KR0172519B1 - Gas supplying head and load lock chamber of semiconductor processing system - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a gas supply head for preventing particle contamination of a processing surface of a substrate to be issued due to introduction of gas into an airtight space, and a load lock chamber using the same. The system has a processing chamber and a load lock chamber. The load lock seal has an airtight casing having an opening for the wafer to pass through, the opening being openable but closed tightly by the gate bell portion. The carrying arm for conveying a wafer is arrange | positioned in a casing. The casing is connected to a gas supply system and an exhaust system of inert gas. The gas supply head is connected to the inner end of the gas supply system. The gas supply head has an outlet filter composed of a porous ceramic plate formed as a cylinder. The porous ceramic plate has a multilayer structure composed of a support layer, an intermediate layer, and a filter layer. The average diameter of the micropores of the filter layer is set to 0.8 µm to 0/1 µm, and the porosity is set to 10% to 50%.

Description

Gas supply head and load lock seal of semiconductor processing system

1 is a schematic diagram showing an etching system of a semiconductor wafer using a load lock seal according to an embodiment of the present invention.

FIG. 2 is a cutaway view of an enlarged view of the gas supply head shown in FIG. 1. FIG.

3 is an enlarged cross-sectional view of the porous plate constituting the outlet filter of the gas supply head shown in FIG.

4A and 4B are respectively a schematic perspective view showing an arrangement form in a load lock interior of a gas supply head shown in FIG. 1, and a plan view showing a positional relationship with a wafer.

FIG. 5 is a graph showing the effect in the load lock chamber of the gas supply head shown in FIG.

6 is a graph showing the relationship between the installation place and the effect of the gas supply head shown in FIG.

FIG. 7 is a view showing a place for installing a gas supply head in the experiment shown in FIG.

8 shows a load lock seal according to another embodiment of the present invention.

FIG. 9 is a graph showing the relationship between the pressure in the load lock room and the gas flow rate in an experiment conducted using the load lock room shown in FIG.

FIG. 10 is a graph showing the relationship between the pressure in the load lock room and the gas flow rate in another experiment conducted using the load lock room shown in FIG.

FIG. 11 is a graph showing the relationship with the gas flow rate in the load lock room in another experiment conducted using the load lock room shown in FIG.

12 is a schematic diagram showing an etching system of a semiconductor wafer using a load lock seal according to another embodiment of the present invention.

13 is a schematic perspective view showing a load lock chamber according to another embodiment of the present invention.

14 is a schematic perspective view showing a load lock seal according to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

2,22: casing 3,13,14,23,24: opening

5,26,65,76: exhaust system 21,51,71: load lock seal

31: gas introduction pipe 32: gas supply head

40,91: outlet filter 45: hollow cylinder

46: gas reservoir 47: support layer

48: intermediate layer 49: filtration layer

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a gas supply head used in a system for performing semiconductor processing on a substrate to be processed, such as a semiconductor wafer or an LCD substrate, and a load lock chamber using the same. It relates to a gas supply head and a load lock chamber using the same to prevent the.

In a semiconductor processing system, a load lock chamber (preparation chamber) is usually disposed in a process chamber, a process chamber, and a process chamber connected via a gate. In the processing chamber, various processing gases are used, and for example, processing is performed on a substrate to be processed such as a semiconductor wafer or an LCD substrate under reduced pressure. The load lock chamber is usually connected to an inert gas supply system and an exhaust system, and is capable of adjusting pressure independently of the processing chamber. The load lock seal for carrying in and the load lock seal for carrying out may be separately provided.

In semiconductor processing, for example, a semiconductor wafer is first brought into a load lock room. Next, the discharge and replacement of the gas in the load lock room are performed, and the load lock room becomes a reduced pressure atmosphere almost the same as that in the processing chamber. The gate is then opened and the process chamber wafer is transferred from the load lock chamber. The gate is then closed and the wafer is processed in the processing chamber.

After processing the wafer, the gate is opened and the wafer is transferred to the load lock chamber. Next, the gate is closed to discharge and replace the gas in the load lock room, and the load lock room becomes an inert gas such as nitrogen gas or an air atmosphere. Next, the wafer is taken out of the load lock chamber.

In the load lock room, the surface of the wafer may be contaminated by particles due to the introduction of inert gas or air. One reason is that particles such as fine dust that adhere to the inner wall of the load lock chamber are blown up by gas introduction. Another cause is that fine particles entering the gas itself are introduced into the load lock room with the gas.

As a general method of preventing particles from flying out, a so-called slow venting method is known in which the opening degree of a gas introduction valve is gradually increased and the increase in gas flow rate is suppressed. However, no matter how carefully the opening degree of the valve is adjusted, the moment when the valve is opened in the depressurized state, especially in the high pressure pressure state, gas flow occurs due to the sudden change in pressure, and particles in the load lock room are blown up. In addition, intrusion of fine particles into the gas itself cannot be prevented.

