CN107210193B

CN107210193B - Method and apparatus for cleaning and drying integrated circuit substrates

Info

Publication number: CN107210193B
Application number: CN201580076075.0A
Authority: CN
Inventors: 王晖; 陈福平; 张晓燕
Original assignee: ACM Research Shanghai Inc
Current assignee: ACM Research Shanghai Inc
Priority date: 2015-02-15
Filing date: 2015-02-15
Publication date: 2020-10-27
Anticipated expiration: 2035-02-15
Also published as: WO2016127423A1; CN107210193A

Abstract

A method and apparatus for cleaning and drying an integrated circuit substrate, the apparatus comprising: a chuck (103) that holds and positions a substrate (104); a driving unit (105) connected with the chuck (103) to drive the chuck (103) to rotate; a solid plate (101) located above the substrate (104); a first nozzle (107) provided on the solid plate (101) to spray a cleaning liquid to the surface of the substrate (104); a second nozzle (106) provided on the solid plate (101) to spray a low-tension liquid to the surface of the substrate (104); a movable arm (102) positioned above the substrate (104) to supply a dry gas to a surface of the substrate (104).

Description

Method and apparatus for cleaning and drying integrated circuit substrates

Technical Field

The invention relates to the field of semiconductor device manufacturing, in particular to a method and a device for cleaning and drying an integrated circuit substrate after the substrate is cleaned by a chemical solution.

Background

In processing semiconductor substrates to fabricate semiconductor devices, it is important to avoid fine particles and other contaminants from contacting the substrate surface, which can result in low device yield and short device life. It is therefore critical that the cleaning process be performed after the process step that generates particles and contaminants. Today, cleaning methods are mainly wet cleaning, either a group of substrates being cleaned simultaneously (tank cleaning) or each substrate being cleaned individually (single wafer cleaning). For a variety of reasons, such as process flexibility, cost effectiveness, and waste management, monolithic wet cleaners have gained great popularity in the field of integrated circuit manufacturing in recent years. In a single wafer wet cleaner, the substrate is subjected to a series of treatments with different process chemistries, the final steps of the process being cleaning and drying. Since drying is the last step of the cleaning process, it is very important for the entire cleaning process.

Spin-clean-dry is a common cleaning method for single-wafer wet cleaners. In this method, most of the cleaning liquid is thrown off the substrate by centrifugal force after the chemical liquid treatment. However, since the cleaning liquid film becomes thin and reaches a point where the centrifugal force is no longer effective for the removal of the cleaning liquid because the viscous resistance of the cleaning liquid film is larger than the centrifugal force, eventually, the cleaning liquid is removed by natural or forced evaporation. Traces of non-volatile contaminants and fine particles are present in the thinned cleaning solution, and these contaminants and fine particles combine together and remain on the substrate after the cleaning process is completed. These non-volatile contaminants and fine particles can cause defects in the substrate, depending on the chemical homogeneity of the substrate, a well-known example being watermarks in hydrophobic areas of the substrate.

The development of the maraconi dryer solves some of the problems described above, and the maraconi dryer primarily uses surface tension gradient forces to pull the cleaning liquid film away from the substrate, leaving a small residual cleaning liquid film on the substrate surface during the drying process. Reference U.S. patent No.6,405,452 discloses a method of drying a substrate in which the substrate is first immersed in deionized water in a container, then a mixture of ethanol vapor and an inert gas is introduced into the upper portion of the container that is not filled with deionized water, and then the substrate leaves the deionized water into the upper portion of the container, thereby removing deionized water molecules from the surface of the substrate. The liquid motion introduced by the maraconi drying method only works in the presence of a surface tension gradient and does not ensure that no particles and contaminants are reattached to the substrate surface elsewhere, and once reattached, the particles and contaminants will be difficult to remove. For better particle and contaminant removal, an effective method is needed to prevent the particles and contaminants from re-attaching to the substrate surface.

