiconductor device. Therefore, the planarization in the semiconductor device constituting the high direct circuit serves as an important element to realize the reliability and high directivity of the circuit.

Representative methods of surface planarization include chemical mechanical polishing (hereinafter referred to as CMP), which is carried out using a slurry polishing solution.

1 is a perspective view of the CMP equipment according to the prior art, Figure 2 is a perspective view of the head of the CMP equipment, Figure 3 is a perspective view of the platen part in the CMP equipment according to the prior art.

1, 2 and 3, the CMP apparatus has four heads 60, which heads 60 are mechanically connected to the drive means 70 and by the drive means 70. You will be taken to each step. Head 60 is composed of a head body 62 and a rubber plate (64), the lower surface of the head 60 is connected to a vacuum pump (not shown) to suck the rubber plate 64 on the upper surface of the head. The diameter of the rubber plate 64 is equal to the diameter of a wafer (not shown), and the wafer is inserted into the rubber plate 64 and vacuum-adsorbed during the process. In the driving means 70, a wafer loss sensor 75 is inclined at an angle toward the head 60. The wafer loss sensor 75 operates when the wafer exits the rubber plate 64 of the head 60 during the polishing process. To stop. In addition, one head cup loading unloading (hereinafter referred to as HCLU) and three platens 10, 20, and 30 (platen) are positioned below the heads 60. The HCLU 40 is mechanically connected to an up-and-down driving device (not shown) to move the wafer transferred from the outside to the rubber plate of the head and to receive the polished wafer from the rubber plate of the head. Pads 12, 22, and 32 are on the top of each platen 10, 20, and 30, and on the bottom are mechanically connected to a rotating device (not shown) so that the platens 10, 20 during the CMP process. , 30) to polish the wafer. At a distance from the platens 10, 20, and 30, supply pipes 15, 25, and 35 supply slurry and deionized water. In the first supply pipe 15 and the second supply pipe 25, The slurry is supplied to each of the platens 10 and 20 to polish the wafer, and the third supply pipe 35 is supplied with deionized water to wash the wafer. The cleaner 50 is located between the HCLU 40 and each platen 10, 20, 30, and passes over the cleaner 50 when the head moves the wafer to each platen, wherein the wafer surface Deionized water is supplied to the wafer to clean the wafer surface.

If water or foreign matter adheres to the back of the wafer, the wafer may not be vacuum-adsorbed to the rubber plate of the head, or even if the vacuum is adsorbed, the wafer may fall from the rubber plate when the head moves. When the polishing of the head approaches each platen while the wafer is not vacuum-adsorbed to the rubber plate of the head, the rubber plate of the head is torn and the pads of the platens become contaminated. Therefore, these rubber plates and pads need to be replaced, which reduces work efficiency. In particular, the rubber plate of the head is expensive, resulting in economic losses.

Accordingly, an object of the present invention is to prevent tearing of the rubber plate and contamination of the pads of each platen when polishing is performed by the head approaching the platen while the wafer is away from the rubber plate of the head during the polishing process of the CMP equipment. It is to provide a CMP equipment that can prevent the work efficiency and economic loss due to replacement.

1 is a perspective view of a CMP equipment according to the prior art,

2 is a head perspective view of the CMP equipment,

Figure 3 is a perspective view of the platen part in the CMP equipment according to the prior art,

4 is a perspective view of the platen part in the CMP equipment according to the present invention.

Explanation of symbols for the main parts of the drawings

10, 110: first platen 20, 120: second platen

30, 130: 3rd platen 40, 140: HCLU (Head Cap Loading Unloading)

50, 150: Cleaner 60: Head

70: drive means 75: wafer loss sensor

155 sensor

In order to achieve the above object, the present invention provides a CMP device characterized in that the optical sensor is mounted on the cleaner between HCLU and each platen to determine whether the wafer is vacuum-adsorbed to the rubber plate of the head. do.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

4 is a perspective view of the platen part in the CMP equipment according to the present invention.

Referring to FIG. 4, the structure according to the present invention is conventional in all structures except that the light sensor 155 is mounted on the cleaner 150 between the HCLU 140 and the platens 110, 120, and 130. Same as CMP equipment according to technology.

The process sequence in the CMP equipment includes the steps of transferring the wafer to the HCLU of the CMP in the cassette tube on which the wafer is mounted, the HCLU moving upward toward the head by the driving means connected to the lower surface of the HCLU, and the rubber plate of the head to the wafer. Vacuum suction the lower surface of the substrate, moving the head to the first platen by driving means mechanically connected to the head, polishing the wafer on the first platen, and driving means mechanically connected to the head. Moving the head to the second platen by means of: polishing the wafer on the second platen; moving the head to the third platen by means of a drive mechanically connected to the head; The wafer is cleaned, the head is moved to the HCLU by driving means mechanically connected to the head, HCL In U, the wafer is transferred to a loading cassette tube and loaded.

If the structure has the same structure as the present invention, it is possible to determine the presence or absence of the wafer in the step of moving the wafer vacuum-adsorbed to the rubber plate of the head to each platen. That is, when there is no wafer in the head, the rubber plate of the head cannot reflect the light emitted from the optical sensor, so that the optical sensor can detect this and stop the polishing operation.

Therefore, according to the structure of the present invention, it is possible to detect the presence or absence of the wafer that is vacuum-adsorbed to the rubber plate of the head, thereby preventing polishing in the absence of the wafer, thereby preventing tearing of the rubber plate and contamination of the pads of each platen. do. Therefore, it is possible to increase the life and work efficiency of the CMP equipment, there is an advantage that can prevent the economic loss due to the replacement of parts.

Claims (2)

A plurality of heads having a rubber plate on the upper surface and vacuum-adsorbing the wafer to the rubber plate portion; Drive means mechanically connected to the head to move the head to a next step; A wafer loss sensor that is mechanically connected to the drive means and is inclined at an angle toward the head to detect that the wafer exits the rubber plate of the head during a polishing process; An HCLU under the head, for loading and unloading a wafer onto a rubber plate of the head; A plurality of platens under the head, having pads on an upper surface thereof, and having a pad on a lower surface thereof, the platens being mechanically connected to a rotating device to polish a wafer; A supply pipe for supplying slurry and deionized water at a distance away from each of the platens; A plurality of cleaners, positioned between the HCLU and each platen, for cleaning the wafer by supplying deionized water when the head moves the wafer to the next step; CMP equipment having a sensor for detecting a wafer, characterized in that it has a sensor that is mounted to the cleaner, the head can detect the presence of a vacuum sucked on the head. The CMP apparatus of claim 1, wherein the sensor is an optical sensor.