Wafer shielding device, semiconductor process apparatus, semiconductor process method

Abstract

The present disclosure provides a wafer shielding device, a semiconductor process equipment and a semiconductor process method. The wafer shielding device comprises: an exhaust ring having a bearing platform; a shadow ring arranged above the bearing platform in a liftable manner, the shadow ring comprising: a shielding ring for shielding the edge area of the wafer during the process; at least three ear parts uniformly distributed along the circumference of the shielding ring; a guide hole arranged in the ear part; and at least three guide parts uniformly distributed along the circumference of the exhaust ring, arranged on the bearing platform and extending in the vertical direction, and corresponding to the guide hole one by one; wherein the guide part and the guide hole are in sliding fit, the number of the guide part is the same as and corresponds to the number of the ear part, to guide the shadow ring to lift in the vertical direction and limit the horizontal displacement of the shadow ring. By using the above technical solution, the accurate guidance of the shadow ring can be realized, and the uniformity of the wafer surface film thickness is improved.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor manufacturing technology, and in particular to a wafer masking device, semiconductor process equipment, and semiconductor process method. Background Technology

[0002] In semiconductor thin film deposition processes, thin films tend to adhere to the chamfered edges of wafers, which may peel off in subsequent processes, forming defects and affecting device performance. Existing technologies address this edge deposition problem by covering the wafer edges with shadow rings to transfer the deposits onto the rings.

[0003] However, in existing equipment, the shadow ring rests on the pump ring platform by gravity, resulting in a large clearance. During wafer lifting and lowering, the shadow ring is passively raised and lowered and is prone to horizontal displacement, which disrupts the concentricity between the shadow ring and the wafer edge, leading to a decrease in film thickness uniformity. This necessitates frequent cavity opening and correction of the equipment, severely impacting operating efficiency.

[0004] Therefore, how to provide a technical solution to achieve precise guidance of the shadow ring and improve the uniformity of the thin film thickness on the wafer surface has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of the present disclosure provide a wafer masking device, semiconductor process equipment, and semiconductor process method, which can achieve precise guidance of the shadow ring and improve the uniformity of the thin film thickness on the wafer surface.

[0006] To address the aforementioned technical problems, this disclosure provides a wafer masking device, comprising: a vacuum ring having a support platform; and a shadow ring movably disposed above the support platform. The shadow ring includes: a shielding ring for shielding the edge region of the wafer during the process; at least three ears evenly distributed circumferentially along the shielding ring; guide holes disposed on the ears; and at least three guide members evenly distributed circumferentially along the vacuum ring, disposed on the support platform and extending vertically, corresponding one-to-one with the guide holes. The guide members slide in conjunction with the guide holes, and the number of guide members is the same as the number of ears and corresponds one-to-one, to guide the shadow ring to rise and fall vertically and limit the horizontal displacement of the shadow ring.

[0007] Optionally, the guide is a ceramic nail, which includes a nail rod; the lower end of the nail rod is fixed in a mounting hole on the bearing platform, and the upper end of the nail rod extends beyond a predetermined length of the bearing platform.

[0008] Optionally, the guide is a ceramic nail, and the ceramic nail further includes a nail head; the nail head is disposed at the top of the nail shank to prevent the shadow ring from dislodging.

[0009] Optionally, each of the ear portions is provided with a guide hole, and the number of guide holes is the same as the number of ceramic nails.

[0010] Optionally, the guide hole is a through hole, the nail rod passes through the through hole, and the outer diameter of the nail rod is smaller than the inner diameter of the guide hole to form a clearance fit.

[0011] Optionally, the ceramic nail is made of a plasma-resistant ceramic material, which includes one or more combinations of alumina, silicon nitride, and silicon carbide.

[0012] Optionally, the mounting holes on the support platform are blind holes or through holes, and the lower end of the nail rod is fixed in the mounting holes by interference fit, adhesive bonding or threaded connection.

[0013] Optionally, the lifting stroke of the shadow ring is limited by the length of the nail rod above the support platform, and the ear does not detach from the nail rod when the shadow ring is at its highest position.

[0014] This disclosure also provides a semiconductor process apparatus, including a process chamber, a heating stage disposed within the process chamber, and a wafer masking device as described in any of the above embodiments, wherein the heating stage is used to support and lift the wafer, and the shadow ring moves up and down with the heating stage.

