TW448504B - Gas diversion apparatus in a plasma etching apparatus - Google Patents

Abstract

The present invention provides a kind of gas diversion apparatus used in a plasma etching apparatus. This plasma etching apparatus includes an upper electrode plate connected with the underneath gas diversion apparatus, in which plural holes are distributed over the upper electrode plate. The gas diversion apparatus contains a gas inlet, which is used to introduce the required gas for etching, and a diversion hood, which is connected with the gas inlet and is used to guide the gas. The diversion hood has an approximately cone-shaped structure.

Description

448504 V. Description of Invention (1)! Fields of Invention

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I 丨 The present invention provides a gas diversion device, particularly a gas diversion device used in a plasma etching device. iBackground description: In the semiconductor manufacturing process, parallel plate (Para 1 1 e 1 Pate type) dry etching is a frequently used touch etch in the plasma etching method (pl asma etching). There is a set of corresponding parallel electrode plates. When performing parallel plate dry etching, the wafer to be etched is placed on the lower electrode plate, and then an RF (radio requency) power is connected to the upper electrode plate or the lower electrode plate, and the last name is entered. The gas required for the etching 'The plasma ionized gas ions bombard the wafer to perform anisotropic etching. j Please refer to FIG. 1 ′ FIG. 1 is a schematic diagram of a gas input device 20 in a conventional plasma etching machine 10. The plasma etching machine 10 includes a reaction chamber 12 ', an upper electrode plate (elec1:; rode) 14 and a lower electrode plate 16 disposed in parallel to both ends of the reaction chamber 12, and a gas input The device 丨 2 0 is connected to the upper electrode plate 14 and an exhaust port 2 2 is provided in the reaction chamber 12

Up ° Generally, when plasma etching is performed, the wafer 18 is first placed on the lower electrode plate 16 and connected to the lower electrode plate 16 with an RF power of about 13.56 MHz. The rest of the reaction | chamber 12 is grounded (grounded ) »Then the reaction gas from gas I

Page 4 V. Description of the invention (2) The body input device 20 is connected to the reaction chamber 12, and after the electric shock is generated, due to the potential difference between the plasma and the electrode plate, the ions in the plasma will affect the wafer 1 8 The surface is strongly bombarded with ions and anisotropically etched. In the conventional plasma etching machine 10, the 'upper electrode plate 1 4' is a flat hollow housing made of metal, and the lower surface is provided with a plurality of uniformly distributed holes, and the gas input device 20 is Connected to the upper electrode plate 1 4 In addition, generally in the etching machine, in order to make the gas fluid distribution in the reaction chamber 12 more uniform, usually before the gas enters the reaction chamber 12, it will pass through a plurality of holes. Shower head to disperse the gas and improve the uniformity of etching. The conventional technique combines the leaching top plate with the upper electrode plate 14 | and, when the reaction gas passes through, flows into the upper electrode | plate 14 through the gas input device 20, and then passes through a plurality of holes in the upper electrode plate 14 Into the reaction chamber 12 to provide the reaction gas required for the etching process and to uniformly disperse the reaction gas entering the reaction chamber 12 i. However, the general gas input device 20 is connected above the center of the upper electrode plate 14, and the pipe diameter of the gas input device 20 is usually much smaller than the diameter of the upper electrode plate 14. Therefore, when the reaction gas enters the upper electrode from the gas input device 20 When the plate 14 |, the gas moves in the direction of fluid movement, which will cause a high density of gas in the central portion of the upper electrode plate 14. And as the gas rains around the electrode plate:: diffusion, the gas density will gradually decrease due to the increase of the diffusion distance, so that the reaction gas diffused to the edge of the upper electrode plate 1 4 is smaller. On the other side—the conventional technology, a plurality of holes provided on the upper electrode plate 14 are evenly distributed on the upper electrode plate.