Accordingly, it is an object of the present invention to provide a gas supply head and a load lock chamber using the same for preventing particle contamination of a surface to be processed in a substrate to be generated due to introduction of gas into an airtight space.

The gas supply head for supplying the gas for pressure adjustment in the casing in a state where the substrate to be processed in the system is supported in the hermetic casing of the semiconductor processing system according to the first aspect of the present invention, provides the gas into the casing. An outlet filter including a gas reservoir connected to a gas introduction pipe for introduction, a porous filtration layer having a plurality of micropores communicating between the gas reservoir and the casing, and an average diameter of the micropores of 0.8 mu m; It is equipped with -0.1 micrometer, and the porosity of the said filtration layer is 10%-50%.

A load lock chamber of a semiconductor processing system for processing a substrate according to a second aspect of the present invention includes an airtight cage (K) having an opening for passage of the substrate, and means for closing the opening and the airtight opening. And support means for supporting the substrate in the casing, a gas introduction pipe for introducing a pressure regulating gas into the casing, an exhaust system for exhausting the inside of the casing, and the gas introduction pipe. A gas supply head for supplying gas from the gas introduction pipe into the casing while the substrate is supported by means, a gas reservoir in which the gas supply head is connected to the gas introduction pipe, and the gas reservoir An outlet filter having a porous filtration layer having a plurality of micropores communicating therein with the inside of the casing; The average diameter of the hole and a void fraction of that 0.8㎛~0.1㎛, the filtration layer is 10% ~50%.

1 is a schematic diagram showing an etching system of a semiconductor wafer using a load lock seal according to an embodiment of the present invention.

The etching system shown in FIG. 1 has a processing chamber 1 and one preliminary chamber for wafer loading and unloading, that is, a load lock chamber 21. The process chamber 1 has an airtight casing 2 with one opening port 3), and the load lock chamber 21 has an airtight casing 22 with two openings 23 and 24 facing each other. It is provided. The opening 3 of the processing chamber 1 and the opening 23 of the load lock chamber 21 are hermetically connected to the processing chamber 1 via the gate belt 18. In addition, the opening port 24 of the load lock chamber 21 is hermetically connected to an in / out section, for example, a mounting portion of a cassette for storing a plurality of wafers by the gate valve 19.

The reaction gas supply system 4 is connected to the upper part of the process chamber 1, and the exhaust system 5 is connected to the lower part. In the processing chamber 1, a susceptor 6 serving as a mounting table and a lower electrode, a shower electrode 7 serving as a showerhead of the upper electrode and the reactive gas supply system 4 facing the lower electrode are disposed. . The susceptor 6 is connected to the high frequency power supply 9 via the matching circuit 8, and the shower electrode 7 is grounded. Since the wafer w is fixed to the susceptor 6 around the susceptor 6, the crimp 11 which can be moved is disposed. In addition, a cooling jacket 12 for cooling the susceptor 6 by introducing a coolant into the susceptor 6 and introducing a coolant into the susceptor 6, the susceptor 6 and the wafer w. The line 13 for supplying heat transfer gas to the difference is embedded.

The upper part of the load lock chamber 21 is connected with a gas supply system 25 for supplying an inert gas such as pressure adjusting or gas replacement nitrogen, or gas such as clean air, and an exhaust system 26 at the lower portion thereof. Accordingly, the load lock seal 21 is independently adjustable in internal pressure. In the center of the load lock chamber 21, a transfer arm 27 for transferring the wafer w is provided through the openings 13 and 14.

The gas supply system 25 of the load lock chamber 21 is provided with a gas introduction pipe 31 which passes through the casing 22 in an airtight manner and is connected to a gas supply source. The gas supply head 32 is connected to the tip of the introduction pipe 31. The pipe 31 is connected to an inert gas such as nitrogen or a gas supply source 35 such as air via the regulator 33 and the valve 34. These members 33 to 35 are controlled by the controller 36.

Next, an example of a wafer etching process using the etching system shown in FIG. 1 will be described.

First, the gate valve 19 of the load lock chamber 21 is opened to communicate the entrance and exit, and the wafer w serving as the substrate to be processed is loaded into the load lock chamber 21. Next, the gate valve 19 is closed to keep the load lock chamber 21 airtight, and the load lock chamber 21 is exhausted through the exhaust system 26 to be in a reduced pressure state. Next, the gas supply head 32 introduces the same atmospheric gas into the load lock chamber 21 into the load lock chamber 21 and replaces the inside of the load lock chamber 21 with the gas in the process chamber 1 (first gas introduction). fair).

The first gas introduction step can also be performed simultaneously with the exhaust step. In addition, it is not necessary to provide a forced exhaust means in the exhaust system. In this case, the inside of the load lock chamber 21 is gas-substituted only by natural exhaust by introducing a replacement gas.