[0015] This disclosure also provides a semiconductor process method for performing a thin film deposition process using the semiconductor process equipment described above, comprising: transferring a wafer to a heated stage, wherein the projection of a shadow ring on the heated stage shields the edge of the wafer; raising the heated stage to lift the wafer onto a support platform, wherein the shadow ring contacts the wafer, and continuing to lift the wafer and the shadow ring along the guide to a process position; depositing a thin film on the wafer; after deposition, lowering the heated stage below the support platform, wherein the shadow ring falls back onto the support platform along the guide; and removing the wafer; wherein, during the lifting and lowering of the shadow ring, the guide restricts its horizontal displacement to ensure that the shadow ring remains concentric with the wafer.

[0016] Compared with the prior art, the technical solution of the present disclosure has the following advantages: This disclosure provides a wafer masking device, comprising: a suction ring having a support platform; a shadow ring, movably disposed above the support platform, the shadow ring including a shielding ring and at least three ears, the shielding ring being used to shield the edge region of the wafer during the process, the at least three ears being evenly distributed circumferentially along the shielding ring, and each ear having a guide hole; and at least three guide members evenly distributed circumferentially along the suction ring, disposed on the support platform and extending vertically, the guide members slidingly engaging with the guide holes one-to-one to guide the shadow ring to move up and down in the vertical direction and limit its horizontal displacement. By providing multiple guide members evenly distributed circumferentially and slidingly engaging with the guide holes on the shadow ring ears one-to-one, precise guiding constraints are provided for the lifting and lowering movement of the shadow ring. This structure effectively eliminates the horizontal offset of the shadow ring caused by various uncertainties during the lifting and lowering process, ensuring that the shadow ring and the wafer edge remain concentric. Therefore, the wafer masking device can achieve precise guidance of the shadow ring and improve the uniformity of the thin film thickness on the wafer surface. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments disclosed in this specification, the drawings used in the description of the embodiments disclosed in this specification or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a top view schematic diagram of a wafer shielding device according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a shadow ring in an embodiment of this disclosure; Figure 3 This is a schematic diagram of another shadow ring structure in an embodiment of this disclosure; Figure 4 This is a cross-sectional schematic diagram of an air extraction ring according to an embodiment of this disclosure; Figure 5 This is a cross-sectional schematic diagram of an air extraction ring according to an embodiment of this disclosure; Figure 6 This is a cross-sectional schematic diagram of an air extraction ring and a guide member in an embodiment of this disclosure. Detailed Implementation

[0019] The technical solutions described herein will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of this disclosure and are used to illustrate the concept of this disclosure. These descriptions are illustrative and exemplary and should not be construed as limiting the implementation methods or the scope of protection of this disclosure. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0020] It should be noted that the accompanying drawings in this embodiment are schematic diagrams used to illustrate the concept of this disclosure, and to schematically show the shape and interrelationship of each part. It should be understood that, in order to clearly show the structure of each component of this disclosure, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0021] As described in the background section, in semiconductor thin film deposition processes, thin films tend to adhere to the chamfered edges of wafers, which may peel off in subsequent processes, forming defects and affecting device performance. Existing technologies address edge deposition problems by covering the wafer edges with shadow rings to transfer deposits onto the rings.

[0022] However, in existing equipment, the shadow ring rests on the pump ring platform by gravity, resulting in a large clearance. During wafer lifting and lowering, the shadow ring is passively raised and lowered and is prone to horizontal displacement, which disrupts the concentricity between the shadow ring and the wafer edge, leading to a decrease in film thickness uniformity. This necessitates frequent cavity opening and correction of the equipment, severely impacting operating efficiency.

[0023] Therefore, how to provide a technical solution to achieve precise guidance of the shadow ring and improve the uniformity of the thin film thickness on the wafer surface has become an urgent technical problem to be solved.

[0024] To address the aforementioned technical problems, this disclosure provides a wafer masking device, comprising: a suction ring having a support platform; a shadow ring, movably disposed above the support platform, the shadow ring including a shielding ring and at least three ears, the shielding ring being used to shield the edge region of the wafer during the process, the at least three ears being evenly distributed circumferentially along the shielding ring, and each ear having a guide hole; and at least three guide members evenly distributed circumferentially along the suction ring, disposed on the support platform and extending vertically, the guide members slidingly engaging with the guide holes one-to-one to guide the shadow ring to rise and fall vertically and limit its horizontal displacement. By providing multiple guide members evenly distributed circumferentially and slidingly engaging with the guide holes on the shadow ring ears one-to-one, precise guiding constraints are provided for the rising and falling movement of the shadow ring. This structure effectively eliminates the horizontal offset of the shadow ring caused by various uncertainties during the rising and falling process, ensuring that the shadow ring remains concentric with the wafer edge. Therefore, the wafer masking device can achieve precise guidance of the shadow ring and improve the uniformity of the thin film thickness on the wafer surface.

