CN100452307C - Method and apparatus for cleaning and drying wafer - Google Patents

Abstract

The present invention relates to a method and a device which are used for cleaning and drying wafers, wherein the device comprises an injection assembly which is provided with a first injection port and a second injection port; the structure of the first injection port and the second injection port is used for injecting different fluids, and the first injection port and the second injection port are arranged in the moving direction of a nozzle or on a line which is adjacent to the moving direction. The injection assembly moves from the center of a wafer to the edge of the wafer along a straight line, and the first and second injection ports are arranged on a moving line of the nozzle in line.

Description

Methods of cleaning and drying wafers

technical field

The present invention relates to apparatus and methods for cleaning and drying wafers while they are being spun.

Background technique

In fabricating a semiconductor device, deposition of insulating and metal layers, etching, application of photoresist, development and removal of photoresist (asher) are repeated to obtain fine patterns. Impurities generated in each process are removed by a wet cleaning process using deionized water (DI water) or chemicals, which is called a wet cleaning process.

These photoresist coating, development and cleaning processes are performed by injecting liquid chemicals or DI water onto the wafer. A typical drying and cleaning apparatus uses a wafer chuck that can only handle one wafer to hold the wafer. When the motor is used to rotate the wafer, chemical or DI water flows from above the wafer through the injection nozzle. Thus, due to the rotational power of the wafer, the chemical or DI water flows across the entire surface of the wafer to perform the treatment process.

The single-type wafer cleaning and drying unit uses DI water to rinse the wafer, and then uses nitrogen to dry the wafer.

However, with the recent trend of developing larger wafers and forming finer patterns on the wafers, the DI water used in the rinse process is often not completely dried or not dried.

Contents of the invention

A feature of the present invention is to provide a method and apparatus for cleaning and drying a wafer, which uses a Marangoni type drying method to improve drying efficiency.

Another feature of the present invention is to provide a method and apparatus for cleaning and drying wafers to shorten the cleaning (rinsing) and drying time.

In order to achieve these features, the present invention provides a wafer processing apparatus. The apparatus includes a spin head, an injector assembly for keeping the surface of the wafer to be processed facing up and rotating the wafer, an injector assembly configured to inject fluid into the wafer to be processed placed on the spin head Surface to clean and dry the nozzle of the wafer, the moving assembly is used to move the injection assembly nozzle from the center of the wafer to its edge. The nozzle has first and second injection ports configured for injecting different fluids and arranged on a line in or adjacent to the direction of movement of the nozzle.

In some embodiments, the nozzle is moved along a straight line from the center of the wafer to its edge by a moving assembly. The first and second injection ports are arranged linearly on the moving straight line of the nozzle.

In some embodiments, the nozzle rotates from the center of the wafer to its edge. The first and second injection ports are linearly arranged on a rotationally moving line of the nozzle.

In some embodiments, the device further includes a fluid supply assembly for supplying fluid to the first and second injection ports. The fluid supply assembly supplies fluid when the first or second injection port is located at the center of the wafer.

In some embodiments, the injection assembly moves toward the edge of the wafer as the first and second injection ports sequentially pass through the center of the wafer. The first injection port injects a first fluid for cleaning the wafer, and the second injection port injects a second fluid for drying the wafer.

In some embodiments, the first fluid may be deionized water (DIW) or a DIW mixed solution including isopropanol (IPA), and the second fluid may be nitrogen or a mixed gas including nitrogen.

In some embodiments, the nozzle further includes at least one third injection port disposed between the first and second injection ports. When the first, third and second injection ports pass through the center of the wafer in sequence, the injection assembly moves toward the edge of the wafer.

In some embodiments, the first injection port injects the first fluid for cleaning the wafer, the third injection port injects the second fluid for primary drying of the wafer, and the second injection port injects the second fluid for secondary drying of the wafer. Three fluids.

To achieve these features, the present invention provides a method of cleaning and drying a wafer in an apparatus having an injection assembly having injection ports arranged in a line in a nozzle moving direction to inject different fluids. The method includes rotating the wafer while holding the wafer and injecting fluid onto the surface of the wafer as the injection assembly moves from the center of the wafer to its edge. The injection of the fluid includes injecting the first fluid for cleaning onto the surface of the wafer when the first injection port moves from the center of the wafer to its edge and injecting the first fluid for drying the cleaned fluid when the second injection port moves following the first injection port. the second fluid on the wafer surface. Wherein the wafer was cleaned and dried under an isopropanol vapor atmosphere formed by supplying isopropanol vapor to the entire upper portion of the wafer.

In some embodiments, the method further includes injecting a third fluid that performs secondary drying on the primary-dried wafer surface when the third injection port moves following the second injection port.

Description of drawings

Fig. 1 is a side view of a wafer processing apparatus according to the present invention.

Figure 2 is a top view of a wafer processing apparatus according to the present invention.

3A to 3D are diagrams for explaining the linear movement manner of the injection assembly according to the present invention.

4 to 7 are diagrams for explaining the wafer cleaning and drying method according to the present invention.

8 to 10 are views for explaining a modified injection port of an injection assembly.

FIG. 11 is a diagram for cleaning and drying a wafer by supplying IPA vapor to the upper portion of the wafer in the state shown in FIG. 8 .

Detailed ways

The present invention will be described more fully hereinafter with reference to the accompanying drawings, which show preferred embodiments of the invention. However, this invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Throughout, like reference numerals refer to like parts.

As shown in FIG. 1, the wafer cleaning and drying apparatus 100 has a spin head 110 on which a wafer is placed. The rotation shaft 112 is connected to the bottom of the rotation head 110 to support the rotation head 110 and transmit rotation power. A rotary motor 114 is connected to the rotary shaft 112 to provide rotary power.

A capture cup 120 is installed around the spin head 110 . The catch cup 120 prevents liquid that has been supplied to the wafer W from being thrown out when the wafer W is washed and dried. In this way, the external device or the adjacent area cannot be contaminated.

Although not shown in this figure, the capture cup 120 and the spin head 110 are configured to be relatively movable up and down. Wafers are put into the catch cup 120 or processed wafers are taken out of the catch cup 120 as they relatively move up and down.

Injection assembly 130 is installed above spin head 110 to inject cleaning (or rinsing) solution and drying gas onto the crystal surface. The nozzles 132 of the injection assembly 130 inject cleaning (or rinsing) solution and drying gas to the surface of the wafer W to be treated while moving from the center c of the wafer to its edge. The injection assembly 130 is connected to the arm 142 of the movement assembly 140 to move the injection assembly 130 .

The moving assembly 140 includes a drive motor 146 , a support shaft 144 that takes rotational power from the drive motor 146 , and an arm 142 mounted on the support shaft 144 . Injection assembly 130 is mounted at the end of arm 142 . The driving motor 146 operates according to a control signal of the control unit 180 for controlling the progress of the wafer cleaning and drying process.

The nozzle 132 of the injection assembly 130 includes a first injection port 134a, a second injection port 134b, and a third injection port 134c configured to inject different fluids. The injection ports are arranged linearly in the direction of movement of the injection assembly 130 or on a line adjacent to the direction of movement. In this embodiment, injection assembly 130 moves rotationally on support shaft 144 . The injection ports 134a, 134b, and 134c are linearly arranged on a line a having the same radius as the rotational movement passing through the center c of the wafer. If the injection assembly 130 does not rotate but moves along a straight line, the injection ports are arranged linearly on a line b passing through the center of the wafer, as shown in FIG. 3 . The injection assembly 130 can have various linear movement modes. As shown in FIGS. 3A and 3B , the injection assembly 130 is linearly moved by the arm 142 of the movement assembly. As shown in FIGS. 3C and 3D , the entire moving assembly 140 moves linearly along the conveying track 148 .

A DIW supply part 162 for cleaning (rinsing) the wafer is connected to the first injection port 134a, and a nitrogen gas supply part 164 for drying the wafer is connected to the second injection port 134b. A high-temperature nitrogen supply part 166 for secondary drying of the wafer is connected to the third injection port 134c. In order to obtain the Marangoni effect when drying the wafer, the DIW mixed solution including IPA vapor and the nitrogen mixed gas including IPA vapor may be supplied to the first and second injection ports, respectively.