Disclosure of Invention

According to one aspect of the present invention, there is provided a method for cleaning and drying an integrated circuit substrate, comprising: rotating the substrate at a first rotational speed and moving the solid plate so that the solid plate is adjacent to the substrate with a gap between a bottom surface of the solid plate and an upper surface of the substrate; spraying a cleaning solution to the upper surface of the substrate to form a cleaning solution film covering the entire upper surface of the substrate; lowering the solid plate such that the solid plate is substantially parallel to the upper surface of the substrate, the solid plate having at least one region overlying a central region of the substrate, the liquid bridge being confined between a bottom surface of the solid plate and the upper surface of the substrate; rotating the substrate at a second rotation speed and spraying a low-tension liquid onto the upper surface of the substrate; the solid plate is moved from a central region of the substrate to an edge of the substrate, the solid plate being substantially parallel to an upper surface of the substrate during the moving, the movable arm being moved to a position above the substrate to supply a drying gas to the upper surface of the substrate.

According to another aspect of the present invention, there is provided an apparatus for cleaning and drying an integrated circuit substrate, comprising: a chuck for holding and positioning the substrate; the driving unit is connected with the chuck and used for driving the chuck to rotate; a solid plate located over the substrate; a first nozzle provided on the solid plate for spraying a cleaning liquid to a surface of the substrate; a second nozzle provided on the solid plate for spraying a low-tension liquid onto the surface of the substrate; and a movable arm positioned above the substrate for supplying a dry gas to a surface of the substrate.

Drawings

In order that the present invention may be more readily understood by those skilled in the art, a more particular description of the invention will be rendered by reference to the appended drawings, in which:

FIG. 1A depicts an embodiment of an apparatus for cleaning and drying an integrated circuit substrate;

FIG. 1B is a top view of the device shown in FIG. 1A;

FIGS. 2A-2G depict an embodiment of a process for cleaning and drying an integrated circuit substrate;

FIGS. 3A-C illustrate the cleaning and drying principles of the integrated circuit substrate;

FIG. 4 depicts the cleaning and drying principles of an integrated circuit substrate;

FIGS. 5A-B illustrate the cleaning and drying principles of the integrated circuit substrate;

FIGS. 6A-D illustrate the cleaning and drying principles of the integrated circuit substrate;

the AC in FIG. 7 depicts the cleaning and drying principles of the integrated circuit substrate;

FIG. 8 depicts the cleaning and drying principles of an integrated circuit substrate;

FIG. 9 depicts another embodiment of an apparatus for cleaning and drying an integrated circuit substrate;

FIG. 10A depicts yet another embodiment of an apparatus for cleaning and drying an integrated circuit substrate;

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

FIGS. 11A-B depict yet another embodiment of an apparatus for cleaning and drying an integrated circuit substrate;

various shapes of the solid plate are depicted in fig. 12 a-F.

Detailed Description

Various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1A-1B illustrate an embodiment of an apparatus for cleaning and drying an integrated circuit substrate in accordance with the present invention. The apparatus comprises a chuck 103 for placing and supporting a substrate 104, the chuck 103 being connected to a drive unit 105, the drive unit 105 being, for example, a motor, the drive unit 105 driving the chuck 103 in rotation, the substrate 104 being rotated with the chuck 103. The driving unit 105 may drive the chuck 103 to rotate in a clockwise direction, a counterclockwise direction, or alternately clockwise and counterclockwise. The solid plate 101 is located above the substrate 104. The bottom surface of the solid plate 101 may be made of any one of the following materials: sapphire glass, quartz, stainless steel, or anodized aluminum. The bottom surface of the solid plate 101 may also be made of a wettable ceramic material selected from any one of: alumina or silica. The bottom surface of the solid plate 101 may also be made of an inert metal or metal alloy coating of any of the following: platinum, gold, titanium or titanium carbide. The bottom surface of the solid plate 101 may also be made of any one of the following wettability-modified plastics: PTFE, PVDF or PEEK.

The first nozzle 107 is provided at an end portion of the solid plate 101 to spray a cleaning liquid to the surface of the substrate 104. The cleaning solution is deionized water or deionized water containing ozone. The second nozzle 106 is provided at an end of the solid plate 101 adjacent to the first nozzle 107, and the second nozzle 106 is closer to the end of the solid plate 101 than the first nozzle 107, and the second nozzle 106 is used to spray a low-tension liquid to the surface of the substrate 104. The low tension liquid may be any of: the liquid is selected from the group consisting of ethanol, IPA, acetone, ethyl acetate, and vapor of ethanol, IPA, acetone, and ethyl acetate. The movable arm 102 is located above the substrate 104 and opposite to the end of the solid plate 101 to supply a dry gas, which may be any one of the following, to the surface of the substrate 104: air, nitrogen or argon, preferably nitrogen.

