A flow guide plate structure for improving the edge effect of a CVD film and a deposition device

Abstract

The application provides a flow guide plate structure for improving the edge effect of CVD film thickness, which comprises a flow guide plate arranged at an air inlet, the flow guide plate is rectangular and matched with the shape of an upper electrode, and air holes on the flow guide plate are distributed in a manner that the density is low in the center and increases towards the periphery, so that the amount of air in the middle is reduced, more chemical gas is obtained by the corners of the upper electrode, the problem of thin film thickness at the edge of the G6 and above large plate is improved, and the deposition quality is improved; the gas distribution is more balanced, the service life of the upper electrode is prolonged, and the maintenance and production costs are reduced. The flow guide plate is an arc curved surface with a concave center and an upturned edge, which can disperse the gas to the surrounding; in addition to the air holes in the center, the axes of the hole channels of the remaining air holes are inclined towards the periphery, which further improves the gas density around the upper electrode and improves the uniformity of the film thickness of the substrate.

Description

Technical Field

[0001] This invention relates to the field of chemical vapor deposition equipment technology for displays, and more particularly to a guide plate structure for improving the edge effect of chemical vapor deposition film thickness and a plasma-enhanced chemical vapor deposition apparatus. Background Technology

[0002] Figure 1 This is a schematic diagram of a plasma-enhanced chemical vapor deposition (PECVD) apparatus. PECVD is used to deposit thin films such as semiconductor layers (amorphous silicon), insulating layers (silicon oxide and silicon nitride), and is an indispensable manufacturing process in the fields of chips, displays, and thin-film solar energy.

[0003] Chemical gas enters the process chamber 2 through the inlet 1, is diverted by the gas guide plate 3, and then diffuses into the process chamber 2 through the upper electrode 4. After being given radio frequency power, the gas dissociates into plasma 5 for thin film deposition. The thin film 6 is deposited on the lower electrode 8 that supports the glass substrate 7.

[0004] In existing CVD equipment, the structural design of the gas guide plate 3 has a significant impact on the film thickness uniformity, especially in the coating process of large plates (such as G6 and above). The film thickness of the thin film 6 is often thinner in the edge area around the perimeter, which leads to problems such as uneven product brightness, threshold voltage drift, and increased leakage current. Figure 2 This is a top view of the traditional guide plate structure and the upper electrode. The traditional guide plate 3 has a circular design with uniform holes 9. Figure 3 This is a cross-sectional view of a traditional guide vane. In existing technologies, the orifices of the guide vane are vertical, and the entire guide vane is planar. This design results in a single gas diffusion path, especially since the four corners of the upper electrode are furthest from the circular guide vane, making it unable to adapt to the flow field inhomogeneity caused by changes in the large plate area. After long-term use, the orifice diameter of the upper electrode enlarges, further exacerbating the film thickness inhomogeneity, leading to a shortened lifespan of the upper electrode, frequent replacements, and a significant increase in cost. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a flow guide plate structure and deposition device that improves the edge effect of CVD film thickness, which can significantly improve the uniformity of film thickness around the large plate and extend the service life of the upper electrode.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a flow guide plate structure for improving the edge effect of CVD film thickness, comprising a flow guide plate disposed at the air inlet of the chemical vapor deposition process chamber. The flow guide plate has a rectangular structure and is provided with a plurality of vent holes, which are distributed in a pattern of low density in the central region and increasing density from the center to the outer region. The rectangular structure of the flow guide plate better matches the rectangular shape of the upper electrode, and the arrangement of the vent holes with low density in the center and increasing density towards the outer edge reduces the amount of air entering the central region, allowing more chemical gas to be obtained at the corners of the upper electrode.

[0007] Furthermore, the guide plate has an arc-shaped curved surface with a concave central area and an upward-curving edge area. In the prior art, the guide plate has a planar structure, while in this invention, the guide plate is set as a curved surface structure, which can disperse the chemical gas in all directions.

[0008] Furthermore, the vent hole at the geometric center of the guide plate has its central axis extending vertically; except for the central vent hole, the central axes of the other vent holes are all inclined towards the periphery of the guide plate.

[0009] Furthermore, except for the central vent, the angle at which the axis of the other vents tilts outward increases as their distance from the center of the guide plate increases.

[0010] In a second aspect, the present invention provides a plasma-enhanced chemical vapor deposition apparatus, including the guide plate structure described in the first aspect. The apparatus further includes a chemical vapor deposition process chamber, wherein a first chamber is provided inside the chemical vapor deposition chamber, an upper electrode is provided at the bottom of the first chamber, a second chamber is provided inside the first chamber, an air inlet communicating with the second chamber is provided at the top of the chemical vapor deposition process chamber, and the guide plate is provided at the bottom of the second chamber. The chemical vapor deposition process chamber is also equipped with a lower electrode, which is located below the upper electrode.

[0011] The beneficial effects of this invention are as follows: 1. This invention sets the guide plate as a rectangular structure that matches the upper electrode, and with the distribution of vent holes that are sparse in the center and dense in the periphery, so that the corners of the upper electrode can obtain more chemical gas, which improves the problem of thin film thickness at the edge of the coating of large plates of G6 and above, and improves the film thickness uniformity by more than 2%, thus greatly improving the film deposition quality.

[0012] 2. The chemical gas distribution is more even, which can also extend the service life of the upper electrode, reduce the replacement frequency, and effectively reduce equipment maintenance and production costs.

[0013] 3. The guide plate has an arc-shaped curved surface with a concave central area and an upward-curving edge area, which can disperse chemical gases in all directions. Except for the central vent, the central axis of the other vents is inclined towards the periphery of the guide plate, which can increase the gas density around the upper electrode, thereby further improving the uniformity of the substrate film thickness during coating. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of an existing ion-enhanced chemical vapor deposition (IECVD) apparatus.

