JP2000218517A - Manufacturing method and device for electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove particles on a polishing pad by successively performing supplying of slurry to the rotational direction of the pad, polishing, pad conditioning and physical cleaning, and repeating the processes. SOLUTION: A polishing device comprises a polishing pad 8, a polishing head 11 chucking and holding a wafer, a dresser 12 holding diamond particles, and a physical washing unit 13. With physical washing performed between the processes of the pad conditining of the dresser 12 as well as polishing of the polishing head 11, generation of foreign matters in the device before polishing operation, coaggulation of abrasive particles, particles of polished chips resulting in generation of scratch can be removed effectively. The position of the physical washing is at the position ahead of the polishing head 11 but behind the dresser 12. In the case that the position is behind the head 11 but ahead of the dresser 12, coaggulated abrasive grains and polished chips can be removed, but foreign matters generated in the device and carried in foreign matters are liable to deposit again until a next polishing position is taken even if they are once removed, and dropped diamond particles are not removed before polishing operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing electronic components having a fine structure such as a semiconductor device and a magnetic recording device or various components related thereto, and further relates to a method for manufacturing the same. The present invention relates to a manufacturing apparatus for realizing the method, and further relates to a method for manufacturing a semiconductor device or a magnetic recording device and a product such as a semiconductor device or a magnetic recording device manufactured using the method.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
Complex irregularities occur on the wafer due to the patterning of the insulating film and the metal film, and the like. However, when pattern formation is performed subsequently. In the exposure process, there is no sufficient depth of focus for the unevenness, resulting in insufficient resolution, or the metal wiring film is damaged at the step portion of the unevenness, so that a desired semiconductor device may not be manufactured in some cases. Similarly, in a magnetic recording device, a desired magnetic recording device may not be able to be produced due to unevenness generated on a wafer mainly in a process of manufacturing a magnetic head. In order to eliminate this defect, the wafer surface is slid by pressing it against a polishing pad attached to a polishing platen and pouring slurry onto the sliding surface, thereby polishing and flattening the unevenness formed on the wafer surface. The CMP method has been widely adopted.

[0003] Further, if the above polishing is continued by the CMP method, fine irregularities on the polishing pad surface are crushed and the polishing rate is lowered, so that pad conditioning called dress is performed. This is a means for rotating a disk called a dresser holding diamond particles of about 100 to 200 μm and shaving off the polishing pad surface to recover irregularities.

However, in such a conventional CMP method, since polishing and dressing are repeated on the same polishing pad for a long time, polishing debris, diamond particles dropped from the dresser, etc. adhere to the polishing pad, and scratches occur on the product. There is a problem of doing.

As a countermeasure for this, as disclosed in Japanese Patent Application Laid-Open No. 10-94964, it has been proposed to remove the slurry after polishing by using a slurry suction device or a pure water spray. However, suction or pure water spray cannot completely remove polishing debris, falling diamond particles, and the like on the polishing pad, which cause scratches. In particular, as shown in FIG. 1, particles of the order of μm can hardly be removed. When manufacturing a semiconductor device or a magnetic recording device, scratches having a size on the order of μm or less pose a problem, and it is necessary to remove even fine particles on the order of μm or less.

As another countermeasure, it has been proposed to remove polishing debris by high-pressure jet spray as described in JP-A-3-10769, JP-A-10-202502, and JP-A-10-225862. Have been. However, as shown in FIG. 2, the high pressure jet spray has an extremely small spot area (area that can be washed at once) of 1 mm ² or less.
On the other hand, the polishing pad reflects the larger diameter of the wafer. Since the diameter is usually as large as about 1 m, the entire surface of the pad cannot be evenly and sufficiently cleaned.

As yet another countermeasure, JP-A-10-20250
As described in Japanese Patent Application Publication No. 7, a method of removing particles on the pad surface with a bristle brush such as nylon has been proposed. However, brushes have a lower ability to remove fine particles than sponges such as PVA, and have a higher probability of reattachment of particles once removed than non-contact cleaning methods such as spraying, so that particles that cause scratches are sufficiently removed. I can't do that.

Further, the effect of removing particles on the surface of the pad largely depends on the order of steps. The particles that cause scratches are not only the polishing debris and diamond particles that have been pointed out so far, but also foreign substances generated in the equipment, foreign substances brought into the equipment, and agglomerated abrasive grains. It must be performed after pad conditioning and before the next polishing, more preferably immediately before the polishing, and a sufficient effect cannot be obtained even if the polishing is performed at other positions.

As a second problem, when a wet cleaning method such as a pure water spray described in JP-A-10-94964 is used, there is a problem that the slurry is diluted with the cleaning liquid. With the conventional CMP method, the cost of slurry is high and slurry recycling is becoming an essential issue,
When the slurry is mixed with the cleaning liquid, recycling becomes difficult.
Further, even if the recycling is not performed, the processing cost is increased because the amount of the waste liquid increases.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide polishing which causes scratches such as foreign matter generated in the apparatus, foreign matter brought into the apparatus, diamond particles dropped from the dresser, agglomerated abrasive grains, and polishing debris. It is an object of the present invention to provide a manufacturing method and an apparatus for effectively removing particles on a pad.

