JP2006286948A - Method and apparatus for cleaning electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove fine particles sufficiently without causing any damage on the surface of an electronic device. <P>SOLUTION: An apparatus for cleaning an electronic device comprises a section 50 for supplying cleaning liquid containing organic solvent, a section 40 for supplying high pressure nitrogen, and a two-fluid nozzle 30 for spraying the cleaning liquid to a semiconductor wafer W while mixing with high pressure nitrogen. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic device cleaning method and an electronic device cleaning apparatus for cleaning an electronic device such as a semiconductor wafer or a display, and more particularly to a device capable of removing particles without damaging a device pattern.

  The manufacturing process of a semiconductor device includes a process of forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of a semiconductor wafer. In order to form a fine pattern, it is necessary to keep both surfaces of the semiconductor wafer, particularly the thin film forming surface, clean, so that the semiconductor wafer is cleaned using a substrate cleaning apparatus. In such a substrate cleaning apparatus for performing a semiconductor wafer cleaning process, a two-fluid nozzle is used to atomize pure water with high-pressure nitrogen or high-pressure nitrogen and remove the particles by hitting the substrate (for example, Patent Documents). 1).

Similar to semiconductor wafers, electronic devices such as liquid crystal displays and PDP substrates are also cleaned using a similar cleaning apparatus.
JP 2002-270564 A

The above-described semiconductor wafer cleaning method has the following problems. That is, in the method of removing particles by atomizing pure water with high-pressure nitrogen or high-pressure nitrogen, water remains on the substrate after cleaning, and thus water is dried by spin rotation, N ₂ blow, or the like. At this time, in the fine pattern, the adjacent patterns are attracted by the surface tension of water, and there is a risk of damage.

  Accordingly, an object of the present invention is to provide an electronic device cleaning method and an electronic device cleaning apparatus that can remove particles without damaging the surface of the electronic device.

  In order to solve the above problems and achieve the object, an electronic device cleaning method and an electronic device cleaning apparatus of the present invention are configured as follows.

(1) Supplying a cleaning liquid containing an organic solvent, supplying a high-pressure gas, mixing the supplied cleaning liquid with the gas, and spraying the electronic device. .

(2) The electronic device cleaning method according to (1), wherein the organic solvent contains at least one of alcohol and hydrofluoroether.

(3) The electronic device cleaning method described in (1) above,
The organic solvent contains at least one of ethyl alcohol, isopropyl alcohol, C ₄ F ₉ OCH ₃ , and C ₄ F ₉ OC ₂ H ₅ .

(4) The electronic device cleaning method according to (1), wherein the pressure of the cleaning liquid and the gas is 0.3 MPa or less.

(5) The electronic device cleaning method according to (1), wherein the flow rate of the gas is 0.0055 m ² or less per 1 mm ² in the nozzle orifice of the two-fluid nozzle.

(6) A cleaning liquid supply means for supplying a cleaning liquid containing an organic solvent, a high-pressure gas supply means for supplying a high-pressure gas, and a mist by mixing the supplied cleaning liquid with the gas and spraying the electronic device. And a fluid nozzle.

  According to the present invention, particles can be removed without damaging the surface of the electronic device.

  FIG. 1 is an explanatory view showing the configuration of a substrate cleaning apparatus (electronic device cleaning apparatus) 10 according to an embodiment of the present invention. FIGS. 2 and 3 show the nitrogen flow rate and the number of device pattern damages in the substrate cleaning apparatus 10. It is a figure which shows a relationship.

  The electronic device cleaning apparatus 10 includes a cleaning unit 20, a high-pressure nitrogen supply unit 40, a cleaning liquid supply unit 50, and a control unit 60 that controls these units in cooperation.

  The cleaning unit 20 is attached to the electric motor 21 controlled by the control unit 60, the rotating shaft 22 of the electric motor 21, the spin chuck 23 that holds the semiconductor wafer W, and the spin chuck 23. And a two-fluid nozzle 30. The two-fluid nozzle 30 includes a gas flow path 31 through which high-pressure nitrogen flows and a cleaning liquid path 32 that surrounds the gas flow path 31 and flows through the cleaning liquid. In FIG. 1, numeral 33 indicates a nozzle orifice. The gas flow path 31 is connected to a nitrogen pipe 42 to be described later, and the cleaning liquid path 32 is connected to a cleaning liquid pipe 52 to be described later, and is configured to introduce high-pressure nitrogen and a cleaning liquid, respectively. Further, the two-fluid nozzle 30 is supported so that the supply position of the cleaning liquid in the surface of the semiconductor wafer W can be changed by an elevating / moving mechanism (not shown).

  The high-pressure nitrogen supply unit 40 includes a high-pressure nitrogen generation unit 41, a nitrogen pipe 42 for sending high-pressure nitrogen from the high-pressure nitrogen generation unit 41 to the two-fluid nozzle 30, and a pressure adjustment unit provided in the middle of the nitrogen pipe 42 43, a pressure sensor 44 for measuring the nitrogen pressure in the pressure adjusting unit 43, and a flow rate sensor 45 provided in the middle of the nitrogen pipe 42. The pressure adjustment unit 43 performs pressure adjustment according to an instruction from the control unit 60. The outputs of the pressure sensor 44 and the flow sensor 45 are input to the control unit 60.

