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Patent Issued for Substrate Treating Method for Treating Substrates with Treating Liquids

March 5, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- Dainippon Screen Mfg. Co., Ltd. (JP) has been issued patent number 8652268, according to news reporting originating out of Alexandria, Virginia, by VerticalNews editors.

The patent's inventor is Hayashi, Toyohide (Kyoto, JP).

This patent was filed on January 28, 2011 and was published online on February 18, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "This invention relates to a substrate treating apparatus for treating, e.g. cleaning, substrates such as semiconductor wafers or glass substrates for liquid crystal displays (hereinafter called simply substrates) with treating liquids such as a chemical solution and deionized water.

"Conventionally, this type of apparatus includes, for example, a treating tank for storing a treating liquid and receiving substrates, and a nozzle for supplying isopropyl alcohol (IPA) gas to an upper space in the treating tank (see Japanese Unexamined Patent Publication H10-22257 (paragraphs '0024' and '0025', and FIG. 3), for example). With this apparatus, after supplying deionized water to the treating tank and cleaning substrates, IPA gas is supplied to the upper space in the treating tank to form an IPA atmosphere therein. Then, the substrates are pulled up from the treating tank to complete cleaning treatment of the substrates with deionized water. By pulling up and moving the substrates in the IPA atmosphere, the deionized water adhering to the substrates is replaced with IPA to promote drying of the substrates.

"The conventional apparatus with such construction has the following drawback.

"The conventional apparatus can promote drying by pulling up the substrates cleaned with deionized water out of the deionized water, and moving the substrates in the IPA atmosphere. However, there is a drawback that the pattern formed on the surface of each substrate can collapse.

"That is, the pattern on the substrate surface collapses due to the surface tension of the deionized water on the substrate pulled up.

"In the latest semiconductor devices, particularly in the field of memory, capacitors constructed in a cylindrical shape have begun to be employed as a technique for drastically increasing the degree of integration. Such a cylindrical structure has a very high aspect ratio, and a capacitor portion of cylindrical structure collapses easily during a manufacture process. Naturally, a collapse of the capacitor portion renders the device defective, and thus lowers yield.

"It is conceivable to reduce the chances of collapse of the pattern by replacing the deionized water in the treating tank with a liquid with low surface tension, after the substrate cleaning with the deionized water in the treating tank noted above, and then pulling up the substrates from the treating tank and drying the substrates. However, the deionized water having entered minutia of the patterns on the substrate surfaces can remain without being fully replaced. It is thus impossible to eliminate collapse of the patterns formed on the substrates completely."

Supplementing the background information on this patent, VerticalNews reporters also obtained the inventor's summary information for this patent: "This invention has been made having regard to the state of the art noted above, and its object is to provide a substrate treating apparatus which can prevent collapse of patterns formed on substrates.

"The above object is fulfilled, according to this invention, by a substrate treating apparatus for treating substrates with treating liquids, comprising a treating tank for storing the treating liquids; a holding mechanism for holding the substrates and placing the substrates in a treating position inside the treating tank; a first treating liquid supply device for supplying a first treating liquid into the treating tank; a second treating liquid supply device for supplying a second treating liquid of lower surface tension than the first treating liquid, and higher boiling point than the first treating liquid, into the treating tank; a temperature control device for controlling temperature of the second treating liquid in the treating tank to be in a temperature range above the boiling point of the first treating liquid and below the boiling point of the second treating liquid; and a control device for controlling the second treating liquid supply device to replace the first treating liquid supplied from the first treating liquid supply device and stored in the treating tank with the second treating liquid, and controlling the temperature control device to maintain the second treating liquid in the temperature range.

"The substrates are placed in the treating position inside the treating tank by the holding mechanism. The substrates inside the treating tank are treated with the first treating liquid. Then, the control device controls the second treating solution supply device to replace the first treating liquid stored in the treating tank with the second treating liquid, and controls the temperature control device to maintain the second treating liquid in the temperature range above the boiling point of the first treating liquid and below the boiling point of the second treating liquid. Therefore, the substrates treated with the first treating liquid in the treating tank are immersed in the second treating liquid controlled to a temperature higher than the boiling point of the first treating liquid. The first treating liquid remaining on the surfaces of the substrates (including the first treating liquid having entered and remaining in minutia of the patterns on the surfaces of the substrates) is evaporated by the thermal energy of the hot second treating liquid. Its bubbles ascend to the surface of the second treating liquid in the treating tank, and leave the treating tank in the form of vapor. Thus, the first treating liquid having entered and remaining in minutia of the patterns on the surfaces of the substrates can be completely replaced with the second treating liquid. The substrates taken out of the treating tank do not pass through an interface of the first treating liquid having high surface tension, but pass only through an interface of the second treating liquid having lower surface tension than the first treating liquid. Only the low surface tension acts on the surfaces of the substrates when passing through the interface of the second treating liquid, thereby preventing collapse of the patterns formed on the substrates. Only the second treating liquid with the low surface tension remains on the surfaces of the substrates pulled up. The surfaces of the substrates are subjected to the low surface tension when drying the second treating liquid, which prevents collapse of the patterns formed on the substrates.