A second object of the present invention is to provide a manufacturing method and an apparatus which facilitate slurry recycling and waste liquid treatment even when a wet cleaning method is used for removing particles on a pad.

[0012]

According to the present invention, there is provided a manufacturing method in which a slurry is supplied in the rotating direction of a polishing pad, polishing, pad conditioning, and physical cleaning are performed in this order, and the process is repeated. And equipment.

Here, the physical cleaning is a combination of one or more of two-fluid spray, ultrasonic spray, and scrub with PVA sponge. Also, the cleaning liquid on the pad may be removed immediately after the physical cleaning,
After the physical cleaning, the rinsing liquid on the pad may be removed after rinsing. Further, the slurry may be collected immediately before the physical cleaning.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

Reference numeral 8 denotes a polishing pad, 11 denotes a polishing head holding a wafer by chuck, 12 denotes a dresser holding diamond particles, and 13 denotes a physical cleaning unit. By performing the physical cleaning between the pad conditioning by the dresser 12 and the polishing by the head 11 as described above, foreign matter generated in the apparatus, foreign substances brought in, diamond abrasive grains dropped from the dresser 12 and agglomerated abrasives before polishing. In addition, particles that cause scratches such as polishing dust can be effectively removed.

Here, the position of the physical cleaning is always after the dresser 12 in the rotation direction of the polishing pad,
Must be 13 positions before 11 For example, at the position 14 after the polishing head 11 and before the dresser 12, the coagulated abrasive grains and polishing debris can be removed, but the dust generated in the apparatus and foreign substances brought in adhere to the polishing position again even after being removed once. There is a possibility that the dropped diamond particles cannot be removed at all before polishing.

The physical cleaning 4 is one of two-fluid spray, ultrasonic spray or PVA sponge scrub.
One or two or more cleaning methods. As shown in FIG. 1, these three physical cleaning methods have much higher foreign substance removing power than the conventional pure water spray, and as shown in FIG. Large washable area. Therefore, the entire surface of the polishing pad having a large area can be sufficiently and uniformly cleaned. It is more desirable to use a plurality of nozzles. As for the two-fluid spray, a type in which gas and liquid are introduced under pressure is desirable.

The type of gas used in the present invention is pressurized air, clean air, nitrogen, inert gas (carbon dioxide,
Argon gas, etc.), but this does not mean that other gases are not used. Air is advantageous mainly from the economical point of view, and nitrogen gas can easily produce high-purity gas containing no impurities, thus preventing pollution and its nonflammability. Carbon dioxide gas is advantageous from the viewpoint of preventing static electricity since it dissolves in water to increase electric conductivity.

The type of liquid used in the present invention is pressurized pure water, a cleaning solution in which a chemical is dissolved, an organic solvent, and the like. Pure water is advantageous mainly from the economical point of view and from the viewpoint of preventing pollution since high-purity pure water containing no impurities can be easily obtained.Washing solutions in which various chemicals are dissolved can be used for cleaning with pure water. Used when a combination of reactions is desired. Organic solvents are used when non-aqueous cleaning is effective.

FIG. 3 shows the case where one polishing head 11, dresser 12, and physical cleaning unit 13 are provided on one polishing pad 1, but a plurality of these may be provided on one polishing pad. . This is the same for the following embodiments.

Using this apparatus, a comparison was made with the conventional method.

Experimental conditions Sample: Liquid glass was spin-coated on the surface of a 200 mm diameter Si wafer and heat-treated to form a Si oxide film having a thickness of about 2 μm. Polishing pad: polyurethane foam, 1 mm thick Slurry: 3% aqueous solution of SiO2 abrasive, 100mL / min Wafer pressing pressure: 500g / cm ² Wafer rotation speed: 20rpm Polishing pad rotation speed: 20rpm Physical cleaning: 2 fluid spray, 10 nozzles Air pressure, flow rate: 0.5MPa, 100L / min. Nozzle pure water pressure, Flow rate: 0.5MPa, 1L / min. Nozzle Pure water shower (conventional method): 10 nozzles Pure water flow rate: 1L / min. Nozzle As a result, compared to the conventional method, the scratches on the oxide film are significantly larger in the present invention. Decreased to. In addition, the polishing rate is stable,
The in-plane uniformity of the polishing rate was also improved.

Next, FIG. 4 shows an example of the second embodiment of the present invention. This embodiment is an example in which a rinse unit is installed immediately after the physical cleaning in the embodiment of FIG.

FIG. 5 shows an example of the third embodiment of the present invention.
Shown in This embodiment is an example in which the slurry recovery unit is installed immediately before the physical cleaning and the rinsing unit and the rinsing liquid removing unit are installed immediately after the physical cleaning in the embodiment of FIG.

