WO2016127423A1

WO2016127423A1 - Method and apparatus for integrated substrate cleaning and drying

Info

Publication number: WO2016127423A1
Application number: PCT/CN2015/073085
Authority: WO
Inventors: Hui Wang; Fuping CHEN; Xiaoyan Zhang
Original assignee: Acm Research (Shanghai) Inc.
Priority date: 2015-02-15
Filing date: 2015-02-15
Publication date: 2016-08-18
Also published as: CN107210193A; CN107210193B

Abstract

A method and an apparatus for integrated substrate cleaning and drying, the apparatus includes: a chuck (103) for holding and positioning a substrate (104); a driving unit (105) connecting with the chuck (103) for driving the chuck (103) to rotate; a solid pad (101) disposed above the substrate (104); a first dispense nozzle (107) disposed on the solid pad (101) for dispensing a rinsing liquid to the surface of the substrate (104); a second dispense nozzle (106) disposed on the solid pad (101) for dispensing a low tension liquid to the surface of the substrate (104); and a movable arm (102) disposed above the substrate (104) for supplying dry gas to the surface of the substrate (104).

Description

METHOD AND APPARATUS FOR INTEGRATED SUBSTRATE CLEANING AND DRYING

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to the field of semiconductor devices manufacture, and more particularly to a method and apparatus for an integrated substrate rinsing and drying after the substrate is cleaned with chemical solution.

2. The Related Art

In processing semiconductor substrates for fabricating semiconductor devices, it is important to prevent fine particles and other forms of contaminates from contacting the surface of the substrate, for that the particles and contaminates may cause low device yield and short device lifetime. It is crucial to perform cleaning process after process steps from where the particles and contaminates are introduced. Nowadays, the main cleaning method is wet cleaning, where the substrates are either cleaned in a group at the same time (batch type) or each substrate is cleaned in individually (single type) . For a number of reasons, such as process flexibility, cost-effectiveness, and chemical waste management, single type wet cleaner has gained tremendous popularity in advanced IC manufacturing in recent years. In a single type wet cleaner, a substrate is subject to a sequence of treatments by different process wet chemicals, followed by a rinsing and drying step at the end of process. As drying is the last step of the cleaning sequence, it bears great importance to the overall cleaning process.

Spin-rinse-dry is a common method for a single type wet cleaner. In this method, most rinse liquid is spun off the substrate under centrifugal force after wet chemical treatment. However, as the rinse liquid film thins down, it reaches to a point where the centrifugal force is no longer effective in removing the rinse liquid as the viscous resistance in the rinse liquid film is larger than the centrifugal force. The final removal of the rinse liquid is thus by natural or forced evaporation. Trace amount of non-volatile contaminates and fine particles existed in the thinned rinse liquid thus are bond to remain on the substrate at the end of cleaning process. Depending on the substrate’s chemical homogeneity, these non-volatile contaminates and fine particles cause various defects on the substrate. A well-known example is the water-mark formation in hydrophobic area of the substrate.

Maragoni dryers are developed to partially overcome such issues. A Maragoni dryer generally uses surface tension gradient force to sheet the rinse liquid film off the substrate, thereby leaving minimal residual rinse liquid film on the surface of the substrate during drying. Referring to U.S. Pat. No. 6,405,452, a method for drying a substrate is disclosed. In this method, a substrate is first immersed in a volume of DI water held in a container. A mixture of alcohol vapor and inert gas is then flown into the upper portion of the container that is not filled with the DI water. The substrate is then withdrawn from the DI water into the upper portion of the container and thereby driving DI water molecules off the surface of the substrate. Maragoni drying method introduces liquid motion only below where surface tension gradient exisits and does not warrant no re-attachement of particles and contaminates to the surface of the substrate elsewhere. Once re-attached, the particles and contaminates are difficult to remove. For the best particles and contaminates removal results, an effective means of preventing particles and contaminates re-attachments to the surface of the substrate is needed.

