KR100698525B1 - Semiconductor Wafer Sawing System with UV Sterilization - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sawing system for separating a semiconductor wafer on which an integrated circuit is formed into respective unit semiconductor chips. The present invention relates to a defect caused by microorganisms remaining in deionized water supplied to a cutting unit and a cleaning unit. In order to prevent the present invention, an ultraviolet sterilizer is provided in a cutting unit for cutting a semiconductor wafer on which an integrated circuit is formed into a unit semiconductor chip, and in addition to a cleaning unit for cleaning the semiconductor wafer with deionized water. Has an installed configuration. Accordingly, the present invention sterilizes and filters almost all microorganisms that can exist in the deionized water, thereby preventing various defects that may occur due to microorganisms in the assembly process of the semiconductor chip, particularly the CCD image sensor chip and the semiconductor assembly process. This has the effect of improving the reliability of the quality, improving the yield and preventing the increase in manufacturing cost.

Wafer sawing, scribing, deionized water, cleaning, UV sterilizer

Description

Sawing system for semiconductor wafer having function of ultraviolet sterilization

1 is a schematic configuration diagram of a semiconductor wafer sawing system according to the prior art;

2 is a schematic structural diagram of a semiconductor wafer sawing system according to the present invention.

Explanation of symbols on the main parts of the drawings

10: semiconductor wafer sawing system

20: cutting unit

30: cleaning unit

40: carbon dioxide bubbler

50: supply piping

60: UV Sterilizer

70: filter

The present invention relates to a semiconductor wafer sawing system, and more particularly, to a semiconductor wafer sawing system having a sterilization function against microorganisms in deionized water supplied.

The semiconductor wafer sawing process is a process of separating the semiconductor wafer in which the integrated circuit is formed into each unit semiconductor chip. This process is usually cut into a unit semiconductor chip by a diamond cutting blade, and prevents silicon dust or various debris from remaining on the wafer surface during the cutting operation. In order to do this, washing with deionized water is performed.

Cleaning with deionized water is carried out both during the semiconductor wafer sawing process and after the cutting is completed. During the first cut, high-pressure deionized water is injected through the nozzle to clean the wafer. Subsequently, cleaning is performed on the semiconductor wafer on which the cutting operation is completed. The semiconductor wafer sawing system includes a cleaning unit in addition to a cutting unit for cutting a wafer for carrying out such a work.

After the cutting operation is completed, the semiconductor wafer is transferred to the cleaning rotary table of the cleaning unit. The wafer is rotated (1000 to 5000 RPM) of the rotating table with the secondary deionized water using a high pressure (50 to 150 kg / cm 2) nozzle. A second cleaning operation is performed on the foreign matter not removed from the cutting unit by spraying. Finally, the cleaning operation is completed by spraying N ₂ or air on the wafer surface. At this time, let's look at the supply path of deionized water is supplied.

1 is a schematic diagram of a wafer sawing system according to the prior art.                         

Referring to FIG. 1, a conventional wafer sawing system 110 includes a cutting unit 120 for cutting a semiconductor wafer and a cleaning unit 130 for cleaning. In addition, a carbon dioxide bubbler (CO ₂ bubbler) 140 is further provided to lower the deionized water sprayed for the purpose of cleaning silicon dust or other debris from high purity to low purity. The carbon dioxide bubbler 140 is installed at a specific point of the pipe 150 to which the deionized water before the cutting unit 120 and the cleaning unit 130 is supplied. The deionized water lowered from the high purity to the low purity by the carbon dioxide bubbler 140 is supplied to the sawing unit 120 and the cleaning unit 130 through the pipe 150.

However, such conventional sawing systems do not consider product defects by microorganisms present in deionized water. Deionized water sprayed onto the wafer surface in the presence of mixed microorganisms from deionized water or from pipes and other paths in the supply path of deionized water may cause defects in semiconductor chips, especially Charged Couple Device (CCD) image sensor chips. do. Some of the microorganisms form biofilms, which are their own energy-supply films for survival and multiplication, even though these biofilms affect only one of the hundreds of thousands of microlenses on the surface of the CCD image sensor chip. This will cause fatal defects in the properties.

Of course, in order to solve this problem, the conventional semiconductor wafer sawing system periodically cleans the pipes supplied with deionized water with hydrogen peroxide (H ₂ O ₂ ) in terms of microbiological water quality management. Microorganisms do not work properly and cause various types of image defects on the microlens surface during the assembly process of CCD image sensor chips.