Page 5 丨 V. Description of the invention (3) The lower surface of 1 4, so the reaction gas flowing into the reaction chamber 12 through the holes will not be able to diffuse uniformly and achieve the purpose of uniform etching. Arrows 2 and 4 in Figure 1 indicate that the reaction gas enters the reaction chamber 12 with uneven distribution.

I SUMMARY OF THE INVENTION [The main purpose of the present invention is therefore to provide a gas diversion device for use in a plasma etching device |; in order to solve the problems of the conventional techniques described above.

i In a preferred embodiment of the present invention, the plasma etching apparatus includes an upper electrode plate connected below the gas guide device, and the upper electrode plate is provided with a plurality of holes. The gas deflector includes an air inlet for introducing the gas required for the etching, and a shroud connected to the air inlet for guiding the incoming gas. The position i of the plurality of holes on the upper electrode plate is sparsely located at the center portion of the upper electrode plate, and is denser at the edge portion of the upper electrode plate. The shroud is an upper narrow lower width approximate cone Construction of type. I! The gas diversion device of the present invention adds a cone-shaped diversion hood under the air inlet to guide the flow direction of the reaction gas as a buffer when the gas is diffused! The area is matched with the center of the upper electrode plate. The sparse edges of the holes are distributed to make the flow uniform when the gas is ejected from the electrode plate on i. ;

'· I I | | 丨 Detailed description of the invention

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Page 6 448504 丨 V. Description of the invention (4) | Please refer to Figure 2 and Figure 3, Figure | Schematic diagram of the gas diversion device 40 | Schematic diagram of the plural holes 58 of the cloth. The j chamber 32, an upper electrode plate 34 and two ends of the lower j, and an exhaust port 42 are provided with a plurality of holes 58 distributed on the upper surface. Plate 3 4 above. As shown in Fig. 2, it is placed on the lower electrode plate 36, and about the electrode plate 36, and the rest of the reaction chamber 32 enters the reaction chamber 32. When the potential difference is generated, the ions in the plasma will | Click for anisotropic etching. ί | The gas deflector of the present invention is used to introduce the reaction gas required for etching between the reaction gas and the upper electrode plate 34, and is used to induce uniform dispersion. The shroud 46 includes a flat plate structure whose end is smaller than the air outlet end, that is, | and is located at the bottom end of the shroud 46. For example, the upper electrode plate j4 6 is correspondingly a cone-shaped | flat plate, and the shroud 46 is a | cover 46 which can make the gas diffusion sufficient in the plasma etching machine 30 of the present invention. FIG. 3 shows the upper electrode plate 34 of the present invention. The plasma etching machine 30 includes a reaction electrode plate 36 arranged parallel to the reaction chamber 32 above the reaction chamber 32. Upper electrode plate 34 The gas deflector 40 is connected to the upper electrode. When plasma etching is performed, first connect the wafer 3 8 13 and the 56MHz RF power to the lower electrode to ground. After the reaction gas is passed through, 'the strong ion bombardment generated on the surface of the wafer 38 between the plasma and the electrode plate includes an air inlet 44 for guiding a shroud 46 connected to the air inlet 44 to guide the gas, The reaction gas has both an air inlet end and an air outlet end, and the air inlet has a narrow upper and lower width and a cone-like structure. The electrode plate 34 is a circular flat plate corresponding to the shroud 46. The shroud structure. Another example is that the upper electrode plate 34 has a polygonal pyramid structure. The diversion word buffer time of the present invention reaches a uniform state β

