Film layer deposition apparatus and film layer deposition method

Abstract

The application relates to the technical field of semiconductor manufacturing, in particular to a film layer deposition device and a film layer deposition method. The film layer deposition device comprises a bearing part for bearing a wafer, a shower head arranged above the bearing part and used for spraying a reaction gas to the wafer on the surface of the bearing part, the reaction gas being used for forming a film layer on the surface of the wafer, and a shielding structure used for shielding the edge area of the shower head to reduce the reaction gas concentration of the edge area of the wafer. According to the application, the uniformity of the film layer thickness is improved, and in the subsequent etching process, the film layer of the edge area can be fully etched, the film layer residue is avoided, and the etching quality is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a film deposition apparatus and a film deposition method. Background Technology

[0002] In the manufacturing process of semiconductor devices such as Dynamic Random Access Memory (DRAM), etching is a crucial step. Existing etching processes mainly include two methods: wet etching and dry etching. Dry etching typically refers to an etching technique that uses glow discharge to generate plasma containing charged particles such as ions and electrons, as well as highly chemically active neutral atoms, molecules, and free radicals, for pattern transfer.

[0003] In both dry and wet etching processes, patterns are transferred downwards through several mask layers to ultimately form on the wafer surface. However, during mask layer deposition, the central and edge regions of the wafer are exposed to different processing conditions, resulting in the film layer thickness at the edge regions being often greater than that at the center. This reduces the uniformity of the film thickness and, during pattern transfer, may lead to incomplete etching at the edge regions due to uneven film thickness, affecting the downward transfer of the pattern. Ultimately, this results in a significant difference between the pattern formed on the wafer surface and the designed pattern, impacting the yield of the final semiconductor device and, in severe cases, even leading to wafer scrap.

[0004] Therefore, improving the uniformity of the film thickness on the wafer surface and avoiding incomplete etching at the film edges to improve etching quality is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] This invention provides a film deposition apparatus and a film deposition method to solve the problem in the prior art that incomplete etching at the film edge is easily caused by uneven film thickness.

[0006] To address the above problems, the present invention provides a film deposition apparatus, comprising:

[0007] The carrier section is used to support the wafer;

[0008] A nozzle, disposed above the support portion, is used to spray a reactive gas onto the wafer located on the surface of the support portion, the reactive gas being used to form a film layer on the wafer surface;

[0009] A shielding structure is used to shield the edge region of the nozzle to reduce the concentration of the reactive gas in the edge region of the wafer.

[0010] Optionally, the surface of the nozzle facing the support portion is a spray surface, and the spray surface has multiple spray holes; the shielding structure includes:

[0011] A plurality of shielding elements, the shielding elements being used to close the plurality of the spray holes;

[0012] A driver, connected to the shielding member, is used to drive the shielding member to move toward the edge of the spray surface.

[0013] Optionally, there are multiple shielding components, and the multiple shielding components are distributed around the periphery of the spray surface, and the ends of adjacent shielding components can be engaged and connected.

[0014] The driver connects to multiple shielding components and drives the multiple shielding components to move synchronously toward the spray surface, so that the multiple shielding components are connected to each other to form a shielding ring.

[0015] Optionally, the plurality of nozzles are arranged in a ring to form a plurality of spray rings, and the plurality of spray rings are nested sequentially along the direction from the center of the spray surface to the edge of the spray surface;

[0016] The shielding ring at least closes the nozzles in the outermost spray ring.

[0017] Optionally, the shielding member is arc-shaped, and the first end of the shielding member has a snap-fit, and the second end opposite to the first end has a protrusion. Two adjacent shielding members are connected by snap-fitting the snap-fit ​​and the protrusion.

[0018] Optional, also includes:

[0019] The reaction chamber, wherein the support unit is located within the reaction chamber;

[0020] An annular support frame is used to support the nozzle, and the reaction gas ejected by the nozzle enters the reaction chamber through an annular opening in the annular support frame;

[0021] The shielding element and the driver are embedded in the annular support frame.

[0022] To address the above problems, the present invention also provides a film deposition method, comprising the following steps:

[0023] The reactive gas used to form the film is delivered to the surface of a wafer through a nozzle;

[0024] The edge region of the nozzle is shielded to reduce the concentration of the reactive gas in the wafer edge region.