SUMMARY

According to one aspect of the present invention, there is provided a method for integrated substrate cleaning and drying, comprising: rotating a substrate at a first rotation speed and moving a solid pad close to the substrate with a gap between the bottom surface of the solid pad and the top surface of the substrate； dispensing a rinsing liquid to the top surface of the substrate to form a rinsing liquid film which covers the entire top surface of the substrate； lowering the solid pad and positioning the solid pad be substantially parallel to the top surface of the substrate, at least one area of the solid pad covering the central area of the substrate, a liquid bridge being restricted between the bottom surface of the solid pad and the top surface of the substrate； rotating the substrate at a second rotation speed and dispensing a low tension liquid to the top surface of the substrate； moving the solid pad from a central area of the substrate to the peripheral of the substrate, the solid pad being substantially parallel to the top surface of the substrate during moving, and moving a movable arm to a certain position above the substrate for supplying dry gas to the top surface of the substrate.

According to the other aspect of the present invention, there is provided an apparatus for integrated substrate cleaning and drying, comprising: a chuck for holding and positioning a substrate； a driving unit connecting with the chuck for driving the chuck to rotate； a solid pad disposed above the substrate； a first dispense nozzle disposed on the solid pad for dispensing a rinsing liquid to the surface of the substrate； a second dispense nozzle disposed on the solid pad for dispensing a low tension liquid to the surface of the substrate； and a movable arm disposed above the substrate for supplying dry gas to the surface of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following description of embodiments thereof, with reference to the attached drawings, in which:

FIG. 1A depicts an exemplary apparatus for integrated substrate cleaning and drying；

FIG. 1B depicts a top view of the apparatus shown in FIG. 1A；

FIGS. 2A-2G depict an exemplary integrated substrate cleaning and drying process；

FIGS. 3A-3C depict a theory of the integrated substrate cleaning and drying；

FIG. 4 depicts a theory of the integrated substrate cleaning and drying；

FIGS. 5A-5B depict a theory of the integrated substrate cleaning and drying；

FIGS. 6A-6D depict a theory of the integrated substrate cleaning and drying；

FIGS. 7A-7C depict a theory of the integrated substrate cleaning and drying；

FIG. 8 depicts a theory of the integrated substrate cleaning and drying；

FIG. 9 depicts another exemplary apparatus for integrated substrate cleaning and drying；

FIG. 10A depicts another exemplary apparatus for integrated substrate cleaning and drying；

FIG. 10B depicts a top view of FIG. 10A；

FIGS. 11A-11B depict another exemplary apparatus for integrated substrate cleaning and drying； and

FIGS. 12A-12F depict variety of shapes of the solid pad.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will now be described in detail with reference to accompanying drawings.

Referring to FIGS. 1A and 1B, an exemplary apparatus for integrated substrate cleaning and drying according to one embodiment of the present invention is illustrated. The apparatus includes a chuck 103 for holding and positioning a substrate 104. The chuck 103 is connected with a driving unit 105 such as motor. The driving unit 105 can drive the chuck 103 to rotate and the substrate 104 rotates along with the chuck 103. The driving unit 105 can drive the chuck 103 to rotate in the direction of clockwise, counter clockwise, or clockwise-counter clockwise alternating. A solid pad 101 is disposed above the substrate 104. The bottom surface of the solid pad 101 is made of one of the following material: sapphire crystal, quartz, stainless steel or anodized aluminum. The bottom surface of the solid pad 101 also can be made of one of the following water wettable ceramic: Al2O3 or SiO2. The bottom surface of the solid pad 101 also can be made of one of the following inert metal or metal alloy coatings: Pt, Au, Ti or Ti Carbide. The bottom surface of the solid pad 101 also can be made of one of the following modified plastics that are water wettable: PTFE, PVDF or PEEK.

A first dispense nozzle 107 is disposed at the end of the solid pad 101 for dispensing a rinsing liquid to the surface of the substrate 104. The rinsing liquid is de-ionized water or de-ionized water containing ozone. A second dispense nozzle 106 is disposed at the end of the solid pad 101 and adjacent to the first dispense nozzle 107. The second dispense nozzle 106 is closer to the tip end of the solid pad 101 than the first dispense nozzle 107. The second dispense nozzle 106 is used for dispensing low tension liquid to the surface of the substrate 104. The low tension liquid can be one kind of the following: Ethanol, IPA, Acetone, Ethyl Acetate or the vapor form of the Ethanol, IPA, Acetone, Ethyl Acetate. Preferably, the low tension liquid is IPA liquid or IPA vapor. A movable arm 102 is situated above the substrate 104 and is opposite to the end of the solid pad 101 for dry gas supplying. The dry gas can be one kind of the following: air, N2 or Ar, and preferably, the dry gas is N2.