4 4 85 0 4! V. Description of the invention (5)!. 丨 In addition, to further enhance the effect of gas uniformity 'the electrode plate of the present invention | 3 4 of the plurality of holes 5 8 distribution positions can be designed as shown in circle The central part is more sparse and the edge part is denser. Or design a plurality of holes on the upper electrode plate 34 to be evenly distributed, and add a plate similar to the shower ceiling plate design between the shroud 46 and the upper electrode plate 34. The plurality of holes on the plate are in the flat plate center The distribution of the parts is relatively sparse, and the edges of the plate are denser. This design can also achieve the effect of uniformly dispersing the reaction gas. In actual design and manufacture, the upper electrode plate 34 and the shroud 46 can be combined to make or divide the upper gas path of the Γ 丨 low gas shadow | gas i small tube 丨 buffered gas cone structure plate 3 4 spray the upper electrode type, and the uniformity of the upper electrode, gradually import the 4 4 and the gas are described. In addition, the flow guide plate 3 4 is installed on the flow guide, and the electrode plate of the flow plate 3 4 is expanded with the expansion plate. 3 4 sides. However, the large reaction holes provided by the large straight uniform diffusion are widened and narrowed by the upper electrode of the present invention, which is often far smaller than the density of the plate, so that the airflow area of the flow direction of the etching allows the reaction plate 3 4 Or the characteristics of the pre-sparseness and the electrode are placed in 40, and the guiding reaction amount is uniform. The diameter, if 34, will dissipate the distance increasing part, and the gas vessel of the present invention will be powered on. The expansion of the hole gas on the other side of the plate's reaction is mainly to facilitate the flow of the gas. Generally, if the reaction gas becomes the upper electrode, the cone of the gas reaction gas guides the upper and lower electrode plates of the electrode plate. Scattered. The direction of movement of the air guide shroud 46 allows the density of the pipe body of the air inlet to gradually decrease from the central portion of the inlet plate 34. The inlet hood 46 is in compliance with the order of 34, so that it is more time-saving. Utilization of upper central Yoshinagai shroud 4 6Ϊ: plasma etching machine

448504 丨 V. Description of the invention (6) | The reaction chamber of 3 units can achieve the purpose of uniform dispersion. The arrow 4 8 in the second table shows the situation where the reaction gas enters the reaction chamber 32 and is evenly distributed. Please refer to FIG. 4. FIG. 4 is a schematic diagram of a gas diversion device 50 according to another embodiment of the present invention. The air-guiding device 50 of this embodiment further adds a buffer zone i 2 to the air inlet 54. The buffer area 5 2 may have an approximately right-angled I structure or an arc structure ′ to make the flow of the reaction gas more uniform when the reaction gas is ejected from the upper electrode plate 3 4. Generally, the pipeline connected to the air inlet is usually designed in a straight line, and because the frictional part of the part in contact with the pipe wall when the gas flows, the velocity distribution of the gas flow is slightly parabolic (that is, the velocity of the central part is greater than the surrounding Part), so the gas is unevenly distributed when entering the shroud or upper electrode plate. In this embodiment, adding a buffer area 5 2 ′ before the gas input pipeline enters the shroud 46 6 can reduce the uneven flow rate of the gas center and the edge.

I!; | Compared with the conventional gas input device, the gas diversion device of the present invention adds a cone-shaped baffle under the air inlet to guide the flow direction of the reaction gas as a buffer for gas diffusion. Area, and cooperate with the hole distribution of I | central body in the upper electrode plate to make the gas flow uniform when the gas is ejected from the upper electrode plate. I The above are only the preferred embodiments of the present invention, and any equivalent changes and modifications made according to the patent application scope of the present invention should be covered by the patent of the present invention.

Page 9 4485 04 Brief description of the diagrams Brief description of the diagrams Figure 1 is a schematic diagram of the gas input device in the conventional electricity gathering machine. Fig. 2 is a schematic diagram of a gas diversion device in a plasma etching machine of the present invention. FIG. 3 is a schematic diagram of a plurality of holes distributed on the electrode plate of the present invention. FIG. 4 is a schematic diagram of a gas diversion device according to another embodiment of the present invention. Explanation of symbols in the diagram 10 Plasma etching machine 12 Reaction chamber 14 Upper electrode plate 16 Lower electrode plate 18 Wafer 20 Gas input device 22 Exhaust port 24 Gas distribution 30 Plasma engraving machine 32 Reaction chamber 34 Upper electrode plate 36 Electrode plate 38 Wafer 40 Gas deflector 42 Exhaust port 44 Air inlet 46 Shroud 48 Gas distribution 50 Gas deflector 52 Cushioning area 54 Air inlet 56 56 Shroud 58 Hole