[0025] Optionally, before shielding the edge region of the nozzle, the following steps are also included:

[0026] Determine whether the time it takes for the nozzle to transmit the reactive gas to the wafer surface reaches a first preset time; if so, then block the edge area of ​​the nozzle.

[0027] Optionally, the surface of the nozzle facing the wafer is a spraying surface, and the spraying surface has multiple spray holes; the specific steps for shielding the edge region of the nozzle include:

[0028] Provide at least one shielding element;

[0029] The shielding member is driven to move toward the edge of the spray surface, thereby closing the nozzle located in the edge region of the spray surface.

[0030] Optionally, the number of the shielding members is multiple, and the multiple shielding members are distributed around the periphery of the spray surface; the specific steps of driving the shielding members to move towards the edge of the spray surface include:

[0031] The multiple shielding components are driven to move synchronously toward the spray surface, so that the multiple shielding components are connected to each other to form a shielding ring.

[0032] Optionally, the plurality of nozzles are arranged in a ring to form a plurality of spray rings, and the plurality of spray rings are nested sequentially along the direction from the center of the spray surface to the edge of the spray surface;

[0033] The shielding ring at least closes the nozzles in the outermost spray ring.

[0034] Optionally, after shielding the edge region of the nozzle, the following steps are also included:

[0035] If the time for which the shielding member closes the nozzle reaches a second preset time, then the shielding member is driven to move away from the spray surface, thereby opening the nozzle located in the edge region of the spray surface.

[0036] The film deposition apparatus and method provided by the present invention reduce the concentration of reactive gas in the edge region of the wafer by shielding the edge region of the nozzle during the film deposition process, thereby controlling the film thickness in the edge region of the wafer surface. On the one hand, this improves the uniformity of the film thickness; on the other hand, it ensures that the film in the edge region can be fully etched during the subsequent etching process, avoiding film residue and improving the etching quality. Attached Figure Description

[0037] Appendix Figure 1 This is a schematic cross-sectional view of the film deposition apparatus in the first state according to a specific embodiment of the present invention;

[0038] Appendix Figure 2 This is a schematic cross-sectional view of the film deposition apparatus in the second state according to a specific embodiment of the present invention;

[0039] Appendix Figures 3A-3C This is a top view of the film deposition apparatus in a specific embodiment of the present invention, showing the transition from the first state to the second state.

[0040] Appendix Figure 4 This is an exploded structural diagram of the film deposition apparatus in a specific embodiment of the present invention;

[0041] Appendix Figure 5 This is a thickness distribution diagram of the film layer formed in a specific embodiment of the present invention;

[0042] Appendix Figure 6 This is a flowchart of the film deposition method in a specific embodiment of the present invention. Detailed Implementation

[0043] The specific embodiments of the film deposition apparatus and film deposition method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0044] This specific embodiment provides a film deposition apparatus, with attachment Figure 1 This is a schematic cross-sectional view of the film deposition apparatus in the first state according to a specific embodiment of the present invention, with attached... Figure 2 This is a schematic cross-sectional view of the film deposition apparatus in the second state according to a specific embodiment of the present invention. Figures 3A-3C This is a top view schematic diagram of the film deposition apparatus in a specific embodiment of the present invention, showing the transition from the first state to the second state. Figure 4 This is an exploded structural diagram of the film deposition apparatus in a specific embodiment of the present invention. (See diagram below.) Figure 1 , Figure 2 , Figures 3A-3C as well as Figure 4 As shown, the film deposition apparatus provided in this specific embodiment includes:

[0045] The support portion 10 is used to support the wafer 11;

[0046] A nozzle 12 is disposed above the support portion 10 and is used to spray a reactive gas onto the wafer 11 located on the surface of the support portion 10. The reactive gas is used to form a film layer on the surface of the wafer 11.

[0047] A shielding structure is used to shield the edge region of the nozzle 12 to reduce the concentration of the reactive gas in the edge region of the wafer 11.

