KR980012026A - Cleaning apparatus for polishing after polishing and cleaning method using same - Google Patents

Abstract

A new cleaning apparatus for a post-polishing process and a cleaning method using the same are disclosed. The CMP equipment and the cleaning equipment are integrated so that the wet dipping type cleaning process can be carried out by transferring the wafers which have been subjected to the chemical mechanical polishing (CMP) process to the carriers stored in the water. It is possible to prevent the wafer from being dried by carrying out the cleaning process by transporting the wafer in water after the CMP process. A cleaning process is performed using a wet dipping method that can obtain a uniform cleaning effect more than a scrubbing cleaning method and a strong cleaning power can be secured by using a chemical solution capable of sufficiently removing metal contamination and slurry residues.

Description

Cleaning apparatus for polishing after polishing and cleaning method using same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus used in a cleaning process after a polishing process, and a cleaning method using the same. More particularly, the present invention relates to a cleaning apparatus and a cleaning method using the same in a cleaning process after a chemical-mechanical polishing (CMP) The present invention relates to a cleaning device for integrating a CMP equipment and a cleaning equipment so that a wafer can be transported underwater while preventing the migration of fine particles and contaminants by a subsequent process using a chemical solution capable of sufficiently removing the slurry residue, and a cleaning method using the same will be.

As the degree of integration of a device increases, a multilayer wiring process is put to practical use, and a global planarization technique for a material layer on a wafer is required in order to secure a margin of a photolithography process and minimize a wiring length. Currently, BPSG Boro-Phospho-Silicate Glass (Reflow), Al flow, SOG (Spin On Glass) etch back, CMP process, etc. have been used for planarizing the underlying film .

In particular, the CMP process is emerging as a promising planarization technology in next-generation devices because of its advantage of achieving global planarization as a low-temperature process, unlike the reflow process or the etch-back process.

A CMP process is a method of chemically-mechanically polishing the surface of a wafer by chemical components in a slurry solution, mechanical components of a polishing pad and an abrasive, thereby performing planarization. The slurry solution contains H ₂ O ₂ , KIO ₃ and various acids or bases for pH control. Since the main component of the abrasive is Al ₂ O ₃ , silica, etc., not only contaminants such as metal ions and abrasive particles are adsorbed in the polishing process, Sometimes a layer of wear occurs. In order to remove the contaminant layer containing the heavy metal contaminating particles and the damaged film, a cleaning process after the CMP process is indispensably required.

In a typical CMP post-treatment cleaning process, a spin scrubber process is performed as a first cleaning process and a wet cleaning process is performed as a second cleaning process. In this case, pure water (D.I water) is usually used in the spin scrubber process or purified water containing a surface active agent is used for effective removal of contaminants. In the wet cleaning process, a hydrofluoric acid (HF) solution is usually used. The spin scrubber cleaning is a method of scrubbing a surface of a wafer in which a large amount of slurry residues remain. In the wet cleaning process, the semiconductor device is immersed in a cleaning bath containing a wet cleaning solution after the CMP process to etch and remove a contaminant layer and damaged layer.

The following points must be considered in the cleaning process after the CMP described above.

(1) The wafer should not be dried until the end of cleaning. When the wafer is dried, it is difficult to remove contaminants, and there is a risk that contaminants may be transferred to another process. Therefore, it is inevitable to carry the wafer in water. Therefore, there is a need for a separate CMP post-treatment cleaning equipment using a dipping method in addition to the supply of a chemical solution separately from a conventional scrubber device. On the other hand, in the scrubber apparatus for supplying a chemical solution, it is important to select a chemical solution. Currently, NH ₄ OH is used and a method using phosphoric acid and fluoroboric acid (HBF ₄ ) Method of cleaning a device after CMP ". In the present invention, a new CMP post-treatment cleaning device using a dipping method is devised.

(2) The ability to remove contaminants, including slurry residues (such as alkali metal ions), contaminants, and heavy metal particles, should be excellent. In the present invention, by using the chemical solution (cleaning solution containing phosphoric acid and fluoroboric acid) described in "cleaning solution for polishing after polishing process and cleaning method using the same " .

(3) The CMP post-treatment cleaning device shall be dedicated to prevent the migration of particulates and contaminants to other processes to be performed after the CMP process.

Therefore, an object of the present invention is to provide a CMP apparatus and a cleaning apparatus capable of carrying a wafer underwater while preventing the migration of fine particles and contaminants in a subsequent process by using a chemical solution capable of sufficiently removing metal contamination and slurry residues, And a cleaning device for cleaning the polishing surface.