Next, the gate valve part 18 which hermetically connects the load lock chamber 21 and the process chamber 1 is opened, and the load lock chamber 21 and the process chamber 1 are communicated. Next, the wafer w is transferred into the processing chamber 1, mounted on the susceptor 6, and fixed with the clamp 11. Next, the gate valve 18 is closed and the load lock chamber 21 and the processing chamber 1 are hermetically isolated from each other. Next, the etching gas such as chlorine-based gas is supplied from the reaction gas supply system 4 into the processing chamber 1, and a high frequency voltage is applied between the upper and lower electrodes 7, 6 to form the etching gas. And the wafer w is etched using this plasma.

After etching the wafer w, the gate valve 18 is opened to communicate the load lock chamber 21 with the processing chamber 1. Next, the wafer w is transferred into the load lock chamber 21, but a part of the atmospheric gas in the processing chamber 1 also moves into the load lock chamber 21. Next, the gate valve 18 is closed and the load lock chamber 21 and the process chamber 1 are hermetically isolated from each other.

Next, the gas is exhausted by the exhaust system 26, and the inside of the load lock chamber 21 is reduced in pressure. Next, for example, an inert gas is introduced into the gas supply head 32 while exhausting the inside of the load lock chamber 21, and the inside of the load lock chamber 21 is reduced in pressure. Next, for example, an inert gas is introduced from the gas supply head 32 while the inside of the load lock chamber 21 is exhausted, and the inside of the load lock chamber 21 is replaced with an inert gas (second gas introduction step). Next, the gate valve 19 is opened to communicate the load lock chamber 21 with the inlet and out of the wafer w.

As shown in FIG. 2, the gas supply head 32 has an outlet filter 40 formed as a hollow cylinder 45 having an outer diameter of about 19 mm and a length of about 100 mm. The outlet filter 40 is composed of an alumina ceramic porous plate having a thickness of about 2 mm. As shown in FIG. 3, the porous plate constituting the outlet filter 40 has a multilayer structure composed of the support layer 47, the intermediate layer 48, and the filter layer 49 in order from the outside. A multilayer structure composed of a support layer 47, an intermediate layer 48, and a filter layer 49 is formed. Each of the support layer 47, the intermediate layer 48, and the filtration layer 49 has an average diameter of about 10 mu m, about 1 mu m, and about 0.2 mu m. The thickness of each of the support layer 47, the intermediate layer 48, and the filter layer 49 is about 2 mm, 20 µm to 30 µm, and 20 µm to 30 µm. When manufacturing the outlet filter 40, first, the thick support layer 47 is fired to form a hollow cylinder, and then the inner layer 48 is coated with the material of the intermediate layer 48, and then the filter layer 49 is finally fired on the inner surface thereof. The material of is coated and fired at the same time.

The end plate 42 made of stainless steel (SUS316L) is fixed to both ends of the filter cylinder 45, that is, the porous cylinder 45, via a gasket made of Teflon, that is, an encapsulant 41. As a result, both ends of the filter cylinder 45 are hermetically closed, and a gas reservoir 46 is formed in the cylinder 45. The stainless steel pipe 43 is inserted into the cylinder 45 through the through hole of one end plate 42. The pipe 43 is connected to the gas inlet pipe 31 outside the filter cylinder, and the end of the pipe 43 in the cylinder 45 is closed.

In the filter cylinder 45, a total of 24 holes 44 having a diameter of about 2 mm are disposed in the pipe 43. The holes 44 extend in the axial direction shifted by the circumferential wall 90 degrees of the pipe 43. It is drilled according to four rows. In each row, six are arranged at regular intervals along the axial direction of the pipe 43. In addition, the holes 44 are arranged in a zigzag form in adjacent rows.

When assembling the gas supply head 32, first, the cylinder 45, the end plate 42, and the sealing material 41 are arranged in the order shown in FIG. Next, the tip end of the pipe 43 is loosely passed through the through hole of one end plate 42, and the tip end of the pipe 43 is fixed to the other end plate 42 by welding. Next, the pipe 43 and the one end plate 42 are welded and fixed while the one end plate 42 is pushed toward the other end plate 42, and the through hole passes through the pipe 43. It is closed confidentially. Moreover, in order to prevent corrosion of metal parts, such as an end plate and the 42, 43, more safely, corrosion prevention processing, such as melting and spraying ceramics of a metal part, can also be performed.