In addition, deionized water containing microorganisms poses many risks that have not been identified in other processes, and the fatal defects described above result in lower yields, higher production costs, and lower reliability of products. As a factor, it adversely affects.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor wafer sawing system capable of preventing poor quality of a semiconductor wafer or semiconductor chip by microorganisms present in deionized water.

The semiconductor wafer sawing system according to the present invention for achieving the above object comprises a cutting unit for cutting a semiconductor wafer on which an integrated circuit is formed into a unit semiconductor chip, a cleaning unit for cleaning the semiconductor wafer, and ultraviolet rays in a path through which deionized water is introduced. Characterized in that the sterilizer is installed. UV sterilizers can be used using ultraviolet lamps to sterilize microorganisms present in deionized water prior to entering the cutting and cleaning units.

Preferably, a filter for filtering the sterilized microorganisms is installed in a supply path of deionized water through an ultraviolet sterilizer to filter the dead bodies of the sterilized microorganisms. In this case, the filter is preferably suitable for filtering microorganism particles having a size of about 0.2 μm or less, so as to filter microorganisms having a size of about 5 μm to about 0.1 μm. In addition, ultraviolet sterilization means and filters are installed in close proximity to the front end of the cutting and cleaning units to reduce the likelihood that microorganisms may remain in deionized water.

Hereinafter, a semiconductor wafer sawing system according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic structural diagram of a semiconductor wafer sawing system according to the present invention.

Referring to FIG. 2, the semiconductor wafer sawing system 10 of the present invention basically cuts the semiconductor wafer during the cutting operation or after the cutting operation and the cutting unit 20 for separating the semiconductor wafer into the respective unit semiconductor chips. A cleaning unit 30 for cleaning and a carbon dioxide bubbler 40 for converting high purity deionized water into low purity deionized water are provided. The ultraviolet sterilizer 60 and the filter 70 are installed in series in the pipe 50 of the deionized water supply path located between the carbon dioxide bubbler 40 and the cutting unit 20 or the cleaning unit 30. . The ultraviolet sterilizer 60 is installed at the rear end of the carbon dioxide bubbler 40 by using an ultraviolet lamp. The filter 70 is capable of filtering microorganisms having a size of 0.2 μm or less, and is installed at the rear end of the ultraviolet sterilizer 60.

The high purity deionized water introduced through the pipe 50 is mixed with carbon dioxide gas at a constant ratio while passing through the carbon dioxide bubbler 40, and is converted into deionized water of low purity so that the cutting unit 20 or the cleaning unit 30 is removed. It is supplied to clean the various contaminants generated during wafer cutting.                     

The deionized water supplied through the pipe 50 passes through the ultraviolet sterilizer 60 installed at the front end of the deionized water before being supplied to the cutting unit 20 and the cleaning unit 30. In this process, almost all of the microorganisms present in the deionized water are sterilized by ultraviolet rays emitted from the ultraviolet sterilizer 60. The dead body of the sterilized microorganisms remains in the deionized water passing through the UV sterilizer 60, and the filter 70 filters the dead bodies of the microorganisms having a size of 0.2 μm or less. The filtered deionized water is supplied to the cutting unit 20 and the cleaning unit 30 to clean the contaminants generated during or after cutting the semiconductor wafer.

Such a semiconductor wafer sawing system sterilizes and filters various microorganisms in deionized water or pipes and other paths for supplying deionized water, thereby preventing the formation of biofilms which microorganisms form for survival and proliferation, thereby preventing the formation of semiconductor chips, in particular, It will not remain on the surface of the CCD image sensor chip.

The semiconductor wafer sawing system according to the present invention as described above can be caused by microorganisms in the assembling process and the assembling process of the semiconductor chip, in particular the CCD image sensor chip, by sterilizing and filtering almost all the microorganisms that may exist in the deionized water. It prevents various defects, which improves the reliability of the product, improves yield, and prevents the increase in manufacturing cost.

Claims (3)

A wafer sawing system comprising a cutting unit for cutting a semiconductor wafer on which an integrated circuit is formed into a unit semiconductor chip, and a cleaning unit for cleaning the semiconductor wafer with deionized water, wherein the deionized water in front of the cleaning unit is introduced into the path. An ultraviolet sterilizer for irradiating ultraviolet rays to ionized water, and a filter for microbial carcass filtration is provided in the deionized water inflow path between the ultraviolet sterilizer and the cleaning unit. delete The semiconductor wafer sawing system of claim 1, wherein the filter is for filtration of microorganisms having a size of about 5 to 0.1 μm.

Images