TWI582886B - Device for wet treatment of single wafer - Google Patents

Description

Single wafer wet processing unit

The present invention relates to a wafer processing apparatus, and more particularly to a single wafer wet processing apparatus suitable for preventing corrosion of the underside of a wafer edge.

Generally, microelectronic components are fabricated on the front side or the device side of a semiconductor wafer. In the process of semiconductor wafer, it is necessary to perform multiple processing steps on the front side of the semiconductor wafer, for example, spraying a treatment liquid (such as chemical or deionized water) on the surface of the wafer to perform etching and cleaning of the wafer. Wet processing procedure. Please refer to FIG. 1 , which is a schematic cross-sectional view of a conventional rotary etching cleaning machine. The conventional rotary etch cleaning machine 10 includes an etching chamber 12. The etching chamber 12 is provided with a loading table 14 for carrying and fixing a wafer W. The rotating shaft 16 below the loading table 14 can be set according to various process parameters. It is required to rotate at a high speed and a low speed to drive the wafer W to rotate, and the etching liquid 19 flows down from the liquid supply unit 18 above the wafer W to etch the front surface of the wafer W.

When the etching is performed, if the process parameters of the wafer W are at a low rotation speed, the chemical liquid film or corrosive gas on the front side of the wafer W may be reduced from the centrifugal force of the wafer, and may flow from the edge of the wafer W to the wafer. The bottom surface of the W and the stage 14 further cause corrosion, and corrosion contaminants such as metal particles, residues or films are formed on the bottom surface of the wafer W. If the above substances are not removed, the components on the front side of the wafer will be destroyed or contaminated. For example, some metal materials used in the process, such as copper, may stick back from the bottom surface of the wafer to the front side of the wafer, which will cause micro-electricity. Sub-components create defects and reduce manufacturing yields. Therefore, when performing the above wet process, the protection measures for the bottom surface of the wafer W are important considerations for the design of the device.

In view of the above, in order to prevent corrosion of the bottom surface of the wafer edge, an object of the present invention is to provide a single-wafer wet processing apparatus which generates a gas wall on the bottom surface of the wafer edge through the annular gas nozzle to isolate the etching liquid or corrosive. The corrosion of the gas on the underside of the wafer overcomes the problem of wafer backside contamination in the prior art.

To achieve the above object, the present invention provides a single wafer wet processing apparatus for preventing corrosion of the bottom surface of a wafer edge, which comprises a rotary chuck, a back wash holder and an annular gas nozzle. The rotary chuck is used to hold and rotate a wafer. The backwashing seat is disposed around the rotating collet and includes an annular plane having a predetermined spacing from a bottom surface of the wafer, and the backwashing seat has a right-angled structure at a periphery of the annular plane. The annular gas nozzle is disposed on the annular plane of the backwashing seat and spaced apart from the edge of the wafer by a predetermined distance, and the direction of the ejected gas is at a predetermined angle with the annular plane for use in the annular plane and the crystal A gas wall is formed between the bottom surfaces of the circle. The predetermined pitch is between 2 mm and 5 mm, and the predetermined distance is between 10 mm and 15 mm, and the predetermined angle is between 30 and 45 degrees.

In a preferred embodiment, the outer circumference of the annular plane is approximately equal to the edge of the wafer, and the right angle structure approximately cuts the edge of the wafer.

In a preferred embodiment, the predetermined spacing is 3 mm.

In a preferred embodiment, the predetermined distance is 13 mm.

In a preferred embodiment, the predetermined angle is 40 degrees.

In a preferred embodiment, the annular gas nozzle is one of the backwashing seats Circular oblique seam structure.

In a preferred embodiment, the annular gas nozzle is used to eject nitrogen gas and the flow rate of nitrogen gas ejected is between 100 LPM (liters per minute) to 150 LPM. Preferably, the flow rate of nitrogen gas is 120 LPM.