[0025] To make the above-described objects, features and advantages of this disclosure more apparent and understandable, the disclosure is illustrated below with reference to the accompanying drawings.

[0026] See Figure 1 , Figure 1 This is a top view schematic diagram of a wafer masking device according to an embodiment of the present disclosure.

[0027] like Figure 1 As shown, in this embodiment, the wafer shielding device includes: a vacuum ring 110.

[0028] The suction ring 110 has a ring structure and is fixedly installed on the inner wall of the process chamber P, surrounding the periphery of the heating stage 100.

[0029] The suction ring 110 can be made of ceramic. Alternatively, the suction ring 110 can be made of a metal material resistant to plasma corrosion, such as aluminum alloy or stainless steel, with its surface treated by anodizing or ceramic coating to enhance corrosion resistance and wear resistance, ensuring long-term stable use in harsh deposition environments containing active free radicals.

[0030] The extraction ring 110 is fixedly installed on the inner wall of the process chamber P, surrounds the periphery of the heating platform 100, and is connected to the exhaust system of the process chamber P.

[0031] See also Figure 1 and Figure 4 , Figure 4 This is a cross-sectional schematic diagram of an extraction ring according to an embodiment of this disclosure.

[0032] It should be noted that, Figure 4 For the suction ring in Figure 1 The cross-sectional view of the suction ring obtained by cutting along the dotted line A1-B1 is not a schematic diagram. Figure 1 A schematic diagram of the cross-sections of all structures obtained by cutting along the dashed line A1-B1.

[0033] The suction ring 110 has a support platform 111.

[0034] Specifically, the support platform 111 is located inside the suction ring 110, i.e., on the side facing the heating platform 100, so as to support the shadow ring 120.

[0035] The support platform 111 is a plane and is used to support the shadow ring 120 in a non-process state.

[0036] The support platform 111 is provided with multiple mounting holes 112.

[0037] The mounting hole 112 is a blind hole or a through hole, used to fix the guide 130.

[0038] As an example, Figure 4 The structure of mounting hole 112 is shown as a blind hole with a closed bottom, which can prevent the mounting hole from penetrating the vacuum ring 110 and affecting the quality of the vacuum ring 110.

[0039] In other embodiments, the mounting hole 112 may also be configured as a through hole to facilitate fixing the guide from below or for cleaning.

[0040] The number of mounting holes 112 corresponds one-to-one with the number of guide members 130, and they are evenly distributed along the inner circumference of the suction ring 110 to ensure that the shadow ring 120 is subjected to uniform force and rises and falls smoothly.

[0041] The mounting hole 112 is used to fix the guide 130. For example, the lower end of the guide 130 is inserted into and fixed in the mounting hole 112 by means of interference fit, adhesive bonding or threaded connection, so as to provide precise lifting guidance for the shadow ring 120 and limit its horizontal displacement, and ensure the concentricity of the shadow ring 120 and the wafer in each process.

[0042] See also Figure 1 and Figure 5 , Figure 5 This is a cross-sectional schematic diagram of an extraction ring according to an embodiment of this disclosure.

[0043] It should be noted that, Figure 5 For the suction ring in Figure 1 The cross-sectional view of the suction ring obtained by cutting along the dotted line A2-B2 is not a schematic diagram. Figure 1A schematic diagram of the cross-sections of all structures obtained by cutting along the dashed line A2-B2.

[0044] The extraction ring 110 can serve as a gas flow channel.

[0045] The inner wall of the extraction ring 110 is provided with uniformly distributed extraction holes 113, which are used to uniformly remove reaction byproducts, unreacted gases and carrier gases during the process, maintain the stability of process gas pressure and the uniformity of flow field distribution in the chamber, thereby ensuring the thickness uniformity and quality consistency of the thin film deposition.

[0046] The vacuum ring 110 can serve as a thermal isolation element, reducing heat radiation and heat conduction from the heating stage 100 to the side wall of the chamber, thereby improving the temperature control accuracy and response speed of the heating stage 100.