According to the embodiment, there is provided cleaning and drying process sequence wherein the de-ionized water, IPA and N2 are dispensed to the surface of the substrate 104 with the application of the solid pad 101. Particles and other contaminates will be eliminated effectively, and introduction of particles on the surface of the substrate 104 and the apparatus itself can be prevented. One operation sequence using the solid pad 101 can be set as follows:

Step 1: rotate the substrate 104 at a first rotation speed of ω, and ω is in the range of 10-50 rpm. Move the solid pad 101 close to the substrate 104 with a gap between the bottom surface of the solid pad 101 and the top surface of the substrate 104.

Step 2: dispense de-ionized water to the top surface of the substrate 104 via the first dispense nozzle 107 to make a water film 108. The water film 108 covers the entire top surface of the substrate 104 and the thickness of the water film 108 is about 3mm. FIG. 2A shows a visual example of step 2.

Step 2 is a de-ionized water rinse step. In this step, the water film 108 is a continuous water film and covers the entire top surface of the substrate 104 as the substrate 104 spins at a relatively low rpm.

Step 3: lower the solid pad 101. The bottom surface of the solid pad 101 is substantially parallel to the top surface of the substrate 104. Here “substantially parallel” means the bottom surface of the solid pad 101 is parallel or near parallel to the top surface of the substrate 104. The solid pad 101 is positioned next to the substrate 104 so that a liquid bridge is formed between the bottom surface of the solid pad 101 and the top surface of the substrate 104 and the liquid bridge is restricted therebetween due to capillarity. At least one area of the solid pad 101 is configured to cover a central area of the substrate 101. The central area includes both the center and the area near the center of the substrate 101.

Step 4: rotate the substrate 104 at a second rotation speed about 300rpm and dispense IPA to the top surface of the substrate 104 for a second. The IPA is dispensed to the top surface of the substrate 104 through the second dispense nozzle 106. FIG. 2B shows a visual example of step 4. Since the substrate 104 keeps rotating, the trail of the IPA dispensed on the top surface of the substrate 104 is in spiral form, as shown in FIG. 2C. In this step, the de-ionized water can be stopped dispensing while the IPA is dispensed to the top surface of the substrate 104.

Step 5: move the solid pad 101 from the central area of the substrate 104 to the peripheral of the substrate 104 at a pre-programmed velocity. The solid pad 101 is substantially parallel to the top surface of the substrate 104 during the movement. Meanwhile, move the movable arm 102 to a certain position above the substrate 104 for supplying nitrogen gas to the top surface of the substrate 104, and then start a to-and-fro movement from the certain position to the peripheral of the substrate 104. The end point of the movement of the movable arm 102 is at the peripheral of the substrate 104. This process sequence has superiority in particle removal. Keep rotating the substrate 104 at the second rotation speed about 300rpm and keep dispensing IPA to the top surface of the substrate 104. FIG. 2D shows a visual example of step 5. FIG. 2E shows a spiral motion of IPA on the top surface of the substrate 104.

Referring to FIG. 2F, in step 5, preferably, when the solid pad 101 is about to move away from the substrate 104, move the movable arm 102 to the center of the substrate 104, and then start a to-and-fro movement from the center to the peripheral of the substrate 104. The end point of the movement of the movable arm 102 is at the peripheral of the substrate 104.

Referring to FIG. 2G, in step 5, preferably, after the solid pad 101 moves away from the substrate 104, move the movable arm 102 to the center of the substrate 104 for nitrogen gas supplying, and then start a to-and-fro movement from the center to the peripheral of the substrate 104. The end point of the movement of the movable arm 102 is at the peripheral of the substrate 104.

As the liquid bridge is formed between the bottom surface of the solid pad 101 and the top surface of the substrate 104 and the liquid bridge is restricted therebetween, the low tension liquid whose surface tension is lower than de-ionized water is introduced at the point on the free surface of the water film 108 adjacent to the end edge of the solid pad 101 at the central area of the substrate 104, that is the center or the area near the center of the substrate 104 to create a surface tension gradient there. Move the solid pad 101 to drive away the water film 108, thereby breaking the continuity of the water film 108 at the central area of the substrate 104. As the solid pad 101 moves outwards, dragging the water film 108 underneath along its way, the water film 108 under the bottom surface of the solid pad 101 is continuously exposed to the low tension liquid delivered by the solid pad 101, maintaining the surface tension gradient near the end edge of the solid pad 101 to drive the water film 108 flowing outwards. As a result, the substrate 104 is dried without watermark and the particles and contaminates are removed with the water film 108 and cannot re-attach to the surface of the substrate 104. The retraction of the water film 108 directionally depends on the moving speed of the solid pad 101 and the rotation speed of the substrate 104.

