KR19980065733A - Abrasive mixing vessels for chemical mechanical polishing (CMP) devices - Google Patents

Abstract

The present invention discloses an abrasive mixing vessel of a chemical mechanical polishing (CMP) apparatus. It is a first liquid bath; A second liquid tank in the first liquid tank; Filtration means for filtering the mixed liquid in the first liquid tank from the surface of the second liquid tank and permeating the second liquid tank; First pumping means for selecting one of an abrasive and deionized water to pump the first liquid tank; Gas injection means for injecting nitrogen gas into the first and second liquid tanks; Second pumping means for circulating the mixed liquid in the second liquid tank to the first liquid tank through the outside of the first liquid tank; And opening and closing means for discharging the mixed liquid in the second liquid tank to the outside of the first liquid tank. In other words, by using a double liquid bath impregnated with a filtration means and circulating the abrasive, it is possible to prevent the formation of fine particles of the abrasive, and as a result, it is possible to proceed a stable process that does not cause defects in the wafer during the CMP process.

Description

Abrasive mixing vessels for chemical mechanical polishing (CMP) devices

TECHNICAL FIELD This invention relates to the manufacturing apparatus of a semiconductor element. Specifically, It is related with the abrasive mixing container of a chemical mechanical polishing (CMP) apparatus.

A CMP (chemical mechanical polishing) apparatus is a device for smoothing a film surface by removing film-like irregularities formed on a wafer. A polishing pad, a slurry, a pad conditioner, and the like are provided.

1 shows an abrasive mixing vessel of a conventional chemical mechanical polishing apparatus.

In the drawings, reference numerals 1 and 2 denote bottles containing abrasive, that is, abrasive supply means, 3 denotes a liquid tank, and 4 to 9 denote opening and closing means, respectively.

The liquid tank 3 is a mixing vessel for mixing the abrasive and deionized water (DI Water) in a 1: 1 ratio.

Deionized water is introduced into the liquid tank 3 using the abrasive of the abrasive supply means 1, 2 and the opening and closing means 7 by using the opening and closing means 4, 5, 6, and nitrogen gas Into the liquid bath (3).

When the abrasive and deionized water are mixed by bubbling the nitrogen gas, it is discharged to proceed with the CMP process using the opening and closing means 8.

The abrasive mixing container such as the liquid tank 3 may merely serve to mix the abrasive and deionized water, and in the liquid tank 3, fine particles are generated due to agglomeration between the abrasives and settle at the bottom of the liquid tank 3. As a result, there is a problem in that the liquid tank 3 needs to be cleaned. In addition, when the abrasive, in which the fine particles remain, is used in the CMP process, defects are caused in the wafer.

An object of the present invention is to provide an abrasive mixing vessel of a chemical mechanical polishing (CMP) device for preventing the formation of fine particles of the abrasive.

1 shows an abrasive mixing vessel of a conventional chemical mechanical polishing apparatus.

Figure 2 shows an abrasive mixing vessel of the chemical mechanical polishing apparatus according to the present invention.

The present invention to achieve the above object, the first liquid tank; A second liquid tank in the first liquid tank; Filtration means for filtering the mixed liquid in the first liquid tank from the surface of the second liquid tank and permeating the second liquid tank; First pumping means for selecting one of an abrasive and deionized water to pump the first liquid tank; Gas injection means for injecting nitrogen gas into the first and second liquid tanks; Second pumping means for circulating the mixed liquid in the second liquid tank to the first liquid tank through the outside of the first liquid tank; And opening and closing means for discharging the mixed liquid in the second liquid tank to the outside of the first liquid tank.

Therefore, the abrasive mixing container of the chemical mechanical polishing (CMP) apparatus according to the present invention can prevent the formation of fine particles of the abrasive by using a double liquid tank impregnated with filtration means and circulating the abrasive, resulting in defects in the wafer during the CMP process. The advantage is that it can proceed with a stable process that does not occur.

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

Figure 2 shows an abrasive mixing vessel of the chemical mechanical polishing apparatus according to the present invention.

Reference numeral 21 占 22 denotes a bottle containing abrasive, i.e., abrasive supply means, 23 a first liquid tank, 24 a second liquid tank, 25 a first pumping means, 26 a second pumping means. , 27 · 28 · 29 denote sensors, 30 denote filtering means, and 31 to 39 denote opening and closing means, respectively.

The abrasive mixing vessel is composed of a double liquid tank having a second liquid tank 24 in the first liquid tank 23.

The abrasive supply means 31 using the first pumping means 25 in a state in which one of the opening and closing means 31 and 32 and the opening and closing means 33 are turned on and the opening and closing means 34 is turned off. , 32) of abrasive is supplied to the first liquid tank 23.

When the sensor 27 of the first liquid tank 23 is turned ON, the abrasive is stopped and the opening and closing means 35 is turned ON to inject the nitrogen gas into the first liquid tank 23. Bubbling

When the supply of the abrasive is stopped as described above, the opening and closing means 34 is turned on and the first pumping means 25 supplies deionized water (DI Water) to the first liquid tank 23. Proceed until 28) is ON.

In the liquid tank 23, the abrasive and deionized water are mixed in a 1: 1 ratio, and the abrasive mixture is filtered through a filter paper attached to the surface of the second liquid tank 24. Seeps into the bath 24.

The material of the second liquid tank 24 is Teflon, and the sensors 27, 28, and 29 are detection means for constantly adjusting the flow rate supplied to the first liquid tank 23.

The second pumping means 26 circulates the abrasive mixed liquid in the second liquid tank 24 to the first liquid tank 23 through a circulation line connected to the outside of the first liquid tank 23.

Thus, the abrasive is circulated through the circulation line provided with the opening and closing means 37 and 38 to the first liquid tank 23, the filtering means 30, and the second liquid tank 24, thereby polishing the abrasive mixture. Generation of fine particles due to coagulation of the liver can be prevented.

In this state, in order to use the abrasive mixture in the CMP process, the second opening is turned off and the opening and closing means 39 is turned on, and the second opening and closing means is turned on. The abrasive mixture liquid in the liquid tank 24 is discharged.

As described above, since the fine particles do not occur in the abrasive mixture, the problem of having to periodically clean the liquid tank due to the fine particles deposited on the bottom of the liquid tank may be solved.

The present invention is not limited to this, and it is apparent that many modifications are possible by those skilled in the art within the technical idea of the present invention.

As described above, the abrasive mixing vessel of the chemical mechanical polishing (CMP) apparatus according to the present invention can prevent the formation of fine particles of the abrasive by using a double liquid tank to which the filtration means is impregnated and circulating the abrasive, and as a result, in the CMP process The advantage is that a stable process can be performed in which no defect occurs in the wafer.

Claims (1)

First liquid bath; A second liquid tank in the first liquid tank; Filtration means for filtering the mixed liquid in the first liquid tank from the surface of the second liquid tank and permeating the second liquid tank; First pumping means for selecting one of an abrasive and deionized water to pump the first liquid tank; Gas injection means for injecting nitrogen gas into the first and second liquid tanks; Second pumping means for circulating the mixed liquid in the second liquid tank to the first liquid tank through the outside of the first liquid tank; And opening / closing means for discharging the mixed liquid in the second liquid tank to the outside of the first liquid tank.