As shown in FIG. 4A, the gas supply head 32 is positioned near the center of the upper portion of the load lock chamber 21, and there is sufficient space between the filter cylinder 45 and the ceiling of the load lock chamber 21. It is arranged to be formed. When the carrier arm 27 holds and waits for the wafer w in the load lock chamber 21, as shown in FIG. 4B, the filter cylinder 45 and the wafer w are substantially centered. In addition, the axis of the filter cylinder 45 and the to-be-processed surface of the wafer w become parallel at this time. Therefore, the porous plate of the cylinder 45 is disposed so as to be symmetrical with respect to the line on the vertical plane lowered with respect to the processing surface of the wafer w on the axis of the cylinder 45.

In the gas supply head 32 having such a configuration, when gas is supplied from the gas introduction pipe 31 to the pipe 43, the gas flows out of the hole 44 of the pipe into the gas reservoir 46 of the filter cylinder 45. do. The gas is constantly discharged in the 360 degree direction from the entire surface of the cylinder 45 through each minute hole of the outlet filter 40. For this reason, the outflow area of gas is large and a flow velocity can be reduced with respect to flow volume. In addition, since the gas flows out into the load lock room in the laminar flow direction in a 360 degree direction, it flows as if it cleans the to-be-processed surface of the wafer W on the carrier arm 27 by rain. Therefore, the flying of the particles is extremely suppressed, and even if the flying of the particles can be prevented from dropping and adhering to the wafer surface.

The gas supply head 32 of this embodiment is designed not only to prevent the particles in the load lock chamber 21 from flying up but also to remove 99.9999% of particles of 0.01 µm or more present in the gas to be introduced. As such, when the diameter of the micropores of the outlet filter 40 is reduced to remove the fine particles only by the filtration action, the pressure loss becomes too large. In the present invention, in addition to the filtration action of the outlet filter 40, fine particles are removed by using the electrostatic adsorption action. For example, in the filtration layer 49 of the outlet filter 40 of this embodiment, the average diameter of the micropores is about 0.2 탆, and the particles smaller than the average diameter are formed by the electrostatic adsorption action of the outlet filter 40. The inner surface of 45 is trapped and removed.

In addition, the porous plate of the outlet filter 40 has a porous structure composed of the support layer 47, the intermediate layer 48, and the filtration layer 49 as described above. Thereby, the thickness of the filtration layer 49 which has a micropore of small average diameter can be 20 micrometers-30 micrometers, and a high filtration function can be obtained without increasing a pressure loss. In addition, by providing the intermediate layer 48 between the support layer 47 and the filtration layer 49, the problem that ceramic particles constituting the filtration layer 49 are embedded in the ceramic particles constituting the support layer 49 can be solved. have. In addition, by arranging the support layer 47 on the outside of the cylinder 45, the main filter layer 49 is not damaged when the outlet filter 40 is handled.

Considering the electrostatic adsorption action, mechanical strength, corrosion resistance, heat resistance, etc. of the outlet filter 40, a preferred material for forming the porous plate for forming the outlet filter 40 is ceramic sintered body such as alumina, silicon nitride, silicon carbide, quartz glass, or the like. It is a metal sintered compact, such as an aluminum alloy. In particular, when using alumina, the purity is preferably 99% or more. In addition, although the support layer 47, the intermediate | middle layer 48, and the filtration layer 49 are formed in the same material like this embodiment, it is also possible to form these in different materials, respectively. In this case, it is preferable to select at least the material of the filtration layer 49 which is a main part in the above-mentioned material.

In consideration of the capacity and mechanical strength of the cylinder 45, the thickness of the porous plate of the outlet filter 40 is preferably 1.5 mm to 5 mm. Moreover, it is preferable that the porosity of each layer 47.48.49 of a porous plate is 10%-50%. If the porosity is larger than 50%, the mechanical strength of the cylinder 45 is lowered. On the contrary, if the porosity is smaller than 10%, the pressure loss is large and the gas flow rate is lowered.

It is preferable that the average diameter of the micropores of the filtration layer 49 is 0.8 micrometer-0.1 micrometer. When the average diameter of the micropores of the filtration layer 49 is larger than 0.8 mu m, not only the particles in the gas are sufficiently removed, but also the gas flowing out of the surface of the cylinder 45 is less likely to be filled. On the contrary, when the average diameter of the micropores is smaller than 0.1 mu m, the pressure loss becomes large and the gas flow rate decreases. In consideration of the pressure loss, the thickness of the filtration layer 49 is preferably 100 µm or less.

When the flow rate of, for example, 10 l / min to 100 l / min is targeted under the conditions of the porous plate of the outlet filter 40, the outer surface area of the porous plate, that is, the effective gas outflow area is 750 mm 2 or more, preferably It is preferable to set it as 1500 mm <2> or more. Considering this point and the size of the lock seal, the outer diameter of the cylinder 45 is preferably 10 mm to 30 mm, the length is preferably 50 mm to 300 mm, and more preferably 50 mm to 100 mm.

5 and 6 show the results of experiments examining the effect of the gas supply head 32 in the load lock chamber 21 described with reference to FIGS. 1 to 4b.