Claims (1)

04 I. Application for Patent Scope 1. A gas deflector used in a plasma etching device, the plasma etching device includes an upper electrode plate connected below the gas deflector, and the upper electrode plate A plurality of holes are distributed, and the gas diversion device includes: an air inlet for introducing a gas required for the etching; and a shroud connected to the air inlet for guiding the incoming gas i Body, so that gas enters the upper electrode plate uniformly, and the shroud has a structure of approximately a cone i. | 2. For example, the gas guide device of the scope of patent application, wherein the guide i cover is a conical structure, and the upper electrode plate is a circular flat plate. I | | 3. For example, the gas guide device of the scope of patent application, wherein the guide shroud is a pyramid-shaped structure, and the upper electrode plate is a polygonal flat plate. II 4. The gas diversion device according to item 1 of the scope of the patent application, wherein the plurality of holes on the power-on | electrode plate are located in the center of the upper electrode plate, which is relatively sparse and located on the edge of the upper electrode plate Some are dense. ! 5. For example, the gas diversion device in the scope of patent application, wherein the plurality of holes on the upper electrode plate are evenly distributed on the upper electrode plate. I 6. If the gas diversion device of item 5 of the patent application scope, wherein a flat plate is provided between the diversion I cover and the upper electrode plate, the plate is provided with a plurality of 448504 6. The distribution position is relatively sparse in the center of the plate, and denser in the edge portion of the plate. I 7. The gas diversion device according to item 1 of the patent application scope, wherein the deflector further includes an air inlet end and an air outlet end, and the air inlet end is smaller than the air outlet end, which is used to make the gas flow from The upper electrode plate has a uniform flow rate when ejected. 8. A gas diversion device used in a plasma etching device, the plasma etching device includes an upper electrode plate connected below the gas diversion device, and a plurality of the electrode plates are distributed on the upper electrode plate A hole, the gas deflector device package includes: | an air inlet for introducing a gas required for the etching; a buffer area connected to the air inlet; and a flow hood connected to the buffer area, It is used to guide the entering gas body so that the gas evenly enters the upper 1: electrode plate, and the shroud is an approximately conical 1j structure; I wherein the buffer area is used for the gas from the upper electrode The flow rate of the plate is uniform. 9. For the gas diversion device according to item 8 of the patent application, wherein the diversion I cover is a conical structure, and the upper electrode plate is a circular flat plate. i I I I 1 0. If the gas deflector of item 8 of the patent application scope, the deflector is a pyramid-shaped structure, and the upper electrode plate is a polygonal flat plate. 448504 丨 VI. Patent Application Range 11_For example, the gas guide device of the 8th patent application range, in which the position of the plurality of holes on the upper electrode plate is located in the central part of the upper electrode plate | The edges of the electrode plate are dense. !! i 1 2. The gas diversion device according to item 8 of the patent application, wherein the plurality of holes on the power-on electrode plate are evenly distributed on the upper electrode plate. 1 3 · If the gas diversion device according to item 12 of the patent application scope, wherein a flat plate is provided between the diversion cover and the upper electrode plate, the plate is provided with a plurality of | holes, and the distribution position is located at The center portion of the plate is sparse, and the edge portion located on the plate is denser. I 1 4 · If the gas diversion device of item 8 of the patent application scope, wherein the diversion guide | hood further includes an air inlet end and an air outlet end, and the air inlet end is smaller than the air outlet end, for Make the gas flow uniform when sprayed from the upper electrode plate. Il5. The gas diversion device according to item 8 of the patent application, wherein the buffer