In a preferred embodiment, the single-wafer wet processing apparatus further includes an inner annular gas nozzle that is disposed on the annular plane of the backwashing seat and is concentric with the annular gas nozzle for An air wall is formed between the annular plane and the bottom surface of the wafer.

In a preferred embodiment, the single-wafer wet processing apparatus further includes a pure water jet head opened on the annular plane of the backwashing seat for flushing the bottom surface of the wafer edge .

Compared with the prior art, the single-wafer wet processing apparatus of the present invention is configured to set the predetermined pitch to be between 2 mm and 5 mm, and the predetermined distance is between 10 mm and 15 mm, and the predetermined angle is between 30 and 45 degrees. Optimize the etchant or corrosive gas that is intended to flow to the underside of the wafer for excellent protection. Further, preferably, the predetermined pitch is set to 3 mm, the predetermined distance is 13 mm, the predetermined angle is 40 degrees, and the flow rate of the discharged nitrogen gas is 120 LPM, thereby obtaining an optimum wafer bottom surface protection effect.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

10‧‧‧Knowledge Rotary Etching Cleaning Machine

12‧‧‧ etching cavity

14‧‧‧Package

16‧‧‧ shaft

18‧‧‧Liquid supply unit

19‧‧‧ etching solution

20‧‧‧Single wafer wet processing apparatus of the first preferred embodiment

22‧‧‧Rotary chuck

24‧‧‧Back wash

26‧‧‧ annular gas nozzle

27‧‧‧Inner ring gas nozzle

28‧‧‧pure water sprinkler

32‧‧‧ edge

34‧‧‧ bottom

40‧‧‧Single wafer wet processing apparatus of the second preferred embodiment

242‧‧‧Circular plane

244‧‧‧ outer periphery

262‧‧‧Circular oblique joint structure

271‧‧‧First gas source

272‧‧‧Second gas source

C‧‧‧Predetermined angle

D‧‧‧Predetermined distance

R‧‧‧right angle structure

P‧‧‧Predetermined spacing

W‧‧‧ wafer

Figure 1 is a schematic cross-sectional view of a conventional rotary etch cleaning machine.

2 is a top plan view of a single wafer wet processing apparatus according to a first preferred embodiment of the present invention; Figure.

Fig. 3 is a schematic cross-sectional view taken along line A-A' of Fig. 2.

Figure 4 is a partial enlarged view of the backside wash and wafer of Figure 3.

Figure 5 is a top plan view of a single wafer wet processing apparatus in accordance with a second preferred embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view taken along line B-B' of Fig. 5.

The present invention has been described in detail with reference to the preferred embodiments in the

Please refer to FIG. 2 and FIG. 3 . FIG. 2 is a top plan view of a single-wafer wet processing apparatus according to a first preferred embodiment of the present invention, and FIG. 3 is a cross-sectional view along line A-A′ of FIG. 2 . schematic diagram. As shown, the single wafer wet processing apparatus 20 of the first preferred embodiment is for preventing the bottom surface 34 of the wafer edge 32 from being corroded by the etchant 19 or gas. For the sake of clarity, the wafer W is not shown in FIG. In detail, as shown in FIG. 3, the single wafer wet processing apparatus 20 of the present embodiment includes a rotary chuck 22, a back wash holder 24, an annular gas nozzle 26, and a pure water spray head 28. The above components may be disposed in an etching chamber (not shown). The rotating chuck 22 is further provided with a liquid supply unit 18 for supplying a fluid such as an etching solution 19 or a cleaning liquid.

As shown in FIG. 3, the rotating chuck (Chuck) 22 is used to hold and rotate the wafer W. Preferably, the rotating chuck 22 generates a vacuum negative pressure to suck and hold the wafer W. In addition, the rotary chuck 22 is coupled to a rotating shaft 16 that can rotate at a high and low speed for rotating the wafer W.