Another object of the present invention is to provide a cleaning method for a post-polishing process using the above-described cleaning apparatus.

FIG. 1 is a cross-sectional view showing the structure of a cleaning apparatus after a polishing process according to the present invention. FIG.

FIG. 2 is a cross-sectional view showing a quantitative bath to which a cleaning solution for polishing after the polishing process according to the present invention is supplied; FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

1: CMP equipment 2: Carrier

3: Robot arm 4:

5: Slurry piping 6: Level sensor

8: vacuum ground 9: vacuum chuck

10: Sliding part 11: Carrier dip bath

In order to accomplish the above object, the present invention provides a polishing apparatus for polishing a wafer, comprising a CMP apparatus and a cleaning apparatus integrally formed so as to carry wafers having undergone the CMP process to a carrier stored in water, And a cleaning device for cleaning the substrate.

The carrier is always dipped in a DI bath except when carrying a wafer.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: transporting all wafers having undergone a CMP process to a carrier that is stored in water; And moving the carrier vertically and then transferring the carrier to a cleaning bath to perform a cleaning process by a wet dipping method.

The step of transferring all the wafers having completed the CMP process to the carrier includes a first step of placing the wafer on which the CMP process has been completed on the vacuum ground; A second step of transporting the wafer with the carrier dipped in the pure water tank up; And the third step in which the carrier again enters the normal pure water bath.

The cleaning process of the dipping method uses a cleaning solution containing phosphoric acid and fluoroboric acid.

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

1 is a cross-sectional view showing the structure of a cleaning apparatus for a post-polishing process according to the present invention.

Referring to FIG. 1, when the CMP equipment 1 is placed on the vacuum ground 8, the carrier dip bath 11, that is, the carrier 2 which has been dipped in the pure water, And is conveyed to the carrier 2. The carrier 2 then enters the carrier dip bath 11 again and waits for the next CMP process to complete the wafer. The carrier is always dipped in the pure water bath 11, except when carrying the wafer. When all the wafers having been subjected to the CMP process are transferred to the carrier 2 by repeating the above-described steps, the carrier 2 is vertically erected and transferred to the cleaning bath by the robot arm 3. When the carrier is transferred as described above, the cleaning process proceeds by a wet dipping method using a chemical solution containing phosphoric acid and fluoroboric acid which can sufficiently remove metal contamination and slurry residues. Here, reference numeral 9 denotes a vacuum chuck, and 10 denotes a sliding portion.

As a result of the test, the chemical solution containing phosphoric acid and fluoroboric acid used in the present invention showed a remarkably excellent result in terms of removing metal contamination with metal contamination of 10 ¹⁰ atom / cm 2 or less. The fluorinated boronic acid component not only cleans the contaminant layer but also effectively removes the damaged film while suppressing the corrosion of the barrier metal layer to the greatest extent. The phosphoric acid component can be removed by excessive etching, which may be caused by boron fluoride acid And combines with metal ions to form complexes to remove heavy metal contaminants.

FIG. 2 is a cross-sectional view showing a quantification tank 4 to which a cleaning solution for polishing after the polishing process according to the present invention, that is, a chemical solution containing phosphoric acid and fluoroboric acid is supplied. Here, reference numeral 5 denotes a slurry pipe, and 6 denotes a level sensor.

As described above, according to the present invention, in order to prevent the wafer from being dried and cleaned after the CMP process, the CMP equipment and the cleaning equipment are integrated so that the underwater wafer can be transported. Further, a cleaning process is performed by using a wet dipping method that can obtain a uniform cleaning effect than a scrubbing cleaning method. Further, by using a chemical solution capable of sufficiently removing metal contamination and slurry residues, a strong detergency can be ensured so that fine particles and contaminants do not migrate in a subsequent process.

It is apparent that the present invention is not limited to the above embodiments, and many modifications are possible within the technical scope of the present invention by those skilled in the art.

Claims (2)

Characterized in that the chemical mechanical polishing equipment and the cleaning equipment are integrally formed so that the wafers which have been subjected to the chemical mechanical polishing (CMP) process are transported to the carriers stored in the water and the cleaning process of the wet dipping type is performed, . Returning all wafers for which a chemical mechanical polishing (CMP) process has been completed to a carrier that is stored in water; And a step of moving the carrier vertically and then transferring the carrier to a cleaning tank to perform a cleaning process by a wet dipping method. ※ Note: It is disclosed by the contents of the first application.