In accordance with this embodiment, the present invention also provides a cleaning and drying process step in which deionized water, IPA and nitrogen gas are sprayed onto the surface of the substrate 104 in conjunction with the application of the solid plate 101, particles and other contaminants are effectively removed, and the introduction of particles onto the surface of the substrate 104 and the apparatus itself is prevented. The operation steps using the solid plate 101 may be set as follows:

step 1: rotating the substrate 104 at a first rotation speed ω in the range of 10-50rpm, and moving the solid plate 101 so that the solid plate 101 is close to the substrate 104 with a gap between the bottom surface of the solid plate 101 and the upper surface of the substrate 104.

Step 2: deionized water is sprayed onto the upper surface of the substrate 104 using the first nozzle 107 to form a water film 108, the water film 108 covering the entire upper surface of the substrate 104, the thickness of the water film 108 being about 3mm, and fig. 2A shows an example of step 2.

Step 2 is a deionized water rinse step in which the water film 108 is a continuous film of water and covers the entire upper surface of the substrate 104 as the substrate 104 is rotated at a relatively low rotational speed.

And step 3: the solid plate 101 is lowered, and the bottom surface of the solid plate 101 is substantially parallel to the upper surface of the substrate 104, where "substantially parallel" means that the bottom surface of the solid plate 101 is parallel or approximately parallel to the upper surface of the substrate 104. The solid plate 101 abuts against the substrate 104 so that a liquid bridge is formed between the bottom surface of the solid plate 101 and the upper surface of the substrate 104, and the liquid bridge is confined between the bottom surface of the solid plate 101 and the upper surface of the substrate 104 due to a capillary phenomenon. At least one region of the solid plate 101 covers a central region of the substrate 101, the central region including a center of the substrate 101 and a region near the center.

And 4, step 4: the substrate 104 is rotated at a second speed of about 300rpm and IPA is sprayed onto the upper surface of the substrate 104 through the second nozzle 106 for one second, an example of step 4 being shown in fig. 2B. As the substrate 104 continues to rotate, the path of the IPA sprayed onto the upper surface of the substrate 104 is helical, as shown in FIG. 2C. In this step, the spraying of the deionized water may be stopped while the IPA is sprayed onto the upper surface of the substrate 104.

And 5: the solid plate 101 is moved at a programmed preset speed from the central area of the substrate 104 to the edge of the substrate 104, during which movement the solid plate 101 is substantially parallel to the upper surface of the substrate 104. At the same time, the movable arm 102 is moved to a specific position above the substrate 104 to supply nitrogen gas to the upper surface of the substrate 104, and then starts reciprocating between the specific position and the edge of the substrate 104, and the movement of the movable arm 102 ends at the edge of the substrate 104, which facilitates the removal of particles. The substrate 104 is continuously rotated at a second rotation speed of about 300rpm and IPA is continuously sprayed onto the upper surface of the substrate 104. An example of step 5 is shown in fig. 2D. Figure 2E shows a spiral motion profile of IPA on the top surface of the substrate 104.

As shown in fig. 2F, in step 5, preferably, when the solid plate 101 is about to leave the substrate 104, the movable arm 102 is moved to the center of the substrate 104, and then the center-to-edge reciprocating motion of the substrate 104 is started, and the moving end point of the movable arm 102 is at the edge of the substrate 104.

As shown in fig. 2G, in step 5, preferably, after the solid plate 101 leaves the substrate 104, the movable arm 102 is moved to the center of the substrate 104 to supply nitrogen gas, and then the center-to-edge reciprocating movement of the substrate 104 is started, and the movement end point of the movable arm 102 is at the edge of the substrate 104.