"The apparatus according to this invention may further comprise a third treating liquid supply device for supplying a third treating liquid of lower surface tension than the first treating liquid, and lower boiling point than the second treating liquid, into the treating tank; wherein the holding mechanism is vertically movable, while holding the substrates, between the treating position inside the treating tank and a standby position above the treating tank; and wherein the control device is arranged to control the third treating liquid supply device to replace the second treating liquid stored in the treating tank with the third treating liquid after substrate treatment with the second treating liquid maintained in the temperature range, and to control the holding mechanism to raise the substrates to the standby position after replacement with the third treating liquid inside the treating tank.

"The substrates are pulled up and dried after the second treating liquid stored in the treating tank is replaced with the third treating liquid of lower surface tension than the first treating liquid and lower boiling point than the second treating liquid. This requires a shorter drying time than where the substrates are pulled up out of the second treating liquid. That is, the third treating liquid allows the substrates to dry more quickly than the second treating liquid because of the lower boiling point.

"The apparatus according to this invention may further comprise a thermal drying device for drying the substrates having undergone treatment with the second treating liquid in a hot atmosphere; wherein the control device is arranged to control the thermal drying device to dry the substrates in the hot atmosphere after treatment with the second treating liquid maintained in the temperature range.

"The treatment with the second treating liquid under temperature control evaporates and removes the first treating liquid having entered and remaining in minutia of the patterns on the surfaces of the substrates. Thus, the second treating liquid on the surfaces of the substrates and having low surface tension can be dried in the hot atmosphere, thereby preventing collapse of the patterns formed on the substrates.

"The apparatus according to this invention may further comprise an air drying device for drying, by air contact, the substrates having undergone treatment with the second treating liquid; wherein the control device is arranged to control the air drying device to dry the substrates by air contact after treatment with the second treating liquid maintained in the temperature range.

"The treatment with the second treating liquid under temperature control evaporates and removes the first treating liquid having entered and remaining in minutia of the patterns on the surfaces of the substrates. Thus, the second treating liquid on the surfaces of the substrates and having low surface tension can be dried by air contact, thereby preventing collapse of the patterns formed on the substrates.

"In another aspect of the invention, a substrate treating apparatus for treating substrates with treating liquids comprises a treating unit having a spin holding mechanism disposed therein for spinnably holding a substrate in horizontal posture, the treating unit treating the substrate held by the spin holding mechanism with the treating liquids; a first treating liquid supply device for supplying a first treating liquid to the substrate spun by the spin holding mechanism inside the treating unit; a second treating liquid supply device for supplying a second treating liquid of lower surface tension than the first treating liquid, and higher boiling point than the first treating liquid, to the substrate spun by the spin holding mechanism inside the treating unit; a temperature control device for controlling temperature of the second treating liquid supplied to the substrate spun by the spin holding mechanism inside the treating unit to be in a temperature range above the boiling point of the first treating liquid and below the boiling point of the second treating liquid; and a control device for controlling the temperature control device the second treating liquid supply device to supply the second treating liquid in the temperature range to the substrate spun by the spin holding mechanism inside the treating unit after treatment of the substrate with the first treating liquid.

"The first treating liquid is supplied to the substrate spinnably held by the spin holding mechanism inside the treating unit to carry out treatment with the first treating liquid. Then, the control device controls the temperature control device and second treating solution supply device, after the treatment of the substrate with the first treating liquid, to supply the second treating liquid in the temperature range above the boiling point of the first treating liquid and below the boiling point of the second treating liquid to the substrate spun by the spin holding mechanism inside the treating unit. Thus, the second treating liquid controlled to a temperature higher than the boiling point of the first treating liquid is supplied to the substrate treated with the first treating liquid in the treating unit. The first treating liquid remaining on the surface of the substrate (including the first treating liquid having entered and remaining in minutia of the pattern on the surface of the substrate) is evaporated by the thermal energy of the hot second treating liquid to leave the surface of the substrate and exit the treating unit in the form of vapor. Thus, the first treating liquid having entered and remaining in minutia of the pattern on the surface of the substrate can be completely replaced with the second treating liquid. Only the second treating liquid with the low surface tension remains on the surface of the substrate. The surface of the substrate is subjected to the low surface tension when drying the second treating liquid, which prevents collapse of the pattern formed on the substrate.

"The above apparatus may further comprise a third treating liquid supply device for supplying a third treating liquid of lower surface tension than the first treating liquid, and lower boiling point than the second treating liquid, to the substrate spun by the spin holding mechanism inside the treating unit; wherein the control device is arranged to control the third treating liquid supply device to supply the third treating liquid to the substrate spun by the spin holding mechanism inside the treating unit after substrate treatment with the second treating liquid maintained in the temperature range, and to control the spin holding mechanism to spin the substrates after completion of supply of the third treating liquid to the substrate.

"The substrate is spin-dried after the second treating liquid on the surface of the substrate is replaced with the third treating liquid of lower surface tension than the first treating liquid and lower boiling point than the second treating liquid. This requires a shorter drying time than where the substrate is spin-dried with the second treating liquid remaining thereon. That is, the third treating liquid allows the substrates to dry more quickly than the second treating liquid because of the lower boiling point."

For the URL and additional information on this patent, see: Hayashi, Toyohide. Substrate Treating Method for Treating Substrates with Treating Liquids. U.S. Patent Number 8652268, filed January 28, 2011, and published online on February 18, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=95&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4737&f=G&l=50&co1=AND&d=PTXT&s1=20140218.PD.&OS=ISD/20140218&RS=ISD/20140218

Keywords for this news article include: Treatment, Electronics, Semiconductor, Dainippon Screen Mfg. Co. Ltd..

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Source: Electronics Newsweekly


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