KR20000027513A - Chemical mechanical polishing device - Google Patents

Abstract

PURPOSE: A chemical mechanical polishing device is provided to prevent the scratch of the surface of film and to obtain uniform slurry by arranging the vibrator and the ultra sonic generator inside the polishing unit and at the lower part of the slurry drum. CONSTITUTION: A device comprises a slurry drum(20), an ultra sonic generator(21a, 23a), an ultra sonic vibrator(21b, 23b), a slurry controlling unit(22), a polishing table(24), a moving tube(25), and a buffing table(26). The polishing unit(30) includes the slurry controlling unit(22) which selectively receives or blocks the slurry when there is slurry providing signal, the polishing table(24) in which the polishing is carried out by the provided slurry and the buffing table(26). The slurry control part includes the pump and the valve. The ultra sonic generator(23a) and the ultra sonic vibrator(23b) is located between the polishing table and the slurry controlling unit.

Description

Chemical mechanical polishing machine

The present invention relates to a chemical mechanical polishing apparatus, and more particularly, to a chemical mechanical polishing apparatus capable of reducing defects caused by an abrasive.

In addition to the advances in semiconductor technology, high speed and high integration of semiconductor devices is progressing, and along with this, the necessity of miniaturization of patterns is increasing, and the size of patterns is also required to be highly accurate. This also applies to device isolation regions that occupy a wide area in semiconductor devices.

LOCOS device isolation films are mostly used for device isolation of current semiconductor devices. This LOCOS device isolation film is obtained by selectively localizing a substrate.

However, the LOCOS isolation layer has a disadvantage in that a bird-shaped bird's beak is generated at an edge thereof, thereby generating a leakage current while expanding the area of the isolation layer.

Therefore, conventionally, a device isolation film of a shallow trench isolation (STI) method having a narrow width and excellent device isolation characteristics has been proposed.

As shown in FIG. 1, the STI device isolation film forms an anti-oxidation pattern (not shown), for example, a silicon nitride film pattern so that the device isolation region is exposed on the semiconductor substrate 1. In this case, the device isolation region may be between the device and the device, or may be a region between the wells. At this time, the device isolation region between the wells occupies a larger area than the device isolation region between the device and the device.

Thereafter, the exposed semiconductor substrate 1 is etched by a predetermined depth to form a trench. Subsequently, an oxide film is deposited to sufficiently fill the inside of the trench, and then a chemical mechanical polishing (CMP) process is performed to expose the surface of the nitride film (oxidation prevention pattern) to form an STI type device isolation film 2. Thereafter, the antioxidant pattern is removed in a known manner.

However, the method of forming the STI device isolation layer using the CMP method as described above has the following problems.

As a slurry used in the CMP process, a corundum slurry having a polishing selectivity of oxide film and nitride film of 1 to 30 is used. However, the corundum slurry 11 is large and uneven in particle, causing scratches on the nitride film 10 as shown in FIG. This lowers the polishing reliability.

Accordingly, an object of the present invention is to solve the above-mentioned conventional problems, and to provide a chemical mechanical polishing apparatus capable of reducing the damage on the surface of a film by making a slurry uniform during the CMP process. .

1 is a cross-sectional view showing a conventional STI device isolation film.

2 is a view showing damage caused to the nitride film when formed by a conventional polishing method.

Figure 3 schematically shows a chemical mechanical polishing apparatus according to the present invention.

(Explanation of symbols for the main parts of the drawing)

20-slurry drum 21a, 23a: ultrasonic generator

21b, 23b-ultrasonic vibrator 22-slurry generator

24-Polishing Table 25-Moving Tube

26-buffing table

In order to achieve the above object of the present invention, according to an embodiment of the present invention, the present invention is a chemical mechanical polishing apparatus including a slurry drum containing a slurry, and a polishing progressing portion that the actual polishing proceeds by the slurry The ultrasonic drum and the ultrasonic vibrator for grinding the slurry into a uniform size are disposed in the slurry drum lower portion and the polishing progress portion, respectively.