Since the liquid bridge is confined between the bottom surface of solid plate 101 and the upper surface of substrate 104, a low tension liquid having a surface tension lower than that of deionized water is introduced onto the free surface of water film 108 near the end edge of solid plate 101 and in the center region of substrate 104, forming a surface tension gradient region at or near the center of substrate 104. Moving solid plate 101 pushes water film 108 outward, thereby breaking the continuity of water film 108 in the center region of substrate 104. As solid plate 101 moves outward, drawing underlying water film 108 to follow the trajectory, water film 108 beneath the bottom surface of solid plate 101 continues to contact the low tension liquid sprayed by solid plate 101, maintaining the surface tension gradient at the edge of the end of solid plate 101, and pushing water film 108 outward. The substrate 104 may be dried without water marks and particles and contaminants are removed along with the water film 108 and may not be re-adsorbed to the surface of the substrate 104. The rate of reduction of water film 108 is directly dependent on the speed of movement of solid plate 101 and the speed of rotation of substrate 104.

At the end of the water film 108 removal process, nitrogen gas may be supplied onto the substrate 104 by a separate delivery device to assist in the evaporation of volatile components remaining on the surface of the substrate 104.

According to the cleaning and drying principle shown in fig. 3 a-C, surface tension is most important for drying performance. In a commonly used maraconi dryer, the particles and water film are removed by pulling the substrate from water covered with an IPA layer. The surface tension of IPA was 21.3mN/m and the surface tension of deionized water was 72.7mN/m at 20 ℃. Since a high surface tension liquid will pull more strongly on the surrounding liquid than a low surface tension liquid, the presence of a surface tension gradient will naturally cause the liquid to flow from the low surface tension region to the high surface tension region. The amount of IPA on the water surface, the temperature in the chamber, and the speed at which the substrate is pulled outward all need to be precisely controlled. IPA drying is also marketed in single-chip washers due to low viscosity and low surface tension. IPA is sprayed onto the surface of the substrate through a nozzle, and then the substrate is rotated at a high speed, and dried by centrifugal force. This approach is convenient, but for mixed silicon substrate surfaces that are hydrophobic and hydrophilic, the surface may have watermarking problems during drying. All the prior maraconi drying techniques have a free liquid surface during the drying process, and the method disclosed by the present invention confines the water film 108 between the bottom surface of the solid plate 101 and the upper surface of the substrate 104, by which the continuity of the moving water film 108 is maintained without breaking, regardless of whether the substrate 104 has a wettable surface or not, by the movement of the solid plate 101 and the rotation of the substrate 104, and by the additional liquid spraying device moving the solid plate 101, and the water film 108 is completely pulled away from the surface of the substrate 104 by the drag force of the solid plate 101 and the surface tension gradient driving force between the two liquids. The continuity of the confined water film 108 is not broken and thus removal from the surface of the substrate 104 effectively avoids dripping drying marks, usually formed in a ring shape on a hydrophobic surface, so-called "watermarks", which are known to reduce device yield in semiconductor manufacturing.

As solid plate 101 moves outward, drawing confined water film 108 beneath solid plate 101 in a path, water film 108 beneath the bottom surface of solid plate 101 continues to contact the low tension liquid sprayed by solid plate 101 to maintain a surface tension gradient zone at the terminal edge of solid plate 101, thereby driving water film 108 to flow outward. The rate of reduction of water film 108 is directly dependent on the speed of movement of solid plate 101 and the speed of rotation of substrate 104. An example of the water film 108 below the bottom surface of the solid plate 101 in contact with the low tension liquid sprayed by the solid plate 101 is shown at C in fig. 3. Yc is the capillary length of the water film 108 above the surface of the substrate 104 and below the solid plate 101, and can be calculated as follows:

where γ is the surface tension, ρ is the liquid density, and g is the acceleration of gravity. During the drying process disclosed in the present invention, γ is gradually reduced by spraying a low-tension liquid, and γ c becomes smaller as the solid plate 101 is separated from the substrate 104.

Referring to fig. 4, fig. 4 illustrates two properties of a substrate. Contact angle

Above 90 deg., the substrate exhibits hydrophobicity. Contact angle

Less than 90 deg., the substrate exhibits hydrophilicity. It is difficult to remove surface particles from hydrophobic substrates, and in the semiconductor industry it is common to change the hydrophobicity of the substrate to hydrophilic, but during processing a slight oxide layer will grow on the substrate, which is detrimental to the electrical properties of the device, especially to critical dimensions of 65nm and below. It is necessary and urgent to develop a method and apparatus for integrated drying with controlled chemical oxidation layer.