[0048] Specifically, the film deposition apparatus has a reaction chamber 17 surrounded by a housing 16, and a support portion 10 is located within the reaction chamber 17 for supporting the wafer 11. Heating components such as heating wires can be embedded inside the support portion 10 for heating the wafer 11 located on the surface of the support portion 10. In the axial direction along the reaction chamber 17 (i.e.... Figure 1 , Figure 2 In the Y-axis direction, the nozzle 12 is positioned above the support portion 10, and the axis of the nozzle 12 coincides with the axis of the support portion 10, that is, the projection of the center of the spray surface 121 of the nozzle 12 coincides with the center of the support surface of the support portion 10 used to support the wafer 11. The projection of the spray surface of the nozzle 12 in the Y-axis direction at least covers the surface of the wafer 11. The reactive gas is sprayed from the nozzle 12 onto the wafer 11 and deposited on the surface of the wafer 11 to form the film layer.

[0049] This specific embodiment, by setting the shielding structure, enables the shielding structure to cover the edge region of the nozzle 12. Since the nozzle 12 sprays the reactive gas along the negative Y-axis, the shielding of the edge region can reduce the concentration of the reactive gas transported to the edge region of the wafer 10, thereby reducing the film thickness of the edge region of the wafer 10 surface. This makes the film thickness of the edge region of the wafer surface more consistent with the film thickness of the center region. On the one hand, it can improve the uniformity of the film thickness deposited on the wafer surface; on the other hand, during the subsequent etching process, the film layer in the edge region of the wafer can be fully etched, avoiding the problem of film residue in the edge region, thereby improving the photolithography quality.

[0050] This specific embodiment does not limit the specific structure of the shielding structure, as long as it can achieve the shielding of the edge area of ​​the nozzle 12, reduce the amount of reactive gas ejected from the edge area of ​​the nozzle 12, and thereby reduce the concentration of the reactive gas in the edge area of ​​the wafer 11 surface.

[0051] Optionally, the surface of the nozzle 12 facing the support portion 10 is a spray surface 121, and the spray surface 121 has a plurality of spray holes 13; the shielding structure includes:

[0052] A plurality of shielding elements 15, the shielding elements 15 being used to close a plurality of the spray holes 13;

[0053] A driver 41, connected to the shielding member 15, is used to drive the shielding member 15 to move toward the edge of the spray surface 121.

[0054] exist Figure 4The actuator 41 is not visible at the angle shown, and is therefore represented by a dashed line. Specifically, the shielding member 15 is initially located around the spray surface 121 of the nozzle 12, as shown... Figure 1 As shown; when it is necessary to block the edge area of ​​the spray surface 121, the driver 41 drives the shielding member 15 to move toward the spray surface 121 until the shielding member 15 blocks several of the nozzles 13 in the edge area of ​​the spray surface 121, such as... Figure 2 As shown. The number of nozzles 13 covered by the shielding member 15 can be one or more. In this specific embodiment, "more" refers to two or more. Those skilled in the art can adjust the shape and / or size of the shielding member 15, and the distance by which the driver drives the shielding member 15 to move, according to actual needs, so that the shielding member 15 can cover a predetermined number of nozzles 13 on the edge of the spray surface 121, or can cover an area of ​​a predetermined size on the edge of the spray surface 121. Those skilled in the art can select the specific type of the driver 41 according to actual needs, for example, it can be, but is not limited to, a stepper motor.

[0055] In this specific embodiment, the surface of the shielding member 15 used to shield the nozzle 13 is parallel to the plane where the spray surface 121 is located. In other specific embodiments, those skilled in the art can also, according to actual needs, set the surface of the shielding member used to shield the nozzle to be inclined at a preset angle relative to the plane where the spray surface 121 is located, as long as the nozzle can be closed.

[0056] The material of the shielding member 15 is preferably a high-resistivity ceramic material with a volume resistivity greater than or equal to 10¹² Ω·m and a relative permittivity less than or equal to 30, so that the shielding member 15 can be used in the temperature range of -55℃ to 860℃.

[0057] Optionally, there are multiple shielding members 15, and the multiple shielding members 15 are distributed around the periphery of the spray surface 121, and the ends of adjacent shielding members 15 can be engaged and connected.