Figures 8 to 10 show the injection port of the improved injection assembly. In FIG. 8, an injection assembly 130a including a DIW injection port and a nitrogen injection port is shown. In FIG. 9, an injection assembly 130b including an injection port for a DIW mixed solution containing IPA vapor and a nitrogen gas injection port is shown. In FIG. 10, an injection assembly 130c including a DIW injection port and an injection port for a nitrogen gas mixture containing IPA vapor is shown.

In FIG. 11 , an example of cleaning and drying a wafer under an IPA vapor atmosphere formed by supplying IPA vapor to the entire upper portion of the wafer is shown.

As described above, the number of injection ports or the type of fluid supplied to the injection ports may vary depending on the method of cleaning and drying the wafer. Likewise, the spacing between injection ports may vary accordingly.

Figures 4 to 7 show the steps of cleaning and drying a wafer using an implant assembly.

If the wafer W is placed on the spin head 110, the wafer is held by vacuum and then rotated. The first injection port 134 a of the injection assembly 130 is positioned at the center of the wafer by the movement assembly 140 . Deionized water (DIW) for cleaning the wafer is injected from the first injection port 134a. If cleaning of the wafer starts at the first injection port 134a, the moving assembly 140 slowly transfers the injection assembly 130 from the center of the wafer to its edge. If the second injection port 134b is located at the center of the wafer, nitrogen gas for drying the wafer is injected from the second injection port 134b (see FIG. 5). If the third injection port 134c is located at the center of the wafer, then the high-temperature nitrogen gas for secondary drying of the wafer is injected from the third injection port 134c (see FIG. 6 ).

The injection assembly 130 of the substrate cleaning and drying apparatus 100 cleans and dries the wafer while moving from the center of the wafer to its edge. Note that the injection ports of the injection assembly 130 are sequentially arranged (according to the process, ie, cleaning-primary drying-secondary drying) on their paths through the center of the wafer, and fluid is injected from the injection ports as they pass through the center of the wafer in sequence.

In the present invention, the above-mentioned wafers include substrates for marking lines, substrates for liquid crystal displays and substrates for plasma displays and other display substrates, substrates for hard disks, and electronic substrates such as semiconductor devices. device wafer.

As mentioned above, cleaning and drying the wafer at the same time reduces the overall process time. This has the advantage that drying defects of the wafer are reduced. Specifically, the entire surface of the wafer is sufficiently dried without watermarking.

It is obvious to those skilled in the art that other modifications and changes can be made to the present invention based on the above disclosure. Therefore, although only particular embodiments of the invention have been described in detail herein, it will be evident that many modifications can be made without departing from the spirit and scope of the invention.

Claims (4)

1. A method for cleaning and drying a wafer in a device having an injection assembly having an injection port arranged linearly in the moving direction of the nozzle to inject different fluids, the method comprising the steps of: rotating the wafer while holding it in place; and As the injection assembly moves from the center of the wafer to its edge, the fluid is injected onto the surface of the wafer, Among them, the injection of fluid includes: injecting a first fluid for cleaning onto the surface of the wafer as the first injection port moves from the center of the wafer to its edge; and injecting a second fluid used to dry the cleaned wafer surface when the second injection port moves following the first injection port; Wherein the wafer was cleaned and dried under an isopropanol vapor atmosphere formed by supplying isopropanol vapor to the entire upper portion of the wafer. 2. The method according to claim 1, wherein the first fluid is deionized water or a mixed solution of deionized water containing isopropanol, and the second fluid is nitrogen or a mixed gas containing nitrogen. 3. The method of claim 1, further comprising: When the third injection port moves following the second injection port, it injects the third fluid which has secondary drying effect on the surface of the wafer which has been dried once. 4. The method of claim 3, wherein the first fluid is deionized water or a mixed solution of deionized water comprising isopropanol; The second fluid is nitrogen or a nitrogen mixture containing isopropanol; and The third fluid is high temperature nitrogen.

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