One embodiment of the basic principle of cleaning and drying of a substrate 104 using a solid plate 101 is shown as a-B in fig. 5. As shown in a of fig. 5, by rotating the substrate 104, a film of deionized water, which is important for the next process step, for example, to prevent a high chemical concentration in a local area, can be maintained on the surface and edge of the substrate 104, and a of fig. 5 illustrates an unstable state due to the separation pressure of the liquid film at the edge of the substrate 104. After spraying IPA and diffusing IPA into the DI water film, a surface tension gradient will be created in the mixed liquid, and the interaction between the surface tension and the separation pressure at the edge of the substrate 104 will cause the entire liquid film to be divided into two parts, as shown in B of FIG. 5. The liquid film shown in B of fig. 5 may solve the problem of the watermark at the edge of the substrate 104, because the portion at the edge of the substrate 104 will drip from the substrate 104 due to centrifugal force and gravity.

Another embodiment of the basic principle of cleaning and drying of a substrate 204 using a solid plate 201 is shown in fig. 6 a-D. A in FIG. 6 is a graph showing the contact angle of the liquid phase on the substrate 204

And the surface properties of the substrate have been presented in figure 4. B in fig. 6 shows the capillary force, which occurs when the liquid fills the minute space between the two movable parts. When the liquid contact angle between two moving parts

Less than 90 deg. due to "liquid bridgesThe formation is such that there is an attractive force between the two surfaces, the surface tension obtained from theory being:

γ＝Fmax/2πr

where Fmax is the maximum excess force and r is the radius of the liquid.

C in fig. 6 shows a phenomenon that may occur during the process of spraying a low-tension liquid onto the surface of the substrate 204, the phenomenon being caused by surface tension and being detrimental to the drying process of the substrate 204. Fortunately, this phenomenon can be avoided by the application of solid plate 201. As shown by D in fig. 6, it can be seen that a uniform liquid film covers the substrate 204 below the solid plate 201, and the gap D between the bottom surface of the solid plate 201 and the upper surface of the substrate 204 should be controlled to be smaller than r.

One example of formal theory regarding the uniform liquid film between the solid plate 301 and the substrate 304 is shown in fig. 7 as a-C. As shown in fig. 7 a, an island-shaped liquid film is theoretically formed in the process of spraying a low-tension liquid onto the surface of the substrate 304. B in fig. 7 shows that the solid plate 301 acts on the surface of the substrate 304. The solid plate 301 is moved away from the substrate 304 at a specific speed, during which the solid plate 301 is substantially parallel to the surface of the substrate 304, while the substrate 304 is rotated at a speed determined by the drying performance. As the solid plate 301 moves away from the base plate 304, there is a laminar flow 309 beneath the solid plate 301. C in fig. 7 shows that the solid plate 301 acts on the surface of the substrate 304. The interaction between the centrifugal force and the surface tension causes a uniform liquid film to cover the substrate 304 below the solid plate 301.

Fig. 8 shows still another example of the substrate cleaning and drying principle using the solid plate 401. Brownian motion appears superficially to be random motion of suspended particles 410 within a liquid, particularly in a liquid film. Brownian motion is exacerbated if the temperature of the liquid film increases and it is still exacerbated if the viscosity of the liquid decreases. Thus, heating of the liquid film by solid plate 401 with a low tension liquid delivery system exacerbates brownian motion of particles 410 and contaminants, preventing more particles 401 and contaminants from adhering to the surface of substrate 404. In addition, the microscopic high-speed flow field induced by the acoustic energy removes particles 401 and contaminants that may reattach to the surface of the substrate 404 by applying megasonic energy to the liquid film by mounting megasonic transducers on the solid plate 401.