[0047] See also Figure 1 and Figure 2 , Figure 3 , Figure 2 This is a schematic diagram of the structure of a shadow ring according to an embodiment of this disclosure. Figure 3 This is a schematic diagram of another shaded ring structure in an embodiment of this disclosure.

[0048] The wafer masking device includes a shadow ring 120.

[0049] The shadow ring 120 is vertically and retractably mounted above the support platform 111.

[0050] The shadow ring 120 includes: an occlusion ring 121.

[0051] The shielding ring 121 has a circular structure and is integrally molded from a ceramic material resistant to plasma corrosion (such as alumina, silicon nitride, or silicon carbide).

[0052] The shielding ring 121 is used to shield the edge region of the wafer during the process.

[0053] Specifically, when the heating stage 100 lifts the wafer to the position of the plane of the support platform 111, the inner edge portion of the shielding ring 121 or the shielding ring 121 covers the edge of the wafer.

[0054] The shielding ring 121 covers a width of 3 mm to 5 mm around the edge of the wafer.

[0055] The shielding ring 121 can effectively prevent the reactants in the chemical vapor deposition process from depositing on the chamfered area of ​​the wafer edge, thereby avoiding particle defects caused by the peeling of the edge film in subsequent processes and ensuring wafer yield.

[0056] The shadow ring 120 includes: an ear portion 122.

[0057] The shadow ring 120 includes at least three ears 122.

[0058] The ear portion 122 is located on the outside of the shielding ring 121.

[0059] The ear portion 122 is evenly distributed along the circumference of the shielding ring 121.

[0060] The design employs at least three ears 122, which can provide multi-point support and guidance during the lifting and lowering of the shadow ring 120, ensuring that the shadow ring 120 is subjected to balanced force and avoiding tilting or jamming problems caused by single-point or two-point guidance.

[0061] In this embodiment, there are four ears 122, which are evenly distributed along the circumference of the shielding ring 121.

[0062] The ear portion 122 extends outward from the main body of the shielding ring 121 to form a convex ear structure. The lower surface of the ear portion 122 contacts the support platform 111 of the suction ring 110 in a non-process state, thereby stably supporting the shadow ring 120 on the support platform 111.

[0063] The shadow ring 120 includes a guide hole 123.

[0064] The guide hole 123 is provided on the ear part 122.

[0065] Specifically, each ear portion 122 is provided with a guide hole 123, which is a through hole that passes through the ear portion 122 in a vertical direction.

[0066] The shape and size of the guide hole 123 are matched with the cross-sectional shape and size of the guide member 130.

[0067] The guide hole 123 can be circular, rectangular, or straight, etc.

[0068] In this embodiment, the guide hole 123 can be a circular hole.

[0069] The diameter of the guide hole 123 is slightly larger than the cross-sectional diameter of the guide member 130, forming a sliding fit clearance between them. This clearance ensures that the shadow ring 120 can move smoothly up and down along the guide member 130, while also effectively limiting the horizontal displacement of the shadow ring 120.

[0070] In the installed state, the guide holes 123 on each ear 122 are respectively fitted onto the corresponding guide members 130. Throughout the entire lifting stroke of the shadow ring 120, the guide members 130 always pass through the guide holes 123, thereby ensuring that the shadow ring 120 remains concentric with the suction ring 110, the heating stage 100, and the wafer. This precisely defines the horizontal position of the shadow ring 120 during the lifting process, eliminating the problem of uneven shading caused by offset, thus ensuring the uniformity of thin film deposition and process repeatability.

[0071] See also Figure 1 and Figure 6 , Figure 6 This is a cross-sectional schematic diagram of an air extraction ring and a guide member in an embodiment of this disclosure.

[0072] It should be noted that, Figure 6 It can be Figure 1 The cross-sectional view of the suction ring and guide component obtained by cutting along the dotted line A1-B1 is not intended to be a complete diagram. Figure 1 A schematic diagram of the cross-sections of all structures obtained by cutting along the dashed line A1-B1.

[0073] The wafer shielding device includes: a guide 130.

[0074] The wafer masking device includes at least three guides 130.

[0075] The guide members 130 are evenly distributed on the bearing platform 111 along the circumference of the suction ring 110.

[0076] The uniform distribution of the guide members 130 ensures that the shadow ring 120 is subjected to balanced force during the lifting and lowering process, avoiding tilting or jamming problems caused by uneven distribution of guide points, thereby improving the stability and reliability of the shadow ring 120's movement.