As shown in FIG. 2 and FIG. 3, the backwashing seat 24 is disposed around the rotating collet 22, and the backseat 24 includes an annular flat surface 242 and a bottom surface 34 of the wafer W. There is a predetermined pitch P, i.e., the annular plane 242 is slightly lower than the plane of the spin chuck 22 such that the wafer W does not contact the annular plane 242. The predetermined pitch P is between 2 mm and 5 mm, and a better anti-erosion effect can be obtained. In the present embodiment, the predetermined pitch P is 3 mm. The backwashing seat 24 is a right angle structure R at the outer periphery 244 of the annular plane 242. That is, the backwashing seat 24 of the present embodiment does not have an arc or a leading angle at the outer periphery 244 of the annular plane 242. The structure is designed to prevent airflow turbulence and erode the bottom surface 34 of the wafer W. It should be noted that the outer circumference 244 of the annular plane 242 is approximately equal to the wafer edge 32, and the right angle structure R is approximately aligned with the wafer edge 32, that is, the outer circumference 244 of the annular plane 242 is approximately equal to the diameter of the wafer W. Define the circle.

Please refer to FIG. 4, which is a partial enlarged view of the backside holder 24 and the wafer in FIG. The annular gas nozzle 26 is disposed on the annular plane 242 of the backwashing seat 24 and spaced apart from the wafer edge 32 by a predetermined distance D, and the direction of the gas (not shown) (ie, the tangential direction of the opening) is The annular plane 242 is sandwiched by a predetermined angle C for forming a gas wall or an air cushion between the annular plane 242 and the bottom surface 34 of the wafer W, and can block the etching of the etching liquid 19 or the gas on the bottom surface 34 of the wafer. . Specifically, the annular gas nozzle 26 is an annular beveled structure 262 on the backwashing seat 24. Further, the predetermined distance D is between 10 mm and 15 mm, and a better gas wall or air cushion effect can be obtained. In the embodiment, the predetermined distance D is 13 mm. In addition, the predetermined angle C is between 30 degrees and 45 degrees, and a better gas wall or air cushion effect is also obtained. In the embodiment, the predetermined angle C is 40 degrees. It is worth mentioning that the annular gas nozzle 26 is used for discharging nitrogen gas, and the flow rate of the nitrogen gas is from 100 LPM (liters per minute) to 150 LPM, which can obtain a better gas wall forming effect. In this embodiment, the flow rate of nitrogen gas ejected was 120 LPM.

Referring to FIG. 2, in addition to blocking the etching liquid 19 or gas by the annular gas nozzle 26, the single wafer wet processing apparatus 20 of the present embodiment further includes a pure water head 28, The pure water spray head 28 is disposed on the annular plane 242 of the backwashing seat 24 for spraying DI water to flush the bottom surface 34 of the wafer edge 32 to further protect the bottom surface 34.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a top plan view of a single-wafer wet processing apparatus according to a second preferred embodiment of the present invention, and FIG. 6 is a cross-sectional view along line BB′ of FIG. schematic diagram. The single wafer wet processing apparatus 40 of the present embodiment is for preventing the bottom surface 34 of the wafer edge 32 from being corroded by the etching liquid 19 or gas. The single wafer wet processing apparatus 40 of the present embodiment includes a rotary chuck 22, a back wash holder 24, an annular gas nozzle 26, a pure water spray head 28, and an inner annular gas nozzle 27. The above components may be disposed in an etching chamber (not shown). The rotating chuck 22 is further provided with a liquid supply unit 18 to provide a fluid such as an etching solution 19 or a cleaning liquid. The first wafer wet processing apparatus 40 of the present embodiment further includes an inner annular gas nozzle 27, and the inner annular gas nozzle 27 is formed on the annular plane 242 of the backwashing seat 24, and A concentric circle is formed with the annular gas nozzle 26 for forming a gas wall between the annular plane 242 and the bottom surface 34 of the wafer W to further enhance the barrier of gas (such as sour gas).