Another embodiment of an apparatus for cleaning and drying an integrated circuit substrate is shown in fig. 9. The apparatus comprises a chuck 503 for placing and supporting a substrate 504, the chuck 503 is connected to a driving unit 505, the driving unit 505 may be, for example, a motor, the driving unit 505 drives the chuck 503 to rotate, and the substrate 504 rotates together with the chuck 503. The solid plate 501 is located above the substrate 504. A first nozzle 507 is provided at an end of the solid plate 501 to spray deionized water toward the surface of the substrate 504. The second nozzle 506 is provided at the end of the solid plate 501 near the first nozzle 507, and the second nozzle 506 is closer to the end of the solid plate 501 than the first nozzle 507, and the second nozzle 506 sprays a low-tension liquid onto the surface of the substrate 504. The movable arm 502 is located above the base plate 504 and opposite to the end of the solid plate 501 to supply nitrogen gas. In addition, the apparatus further includes a temperature control device 511 disposed on the solid plate 501, the temperature control device 511 being coated with PEEK, the temperature control device 511 being a plurality of resistance heating blocks or a plurality of radiant heating lamps. During the process of cleaning and drying the substrate 504, thermal energy is provided through the solid plate 501, which accelerates brownian motion of small particles and contaminants, preventing more particles 501 and contaminants from adhering to the surface of the substrate 504. By using the temperature control device 511, the temperature of the low tension liquid on the surface of the substrate 504 is maintained within a specific range according to the process requirements. The device can improve the processing capacity without reducing the process performance. The apparatus further includes a megasonic transducer disposed on the solid plate 501 that provides megasonic energy to the liquid film to generate cavitation micro-streaming in the confined liquid film to prevent small particles and contaminants from re-adsorbing to the surface of the substrate 504 during the cleaning and drying processes.

Fig. 10A-10B are schematic and top views of another embodiment of an apparatus for cleaning and drying an integrated circuit substrate. The apparatus comprises a chuck 603 for placing and supporting a substrate 604, the chuck 603 being connected to a drive unit 605, the drive unit 605 being, for example, a motor, the drive unit 605 driving the chuck 603 in rotation, the substrate 604 rotating with the chuck 603. The apparatus further comprises a solid plate 601, the solid plate 601 being rectangular and covering a substantial part of the substrate 604. The first nozzle 607 and the second nozzle 606 are fixed to the center of the solid plate 601, respectively. A movable arm 602 is positioned above the substrate 604 for supplying nitrogen. The horizontal moving speed of the solid plate 601 is increased as compared with the apparatus shown in fig. 1A.

As shown in fig. 11A-B, which is yet another embodiment of the apparatus for washing and drying an integrated circuit substrate, the apparatus in this embodiment is different from the apparatus shown in fig. 1A in that a first nozzle 707 is provided at the end of the solid plate 701, a second nozzle 706 is provided on the oblique side of the solid plate 701, and the second nozzle 706 is movable along the oblique side of the solid plate 701. After the deionized water rinsing process is completed, the second nozzle 706 sprays a low-tension liquid onto the substrate 704 and moves along the oblique side of the solid plate 701 regardless of whether the solid plate 701 moves to the outside of the substrate 704. The second nozzle 706 may reciprocate along the oblique side of the solid plate 701. During the spraying of the low-tension liquid, the moving second nozzle 706 may keep the low-tension liquid film continuously coated on the substrate 704 while the substrate 704 is rotated. Fig. 11B shows a state in which the solid plate 701 moves to the outside of the substrate 704 during the drying process. During this process, the second nozzle 706 may be reciprocated along the bevel of the solid plate 701 as the second nozzle 706 sprays a low tension liquid that continuously covers the substrate 704 to avoid problems with watermarks and contaminants.

Fig. 12 a-F show various shapes of the solid plate of the present invention. The shape of the solid plate may be selected from: a hexagon as shown in a in fig. 12, a circle as shown in B in fig. 12 covering the entire substrate, a three-quarter circle as shown in C in fig. 12 covering a portion of the substrate, a concentric circle as shown in D in fig. 12, a triangle, a semicircle as shown in E in fig. 12 covering a half of the substrate, an ellipse as shown in F in fig. 12, and the like.

The present invention can be applied not only to the semiconductor industry but also to other objects to be processed, such as solar cell substrates and LCD substrates.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Thus, modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit of the invention. The scope of the invention is to be determined by the claims that follow.

Claims

1. A method for cleaning and drying an integrated circuit substrate, comprising:

rotating the substrate at a first rotational speed and moving the solid plate so that the solid plate is adjacent to the substrate with a gap between a bottom surface of the solid plate and an upper surface of the substrate;

spraying a cleaning solution to the upper surface of the substrate to form a cleaning solution film covering the entire upper surface of the substrate;

lowering the solid plate such that the solid plate is substantially parallel to the upper surface of the substrate, the solid plate having at least one region overlying a central region of the substrate, the liquid bridge being confined between a bottom surface of the solid plate and the upper surface of the substrate;

rotating the substrate at a second rotation speed and spraying a low-tension liquid onto the upper surface of the substrate;

the solid plate is moved from a central region of the substrate to an edge of the substrate, the solid plate being substantially parallel to an upper surface of the substrate during the moving, the movable arm being moved to a position above the substrate to supply a drying gas to the upper surface of the substrate.