In the experiments shown in FIG. 5, before the wafer w is brought into the load lock chamber 21 and into the load lock chamber 21, the load lock chamber 21 is exhausted once, and the atmospheric pressure is again maintained. (V) After returning to inside the load lock chamber 21 and counting the number of particles, the difference between them was obtained. In addition, the time required until the inside of the load lock chamber returned to normal pressure in a predetermined vacuum state was set to 30 seconds. The measurement object of particle number was made into 0.2 micrometer or more in size.

In Fig. 5, the horizontal axis represents the test numbers 1 to 9, and the vertical axis represents the number of particles of 0.2 mu m or more attached to the 6-inch diameter wafer W. Curves A, B, C, and D show the results of examples A, B, C, and D when the gas supply head 32 is not attached or attached to the position shown in FIG. . In Example A, gas was introduced into the load lock chamber 21 directly from the introduction pipe 31 without attaching the gas supply head 32. In Example B, a gas supply head 32 having a ceramic filter cylinder 45 having an outer diameter of 19 mm and a length of 100 mm was used. That is, the outlet filter of the cylinder 40 forms the multilayer structure shown in FIG. 3, and the average diameter of the micropore of the filtration layer 47 is 0.2 micrometer. In Example C, a gas supply head 32 having a stainless sintered filter cylinder 45 having an outer diameter of 19 mm, a length of 75 mm, and an average diameter of fine pores of 3 µm was used. In Example D, the gas supply head 32 was not attached. Instead, a stainless sintered compact filter having a diameter of 150 mm and an average diameter of 1 micron was attached to the opening end of the inlet pipe 31.

As shown in Fig. 5, in Example A, about 1000 particles were deposited on the wafer w. On the other hand, in Examples B, C, and D, the number of particles became several to several tens. Example B showed the smallest number of particles.

In the experiments shown in FIG. 6, the relationship between the installation location of the gas supply head 32 and the number of particles attached was examined. In this experiment, the gas supply head 32 which has the filter cylinder 45 made from ceramics like Example B mentioned above was used. The order of the experiment is the same as the experiment showing the result in FIG.

In Fig. 6, the horizontal axis represents the test numbers 1 to 9, and the vertical axis represents the number of particles of 0.2 mu m or more attached to the 6-inch diameter wafer w. Curves E, F, and G show the results of the installation examples E, F, and G of the gas supply head 32, which are outlined in FIG. That is, Example E is a position immediately above the wafer w. Example F is a position on the side of the wafer w, and Example G is a position below the wafer w.

As shown in FIG. 6, it is superior to Examples F and G besides Example E. That is, it is understood that the gas supply head 32 is most preferably provided above the wafer w. In the case of Example E, the number of particles was about 3 on average and the amount of particles was most reduced. This is because when the gas supply head 32 is disposed above the wafer w, the gas flowing out of the gas supply head 32 first collides with the wafer w, and then goes to the bottom of the load lock chamber 21 or the like. A gas flow is formed, and it is guessed because particle | grains do not adhere to the wafer w even if a particle rises because of this. However, when the gas supply head 32 is not disposed above the load lock chamber 21 due to design constraints, the gas supply head 32 may be disposed on the side or the lower side of the wafer w. Even when the gas supply head 32 is disposed at such a position, the adhesion amount of the particles can be 1/10 or less as compared with the conventional art.

Moreover, the experiment was also carried out when the mesh filter which has a big net hole was attached by the opening end of the inlet pipe 11. As shown in FIG. In this experiment, the mesh filter was made of resin or metal such as Teflon and had a size of 20 to 30 mesh (each net hole dimension of about 1 mm square). However, as a result of repeating the performance test on the load lock chamber equipped with such a filter, the following problems were found.

The mesh size of this filter is too large and cannot suddenly suppress sudden fluctuations in pressure. In addition, when corrosive gas is used in the processing chamber, it is difficult to completely prevent the corrosive gas from diffusing into the load lock room from the processing chamber. For this reason, metal parts of a filter, for example, attachment parts, such as a filter itself and a screw, are easy to corrode. In addition, since the filter further limits the opening area of the gas inlet, the pressure loss increases. For this reason, it takes time to adjust pressure, such as returning room pressure to atmospheric pressure. In addition, there is a limit to the mechanical strength of the filter itself and its attachment portion, and it is not possible to keep the state where the differential pressure is large by inserting the filter. That is, since the gas introduction valve cannot be opened slowly, there is a limit in reducing the pressure fluctuation.

8 is a conceptual diagram showing another embodiment of the load lock chamber in which the gas supply head 32 is disposed.