During the removal of the water film 108 at the end of the process, nitrogen gas may be applied to the substrate 104 from a separate delivery device to aid evaporation of any remaining volatile component on the surface of the substrate 104.

According to the cleaning and drying theory shown in FIGS. 3A-3C, surface tension is most important for drying performance. In a traditional maragoni dryer, particles and a water film are eliminated by pull a substrate from water covered with IPA layer. The surface tension of IPA is 21.3 mN/m at 20℃, and the surface tension of de-ionized water is 72.7 mN/m at 20℃. Since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low surface tension, the presence of a gradient in surface tension will naturally cause the liquid to flow away from regions of low surface tension. The IPA amount on the water surface, chamber temperature and substrate pull out speed need to be controlled exactly. IPA drying also has market in single cleaning machine, due to the low viscosity and low surface tension. IPA is dispensed to the surface of the substrate by use of nozzle, and then rotate the substrate at a high speed to dry the substrate via centrifugal force. This method is convenient, but for hydrophobic and hydrophilic mixed silicon substrate surface, there may have water mark issue during drying process. All existing Maragoni drying techniques have a free surface during the drying process, but the method disclosed in this present invention has a restricted water film 108 between the bottom surface of the solid pad 101 and the top surface of the substrate 104. In this method, the continuity of the moving water film 108 is enforced by restricting it between the moving solid pad 101 and the rotating substrate 104, regardless the wettability of the surface of the substrate 104. The continuity of the moving water film 108 can be further ensured by implementing additional liquid delivery devices on the moving solid pad 101. The water film 108 is pulled away from the surface of the substrate 104 entirely by a combination of dragging from the moving solid pad 101 and surface tension driven flow at the contact region between the de-ionized water and the low tension liquid. As the restricted water film 108 is removed from the surface of the substrate 104 as a whole without breakage, drying residues from droplets due to liquid film rapture are effectively avoided. These drying residues, often form on hydrophobic surfaces in ring shape, are referred as “Watermarks” . They are known for lowering device yield in semiconductor manufacturing.

As the solid pad 101 moves outwards, dragging the restricted water film 108 underneath along its way, the water film 108 under the bottom surface of the solid pad 101 is continuously exposed to the low tension liquid delivered by the solid pad 101, maintaining the surface tension gradient near the end edge of the solid pad 101 to drive the water film 108 flowing outwards. The retraction of the water film 108 directionally depends on the moving speed of the solid pad 101 and the rotation speed of the substrate 104. FIG. 3C shows an embodiment of the water film 108 under the bottom surface of the solid pad 101 exposed to the low tension liquid sequence. γc is the capillary length of the water film 108 on the surface of the substrate 104 and underneath the solid pad 101. It can be calculated as follow:

Where γ is surface tension, ρ is the density of the liquid, g is the acceleration due to gravity. During the drying process disclosed in this present invention, γ is decreasing due to the dispensing of low tension liquid, and the γc is becoming smaller and smaller when the solid pad 101 moves away from the substrate 104.

Please refer to FIG. 4. FIG. 4 shows two properties of a substrate. For contact angle

larger than 90°, the substrate shows hydrophobic. For contact angle

smaller than 90°, the substrate shows hydrophilic. It is difficult to remove surface particles from a hydrophobic substrate. A normal method for particles removal in the semiconductor industry is to change the substrate from hydrophobic to hydrophilic surface. But during this process, it will grow a slight oxide layer on the substrate, which is harmful to the device electric property especially the critical dimension decreases to 65 nm and beyond. Developing an integrated drying method and apparatus for the hydrophobic substrate with controllable chemical oxide generation is necessary and urgent.

Referring to FIGS. 5A-5B, showing one embodiment of substrate 104 cleaning and drying basic theory by using the solid pad 101, as shown in FIG. 5A, de-ionized water film can be maintained on the surface of the substrate 104 and the edge of the substrate 104 by rotating the substrate 104. The de-ionized water film is important for the following process step, for example, preventing chemical concentration high in a partial area. FIG. 5A is not a stable status due to the disjoining pressure at the edge circle point of the substrate 104. After IPA dispenses and diffuses into the de-ionized water film, surface tension gradient will generate inside the liquid mixture. Interaction between the surface tension and the disjoining pressure at the edge circle point of the substrate 104 of the liquid mixture and the substrate 104 causes the whole liquid film separate to two parts as shown in FIG. 5B. The part locates at the edge circle point of the substrate 104 will drop away from the substrate 104 due to centrifugal force and gravitation. The liquid film shown in FIG. 5B can solve watermark issue at the edge of the substrate 104.

Referring to FIGS. 6A-6D, showing another embodiment of substrate 204 cleaning and drying basic theory by using the solid pad 201, FIG. 6A shows a contact angle

of liquid phase on the substrate 204. The relationship between

and surface property of the substrate has already presented in FIG. 4. In FIG. 6B, capillary force is illistrated, which occurs when a liquid fills the tiny space bweteen two movable parts. A liquid contact angle

smaller than 90° between two movable parts sets up an attractive force between the surfaces “bridged” by the liquid. Surface tension given by theory is:

γ ＝ Fmax/2πr

Where, Fmax is the maximum of the excess force； r is the radius of the liquid.

FIG. 6C shows a phenomenon that may happen during low tension liquid dispensed to the surface of the substrate 204. The phenomenon is caused by surface tension, and is harmful to the drying process for the substrate 204. Fortunately, this phenomenon can be avoided by the application of the solid pad 201. With reference to FIG. 6D, there is seen a uniform liquid film covering the substrate 204 under the solid pad 201. The gap d between the bottom surface of the solid pad 201 and the top surface of the substrate 204 should be controlled smaller than r.

Please refer to FIGS. 7A-7C showing an embodiment of the formal theory about the uniform liquid film between the solid pad 301 and the substrate 304. FIG. 7A shows the theoretic island type liquid phase during low tension liquid dispensed to the surface of the substrate 304. FIG. 7B shows the solid pad 301 working on the surface of the substrate 304. The solid pad 301 moves away from the substrate 304 at a certain velocity, the solid pad 301 is substantially parallel to the surface of the substrate 304 during the movement. Meanwhile, the substrate 304 is rotating and the speed is determined by the drying performance. By the way, there is a laminar flow 309 under the solid pad 301 when the solid pad 301 moves away from the substrate 304. FIG. 7C shows the solid pad 301 working on the surface of the substrate 304. Interaction between centrifugal force and surface tension results in the generation of the uniform liquid film covering the substrate 304 under the solid pad 301.

Referring to FIG. 8, FIG. 8 depicts another exemplary cleaning and drying theory by use of the solid pad 401. Brownian motion is the seemingly random movement of particles 410 suspended in a liquid, especially in a liquid film. If the temperature of the liquid film increases, Brownian motion works up. If viscosity of the liquid reduces, Brownian motion also works up. So, the Brownian motion of the particles 410 and contaminates can be enhanced by implementing a thermal energy to it through the moving solid pad 401 with low tension liquid dispense system, preventing more particles 410 and contaminates from attaching to the surface of the substrate 404. Furthermore, mega sonic energy can be applied to the liquid film by installing a mega sonic transducer to the solid pad 401. The microscopic high-speed flow field induced by the sonic energy dislodges particles 410 and contaminates that may have reattached back to the surface of the substrate 404.

Referring to FIG. 9 showing another exemplary apparatus for integrated substrate cleaning and drying, the apparatus includes a chuck 503 for holding and positioning a substrate 504. The chuck 503 is connected with a driving unit 505 such as motor. The driving unit 505 can drive the chuck 503 to rotate and the substrate 504 rotates along with the chuck 503. A solid pad 501 is disposed above the substrate 504. A first dispense nozzle 507 is disposed at the end of the solid pad 501 for dispensing de-ionized water onto the surface of the substrate 504. A second dispense nozzle 506 is disposed at the end of the solid pad 501 and adjacent to the first dispense nozzle 507. The second dispense nozzle 506 is closer to the tip end of the solid pad 501 than the first dispense nozzle 507. The second dispense nozzle 506 is used for dispensing low tension liquid onto the surface of the substrate 504. A movable arm 502 is situated above the substrate 504 and is opposite to the end of the solid pad 501 for nitrogen gas supplying. Besides, the apparatus further includes a temperature controlling device 511 which is disposed on the solid pad 501. The temperature controlling device 511 is covered with PEEK. The temperature controlling device 511 are a plurality of resistive heating blocks or a plurality of radiation heating lamps. During the cleaning and drying process for the substrate 504, the Brownian motion of the minor particles and contaminates can be enhanced by implementing a thermal energy to it through the solid pad 501, preventing more particles and contaminates from attaching to the surface of the substrate 501. By the implementing of the temperature controlling device 511, the temperature of the low tension liquid on the surface of the substrate 504 can be maintained within a certain range according to the process request. The apparatus may enhance the process capability without process performance reduction. The apparatus further includes a mega sonic transducer disposed on the solid pad 501 for providing mega sonic energy to the liquid film for implement cavitation-triggered micro-streaming in the restricted liquid film to prevent minor contaminates and fine particles from re-attaching back to the surface of the substrate 504 throughout the rinsing and drying processes.

Referring to FIGS. 10A-10B, FIGS. 10A-10B are a schematic view and a top view showing another exemplary apparatus for integrated substrate cleaning and drying. The apparatus includes a chuck 603 for holding and positioning a substrate 604. The chuck 603 is connected with a driving unit 605 such as motor. The driving unit 605 can drive the chuck 603 to rotate and the substrate 604 rotates along with the chuck 603. The apparatus also includes a solid pad 601. The solid pad 601 is in rectangular shape and covers most of the substrate 604. A first dispense nozzle 607 and a second dispense nozzle 606 are respectively fixed at the center of the solid pad 601. A movable arm 602 is situated above the substrate 604 for nitrogen gas supplying. Comparing to the apparatus shown in FIG. 1A, the horizontal moving speed of the solid pad 601 can be increased.

Referring to FIGS. 11A-11B, showing another exemplary apparatus for integrated substrate cleaning and drying, comparing to the apparatus shown in FIG. 1A, the difference is that the apparatus in this embodiment includes a first dispense nozzle 707 disposed at the end of a solid pad 701 and a second dispense nozzle 706 disposed at the bevel edge of the solid pad 701, and the second dispense nozzle 706 can move along the bevel edge of the solid pad 701. After the de-ionized water rinsing process finished, the second dispense nozzle 706 can dispense low tension liquid to the substrate 704 and move along the bevel edge of the solid pad 701 regardless of the solid pad 701 moves outwards the substrate 704 or not. The second dispense nozzle 706 can move to-and-fro along the bevel edge of the solid pad 701. During dispensing the low tension liquid, moving the second dispense nozzle 706 can keep the low tension liquid film continuously covers the substrate 704 while the substrate 704 rotating. FIG. 11B shows one status of the solid pad 701 moving outwards the substrate 704 during the drying process. During this process period, the second dispense nozzle 706 can move to-and-fro along the bevel edge of the solid pad 701 while the second dispense nozzle 706 dispensing the low tension liquid. The low tension liquid covers the substrate 704 continuously to avoid watermark and contamination issues.

Referring to FIGS. 12A-12F, showing variety of shapes of the solid pad according to the present invention, the shape of the solid pad can be selected from the followings: hexagon as shown in FIG. 12A, full circle to cover entire substrate as shown in FIG. 12B, three-quarter circle to cover partial of substrate as shown in FIG. 12C, concentric circle as shown in FIG. 12D, triangle, half circle to cover half of substrate as shown in FIG. 12E, and elliptical as shown in FIG. 12F, and so on.

The present invention is not only applied in semiconductor industry, but also applied in the case wherein other objects to be treated, such as solar cell substrates and LCD substrates, ect.

The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.