[0077] The guide member 130 is disposed on the support platform 111 and extends in the vertical direction.

[0078] Specifically, each guide 130 is positioned corresponding to an ear 122 on the shadow ring 120, and the number of guides 130 is the same as the number of ears 122.

[0079] In this embodiment, there are four guide members 130, each corresponding to one of the four ears 122 evenly distributed around the circumference of the shadow ring 121. This one-to-one correspondence arrangement ensures that each ear 122 is guided by an independent guide member 130, guaranteeing the precise positioning of the shadow ring 120 during the lifting and lowering process.

[0080] The guide member 130 is slidably engaged with the guide hole 123 opened on the ear part 122.

[0081] Specifically, the guide member 130 passes through the guide hole 123, and the guide member 130 corresponds one-to-one with the guide hole 123, forming a relatively slidable connection between them. Through this sliding fit structure, the guide member 130 can effectively guide the shadow ring 120 to rise and fall in the vertical direction, while precisely limiting the displacement of the shadow ring 120 in the horizontal direction. When the heating stage 100 is raised or lowered, the shadow ring 120 can only move along the axial direction of the guide member 130, and cannot be offset in the horizontal direction, thereby ensuring that the shadow ring 120 always remains concentric with the suction ring 110, the heating stage 100, and the wafer.

[0082] The guide component 130 is made of ceramic.

[0083] The guide component 130 is a ceramic nail.

[0084] The ceramic nail includes a nail rod 131, which is cylindrical and its axis extends vertically.

[0085] The lower end of the nail rod 131 is fixedly installed in the mounting hole 112 opened on the bearing platform 111.

[0086] The upper end of the nail rod 131 is higher than the upper surface of the bearing platform 111 by a preset length. The preset length is set according to the required lifting stroke of the shadow ring 120 to ensure that the shadow ring 120 can move smoothly between the process position and the bearing position of the bearing platform 111.

[0087] In some embodiments, the preset length is the length by which the upper end of the nail rod 131 extends beyond the upper surface of the support platform 111.

[0088] In other embodiments, the upper end of the nail rod 131 extends beyond the upper surface of the bearing platform 111 by a length greater than the preset length.

[0089] The ceramic nail also includes a nail head 132.

[0090] The nail cap 132 can prevent the shadow ring 120 from detaching from the guide 130 during the upward movement.

[0091] The nail cap 132 is disposed at the top end of the nail rod 131.

[0092] The diameter of the nail head 132 is larger than the diameter of the nail rod 131, and also larger than the diameter of the guide hole 123 on the ear 122.

[0093] When the shadow ring 120 rises to its highest position, the upper surface of the ear 122 contacts or approaches the lower surface of the nail head 132. The nail head 132 acts as a limiter, preventing the shadow ring 120 from continuing to move upward, thereby preventing it from coming off the top of the nail rod 131 and ensuring the safety of the device operation.

[0094] Each of the ear portions 122 is provided with a guide hole 123, and the number of guide holes 123 is the same as the number of ceramic nails.

[0095] The guide hole 123 is precisely aligned with the position of the corresponding ceramic nail, ensuring that each nail shank 131 can smoothly pass into the corresponding guide hole 123 during installation. This one-to-one hole design simplifies the installation process while ensuring guiding accuracy.

[0096] In this embodiment, the guide hole 123 is a through hole that passes through the ear portion 122.

[0097] The nail shank 131 passes through the through hole, and the outer diameter of the nail shank 131 is slightly smaller than the inner diameter of the guide hole 123, forming a clearance fit between them. This clearance should not be too large to avoid excessive horizontal wobbling of the shadow ring 120, nor too small to prevent jamming due to thermal expansion or particulate contamination.

[0098] In some embodiments, the single-sided gap between the nail rod 131 and the guide hole 123 is controlled within the range of 0.1mm to 1mm, which ensures smooth sliding and achieves effective horizontal limiting.

[0099] The guide 130 is made of a ceramic material resistant to plasma corrosion.

[0100] Specifically, the ceramic materials include, but are not limited to, one or more combinations of alumina (Al2O3), silicon nitride (Si3N4), and silicon carbide (SiC). These materials possess excellent resistance to plasma erosion, high-temperature stability, and mechanical strength, enabling them to be used for extended periods in the harsh environment of chemical vapor deposition processes without corrosion or deformation, thus ensuring the long-term stability of guiding accuracy.

[0101] The mounting holes 112 on the support platform 111 can be blind holes or through holes.