[0058] The driver 41 is connected to a plurality of shielding members 15 and is used to drive the plurality of shielding members 15 to move synchronously toward the spray surface 121, so that the plurality of shielding members 15 are connected to each other to form a shielding ring 30.

[0059] Optionally, the plurality of nozzles 13 are arranged in a ring to form a plurality of spray rings, and the plurality of spray rings are nested sequentially along the direction from the center of the spray surface 121 to the edge of the spray surface 121;

[0060] The shielding ring 30 at least closes the nozzle 13 in the outermost spray ring.

[0061] Optionally, the shielding member 15 is arc-shaped, and the first end of the shielding member 15 has a latch 31, and the second end opposite to the first end has a protrusion 32. Two adjacent shielding members 15 are connected by the latch 31 and the protrusion 32.

[0062] Specifically, the plurality of nozzles 13 on the spray surface 121 are arranged to form multiple concentric rings, each ring constituting a spray ring, meaning each spray ring is formed by multiple nozzles surrounding it. The inner diameters of the multiple spray rings are different, allowing them to be nested sequentially along the direction from the center of the spray surface 121 to its edge. In this specific embodiment, all the nozzles 13 on the spray surface 121 may be arranged together to form multiple spray rings, and these rings may be nested sequentially along the radial direction of the spray surface 121 (i.e., along the direction from the center of the spray surface 121 to its edge); alternatively, some of the nozzles 13 on the spray surface 121 may be arranged to form multiple spray rings, for example, several nozzles located in the edge region of the spray surface 121 may be arranged to form multiple spray rings, while the nozzles located in the central region of the spray surface 121 may be arranged radially (e.g.,...). Figure 3A As shown in the diagram, the multiple spray rings located in the edge region are nested sequentially along the radial direction of the spray surface 121. In this specific embodiment, "multiple rings" refers to two or more rings.

[0063] The following explanation uses an example where the shape of the shielding member 15 is arc-shaped and the number of shielding members 15 in the shielding structure is four. At the initial moment of the film deposition process, multiple shielding members 15 are distributed around the periphery of the spray surface 121. The reactive gas is sprayed from all the nozzles 13 on the spray surface 121 toward the surface of the wafer 11, meaning all the nozzles 13 on the spray surface 121 are in the open state. Figure 3A As shown. When as Figure 3A After the state shown continues for a first preset time, the driver 41 begins to drive the four shielding members 15 to move synchronously toward the edge of the spray surface 121, as shown. Figure 3B As shown. In Figure 3B Each arrow in the diagram indicates the direction of movement of its corresponding shielding member 15. The first preset time is determined by the film thickness of the film to be formed on the surface of the wafer 11. When the four shielding members 15 move to the edge of the spray surface 121, adjacent shielding members 15 engage with the protrusion 32 through the end slots 31, forming a... Figure 3CThe shielding ring 30 is shown. The shielding member 30 at least blocks all the nozzles 13 located on the outermost ring of the spray surface 121. By adjusting the driving force of the driver 41, the engagement force between adjacent shielding members 15 can also be adjusted to prevent the reactive gas from being transmitted from the gap between the adjacent shielding members 15 to the edge region of the wafer 11 surface.

[0064] In other specific embodiments, the configuration may also be as follows: the number of shielding members 15 is multiple, and the multiple shielding members 15 are distributed around the periphery of the spray surface 121; the driver 41 is connected to the multiple shielding members 15 and is used to drive at least one shielding member 15 to move toward the spray surface 121 to close a number of the spray holes 13 on the spray surface 121. That is, the driver 41 can be controlled as needed to drive some of the multiple shielding members 15 to move toward the spray surface 121, thereby blocking a portion of the edge of the spray surface 121, thus enabling flexible adjustment of the number of spray holes to be closed.

[0065] Appendix Figure 5 This is a thickness distribution diagram of the film layer formed according to a specific embodiment of the present invention. (See attached diagram.) Figure 5 It can be seen that by blocking the nozzle 13 in the edge region of the spray surface 121, the thickness of the film layer in the edge region of the wafer 11 can be made close to the thickness of the film layer in the center region of the wafer 11.