Claims

A method for integrated substrate cleaning and drying comprising:

rotating a substrate at a first rotation speed and moving a solid pad close to the substrate with a gap between the bottom surface of the solid pad and the top surface of the substrate；

dispensing a rinsing liquid to the top surface of the substrate to form a rinsing liquid film which covers the entire top surface of the substrate；

lowering the solid pad and positioning the solid pad be substantially parallel to the top surface of the substrate, at least one area of the solid pad covering a central area of the substrate, a liquid bridge being restricted between the bottom surface of the solid pad and the top surface of the substrate；

rotating the substrate at a second rotation speed and dispensing a low tension liquid to the top surface of the substrate；

moving the solid pad from the central area of the substrate to the peripheral of the substrate, the solid pad being substantially parallel to the top surface of the substrate during moving, and moving a movable arm to a position above the substrate for supplying dry gas to the top surface of the substrate.
The method as claimed in claim 1, wherein the rinsing liquid is de-ionized water or de-ionized water containing ozone.
The method as claimed in claim 1, wherein the surface tension of the low tension liquid is lower than the surface tension of the rinsing liquid.
The method as claimed in claim 3, wherein the low tension liquid is one kind of the following: Ethanol, IPA, Acetone, Ethyl Acetate or the vapor form of the Ethanol, IPA, Acetone, Ethyl Acetate.
The method as claimed in claim 1, wherein the first rotation speed is lower than the second rotation speed.
The method as claimed in claim 1, wherein when the solid pad is about to move away from the substrate, move the movable arm to the center of the substrate, and then start a to-and-fro movement from the center to the peripheral of the substrate.
The method as claimed in claim 1, wherein after the solid pad moves away from the substrate, move the movable arm to the center of the substrate, and then start a to-and-fro movement from the center to the peripheral of the substrate.
The method as claimed in claim 1, further comprising heating the liquid bridge restricted between the bottom surface of the solid pad and the top surface of the substrate.
The method as claimed in claim 1, further comprising providing sonic energy to the liquid bridge restricted between the bottom surface of the solid pad and the top surface of the substrate.
The method as claimed in claim 1, wherein the dispensing of rinsing liquid is stopped while the low tension liquid is dispensed to the top surface of the substrate.
The method as claimed in claim 1, wherein the dry gas is one kind of the following: air, N₂ or Ar.
An apparatus for integrated substrate cleaning and drying comprising:

a chuck for holding and positioning a substrate；

a driving unit connecting with the chuck for driving the chuck to rotate；

a solid pad disposed above the substrate；

a first dispense nozzle disposed on the solid pad for dispensing a rinsing liquid to the surface of the substrate；

a second dispense nozzle disposed on the solid pad for dispensing a low tension liquid to the surface of the substrate； and

a movable arm disposed above the substrate for supplying dry gas to the surface of the substrate.
The apparatus as claimed in claim 12, further comprising a temperature controlling device disposed on the solid pad.
The apparatus as claimed in claim 13, wherein the temperature controlling device includes a plurality of resistive heating blocks.
The apparatus as claimed in claim 13, wherein the temperature controlling device includes a plurality of radiation heating lamps.
The apparatus as claimed in claim 12, further comprising a sonic transducer disposed on the solid pad.
The apparatus as claimed in claim 12, wherein the second dispense nozzle is disposed at a bevel edge of the solid pad, and the second dispense nozzle is capable of moving along the bevel edge of the solid pad.
The apparatus as claimed in claim 17, wherein the second dispense nozzle is capable of moving to-and-fro along the bevel edge of the solid pad.
The apparatus as claimed in claim 12, wherein the shape of the solid pad is one of the following: triangle, rectangle, hexagon, full circle, three-quarter circle, concentric circle, half circle, and elliptical.
The apparatus as claimed in claim 12, wherein the driving unit drives the chuck to rotate in the direction of clockwise, counter clockwise, or clockwise-counter clockwise alternating.
The apparatus as claimed in claim 12, wherein the bottom surface of the solid pad is made of one of the following material: sapphire crystal, quartz, stainless steel or anodized aluminum.
The apparatus as claimed in claim 12, wherein the bottom surface of the solid pad is made of one of the following water wettable ceramic: Al₂O₃ or SiO₂.
The apparatus as claimed in claim 12, wherein the bottom surface of the solid pad is made of one of the following inert metal or metal alloy coatings: Pt, Au, Ti or Ti Carbide.
The apparatus as claimed in claim 12, wherein the bottom surface of the solid pad is made of one of the following modified plastics that are water wettable: PTFE, PVDF or PEEK.
The apparatus as claimed in claim 12, wherein the rinsing liquid is de-ionized water or de-ionized water containing ozone.
The apparatus as claimed in claim 12, wherein the low tension liquid is one kind of the following: Ethanol, IPA, Acetone, Ethyl Acetate or the vapor form of the Ethanol, IPA, Acetone, Ethyl Acetate.