Further, the single-wafer wet processing apparatus 40 of the second preferred embodiment can be used for large-sized wafers such as 12, 18, etc. through the inner annular gas nozzles 27 disposed in the inner circumference of the annular gas nozzle 26. A better anti-erosion effect is obtained. In addition, the annular gas nozzle 26 and the inner annular gas nozzle 27 may be connected to the first gas source 271 and the second gas source 272, respectively. The first gas source 271 and the second gas source 272 can simultaneously supply nitrogen gas to the annular gas nozzle 26 and the inner annular gas nozzle 27, and can also control the first gas source 271 and the second gas source 272, respectively, without supplying nitrogen at the same time, or Only one of the annular gas nozzle 26 and the inner annular gas nozzle 27 is supplied.

In summary, the single-wafer wet processing apparatus 20, 40 of the present invention is configured to set the predetermined pitch P to be between 2 mm and 5 mm, the predetermined distance D being between 10 mm and 15 mm, and the predetermined clip. The angle C is between 30 and 45 degrees, and the etching liquid 19 or gas which is intended to flow to the bottom surface 34 of the wafer W can be optimized to obtain an excellent protective effect. Further, preferably, the predetermined pitch is set to 3 mm, the predetermined distance is 13 mm, the predetermined angle is 40 degrees, and the flow rate of the discharged nitrogen gas is 120 LPM, so that an optimum bottom surface 34 protection effect can be obtained.

While the invention has been described above in the preferred embodiments, it is not intended to limit the invention. Various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

16‧‧‧ shaft

18‧‧‧Liquid supply unit

19‧‧‧ etching solution

20‧‧‧Single wafer wet processing apparatus of the first preferred embodiment

22‧‧‧Rotary chuck

24‧‧‧Back wash

26‧‧‧ annular gas nozzle

32‧‧‧ edge

34‧‧‧ bottom

242‧‧‧Circular plane

R‧‧‧right angle structure

P‧‧‧Predetermined spacing

W‧‧‧ wafer

Claims (10)

A single-wafer wet processing apparatus for preventing corrosion of a bottom surface of a wafer edge, comprising: a rotating chuck for holding and rotating a wafer; and a back washing seat disposed around the rotating chuck, including a ring a circular plane having a predetermined spacing from a bottom surface of the wafer, the backwashing seat being a right-angled structure at a periphery of the annular plane; and an annular gas nozzle opening in the annular plane of the backwashing seat And a predetermined distance from the edge of the wafer, and the direction of the ejected gas is at a predetermined angle with the annular plane for forming a gas wall between the annular plane and the bottom surface of the wafer; wherein the predetermined spacing It is between 2 mm and 5 mm, and the predetermined distance is between 10 mm and 15 mm, and the predetermined angle is between 30 and 45 degrees. The single wafer wet processing apparatus of claim 1, wherein a peripheral edge of the annular plane is approximately equal to the edge of the wafer, and the right angle structure approximately cuts the edge of the wafer. The single wafer wet processing apparatus of claim 1, wherein the predetermined pitch is 3 mm. The single wafer wet processing apparatus of claim 1, wherein the predetermined distance is 13 mm. The single wafer wet processing apparatus of claim 1, wherein the predetermined angle is 40 degrees. The single wafer wet processing apparatus according to claim 1, wherein the annular gas nozzle is an annular oblique slit structure on the backwashing seat. The single-wafer wet processing apparatus according to claim 1, wherein the annular gas nozzle is used for discharging nitrogen gas, and the flow rate of the discharged nitrogen gas is from 100 LPM (liters/minute) to 150 LPM. The single-wafer wet processing apparatus according to claim 7, wherein the flow rate of the nitrogen gas is 120 LPM. The single-wafer wet processing apparatus according to claim 1, further comprising an inner annular gas nozzle which is disposed on the annular plane of the backwashing seat and is concentric with the annular gas nozzle. An air wall is formed between the annular plane and the bottom surface of the wafer. The single-wafer wet processing apparatus according to claim 1, further comprising a pure water jet head opened on the annular plane of the backwashing seat for the edge of the wafer The bottom surface is rinsed.