[0066] Optionally, the film deposition apparatus further includes:

[0067] The reaction chamber 17, and the support portion 10 is located inside the reaction chamber 17;

[0068] An annular support frame 40 is used to support the nozzle 12, and the reaction gas sprayed by the nozzle 12 enters the reaction chamber 17 through the annular opening in the annular support frame 40;

[0069] The shielding member 15 and the driver 41 are embedded in the annular support frame 40.

[0070] Figure 4 Only a portion of the structure of the annular support frame 40 is shown. Taking an example where the shielding structure includes four shielding elements, Figure 4Only a quarter of the annular support frame 40 is shown. The shielding member 15 and the actuator 41 are embedded in the housing interlayer of the annular support frame 40. When it is necessary to shield the edge area of ​​the nozzle 12, the actuator 41 drives the shielding member 15 to extend out of the housing interlayer of the annular support frame 40; when it is no longer necessary to shield the edge area of ​​the nozzle 12, the actuator 41 can also drive the shielding member 15 to retract into the housing interlayer of the annular support frame 40, and the nozzle orifice 13 at the edge area of ​​the nozzle 12 opens again, so that the reactive gas can be transmitted again from the nozzle orifice 13 at the edge to the edge of the wafer 11.

[0071] Furthermore, this specific embodiment also provides a film deposition method, with attached... Figure 6 This is a flowchart of a film deposition method according to a specific embodiment of the present invention. The film deposition method provided in this specific embodiment can be employed as follows: Figure 1 , Figure 2 , Figures 3A-3C as well as Figure 4 The film deposition apparatus shown is implemented. Figures 1-2 , Figures 3A-3C , Figure 4 and Figure 6 As shown, the film deposition method provided in this specific embodiment includes the following steps:

[0072] Step S61: The reactive gas for forming the film layer is transmitted to the surface of a wafer 11 through a nozzle 12;

[0073] Step S62: The edge region of the nozzle 12 is shielded to reduce the concentration of the reactive gas in the edge region of the wafer 11.

[0074] Optionally, before shielding the edge region of the nozzle 12, the following steps are also included:

[0075] Determine whether the time for the nozzle 12 to transmit the reactive gas to the surface of the wafer 11 has reached a first preset time. If so, then block the edge area of ​​the nozzle 12.

[0076] Optionally, the surface of the nozzle 12 facing the wafer 11 is a spray surface 121, and the spray surface 121 has a plurality of spray holes 13; the specific steps for shielding the edge region of the nozzle 12 include:

[0077] Provide at least one shielding element 15;

[0078] The shielding member 15 is driven to move toward the edge of the spray surface 121, thereby closing the nozzle 13 located in the edge region of the spray surface 121.

[0079] Optionally, the number of the shielding members 15 is multiple, and the multiple shielding members 15 are distributed around the periphery of the spray surface 121; the specific steps of driving the shielding members 15 to move toward the edge of the spray surface 121 include:

[0080] The multiple shielding members 15 are driven to move synchronously toward the spray surface 121, so that the multiple shielding members 15 are connected to each other to form a shielding ring 30.

[0081] Optionally, the plurality of nozzles 13 are arranged in a ring to form a plurality of spray rings, and the plurality of spray rings are nested sequentially along the direction from the center of the spray surface 121 to the edge of the spray surface 121;

[0082] The shielding ring 30 at least closes the nozzle 13 in the outermost spray ring.

[0083] Optionally, after shielding the edge region of the nozzle 12, the following steps are also included:

[0084] If the time for which the shielding member 15 closes the nozzle 13 reaches the second preset time, then drive the shielding member 15 to move away from the spray surface 121 and open the nozzle 13 located in the edge region of the spray surface 121.

[0085] Specifically, by controlling the time that the shielding member 15 blocks the nozzle 13 at the edge of the spray surface 121, the total amount of the reactive gas transmitted to the edge of the wafer 11 can be adjusted, thereby achieving control over the thickness of the film layer at the edge of the wafer 11 surface.

[0086] The film deposition apparatus and method provided in this specific embodiment reduce the concentration of reactive gas in the wafer edge region by shielding the edge region of the nozzle during the film deposition process, thereby controlling the film thickness in the wafer surface edge region. On the one hand, this improves the uniformity of the film thickness; on the other hand, it ensures that the film in the edge region can be fully etched during the subsequent etching process, avoiding film residue and improving the etching quality.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A film deposition apparatus, wherein during film deposition, the film thickness in the edge region of a wafer surface tends to be consistent with the film thickness in the center region, characterized in that, include: The carrier section is used to support the wafer; A nozzle is disposed above the support portion and is used to spray a reactive gas onto the wafer located on the surface of the support portion. The reactive gas is used to form a film layer on the surface of the wafer. The surface of the nozzle facing the support portion is a spray surface. The spray surface has multiple spray holes, which are arranged in a ring to form multiple spray rings. The multiple spray rings are nested sequentially along the direction from the center of the spray surface to the edge of the spray surface. A shielding structure is used to shield the edge region of the nozzle to reduce the concentration of the reactive gas in the edge region of the wafer. The shielding structure includes: a plurality of shielding members for closing a plurality of the nozzles and a driver connected to and driving the shielding members to move toward the edge of the spray surface. The shielding members are made of a high-resistivity ceramic material with a volume resistivity greater than or equal to 10¹² Ω·m and a relative permittivity less than or equal to 30.

2. The film deposition apparatus according to claim 1, characterized in that, The number of shielding components is multiple, and the multiple shielding components are distributed around the periphery of the spray surface, and the ends of adjacent shielding components can be engaged and connected. The driver connects to multiple shielding components and drives the multiple shielding components to move synchronously toward the spray surface, so that the multiple shielding components are connected to each other to form a shielding ring.

3. The film deposition apparatus according to claim 2, characterized in that, The shielding ring at least closes the nozzles in the outermost spray ring.

4. The film deposition apparatus according to claim 2, characterized in that, The shielding component is arc-shaped, and the first end of the shielding component has a snap-fit, and the second end opposite to the first end has a protrusion. Two adjacent shielding components are connected by snap-fitting the snap-fit ​​and the protrusion.

5. The film deposition apparatus according to claim 2, characterized in that, Also includes: The reaction chamber, wherein the support unit is located within the reaction chamber; An annular support frame is used to support the nozzle, and the reaction gas ejected by the nozzle enters the reaction chamber through an annular opening in the annular support frame; The shielding element and the driver are embedded in the annular support frame.

6. A film deposition method using the film deposition apparatus according to any one of claims 1-5, wherein the deposition method enables the film thickness in the edge region of the wafer surface to be approximately the same as the film thickness in the center region during film deposition, characterized in that, Includes the following steps: The reactive gas used to form the film is delivered to the surface of a wafer through a nozzle; The edge region of the nozzle is shielded to reduce the concentration of the reactive gas in the wafer edge region.

7. The film deposition method according to claim 6, characterized in that, Before shielding the edge region of the nozzle, the following steps are also included: Determine whether the time it takes for the nozzle to transmit the reactive gas to the wafer surface reaches a first preset time; if so, then block the edge area of ​​the nozzle.

8. The film deposition method according to claim 6, characterized in that, The surface of the nozzle facing the wafer is the spraying surface, and the spraying surface has multiple spray holes; the specific steps for shielding the edge region of the nozzle include: Provide at least one shielding element; The shielding member is driven to move toward the edge of the spray surface, thereby closing the nozzle located in the edge region of the spray surface.

9. The film deposition method according to claim 8, characterized in that, The number of shielding components is multiple, and the multiple shielding components are distributed around the periphery of the spray surface; the specific steps of driving the shielding components to move towards the edge of the spray surface include: The multiple shielding components are driven to move synchronously toward the spray surface, so that the multiple shielding components are connected to each other to form a shielding ring.

10. The film deposition method according to claim 9, characterized in that, The plurality of nozzles are arranged in a ring to form a plurality of spray rings, and the plurality of spray rings are nested sequentially along the direction from the center of the spray surface to the edge of the spray surface; The shielding ring at least closes the nozzles in the outermost spray ring.

11. The film deposition method according to claim 8, characterized in that, After shielding the edge area of ​​the nozzle, the following steps are also included: If the time for which the shielding member closes the nozzle reaches a second preset time, then the shielding member is driven to move away from the spray surface, thereby opening the nozzle located in the edge region of the spray surface.

Images