[0016] Figure 2 This is a top view of the guide plate structure and upper electrode in the prior art.

[0017] Figure 3 This is a cross-sectional view of a deflector in the prior art.

[0018] Figure 4 This is a schematic diagram of the connection structure between the flow guide plate and the upper electrode in order to improve the edge effect of CVD film thickness in this invention.

[0019] Figure 5 for Figure 4 A cross-sectional view of the deflector in the structure shown.

[0020] Figure 6 This is a schematic diagram of a specific embodiment of a flow guide plate for improving the edge effect of CVD film thickness in this invention.

[0021] Explanation of the labels in the diagram: 10. Guide plate; 11. Vent hole; 12. Chemical vapor deposition process chamber; 13. First chamber; 14. Upper electrode; 15. Second chamber; 16. Air inlet; 17. Lower electrode. Detailed Implementation

[0022] Please see Figures 4 to 6 In Embodiment 1, the present invention provides a flow guide plate structure for improving the edge effect of CVD film thickness, including a flow guide plate 10 disposed at the air inlet 16 of the chemical vapor deposition process chamber 12. The flow guide plate 10 has a square structure and a plurality of vent holes 11 are provided on the flow guide plate 10. The plurality of vent holes 11 are distributed in a form with low density in the central area and increasing density from the center to the outer area.

[0023] Specifically, the guide plate 10 has an arc-shaped curved surface with a concave central area and an upward-curving edge area.

[0024] Specifically, the vent 11 at the geometric center of the guide plate 10 has its central axis extending vertically; except for the central vent 11, the central axes of the other vents 11 are all inclined toward the periphery of the guide plate 10, as shown in the figure. The inclined vents 11 can guide the chemical gas to the edge of the upper electrode 14.

[0025] like Figure 3 As shown, in the prior art, the holes in the guide plate are vertical and the guide plate as a whole is planar, which is not conducive to the diffusion of chemical gases. In this application, the guide plate 10 is set as an arc-shaped curved surface with a concave central area and an upward curved edge area, and the channels of the vent holes 11 on the outer side are set as inclined, which can disperse the chemical gases in all directions to increase the chemical gas density around the upper electrode 14.

[0026] Specifically, except for the vent 11 located in the center, the angle at which the channel axis of the other vents 11 tilts outward increases as their distance from the center of the guide plate 10 increases.

[0027] Example 2: The present invention provides a plasma-enhanced chemical vapor deposition apparatus, including the flow guide plate 10 structure described in Example 1. The apparatus further includes a chemical vapor deposition process chamber 12, a first chamber 13 is provided inside the chemical vapor deposition chamber, an upper electrode 14 is provided at the bottom of the first chamber 13, a second chamber 15 is provided inside the first chamber 13, an air inlet 16 communicating with the second chamber 15 is provided at the top of the chemical vapor deposition process chamber 12, and the flow guide plate 10 is provided at the bottom of the second chamber 15, that is, an installation position is opened at the bottom of the second chamber 15, and the flow guide plate 10 is provided at the installation position. The chemical vapor deposition process chamber 12 is also provided with a lower electrode 17, which is located below the upper electrode 14.

[0028] This invention designs the flow guide plate 10 as a rectangular structure matching the upper electrode 14, with a distribution of vent holes 11 that are sparse in the center and dense at the periphery. This allows more chemical gas to be obtained at the corners of the upper electrode 14, improving the problem of thinner film thickness at the edges of large plates of G6 and above, increasing film thickness uniformity by more than 2%, and significantly improving the quality of thin film deposition. Experiments show that the optimized flow guide plate 10 structure can reduce film thickness uniformity (U%) from 18.4% to 13.0%, and increase process capability Cpk to 1.33. The more even distribution of chemical gas can also extend the service life of the upper electrode 14, reduce replacement frequency, and effectively reduce equipment maintenance and production costs. The flow guide plate 10 has an arc-shaped curved surface with a concave central area and an upward-curving edge area, which can disperse the chemical gas in all directions. Except for the central vent hole 11, the central axis of the other vent holes 11 is inclined towards the periphery of the flow guide plate 10, which can increase the gas density around the upper electrode 14, thereby further improving the uniformity of the substrate film thickness during deposition.

[0029] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A flow guide plate structure for improving the edge effect of CVD film thickness, characterized in that: It includes a baffle plate located at the air inlet of the chemical vapor deposition process chamber. The baffle plate has a square structure and is provided with a number of vent holes. The number of vent holes are distributed in a pattern where the density is low in the central area and increases from the center to the outer area. The guide plate has an arc-shaped curved surface with a concave central area and an upward curved edge area; The ventilation hole at the geometric center of the guide plate has its central axis extending vertically; except for the central ventilation hole at the center, the central axes of the other ventilation holes are all inclined towards the periphery of the guide plate.

2. The flow guide plate structure for improving the edge effect of CVD film thickness as described in claim 1, characterized in that: Except for the central vent, the angle at which the axis of the other vents tilts outward increases as their distance from the center of the guide plate increases.

3. A plasma-enhanced chemical vapor deposition apparatus, characterized in that: The device includes a flow guide plate structure as described in any one of claims 1 to 2, and further includes a chemical vapor deposition process chamber, wherein a first chamber is provided inside the chemical vapor deposition process chamber, an upper electrode is provided at the bottom of the first chamber, a second chamber is provided inside the first chamber, an air inlet communicating with the second chamber is provided at the top of the chemical vapor deposition process chamber, and the flow guide plate is provided at the bottom of the second chamber. The chemical vapor deposition process chamber is also equipped with a lower electrode, which is located below the upper electrode.

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