When a comparison was made with the conventional method under the above conditions using the apparatus shown in FIGS. 4 and 5, scratches on the oxide film were greatly reduced, and the polishing rate was further reduced, as in the case of the first embodiment. And the in-plane uniformity of the polishing rate was also improved.

In addition, a combination of slurry recovery → physical cleaning, physical cleaning → rinse → rinse liquid removal, physical cleaning → cleaning liquid removal, etc. is effective, and the embodiment of the present invention is not limited to the above example. is not.

[0027]

The greatest effect obtained by the present invention is the reduction of product scratches, and also has the effect of stabilizing the polishing rate and improving the in-plane uniformity. These effects can improve the reliability of the product and the yield. Further, there is an effect of reducing the recycling cost of the polishing slurry and the waste liquid treatment cost.

As a result, it is possible to provide high-performance electronic device products at low cost, so that the economic effects of the present invention are immeasurable.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram showing a comparison between a physical cleaning method adopted in the present invention and a pure water shower (conventional method) with respect to a removal rate of 100 μm diameter diamond particles when treated for 10 seconds.

FIG. 2 is a characteristic diagram showing a comparison between a physical cleaning method adopted in the present invention and a high-pressure jet spray (conventional method) with respect to a spot area (area that can be cleaned at one time).

FIG. 3 is a plan view of a polishing apparatus showing an example of an embodiment of the present invention.

FIG. 4 is a plan view of a polishing apparatus showing an example of an embodiment of the present invention.

FIG. 5 is a plan view of a polishing apparatus showing an example of an embodiment of the present invention.

[Explanation of symbols]

1: removal rate by pure water shower, 2: removal rate by 2-fluid spray, 3: removal rate by ultrasonic spray, 4: PV
A Removal rate by sponge scrub, 5: spot area of high pressure jet spray, 6: spot area of ultrasonic spray, 7: spot area of 2 fluid spray, 8: polishing pad, 9: slurry supply pipe, 10: slurry supply unit , 11: polishing head, 12: dresser, 13: physical cleaning unit, 14: unfavorable installation position of physical cleaning unit, 15: rinsing unit, 16: slurry recovery unit, 17: rinsing liquid recovery unit.

Continuing from the front page (72) Inventor Hiroyuki Kojima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in Hitachi, Ltd. Production Technology Research Institute F-term (reference) 3C058 AA07 AA09 AA19 AC04 AC05 BA02 CB03 CB06 DA12

Claims (16)

[Claims] 1. An electronic component CMP (Chemical Mechanical P
an olishing step, in which a slurry supply, a polishing, a pad conditioning, and a physical cleaning are performed in the rotation direction of the polishing pad in this order, and the processing is repeated. 2. The method for manufacturing an electronic component according to claim 1, wherein said physical cleaning is a cleaning method using a two-fluid spray. 3. The method for manufacturing an electronic component according to claim 1, wherein said physical cleaning is a cleaning method using an ultrasonic spray. 4. The physical cleaning according to claim 1, wherein the physical cleaning is PVA (Polyvin).
(ylalcohol) A method for producing an electronic component, which is scrub cleaning with a sponge. 5. The method for manufacturing an electronic component according to claim 1, wherein said physical cleaning is a cleaning method using two or more of two-fluid spray, ultrasonic spray, and PVA scrub. 6. A method for manufacturing an electronic component, wherein a gas and a liquid are introduced under pressure into a nozzle by the two-fluid spray according to claim 2. 7. The two-fluid spray nozzle according to claim 2, wherein at least a portion of the gas and the liquid flow passage which is in contact with the fluid is made of Ti, an iron-based alloy, ceramics, quartz, quartz, or a polymer material. Characteristic electronic component manufacturing method. 8. A method for manufacturing an electronic component according to claim 6, wherein said gas is air, clean air, nitrogen or an inert gas. 9. A method for manufacturing an electronic component, comprising using pure water, a cleaning solution in which a chemical is dissolved, or an organic solvent in the physical cleaning according to any one of claims 1 to 8. 10. A method for manufacturing an electronic component, comprising rinsing immediately after the physical cleaning according to claim 1. 11. A method for manufacturing an electronic component, wherein pure water or an organic solvent is used in the rinsing according to claim 10. 12. A method for manufacturing an electronic component, comprising: removing a cleaning liquid on a pad immediately after the physical cleaning according to claim 1. 13. A method for manufacturing an electronic component, comprising: removing a rinsing liquid on a pad immediately after said rinsing according to claim 10. 14. A method for manufacturing an electronic component, wherein slurry recovery is performed immediately before said physical cleaning according to claim 1. 15. An electronic component manufacturing apparatus using the manufacturing method according to claim 1. Description: 16. A method for manufacturing an electronic component, wherein the method is performed by using the method according to claim 1. Description: