CN104624545A - Wafer cleaning device and wafer cleaning method - Google Patents

Abstract

The invention discloses a wafer cleaning device and a wafer cleaning method. The wafer cleaning apparatus includes: the platform is used for bearing a wafer, the wafer is provided with a surface to be washed, a first nozzle is arranged above the wafer, a first height is formed between the first nozzle and the surface to be washed of the wafer, a second nozzle is arranged above the wafer, a second height is formed between the second nozzle and the surface to be washed of the wafer, and the first height is smaller than the second height.

Description

Wafer cleaning device and wafer cleaning method

This application is a divisional application of a patent application with an application date of December 24, 2009, an application number of 200910266338.0, and an invention title of "wafer cleaning device and wafer cleaning method".

technical field

The invention relates to a wafer cleaning device and a cleaning method, in particular to a cleaning device and a cleaning method which use cleaning liquids with different flow rates to wash the center of the wafer and the periphery of the wafer respectively.

Background technique

Semiconductor devices are fabricated from semiconductor wafers that undergo several processing operations. These operations include such operations as dopant implantation, gate oxide generation, interlayer dielectric layer formation, metallization deposition, line patterning, etching operations, chemical mechanical polishing (CMP), and the like. Usually after chemical mechanical grinding, etching, or photoresist development, there will be residues left on the wafer surface, such as chemical liquid components or chemical polymers. Therefore, in order to keep the wafer surface clean, it is necessary to properly clean the wafer. Give cleansing treatment. Usually, a liquid spraying device is used to use a rinsing liquid, such as a specific cleaning solution or deionized water, to remove the chemical liquid components or chemical polymers that remain on the wafer, and through rotation Wafer surface residues and rinse fluid are flung off the wafer surface.

The existing wafer cleaning device includes a housing containing liquid spraying equipment, a liquid supply system containing a plurality of conveying lines and a plurality of straight nozzles (straight nozzles) arranged on the lower side thereof, and a driving device for driving the spraying movement. However, in the existing cleaning device, which rotates the wafer while supplying the cleaning solution from the linear nozzle for cleaning, the cleaning solution on the peripheral wafer surface will generate turbulent flow, causing the center of the wafer to be cleaned and removed. The problem of substances remaining on the peripheral wafer surface and producing defects or water marks on the wafer periphery.

Therefore, the effect of the cleaning process is greatly reduced, which will inevitably affect the pass rate of subsequent production processes. Therefore, how to completely clean the wafer to avoid residues, defects and water marks is an important issue that cannot be delayed.

Contents of the invention

According to a preferred embodiment of the present invention, the present invention provides a wafer cleaning device, comprising: a platform for carrying a wafer, the wafer has a surface to be cleaned, and a first nozzle is arranged above the wafer. There is a first height between a nozzle and the surface to be cleaned of the wafer, and a second nozzle is arranged above the wafer, and there is a second height between the second nozzle and the surface to be cleaned of the wafer, wherein the first height is smaller than the second high.

According to another preferred embodiment of the present invention, the present invention provides a wafer cleaning device, comprising: a platform for carrying a wafer and a nozzle disposed above the wafer, the aforementioned nozzles include a plurality of openings, each of which The distance between the opening and a surface to be cleaned of the aforementioned wafer varies with the position of each opening relative to the wafer.

According to yet another preferred embodiment of the present invention, the present invention provides a kind of wafer cleaning method: first provide a wafer to comprise a surface to be cleaned and at least one nozzle to be positioned at the wafer top, then rotate the wafer, and spray a cleaning liquid through the nozzle to rinse the aforementioned The surface to be cleaned, the nozzle has a spray parameter, and the spray parameter is a function of the position of the nozzle relative to the wafer.

According to still another preferred embodiment of the present invention, the present invention provides a kind of wafer cleaning method: a kind of wafer cleaning method: at first, provide a wafer and comprise a surface to be cleaned and a nozzle comprise a plurality of openings and be positioned at above the wafer and rotate the wafer, And a cleaning liquid is sprayed through each of the openings to rinse the surface to be cleaned, and each of the openings has a spraying parameter, and the spraying parameter is a function of the position of each of the openings relative to the wafer.

The invention is characterized in that the nozzle has a spraying parameter which is a function of the position of the nozzle relative to the wafer or the position of the opening on the nozzle relative to the wafer, e.g. when the position of the nozzle in the horizontal direction is different One of the flow rate of the cleaning liquid sprayed from each nozzle, the type of cleaning liquid, the mixing ratio of the cleaning liquid and the gas, and the concentration of the cleaning liquid will be different. For example, when the wafer is being cleaned, the nozzles receiving the nozzles at the center of the wafer and the edges of the wafer spray cleaning fluid at different flow rates, and the cleaning fluid can smoothly leave the wafer surface together with the residue after rinsing off the residue.

Description of drawings

FIG. 1 is a wafer cleaning device shown in a first preferred embodiment of the present invention;

The first Fig. 2a, Fig. 2b, Fig. 3a, Fig. 3b are the top views of the wafer rotation direction and cleaning solution flushing mode;

FIG. 4 is a wafer cleaning device shown in a second preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of a variant of the second embodiment of the present invention.

Description of main component symbols

10, 100 Wafer cleaning device 12, 112 Housing

14, 114 interior cabin 16, 116 platform

18, 118 Wafers 20, 120 Surface to be cleaned

22 The first conveying pipe 24 The first nozzle

26 Second Delivery Pipe 28 Second Nozzle

30 The first cleaning solution 32 The second cleaning solution

34 Predetermined Direction 36, 136 Gas

38 Bracket 122 Delivery pipe

124 nozzle 150, 152, opening

...

158

Detailed ways

FIG. 1 shows a wafer cleaning device according to a first preferred embodiment of the present invention. As shown in Figure 1, a wafer cleaning device 10 includes a housing 12 which includes an inner cabin 14, and a platform 16 is provided at the bottom of the inner cabin 14 for carrying and rotating a wafer 18, wherein the wafer 18 has a wafer to be cleaned. The surface 20 and the inner chamber 14 can be an environment controlled by parameters such as temperature and pressure or an open space, and the platform 16 can fix the wafer 18 on the platform 16 by vacuum attraction, electrostatic attraction or mechanical capture. A first conveying pipe 22 is arranged on the upper side of the inner cabin 14, a first nozzle 24 is arranged at the end of the first conveying pipe 22 and is closer to the top of the center of the wafer 18, and a second conveying pipe 26 is also arranged inside On the upper side of the cabin 14 , a second nozzle 28 is located at the end of the second conveying pipe 26 and is relatively farther away from the center of the wafer 18 than the first nozzle 24 . There is a first height D ₁ between the first nozzle 24 and the surface 20 to be cleaned of the wafer 18; there is a second height D ₂ between the second nozzle 28 and the surface 20 to be cleaned of the wafer, it is noteworthy that: the first The height D ₁ is smaller than the second height D ₂ , preferably, the first height D ₁ is 1 cm smaller than the second height D ₂ , in this way, under the same flow rate of the fluid sprayed by the two, the first height D 1 can be sprayed by the second height D 2 A first cleaning solution 30 sprayed from a nozzle 24 reaches the surface 20 to be cleaned earlier than a second cleaning solution 32 sprayed from the second nozzle 28 . Make the surface residue in the central part of the wafer 18 can be washed away by the first cleaning solution 30 first, then the second cleaning solution 32 rinses the edge of the wafer 18, and the center of the wafer 18 can be washed away by the first cleaning solution 30 The residue on the surface of the wafer is brought to the periphery of the wafer 18, and then the residue and the cleaning solution are thrown out together by the centrifugal force caused by the rotation of the wafer 18. In addition, in order to enhance the cleaning effect, the flow rate of the first cleaning liquid 30 can be increased by 0.1 liter/min compared with the flow rate of the second cleaning liquid 32 by means of pressurization. Although in this embodiment the first delivery pipe 22 and the second delivery pipe 26 feed the first nozzle 24 and the second nozzle 28 respectively, in other embodiments of the present invention the first nozzle 24 and the second nozzle 28 may be provided by the same The delivery tubes are supplied with the same cleaning fluid.

Fig. 2a and Fig. 2b are top views showing the rotation direction of the wafer and the rinsing method of the cleaning solution according to the first preferred embodiment of the present invention. As shown in Fig. 1 and Fig. 2a, Fig. 2b, when the first cleaning liquid 30 is sprayed, the surface to be cleaned 20 of a first spraying area A ₁ covering part will be formed, and when the second cleaning liquid 32 is sprayed, a surface to be cleaned will be formed. The second spraying area _A2 covers part of the surface to be washed 20, and the size of the first spraying area _A1 and the second spraying _A2 can be adjusted independently. Preferably, the first spraying area A ₁ and the second spraying area A ₂ are alternately arranged forward and backward, that is, the first spraying area A ₁ and the second spraying area A ₂ are not on the same radius of the wafer 18 . In addition, the first spraying area _A1 also covers around the center of the circle. When the wafer 18 rotates, the first spraying area A ₁ will form a circular first cleaning surface B ₁ on the wafer 18 after the wafer 18 rotates one circle, and the second spraying area A ₂ will form a circular cleaning surface B 1 on the wafer 18. An annular second cleaning surface B ₂ .

When cleaning, the wafer 18 can rotate to a predetermined direction 34, such as clockwise or counterclockwise. When rotating, a given point Q on the surface 20 to be cleaned of the wafer 18 will first pass through the first spraying area A ₁ , and then Pass through the second spraying area A ₂ . The purpose of this design is to allow the wafer 18 to be rotated, at each point on the same radius on the wafer 18, the point closer to the center of the wafer 18 will be washed by the first cleaning solution 30 earlier than the point farther away from the center of the wafer 18 . Afterwards, the residue in the center of the wafer 18 mixed with the first cleaning solution 30 will flow for a certain distance along the direction of the centrifugal force, and then the residue and the first cleaning solution 30 will be taken to the wafer 18 by the second cleaning solution 32 of the subsequent rinse. In this way, the flow directions of the first cleaning solution 30 and the second cleaning solution 32 will not form turbulent flow, and the residues can be thrown off the surface of the wafer 18 smoothly.

The first cleaning solution 30 and the second cleaning solution 32 can be the same or different cleaning solutions, and the first cleaning solution 30 and the second cleaning solution 32 can be independently selected from deionized water, ammonia water or other chemical cleaning solutions. The first cleaning liquid 30 can be mixed with a gas 36 before spraying out, such as nitrogen or carbon dioxide, and the second cleaning liquid 32 can also be mixed with the gas 36 before spraying. In other words, during operation of this preferred embodiment, the mixed gas can be used to respectively pressurize the first cleaning liquid 30 and the second cleaning liquid 32 to regulate the flow rate of the cleaning liquid. Therefore, the first cleaning liquid 30 and the gas The mixing ratio of 36 can be different from the mixing ratio of the second cleaning liquid 32 and the gas 36, and its flow rate can be different. Preferably, the flow rate of the first cleaning liquid 30 is 0.1 liter/min larger than that of the second cleaning liquid 32 . It is worth noting that the gas for pressurization is preferably a gas component that does not participate in the cleaning reaction such as nitrogen, or a gas component that can react with cleaning can be used to increase the cleaning effect while increasing the pressure. In addition, when the first cleaning solution 30 and the second cleaning solution 32 are the same chemical solution, their concentrations can be different, for example, the first cleaning solution 30 can be 15% ammonia water, and the second cleaning solution 32 can be 17% ammonia water. % ammonia water.

In addition, FIG. 3 a and FIG. 3 b are top views of variations of the wafer rotation direction and cleaning liquid rinsing method according to the first preferred embodiment of the present invention. As shown in FIG. 3a and FIG. 3b, the first spraying area _A1 and the second spraying area _A2 can be adjusted to jointly cover a radius of the wafer. The rest of the operating conditions can be implemented according to the operating conditions in Fig. 2a and Fig. 2b.

The aforementioned surface to be cleaned 20 may be the front side of the wafer 18 , such as the active surface of the wafer 18 or the back side of the wafer 18 . The wafer 18 can be cleaned by the above-mentioned wafer cleaning device after the chemical mechanical polishing process, the etching process or the photoresist development process. According to different requirements, the first nozzle 24 and the second nozzle 28 can be fixed on the same support 38, that is to say, the relative positions between the first nozzle 24 and the second nozzle 28 are fixed, so that when cleaning, except In addition to the rotation of the wafer 18 in the predetermined direction 34 , the support 38 can also move horizontally back and forth in a scanning manner, while simultaneously translating the first nozzle 24 and the second nozzle 26 .

In summary, the first embodiment is characterized in that each nozzle has a spraying parameter, wherein the spraying parameter is a function of the position of the nozzle in the horizontal direction relative to the wafer, for example, the spraying parameter includes the distance between the nozzle and the surface to be cleaned, the cleaning liquid The flow rate of the cleaning liquid, the type of cleaning liquid, the mixing ratio of cleaning liquid and gas, and the concentration of cleaning liquid, in other words, the flow rate of cleaning liquid, the type of cleaning liquid, the mixing ratio of cleaning liquid and gas, and the concentration of cleaning liquid, etc. Varies with the position of the nozzle relative to the wafer in the horizontal direction. In view of the foregoing first preferred embodiment, the positions of the first nozzle 24 and the second nozzle 26 are different relative to the wafer 18, and the flow rate of the cleaning liquid, the type of cleaning liquid, the mixing ratio of the cleaning liquid and the gas, and the cleaning liquid are different. Concentrations of at least one of them will differ.

FIG. 4 shows a wafer cleaning device according to a second preferred embodiment of the present invention. As shown in Figure 4, a wafer cleaning 100 device comprises a housing 112 which includes an inner compartment 114, and a platform 116 is provided at the bottom of the inner compartment 114 for carrying and rotating a wafer 118, wherein the wafer 118 has a wafer to be cleaned. Surface 120. A conveying pipe 122 is arranged on the upper side of the inner chamber 114, a nozzle 124 is arranged at the end of the conveying pipe 122 and is positioned above the wafer 118, and the nozzle 124 includes a plurality of openings, such as openings 150, 152, 154, 156, 158 , the height of each opening and the surface to be cleaned 120 varies with the position of each opening relative to the wafer 118, for example, the height D ₃ between the opening 150 and the surface to be cleaned 120, and the height D 3 between the opening 158 and the surface to be cleaned 120 The height D ₄ is different. According to a preferred embodiment of the present invention, relative to the opening above the center of the wafer 118, such as the opening 150, it will be closer to the surface 120 to be cleaned, while the opening at the edge of the wafer 118, such as the opening 158, will be farther away from the surface 120 to be cleaned. . In this way, under the same flow rate, the cleaning solution sprayed from the opening 150 can reach the surface to be cleaned 120 earlier than the cleaning solution discharged from the opening 158 . In addition, the distances between the openings can be the same or different. For example, the opening 154 and its adjacent openings 152 and 156 have a first distance P ₁ and a second distance P ₂ , wherein the first distance P ₁ and the second distance P 2 The pitch _P2 is different.

Similarly, when cleaning the wafer 118, the wafer 118 can rotate clockwise or counterclockwise. At this time, the cleaning liquid sprayed from each opening will form a spraying area respectively, such as the cleaning liquid sprayed from the opening 156 forms a spraying area A _3. The cleaning liquid sprayed from the opening 158 forms a spraying area A ₄ , and each spraying area formed by all the openings together covers the radius of the wafer 118 . In addition, the conveying pipe 122 may include a plurality of manifolds, which are respectively connected to each opening, so the cleaning liquid sprayed from each opening may be the same or different cleaning liquids, and the cleaning liquid may be deionized water, ammonia water or chemical Cleaning fluid, etc. The cleaning fluid may be mixed with a gas 136, such as nitrogen or carbon dioxide, before being sprayed out from the openings. During operation, the mixed gas can be used to pressurize the cleaning liquid separately to regulate the flow rate of the cleaning liquid. Therefore, since the mixing ratio of the cleaning liquid and gas ejected from each opening can be different, the flow rate can also be different. In addition, the concentration of the cleaning liquid sprayed from each opening can be different, for example, the cleaning liquid sprayed from the opening 150 can be 15% ammonia water, and the cleaning liquid sprayed from the opening 158 can be 17% ammonia water.

Of course, although only one nozzle 124 with multiple openings is shown in FIG. 4 , according to different operation requirements, multiple nozzles can also be provided at the same time to increase the cleaning capacity.

What Fig. 5 depicts is the variation of the second embodiment of the present invention, and wherein the element of same function will use the label among Fig. 4, as shown in Fig. 5, nozzle 124 can be a V shape, also can be provided with on it The difference between the plurality of openings and the nozzle in FIG. 4 is that each spraying area formed by the cleaning liquid sprayed from each opening of the nozzle in FIG. 5 covers a diameter of the wafer together.

In the embodiment of FIG. 4 and FIG. 5 , the surface to be cleaned of the wafer 118 may be the front side of the wafer 118 , such as the active surface of the wafer 118 or the back side of the wafer 118 . The wafer 118 may be cleaned by the above-mentioned wafer cleaning device after a chemical mechanical polishing process, an etching process, or a photoresist development process. During cleaning, in addition to rotating the wafer 118 in a predetermined direction, the nozzle 124 can also move horizontally back and forth in a scanning manner.

In summary, the second embodiment and its variations are characterized in that the nozzle has a spraying parameter, wherein the spraying parameter is a function of each opening on the nozzle relative to the position of the wafer in the horizontal direction, and the spraying parameter includes the opening and the surface to be cleaned The distance between the openings, the flow rate of the cleaning liquid, the type of cleaning liquid, the mixing ratio of the cleaning liquid and the gas, and the concentration of the cleaning liquid, in other words, the distance between the opening and the surface to be cleaned, the flow rate of the cleaning liquid, the concentration of the cleaning liquid The ratio of kind, cleaning liquid and gas mixing and the concentration of cleaning liquid can change along with the position of opening relative to wafer, with regard to aforementioned second preferred embodiment, opening 150 and opening 158 are relative to the position of wafer 118 in horizontal direction. The positions are different, but at least one of the distance between the opening and the surface to be cleaned, the flow rate of the cleaning solution, the type of cleaning solution, the mixing ratio of cleaning solution and gas, and the concentration of the cleaning solution will be different. In this way, the cleaning conditions of the wafer surface can be adjusted according to different requirements from the center edge, for example, the cleaning solution with a faster flow rate is used at the center of the wafer, and the cleaning solution with a slower flow rate is used at the edge of the wafer. Therefore, cleaning the wafer can avoid the problem of residue remaining on the wafer after wafer cleaning.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (9)

1. a wafer cleaning mode, comprises:

There is provided a wafer, it comprises surface to be washed and at least one nozzle is positioned at above this wafer;

Rotate this wafer, and rinse this surface to be washed by this nozzles spray one cleaning fluid, this nozzle has spraying parameter, and this spraying parameter is that this nozzle is in the horizontal direction relative to the function of the position of wafer.

2. wafer cleaning mode as claimed in claim 1, wherein this cleaning fluid is before sprinkling, at least with one gas and vapor permeation.

3. wafer cleaning mode as claimed in claim 2, wherein this spraying parameter is selected from following group: the kind of the distance between this nozzle and this surface to be washed, the flow velocity of this cleaning fluid, this cleaning fluid, this cleaning fluid and the ratio of this gas and vapor permeation and the concentration of this cleaning fluid.

4. wafer cleaning mode as claimed in claim 1, wherein this wafer cleaning mode is carried out after being surface after cmp manufacture craft, after etching process or development of photoresist manufacture craft.

5. a wafer cleaning mode, comprises:

There is provided a wafer to comprise surface to be washed and nozzle, this nozzle comprises multiple opening and is positioned at above this wafer; And

Rotate this wafer, and respectively spray a cleaning fluid by each this opening and rinse this surface to be washed, respectively this opening respectively has spraying parameter, this spraying parameter be respectively this opening in the horizontal direction relative to the function of the position of this wafer.

6. wafer cleaning mode as claimed in claim 5, wherein this cleaning fluid is before sprinkling, at least with one gas and vapor permeation.

7. wafer cleaning mode as claimed in claim 6, wherein this spraying parameter is selected from following group: the kind of the distance respectively between this opening and this surface to be washed, the flow velocity of this cleaning fluid, this cleaning fluid, this cleaning fluid and the ratio of this gas and vapor permeation and the concentration of this cleaning fluid.

8. wafer cleaning mode as claimed in claim 5, wherein this wafer cleaning mode is carried out after being surface after cmp manufacture craft, after etching process or development of photoresist manufacture craft.

9. wafer cleaning mode as claimed in claim 5, wherein this cleaning fluid is by when respectively this opening sprays, and each formation one spray area covers the diameter of this wafer jointly.