2. The method of claim 1, wherein the cleaning solution is deionized water or ozone-containing deionized water.

3. The method of claim 1, wherein the low tension liquid has a surface tension lower than the surface tension of the cleaning liquid.

4. A method according to claim 3, wherein the low tension liquid is any one of: ethanol, IPA, acetone, ethyl acetate.

5. The method of claim 1, wherein the first rotational speed is lower than the second rotational speed.

6. The method of claim 1, wherein the movable arm is moved to the center of the substrate and then starts reciprocating from the center of the substrate to the edge of the substrate when the solid plate is about to leave the substrate.

7. The method of claim 1, wherein after the solid plate is separated from the substrate, the movable arm is moved to the center of the substrate and then starts to reciprocate from the center of the substrate to the edge of the substrate.

8. The method of claim 1, further comprising heating the liquid bridge confined between the bottom surface of the solid plate and the upper surface of the substrate.

9. The method of claim 1 further comprising providing sonic energy to a liquid bridge confined between the bottom surface of the solid plate and the upper surface of the substrate.

10. The method of claim 1, wherein the spraying of the cleaning solution is stopped when the low tension liquid is sprayed onto the upper surface of the substrate.

11. The method of claim 1, wherein the drying gas is any one of: air, nitrogen or argon.

12. An apparatus for cleaning and drying an integrated circuit substrate, comprising:

a chuck for holding and positioning the substrate;

a driving unit connected with the chuck, the driving unit driving the chuck to rotate;

a solid plate positioned over the substrate, the solid plate moving from a central region of the substrate to an edge of the substrate, the solid plate having at least one area overlying the central region of the substrate, a liquid bridge being confined between a bottom surface of the solid plate and an upper surface of the substrate;

a first nozzle provided on the solid plate, the first nozzle spraying a cleaning liquid to a surface of the substrate;

a second nozzle provided on the solid plate, the second nozzle spraying a low-tension liquid to the surface of the substrate;

a movable arm positioned above the substrate, the movable arm supplying a drying gas to a surface of the substrate.

13. The apparatus of claim 12, further comprising a temperature control device disposed on the solid plate.

14. The apparatus of claim 13, wherein the temperature control device comprises a plurality of resistance heating blocks.

15. The apparatus of claim 13, wherein the temperature control device comprises a plurality of radiant heating lamps.

16. The apparatus of claim 12, further comprising an acoustic transducer disposed on the solid plate.

17. The apparatus of claim 12 wherein the second nozzle is disposed on the angled edge of the solid plate and the second nozzle is movable along the angled edge of the solid plate.

18. The apparatus of claim 17, wherein the second nozzle is reciprocable along the oblique edge of the solid plate.

19. The apparatus of claim 12, wherein the solid plate is shaped as any one of: triangular, rectangular, hexagonal, circular, three-quarters circular, concentric, semi-circular, and elliptical.

20. The apparatus of claim 12, wherein the drive unit drives the chuck to rotate in a clockwise direction, a counterclockwise direction, or alternating clockwise and counterclockwise directions.

21. The apparatus of claim 12, wherein the bottom surface of the solid plate is made of any one of the following materials: sapphire glass, quartz, stainless steel, or anodized aluminum.

22. The apparatus of claim 12, wherein the bottom surface of the solid plate is made of a wettable ceramic material selected from any one of: alumina or silica.

23. The apparatus of claim 12, wherein the bottom surface of the solid plate is made of an inert metal or metal alloy coating of any one of: platinum, gold, titanium or titanium carbide.

24. The apparatus of claim 12, wherein the bottom surface of the solid plate is made of a wettability-modified plastic of any one of: PTFE, PVDF or PEEK.

25. The apparatus of claim 12, wherein the cleaning fluid is deionized water or ozone-containing deionized water.

26. The apparatus of claim 12, wherein the low tension liquid is any one of: ethanol, IPA, acetone, ethyl acetate.