The load lock chamber 51 shown in FIG. 8 includes a rack 55 for temporarily storing the wafer w, and a gas supply head 32 is disposed thereon. When the wafer w of 6 inches in diameter is set on the rack 55, the positional relationship between the gas supply head 32 and the wafer w becomes the same as that shown in FIG. 4B. The gas introduction pipe 52 is connected to the pipe 43 of the gas supply head 32 through the valve V1. In addition, an exhaust pipe 53 is connected to the load lock chamber 51, and a valve V2 is disposed in the exhaust pipe 53. Further, the fine adjustment valve V3 bypasses the valve V2 and is disposed in the exhaust pipe 53. In addition, a pressure gauge 54 for measuring the pressure in the load lock chamber 51 is disposed.

Tables 1 to 3 show experimental results of investigating the effect of the gas supply head 32 using the load lock chamber 51 shown in FIG.

First, as a first example, a gas supply head 32 having a ceramic filter cylinder 45 having an outer diameter of 19 mm and a length of 100 mm was disposed in the load lock chamber 51. That is, the outlet filter 40 of the cylinder 45 has the multilayer structure shown in FIG. 3, and the average diameter of the microholes of the filtration layer 47 is 0.2 micrometer. Next, the wafer W having a 6-inch diameter was set on the rack 55, and the load lock chamber 51 was set to a reduced pressure of 5 x 10 &lt; -2 &gt; Torr. Next, high-purity nitrogen gas was supplied to the gas supply head 32 to flow out into the load lock chamber 51 so that the flow volume became constant, and the load lock chamber 51 was boosted to atmospheric pressure. 9 shows a relationship between the pressure in the load lock chamber 51 and the gas flow rate. Next, the wafer w was taken out, and the number and size of particles adhering on the surface thereof were measured by a wafer surface defect inspection apparatus. The same test was carried out three times to obtain an average of the measurements.

As Examples 2, 3 and 4, the test was performed three times under the same conditions as in Example 1 except that the lengths of the ceramic filter cylinders 45 were set to 50 mm, 200 mm and 300 mm, respectively. For Examples 2, 3 and 4, only the total number of particles was measured.

As Comparative Example 1, the test was carried out three times under the same conditions as in Example 1 except that the gas supply head 32 was not attached and gas was directly introduced into the inlet pipe 52 end. As a comparative example 2, the test was performed 3 times on the conditions similar to Example 1 except having used the metal filter cylinder of length 100mm and an average micropore diameter of 3 micrometers. In Comparative Examples 1 and 2, only the total number of particles was measured.

Table 1 shows the experimental results of Examples 1 to 4 and Comparative Examples 1 and 2.

As an example 5, a gas supply head 32 having a ceramic filter cylinder 45 having an outer diameter of 19 mm and a length of 100 mm was disposed in the load lock chamber 51. That is, the outlet filter 40 of the cylinder 45 has the multilayer structure shown in FIG. 3, and the average diameter of the microholes of the filtration layer 47 is 0.2 micrometer. The test was conducted under the same conditions as in Example 1 except that high-purity nitrogen gas was supplied so that the flow rate was constant, and the number and size of particles were measured by a wafer surface defect inspection apparatus. 10 shows a relationship between the pressure in the load lock chamber 51 and the gas flow rate. The same test was carried out three times to obtain an average of the measurements.

As examples 6, 7, and 8, the test was performed three times under the same conditions as in Example 5 except that the lengths of the ceramic filter cylinders 45 were set to 50 mm, 200 mm, and 300 mm, respectively. About Examples 6, 7, and 8, only the total number of particles was measured.

As Comparative Example 3, the test was performed three times under the same conditions as in Example 5 except that the gas supply head 32 was not attached and gas was directly introduced from the end of the introduction pipe 52. The test was carried out three times under the same conditions as in Example 5 except that a metal filter cylinder having a length of 100 mm and a fine micropore diameter of 3 µm was used as a comparison. In Comparative Examples 3 and 4, only the total number of particles was measured.

Table 2 shows the experimental results of Examples 5 to 8 and Comparative Examples 3 and 4.

As an example 9, a gas supply head 32 having a ceramic filter cylinder 45 having an outer diameter of 19 mm and a length of 100 mm was disposed in the load lock chamber 51. That is, the outlet filter 40 of the cylinder 45 has the multilayer structure shown in FIG. 3, and the average diameter of the microholes of the filtration layer 47 is 0.2 micrometer. In addition, the test was carried out under the same conditions as in Example 1 except that the flow rate increased in proportion to time to supply high-purity nitrogen gas from the beginning to the middle, and the number and size of particles were measured by a wafer surface defect inspection apparatus. The relationship with the pressure gas flow volume in the load lock chamber 51 at this time is shown in FIG. The same test was carried out three times to obtain an average of the measurements.

As examples 10, 11, and 12, the test was performed three times under the same conditions as in Example 9 except that the lengths of the ceramic filter cylinders 45 were set to 50 mm, 200 mm, and 300 mm, respectively. In Examples 10, 11 and 12, only the total number of particles was measured.