In addition, the polishing progress unit includes a slurry adjusting unit for selectively supplying or blocking the slurry, and a polishing table receiving the slurry from the slurry adjusting unit and performing polishing.

Here, the ultrasonic generator and the ultrasonic vibrator in the polishing progressing portion is disposed between the slurry adjusting portion and the polishing table.

According to the present invention, an ultrasonic generator and a vibrator are installed in the lower portion of the slurry drum and the polishing progression of the chemical mechanical polishing apparatus, and the slurry is ground to a fine size. Accordingly, scratches are not generated on the polished surface during polishing.

(Example)

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

3 is a view schematically showing a polishing apparatus of a semiconductor device according to the present invention.

Referring to FIG. 3, the chemical mechanical polishing apparatus according to the present invention includes a slurry drum 20 in which a slurry is contained, a polishing progress portion 30 and a slurry drum 20 under which polishing is actually performed by the slurry. The first and second ultrasonic generators 21a and 23a and the ultrasonic vibrators 21b and 23b respectively disposed in the moving part 30 and crushing the slurry to a uniform size are included.

Here, the polishing progress unit 30 is supplied through the slurry control unit 22 and the slurry control unit 22 to selectively supply or block the slurry when a slurry supply signal is applied from the polishing progress unit 30. And a buffing table (26) and a buffing table (26) in which polishing is advanced by the prepared slurry.

At this time, the slurry control unit 22 is composed of several valves and pumps.

In addition, the ultrasonic generator 23a and the ultrasonic vibrator 23b in the polishing progressing section 30 are disposed between the slurry adjusting section 22 and the polishing table 24, and preferably, the slurry is moved to the polishing table 24. The slurry is disposed on a moving tube 25 to secondaryly grind the slurry.

The chemical mechanical polishing apparatus having such a configuration operates as follows.

First, the first ultrasonic generator 21a is operated to pulverize the slurry contained in the slurry drum 20. Then, the first ultrasonic vibrator 21b vibrates by the first ultrasonic generator 21a, and the slurry is primarily pulverized in the slurry drum 20. In this case, the first ultrasonic generator 21a may selectively change the frequency according to the size of the slurry, and may not operate the first ultrasonic generator 21a according to the type of slurry.

Subsequently, when a feed signal is applied from the polishing progress unit 30, the slurry primarily ground in the slurry drum 20 reaches the polishing table 24 via the slurry adjusting unit 22. At this time, before the slurry is sprayed on the polishing table 24, the second ultrasonic generator 23a and the second ultrasonic vibrator 23b are operated to pulverize secondarily.

Accordingly, the slurry sprayed on the polishing table 24 is crushed twice by the first and second ultrasonic generators and the vibrators 21a, 23a, 21b, and 23b, so that there is almost no agglomerated portion. Thus, the wafer surface (wafer result surface) mounted on the polishing table can be polished evenly without scratching.

As described in detail above, according to the present invention, an ultrasonic generator and a vibrator are installed in the lower portion of the slurry drum and the polishing progression portion of the chemical mechanical polishing apparatus, and the slurry is ground to a fine size. Accordingly, scratches are not generated on the polished surface during polishing.

Therefore, polishing reliability is improved.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (3)

A chemical mechanical polishing apparatus comprising a slurry drum in which a slurry is contained, and a polishing progressing portion in which actual polishing is performed by the slurry, And a ultrasonic generator and an ultrasonic vibrator for crushing the slurry to a uniform size in the slurry drum lower portion and the polishing progress portion, respectively. The chemical mechanical polishing apparatus according to claim 1, wherein the polishing progress unit comprises a slurry adjusting unit for selectively supplying or blocking the slurry, and a polishing table supplied with the slurry from the slurry adjusting unit to perform polishing. . 3. The chemical mechanical polishing apparatus according to claim 1 or 2, wherein the ultrasonic generator and the ultrasonic vibrator in the polishing progressing portion are disposed between the slurry adjusting portion and the polishing table.