KR20000003923A - Method of cleaning semiconductor device using electrolytic solution - Google Patents

Abstract

PURPOSE: A method of cleaning semiconductor device is provided to enable cleaning time to be decreased, lowering consumption of chemicals and accomplishing miniaturization of a cleaning apparatus. CONSTITUTION: A semiconductor device is cleaned with anodic water(H¬+) having a pH value of 2 to 5 formed by electrolyzing pure water, to thereby obtain the same effect as may be obtained by using a conventional mixed solution of sulfuric acid or hydrochloric acid, hydrogen peroxide and pure water. Thereafter, the semiconductor device is cleaned using cathodic water(OH¬-) having a pH value of 8 to 13 formed by electrolyzing pure water, to thereby obtain the same effect as may be obtained by using a conventional mixed solution of ammonia water, hydrogen peroxide and pure water.

Description

Method of cleaning semiconductor device using electrolytic solution

TECHNICAL FIELD The present invention relates to the field of semiconductor device manufacturing, and more particularly, to a method for cleaning a semiconductor device using an electrolytic solution.

In order to remove particles or contaminants on the wafer during the semiconductor device manufacturing process, different solutions are used according to the removal targets as shown in Table 1 below.

In the actual semiconductor device manufacturing process, the above solutions are used in combination according to the purpose of use.

For example, in order to clean organic and inorganic substances, it is washed with a solution of sulfuric acid (H ₂ SO ₄ ) or ammonia water (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ) and pure water, and deionized water. ), And then dry the wafer.

In addition, when the organic, inorganic and oxide films are removed, a primary cleaning process is performed using a solution containing sulfuric acid (H ₂ SO ₄ ) or aqueous ammonia (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ), and pure water. After washing with deionized water, using a hydrofluoric acid (HF) solution or a buffered hydrofluoric acid solution, a secondary washing step for removing an oxide film is performed, followed by washing with pure water, followed by hydrochloric acid (HCl). A third washing process is performed with a solution, a solution of hydrogen peroxide (H ₂ O ₂ ) and pure water, and the wafer is dried. After the third washing step, a step of washing with pure water may be added.

Conventional cleaning process as described above has the disadvantage that not only consume a large amount of chemicals, but also a long cleaning time, the size of the cleaning equipment increases the production cost.

The present invention devised to solve the above problems is to provide a method for cleaning a semiconductor device using an electrolyte solution, which can shorten the cleaning time, reduce the consumption of chemicals and lower the production cost. have.

The present invention for achieving the above object is a first step of performing a cleaning process using an anode water (H ⁺ ) obtained by electrolysis of pure water in order to remove contamination on the wafer; A second step of performing a cleaning process using a hydrofluoric acid solution to remove the oxide film on the wafer; A third step of performing a cleaning process using cathode water (OH ⁻ ) obtained by electrolysis of pure water to remove contamination on the wafer; And a fourth step of drying the wafer.

The present invention is a method that can reduce the consumption of chemicals, and lower the production cost by performing a cleaning process using an electrolytic solution. The electrolytic solution can be obtained by electrolysis of pure water. Electrolyzed pure water is used as H ⁺ solution (anode) and OH ^- solution (cathode), respectively.

Anodic water is an acid solution having a pH of 2 to 5, and has the same acidity as a conventional solution of sulfuric acid (H ₂ SO ₄ ) or hydrochloric acid (HCl), hydrogen peroxide (H ₂ O ₂ ), and pure water. Electrolytic salt such as HCl is added to 1000 ppm to maintain the acidity and Oxidation Reduction Potential (ORP) for a long time, and is used for cleaning organic and inorganic materials.

Cathode water is a basic solution with a pH of 8 to 13, and is used for removing particles and inorganic substances, such as a solution in which ammonia water (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ), and pure water are mixed. The electrolytic salt added to the negative water is a basic substance such as NH ₄ OH, and the amount of the electrolytic salt added is about 100 ppm.

Hereinafter, a washing process according to a preferred embodiment of the present invention will be described.

Electrolytic salts in pure water to first remove organic, inorganic and metal contaminant particles from the particles, organics, inorganics and slurries used in the polishing process remaining on the wafer where the chemical mechanical polishing process is completed. HCl was dissolved in about 1000 ppm and electrolyzed to form a first electrolytic solution. The first electrolytic solution had a temperature of 60 ° C. to 80 ° C., a QDR (Quick Drum Rinse) method, an over flow method, The washing step is performed by either a dip method or spray method, followed by washing with pure water.

Subsequently, in order to remove an oxide film, the washing | cleaning process using an impurity or buffer dispersion solution is performed, and it wash | cleans using pure water.

Next, in order to remove inorganic matters and fine silicon particles, 100 ppm of NH ₄ OH is dissolved in pure water with an electrolytic salt and electrolyzed to form a second electrolyte solution. The temperature of the second electrolysis solution is 60 ° C. to 80 ° C. Then, the washing step is carried out by any one of the QDR method, the overflow method, the dipping method, or the spray method, followed by washing with pure water. The wafer is then dried.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

The present invention made as described above can reduce the consumption of chemicals by forming an electrolytic solution with pure water, and can reduce the consumption of chemicals, and can also reduce the size of the cleaning equipment to reduce the production and installation costs. There is an effect to improve the productivity can be reduced.

Claims (4)

In the semiconductor device manufacturing method, In order to remove the contamination on the wafer, a first step of performing a cleaning process using anodic water (H ⁺ ) obtained by electrolysis of pure water; A second step of performing a cleaning process using a hydrofluoric acid solution to remove the oxide film on the wafer; A third step of performing a cleaning process using cathode water (OH ⁻ ) obtained by electrolysis of pure water to remove contamination on the wafer; And Fourth step of drying the wafer A semiconductor device manufacturing method comprising a. The method of claim 1, In the first step, Dissolve 500 ppm to 1000 ppm HCl in the positive water, In the third step, A semiconductor device manufacturing method for dissolving 50 ppm to 100 ppm of NH ₄ OH in the cathode water. The method according to claim 1 or 2, The temperature of the anode water and the cathode water is 60 ℃ to 80 ℃ characterized in that the manufacturing method of a semiconductor device. The method of claim 3, wherein The first step and the second step, A semiconductor device manufacturing method performed by any one of a quick dump rinse (QDR) method, an overflow method, a dip method, or a spray method.