As Comparative Example 5, the test was performed three times under the same conditions as in Example 9 except that the gas supply head 32 was not attached and gas was directly introduced from the end of the introduction pipe 52. As a comparative example 6, the test was performed 3 times on the conditions similar to Example 9 except having used the metal filter cylinder of length 100mm and an average micropore diameter of 3 micrometers. In Comparative Examples 5 and 6, only the total number of particles was measured.

Tables 3 and 5 show the experimental results of Examples 9 to 12 and the comparison.

As shown in Tables 1 to 3, when the gas supply head 32 having the ceramic filter cylinder 45 according to the present invention is used, the adhesion of particles is extremely reduced as well as the absence of a filter, as well as a metal filter. . The larger the length of the filter cylinder 45 is, the smaller the number of adhered particles is.

12 is a schematic diagram showing an etching system of a semiconductor wafer having a load lock chamber according to another embodiment in which the gas supply head 32 is disposed.

The etching system shown in FIG. 12 has a processing chamber 61 and two preparatory chambers for wafer loading and unloading, that is, a load lock chamber 71. The processing chamber 61 is connected to the load lock chamber 71 via the transfer chamber 81, respectively. Each chamber 61, 71, 81 is hermetically connected via a gate valve 82.

A half gas supply system 64 is connected to the upper part of the processing chamber 61, and a doubling system 65 is connected to the lower part. In the processing chamber 61, a susceptor 66 serving as a mounting table and a lower electrode for placing a plurality of wafers w and an upper electrode 67 facing the lower electrode are disposed. The susceptor 66 is connected to the high frequency power source 69 through the matching circuit 68, and the upper electrode 67 is grounded. The susceptor 66 is adapted to rotate during the etching of the wafer w. The load lock chamber 71 is provided with a rack 72 for accommodating a plurality of wafers w at intervals in the vertical direction, and the rack 72 is driven in the vertical direction by the elevator 73. The upper part of the load lock chamber 71 is connected with the gas supply system 75 which supplies inert gas, such as nitrogen, or gas, such as air, to the upper part of the rack 72, and the exhaust system 76 is connected to the lower part. Therefore, the load lock seal 71 is independently adjustable in internal pressure. The gas supply system 75 of the load lock chamber 71 has a gas introduction pipe connected to the gas supply source, which hermetically penetrates through the casing of the load lock chamber 71, and the gas supply head 32 at the tip thereof. Is connected.

In the conveyance chamber 81, the conveyance arm 83 for conveying the wafer w is arrange | positioned. The gas supply system and the exhaust system are also connected to the transfer chamber 81. However, since the transfer chamber 81 does not supply gas at the time of normal operation, the gas supply head 32 which concerns on this invention is not arrange | positioned.

As described above, unlike the load lock chambers 21 and 51 shown in FIGS. 1 and 8, the load lock chamber 71 of the etching system shown in FIG. 12 is capable of accommodating a plurality of wafers w at one time. . Even in such a load lock chamber 71, the gas supply head 32 according to the present invention can provide the same advantages as the load lock chamber 71 for accommodating one wafer at a time.

In addition, the porous ceramic plate serving as the gas outlet in the gas supply head is not limited to a cylindrical shape, but can take various forms.

For example, the gas supply head 90 shown in FIG. 13 is provided with the outlet filter 91 formed as a rectangular box. More specifically, the outlet filter 91 is formed by bonding a pair of porous ceramic plates 92 having a multi-layer structure as shown in FIG. 3 so as to form a gas reservoir and joining them through the encapsulant 93. do. Here, both ceramic plates 92 are arranged in parallel with the wafer w, and sufficient space is formed between the upper ceramic plates 92 and the load lock chamber 21 with the ceiling.

The outlet filter 96 of the gas supply head 95 shown in FIG. 14 is a porous ceramic plate having a multilayer structure shown in FIG. 3, which constitutes almost the entire inner surface of the ceiling of the load lock chamber 21. As shown in FIG. It consists of 97. On the back side of the ceramic plate 97, an auxiliary chamber 98 for forming a gas reservoir is disposed.

In addition, a semi-cylindrical outlet filter in which the upper half of the filter cylinder 45 shown in FIG. In either case, in the part facing the wafer w, the outlet filter is parallel to the Peterley surface of the wafer w, where the outflowed gas flows at a substantially right angle to the surface to be processed of the wafer w in a laminar flow state. have.