[0102] When a blind hole structure is used, the bottom of the hole is closed, which can prevent the installation hole from penetrating the suction ring 110 and affecting the airtightness of the chamber; when a through hole structure is used, it is convenient to clean or disassemble from below.

[0103] The lower end of the nail rod 131 is fixed in the mounting hole 112 by means of interference fit, adhesive bonding, or threaded connection. The interference fit method is simple and reliable, and is suitable for fixing ceramics and metals; the adhesive bonding method can fill small gaps and improve the connection stability; the threaded connection method facilitates disassembly and replacement. Those skilled in the art can choose one or more combinations of these fixing methods according to actual needs.

[0104] The lifting stroke of the shadow ring 120 is limited by the length of the nail rod 131 above the bearing platform 111.

[0105] Specifically, the vertical distance from the upper surface of the support platform 111 to the lower surface of the nail head 132 on the nail rod 131 is the maximum travel range of the shadow ring 120. When the shadow ring 120 rises to its highest working position, the ear 122 is still fitted onto the nail rod 131, and the distance between the lower surface of the shadow ring 120 and the support platform 111 reaches its maximum, but the upper surface of the ear 122 has not yet contacted or has just contacted the nail head 132, ensuring that the shadow ring 120 does not leave the guide range of the nail rod 131. Through this travel-limiting design, it is ensured that the shadow ring 120 is always effectively constrained by the guide member 130 throughout the entire movement.

[0106] Accordingly, this disclosure also provides a semiconductor process apparatus.

[0107] See Figure 1 The semiconductor process equipment is used to deposit thin film materials on the surface of a wafer, particularly in process scenarios where the wafer edge needs to be shielded to prevent thin film deposition.

[0108] The semiconductor process equipment includes a process chamber P, a heating stage 100 disposed in the process chamber P, and a wafer masking device as described in any of the above embodiments.

[0109] The process chamber P is a sealed cavity made of corrosion-resistant ceramic or metallic materials (such as aluminum alloy or stainless steel), and its inner wall is surface-treated to adapt to the chemical vapor deposition process environment.

[0110] The process chamber P is equipped with a gas inlet and an exhaust outlet, which are connected to the gas source system and the vacuum pump system, respectively, to introduce reaction gas into the chamber and maintain a stable process gas pressure.

[0111] The heating stage 100 is located in the center of the process chamber P.

[0112] The heating stage 100 is used to support and lift the wafer.

[0113] Specifically, the upper surface of the heating stage 100 is a wafer carrier surface, and multiple lifting devices 101 (pin holes or electrostatic chuck electrodes) are provided on the carrier surface to lift or adsorb and fix the wafer during the wafer transfer process.

[0114] The heating stage 100 is equipped with heating elements (such as resistance heating wires) and temperature sensors, which can heat the wafer to the temperature required for the process (e.g., 200°C to 700°C) and monitor and control the temperature uniformity in real time to ensure the consistency of thin film deposition quality.

[0115] The heating stage 100 is connected to a lifting drive mechanism (such as a motor-driven lifting rod or a cylinder), which can drive the heating stage 100 to move up and down in the vertical direction. The heating stage 100 has at least two working positions: a lower release position for receiving and delivering the wafer; and an upper process position for lifting the wafer to a deposition height that mates with the shadow ring 120.

[0116] The wafer shielding device is installed inside the process chamber P and surrounds the heating stage 100.

[0117] Specifically, the vacuum ring 110 of the wafer shielding device is fixedly installed on the inner wall of the process chamber P, and the guide 130 on its support platform 111 extends vertically. The shadow ring 120 is sleeved on the guide 130 through the guide hole 123 on the ear 122 and is vertically and flexibly set above the support platform 111 of the vacuum ring 110.

[0118] The shadow ring 120 rises and falls with the heating stage 100. When the heating stage 100, carrying the wafer, rises from the release position to the process position and reaches the plane position of the support platform 111, the edge of the wafer on the upper surface of the heating stage 100 contacts the lower surface of the shielding ring 121 of the shadow ring 120. This lifts the shadow ring 120. Driven by the heating stage 100, the shadow ring 120 rises vertically along the guide 130 until it reaches the process position.

[0119] When the heating platform 100 descends from the process position to the planar position of the support platform 111, the shadow ring 120, under its own gravity, falls smoothly back along the guide member 130 and finally rests on the support platform 111 of the suction ring 110.