  The cleaning liquid supply unit 50 includes a cleaning liquid supply tank 51, a cleaning liquid pipe 52 for sending the cleaning liquid from the cleaning liquid supply tank 51 to the two-fluid nozzle 30, a pressure adjusting unit 53 provided in the middle of the cleaning liquid pipe 52, A pressure sensor 54 for measuring the cleaning liquid pressure in the pressure adjusting unit 53 and a flow rate sensor 55 provided in the middle of the cleaning liquid pipe 52 are provided. The pressure adjustment unit 53 performs pressure adjustment according to an instruction from the control unit 60. The outputs of the pressure sensor 54 and the flow rate sensor 55 are input to the control unit 60.

The cleaning liquid containing an organic solvent contains alcohol (eg, ethyl alcohol, isopropyl alcohol, etc.) or hydrofluoroether (eg, C ₄ F ₉ OCH ₃ , C4F ₉ OC ₂ H _5, etc.).

  In the substrate cleaning apparatus 10 configured as described above, the semiconductor wafer W is cleaned as follows. That is, the semiconductor wafer W is rotated by rotating the electric motor 21. The rotation speed at this time is about 500 rpm, for example.

  Next, when the pressure adjusting units 43 and 53 are opened by a signal from the control unit 60 and nitrogen and cleaning liquid are supplied to the two-fluid nozzle 30, the cleaning liquid is atomized by high-pressure nitrogen and sprayed on the surface of the semiconductor wafer W. The Thereby, particles are poured out. At this time, a control signal is sent from the control unit 60 to each of the pressure adjusting units 43 and 53, and the pressures of nitrogen and the cleaning liquid are appropriately adjusted so that the cleaning liquid having a predetermined pressure is sprayed. At the same time, the results detected from the pressure sensors 44 and 54 and the flow rate sensors 45 and 55 are fed back to the controller 60 sequentially.

  Here, the operation in the case where a cleaning liquid containing an organic solvent is used will be described in detail. That is, the organic solvent has a smaller surface tension than pure water. Therefore, even when the water remaining between the device patterns is dried, adjacent patterns are not attracted and are not damaged.

  As described above, according to the electronic device cleaning method performed by the electronic device cleaning apparatus 10 according to the present embodiment, the cleaning liquid containing an organic solvent having a surface tension smaller than that of pure water is used. Even when the water remaining between them is dried, the adjacent patterns are not attracted and are not damaged.

  Here, an experimental example will be described. A semiconductor wafer W on which an isolated pattern of 55 nm was formed was measured with a pattern inspection apparatus, and the number of defects was counted. The semiconductor wafer was cleaned by the substrate cleaning apparatus 10 under the following “condition 1” to “condition 3”.

Condition 1 is C ₄ F ₉ OCH ₃ 0.2 MPa (100 mL / min), high-pressure nitrogen 0.2 MPa (60 L / min), and a semiconductor wafer rotational speed of 500 rpm. Condition 2 is C ₄ F ₉ OC ₂ H ₅ 0.2 MPa (100 mL / min), high-pressure nitrogen 0.2 MPa (60 L / min), and semiconductor wafer rotation speed 500 rpm. Condition 3 is pure water 0.2 MPa (100 mL / min), high-pressure nitrogen 0.2 MPa (60 L / min), and semiconductor wafer rotation speed 500 rpm.

  The semiconductor wafer W after the above processing was measured with a pattern inspection apparatus, and the number of defects was counted. Moreover, the increased defect was observed by review SEM and it was confirmed whether the pattern was damaged. As a result, the defect removal rate was 60% under Condition 1, 70% under Condition 2, and 80% under Condition 3. Further, no damage to the pattern was observed under conditions 1 and 2, but damage was observed at 7 locations under condition 3. Therefore, the pressure of the cleaning liquid and the high-pressure nitrogen is preferably 0.3 MPa or less.

2 and 3 are graphs showing the relationship between the nitrogen flow rate and the number of device pattern damages in the substrate cleaning apparatus 10. Based on this relationship, it can be seen that the flow rate of nitrogen is preferably 70 L / min or less, that is, 0.0055 m ² or less per 1 mm ^{2 at} the nozzle orifice 33 of the two-fluid nozzle 30.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the structure of the board | substrate cleaning apparatus which concerns on one embodiment of this invention. The figure which shows the relationship between the nitrogen flow rate and the number of damages of a device pattern in the same board | substrate cleaning apparatus. The figure which shows the relationship between the nitrogen flow rate and the number of damages of a device pattern in the same board | substrate cleaning apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electronic device washing | cleaning apparatus, 20 ... Washing | cleaning part, 30 ... Two fluid nozzle, 40 ... High-pressure nitrogen supply part, 50 ... Cleaning liquid supply part.

Claims (6)

Supply cleaning liquid containing organic solvent,
Supply high pressure gas,
An electronic device cleaning method, wherein the supplied cleaning liquid is mixed with the gas to form a mist and sprayed onto the electronic device.   The electronic device cleaning method according to claim 1, wherein the organic solvent contains at least one of alcohol and hydrofluoroether. The electronic device cleaning method according to claim 1, wherein the organic solvent contains at least one of ethyl alcohol, isopropyl alcohol, C ₄ F ₉ OCH ₃ , and C ₄ F ₉ OC ₂ H ₅ .   2. The electronic device cleaning method according to claim 1, wherein the pressure of the cleaning liquid and the gas is 0.3 MPa or less. ^2. The electronic device cleaning method according to claim 1, wherein a flow rate of the gas is 0.0055 m ² or less per 1 mm ² in a nozzle orifice of the two-fluid nozzle. Cleaning liquid supply means for supplying a cleaning liquid containing an organic solvent;
High-pressure gas supply means for supplying high-pressure gas;
An electronic device cleaning apparatus comprising: a two-fluid nozzle that sprays the supplied cleaning liquid into the mist by mixing with the gas and sprays the electronic device.

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