Claims (21)

The gas supply head 32 for supplying the pressure regulating gas into the casings 2 and 22 while the substrate to be processed in the system is supported in the airtight casings 2 and 22 of the semiconductor processing system includes the casing ( A plurality of gas reservoirs 46 connected to a gas introduction pipe 31 for introducing the gas into the gas reservoirs 2, 22 and a plurality of the gas reservoirs 46 and the casings 2, 22 which communicate with each other. Outlet filters 40 and 91 having a porous filtration layer 49 having micropores, an average diameter of the micropores of 0.8 µm to 0.1 µm, and a porosity of the filtering layer 49 of 10% to 50%. And a gas supply head of a semiconductor processing system. 2. The filtration layer (49) according to claim 1, characterized in that the filtration layer (49) is formed of a material which removes particles in the gas by filtration and electrostatic adsorption and supplies the gas into the casings (2, 22). Gas supply head of semiconductor processing system. 3. The gas supply head of a semiconductor processing system according to claim 2, wherein said filtration layer (49) is formed of a porous ceramic layer. The filter of claim 3, wherein the outlet filter comprises a multilayer structure including the filter layer 49 and a support layer 47 formed of a porous ceramic layer, and the support layer 47 has an average diameter of the filter layer 49. A gas supply head of a semiconductor processing system, characterized in that it has a plurality of fine pores substantially larger than that of the &lt; RTI ID = 0.0 &gt; The semiconductor processing system according to claim 4, wherein each of the filtration layer 49 and the support layer 47 is made of a sintered body of a material selected from the group consisting of alumina, silicon nitride, silicon carbide, quartz glass, and the like. Gas supply head. The gas supply head of a semiconductor processing system according to claim 4, wherein the filtration layer has a thickness of 100 µm or less. 5. The gas supply head of a processing system according to claim 4, wherein the gas is supplied from the outlet filter (40,91) in a substantially laminar flow state. 5. The outlet filter (40, 91) according to claim 4, wherein the outlet filters (40,91) form a hollow cylinder (45) for defining the gas reservoir (46), and the gas is in a 360 degree direction from the outlet filters (40,91). A gas supply head of a semiconductor processing system, characterized in that the supply. 5. The gas supply head of a semiconductor processing system according to claim 4, wherein said outlet filter (40,91) forms a rectangular box for defining said gas reservoir (46). 5. The gas supply head of a semiconductor processing system according to claim 4, wherein said outlet filter (40,91) constitutes a part of an inner surface of said casing (2,22). Hermetic casing (2,22) having openings (3,13,14,23,24) for the substrate to pass through, and opening and opening of the openings (3,13,14,23,24) Means for closing it securely, support means for supporting the substrate in the casings 2 and 22, a gas introduction pipe 31 for introducing a pressure regulating gas into the casings 2 and 22, and the casing; Exhaust gas (5, 26, 65, 76) for exhausting the inside of the (2, 22) and the gas introduction pipe (31) while being connected to the gas introduction pipe (31) and the substrate supported by the support means A gas supply head 32 for supplying gas into the casings 2 and 22, a gas reservoir 46 to which the gas supply head 32 is connected to the gas introduction pipe 31, An outlet filter (40,91) having a porous filtration layer (49) having a plurality of micropores communicating with the gas reservoir (46) and the casing (2,22), and The average diameter of the three holes 0.8㎛~0.1㎛, the load lock chamber of a semiconductor processing system, characterized in that provided that the porosity of the filter layer is 10% ~50%. 12. The semiconductor processing system according to claim 11, wherein the filtration layer is formed of a material which removes particles in the gas and supplies the gas into the casings 2 and 22 by filtration and electrostatic adsorption. Load lock room. 13. The load lock chamber of claim 12, wherein the filtration layer (49) is formed of a porous ceramic layer. The method of claim 13, wherein the outlet filter (40,91) has a multi-layer structure comprising the filter layer 49 and the support layer 47 composed of a porous ceramic layer, the support layer 47 has an average diameter And a plurality of fine pores substantially larger than that of said filtration layer (49). 15. The semiconductor processing system according to claim 14, wherein each of the filtration layer 49 and the support layer 47 is made of a sintered body of a material selected from the group consisting of alumina, silicon nitride, silicon carbide, and quartz glass. Load lock room. 15. The load lock seal of claim 14, wherein the filtration layer (49) has a thickness of 100 mu m or less. 15. The load lock chamber of claim 14, wherein the gas is supplied in the outlet filter (40,91) in a substantially laminar flow state. 15. The method of claim 14, wherein said outlet filters (40,91) form a hollow cylinder (45) for defining said gas reservoir (46), and said gas is directed at 360 degrees in said outlet filters (40,91). Load lock chamber of the semiconductor processing system, characterized in that supplied to. 15. The load lock seal of claim 14 wherein the outlet filter (40,91) forms a rectangular box for defining the gas reservoir (46). 15. The load lock seal of a semiconductor processing system according to claim 14, wherein said on-exit filter (40,91) constitutes a part of an inner surface of said casing (2,22). 15. The load lock seal of claim 14, wherein the outlet filter (40,91) is disposed above the substrate in a state supported by the support means.