[0120] In this embodiment, the wafer shielding device is used in a chemical vapor deposition (CVD) apparatus, and is particularly suitable for plasma-enhanced chemical vapor deposition (PECVD) processes that require shielding at the wafer edge to prevent thin film deposition.

[0121] In plasma-enhanced chemical vapor deposition (APF), a reactive gas (such as a hydrocarbon gas used for depositing APF thin films) is introduced into the process chamber P, and plasma is generated by excitation with a radio frequency power supply. The active groups in the plasma undergo a chemical reaction on the wafer surface, depositing and forming a thin film.

[0122] The shadow ring 120 covers a 3mm to 5mm area at the wafer edge during the process, preventing reactive gases from reaching this area. Therefore, the thin film is deposited only on the effective area of ​​the wafer, avoiding deposition at the chamfered edges. This effectively prevents edge film peeling and particle defects in subsequent processes, thereby improving wafer yield and device reliability. The shadow ring 120 maintains precise alignment with the wafer throughout its raising and lowering process, ensuring a uniform shielding width and guaranteeing uniform film deposition and process repeatability.

[0123] Accordingly, this disclosure also provides a semiconductor process method.

[0124] See Figure 1 The semiconductor process method uses semiconductor process equipment as described above to perform thin film deposition processes, and is particularly suitable for plasma-enhanced chemical vapor deposition processes that require shielding at the wafer edge to prevent thin film deposition.

[0125] By employing the wafer masking device with the aforementioned guiding structure, this method can effectively limit the horizontal displacement of the shadow ring during its lifting and lowering process, ensuring that the shadow ring and the wafer remain concentric, thereby improving the uniformity of thin film deposition.

[0126] The semiconductor process method includes the following steps: The wafer is transferred to the heated stage 100.

[0127] Specifically, when the heating stage 100 is in the lower release position, the robot arm delivers the wafer into the process chamber P and places the wafer on the upper surface of the heating stage 100. At this time, the shadow ring 120 rests on the support platform 111 of the vacuum ring 110, in a waiting state. The projection of the shadow ring 120 on the heating stage 100 shields the edge of the wafer; that is, when viewed vertically, the inner edge of the shadow ring 120 covers the upper part of the wafer edge area, preparing for subsequent shielding operations.

[0128] The heating stage 100 is raised, allowing it to lift the wafer upwards. The heating stage 100 first rises to a height near the support platform 111, at which point the edge of the wafer contacts the lower surface of the shielding ring 121 of the shadow ring 120.

[0129] The wafer continues to be lifted, causing the shadow ring 120 to rise from the support platform 111. Under the continued pushing of the heated stage 100, the shadow ring 120 rises vertically along the guide 130 along with the wafer. The guide hole 123 on the lug 122 of the shadow ring 120 (see...) Figure 2 ) and guide member 130 nail rod 131 (see Figure 6 The sliding fit guides the shadow ring 120 to rise smoothly, while the guide member 130 restricts the horizontal displacement of the shadow ring 120.

[0130] The heated stage 100 continues to rise until it reaches a preset process position. At this process position, the wafer is heated to the temperature required for the process, and the shadow ring 120 covers a preset width area (e.g., 3 mm to 5 mm) of the wafer edge, in preparation for thin film deposition.

[0131] A thin film is deposited on the wafer. A reactive gas is introduced into the process chamber P, and radio frequency power is applied to generate plasma according to process requirements.

[0132] After deposition is completed, the heated stage 100 is lowered below the support platform 111. The heated stage 100 carrying the wafer begins to move downward. As the heated stage 100 descends, the shadow ring 120, under its own gravity, detaches from the wafer and slowly falls back along the guide 130.

[0133] The shadow ring 120 continues to descend until the lower surface of the ear 122 rests again on the support platform 111 of the suction ring 110. Throughout the descent, the guide 130 remains inside the guide hole 123, limiting the horizontal displacement of the shadow ring 120 and ensuring that its descent position remains consistent with its initial position without any deviation.

[0134] The wafer is removed. The heated stage 100 continues to descend to the release position, at which point the shadow ring 120 has completely detached and is stably placed on the support platform 111. The robotic arm enters the chamber and removes the wafer with the deposited thin film from the heated stage 100.

[0135] During the lifting and lowering of the shadow ring 120, the guide 130 restricts its horizontal displacement to ensure that the shadow ring 120 remains concentric with the wafer.

[0136] Specifically, due to the precise sliding fit between the guide member 130 and the guide hole 123, the horizontal position of the shadow ring 120 is precisely defined throughout its entire stroke as it rises and falls with the heating stage 100. Even after multiple process cycles, the shadow ring 120 returns to the same initial position each time it falls back to the support platform 111, without any cumulative shift due to mechanical vibration or friction.

[0137] In this way, the shading width of the shadow ring 120 on the wafer edge remains consistent during each process, eliminating film thickness differences caused by uneven shading, thereby improving wafer consistency and yield in mass production. Simultaneously, the stable movement of the shadow ring 120 reduces the need for cavity correction maintenance, increasing equipment uptime and production efficiency.

[0138] It should be noted that the illustrated embodiments only show a portion of the wafer masking device. Those skilled in the art should understand that other embodiments obtained by mirroring, flipping, rotating, or adapting the position, relative connection, or orientation of the various structures in the wafer masking device based on the structure shown in the drawings, or by making adaptive adjustments to its shape and size, should all be considered within the scope of this disclosure.

[0139] The foregoing describes several embodiments of the wafer masking device. The various options described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as embodiments disclosed in this disclosure.

[0140] In the embodiments of this application, "multiple" refers to two or more.

[0141] While the embodiments disclosed herein are as described above, this disclosure is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A wafer masking device, characterized in that, include: A vacuum ring, wherein the vacuum ring has a support platform; A shadow ring, which is vertically and retractably disposed above the support platform, comprises: A shielding ring is used to shield the edge areas of a wafer during the manufacturing process. At least three ears are evenly distributed along the circumference of the shielding ring; A guide hole is provided in the ear portion; At least three guide members, evenly distributed around the circumference of the suction ring, are disposed on the support platform and extend vertically, corresponding one-to-one with the guide holes; The guide member slides with the guide hole, and the number of guide members is the same as the number of ears and corresponds one-to-one, so as to guide the shadow ring to rise and fall in the vertical direction and limit the horizontal displacement of the shadow ring.

2. The wafer masking device according to claim 1, characterized in that, The guide component is a ceramic nail, and the ceramic nail includes a nail shank; The lower end of the nail rod is fixed in the mounting hole on the bearing platform, and the upper end of the nail rod extends beyond the bearing platform by a predetermined length.

3. The wafer masking device according to claim 2, characterized in that, The guide component is a ceramic nail, and the ceramic nail further includes a nail head; The nail cap is positioned at the top of the nail bar to prevent the shadow ring from coming off.

4. The wafer masking device according to claim 2 or 3, characterized in that, Each of the ear parts is provided with a guide hole, and the number of guide holes is the same as the number of ceramic nails.

5. The wafer masking device according to claim 4, characterized in that, The guide hole is a through hole, and the nail rod passes through the through hole. The outer diameter of the nail rod is smaller than the inner diameter of the guide hole to form a clearance fit.

6. The wafer masking device according to claim 2 or 3, characterized in that, The ceramic nail is made of a plasma-resistant ceramic material, which includes one or more combinations of alumina, silicon nitride, and silicon carbide.

7. The wafer masking device according to claim 2, characterized in that, The mounting holes on the support platform are blind holes or through holes, and the lower end of the nail rod is fixed in the mounting holes by interference fit, adhesive bonding or threaded connection.

8. The wafer masking device according to claim 2, characterized in that, The lifting stroke of the shadow ring is limited by the length of the nail rod above the support platform, and the ear does not detach from the nail rod when the shadow ring is at its highest position.

9. A semiconductor process apparatus, characterized in that, The device includes a process chamber, a heating stage disposed within the process chamber, and a wafer shielding device as described in any one of claims 1 to 8, wherein the heating stage is used to support and lift the wafer, and the shadow ring lifts and lowers with the heating stage.

10. A semiconductor manufacturing process, characterized in that, Performing a thin film deposition process using the semiconductor process equipment as described in claim 9 includes: The wafer is transferred to a heated stage, and the shadow ring's projection on the heated stage obscures the wafer's edge; The heating stage is raised so that it lifts the wafer onto the support platform, the shadow ring contacts the wafer, and the wafer and shadow ring continue to be lifted and rise along the guide to the process position; A thin film is deposited on the wafer; After deposition is completed, the heating stage is lowered below the support platform, and the shadow ring falls back to the support platform along the guide. Remove the wafer; During the raising and lowering of the shadow ring, the guide restricts its horizontal displacement to ensure that the shadow ring remains concentric with the wafer.

Images