A high-uniformity oblique-angle electron beam evaporation device and a control method thereof

Abstract

The application provides a high-uniformity oblique-angle electron beam evaporation device and a control method thereof, and relates to the technical field of semiconductor equipment. The device comprises a vacuum cavity and an electron beam evaporation source; a substrate is obliquely arranged in the vacuum cavity, and further comprises a guard plate sleeved on the exit side of the evaporation source, wherein the guard plate is provided with an opening coaxial with the center point of the substrate and facing the evaporation source; a shielding plate is arranged above the opening and can be programmed to move linearly, and the stroke of the shielding plate is suitable for being arranged in the horizontal direction to time-domain modulate the size of the evaporation beam passing through the opening during the evaporation process; and a controller is used to drive the shielding plate to perform step-by-step opening according to a predetermined scanning track after the deposition rate is stabilized, and the travel direction of the predetermined scanning track is implemented according to a compensation strategy of exposing first away from the evaporation source area and then exposing close to the evaporation source area. The scheme is used to control the uniformity of the sputtering of the substrate film coating.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and more specifically, to a high-uniformity tilt angle electron beam evaporation apparatus and its control method. Background Technology

[0002] In the field of superconducting quantum computing, the performance of qubits is highly dependent on the precise uniformity of Josephson junction parameters. The barrier layer thickness of a Josephson junction is typically on the nanometer scale, placing extremely stringent requirements on film uniformity. Electron beam evaporation, a key physical vapor deposition process, uses an evaporation source that can be approximated as a point source, resulting in the deposition thickness distribution being simultaneously influenced by both the cosine law and the inverse square law of distance. When the substrate is tilted at a specific angle, the deposition rate at the upper edge of the substrate is significantly higher than at the lower edge due to its proximity to the evaporation source and smaller incident angle, thus forming a systematic thickness gradient from top to bottom. This non-uniformity is particularly pronounced on large-size substrates, with uniformity differences often exceeding 20% ​​in conventional equipment, severely restricting the performance consistency and manufacturing yield of multi-qubit chips. Specifically, uneven thickness of the bottom electrode film directly leads to abnormal barrier layer thickness distribution during subsequent oxidation, resulting in excessively large dispersion of junction resistance values ​​on the same chip. Simultaneously, thickness fluctuations in the coplanar waveguide film used for microwave signal transmission can cause characteristic impedance mismatch, resulting in signal reflection and energy loss, thereby reducing the readout accuracy and coherence time of the qubits. Existing technologies are only applicable to small-sized substrates, such as 2-inch or 4-inch substrates. When applying tilted coatings to large-sized substrates of 6 inches and above, the uniformity problem worsens dramatically. Traditional solutions attempt to add baffle structures to the sample stage surface, but due to the physical gap between the baffle and the substrate, non-uniform shading effects are easily generated in the tilted state, especially for large-sized sample stages. In addition, mechanical structures in ultra-high vacuum environments face challenges such as lack of lubrication, large space occupation, and complex maintenance, resulting in high equipment costs and insufficient process stability, making it difficult to meet the industrialization requirements of large-scale quantum chip manufacturing. Summary of the Invention

[0003] The purpose of this application is to provide an electron beam evaporation apparatus with a high uniformity tilt angle.

[0004] The present invention adopts the following solution:

[0005] A high-uniformity tilt angle electron beam evaporation apparatus includes a vacuum chamber and an electron beam evaporation source; a substrate is tilted and disposed within the vacuum chamber, and the apparatus further includes: A protective plate is fitted onto the emission side of the evaporation source, and the protective plate is provided with an opening facing the evaporation source and coaxial with the center point of the substrate; A baffle plate, which is set above the opening and can be programmably linearly moved, has a travel adapted to be set in the horizontal direction to modulate the size of the evaporation beam passing through the opening in the time domain during the evaporation process. The controller is used to drive the shield to open segment by segment according to a predetermined scanning trajectory after the deposition rate stabilizes. The direction of travel of the predetermined scanning trajectory is implemented according to a compensation strategy of exposing areas away from the evaporation source first and areas closer to the evaporation source later.

[0006] Furthermore, the protective plate is configured as a convex barrel-shaped structure with openings, and the diameter of the openings is smaller than the diameter of the substrate.

[0007] Furthermore, it also includes at least one crystal film thickness gauge connected to the controller for detecting the deposition rate before deposition and serving as an input to the controller.

[0008] This invention also provides a method for controlling high-uniformity tilt-angle electron beam evaporation, utilizing the aforementioned high-uniformity tilt-angle electron beam evaporation apparatus, with the following steps: S1. The substrate is arranged relative to the evaporation source at a preset tilt angle α. Before evaporation, the evaporation material is melted to a stable state. After the crystal oscillator film thickness gauge shows that the evaporation rate has stabilized at the set value, the compensation program is started. S2. Divide the stroke S of the shield from fully open to fully closed into N segments (N≥1) to correspond to the corresponding segments on the substrate. Move the shield parallel to open the openings segment by segment and control the time of the corresponding evaporation beam. Expose the substrate away from the evaporation source area first and then expose it closer to the evaporation source area. Control the dwell time of the shield in each segment to control the deposition time of the substrate on each corresponding segment, so that the film thickness at any point on the substrate axis is close to the center film thickness. The required dwell time of the barrier at any point within each segment is:

[0009] Where T2 is the target film thickness deposited at the center of the substrate. The deposition rate at the center of the substrate is measured by a crystal oscillator film thickness sensor; D2 is the distance from the center of the substrate to the evaporation source; R is the substrate radius; and L is the distance from any point on the substrate axis to the left end of the substrate. S3. After the baffle reaches the fully open position, keep it fully open. At the end, quickly close the baffle to complete the deposition.

[0010] Furthermore, if the full stroke of the shielding plate is set to S, then the positions of the shielding plate at any two points that are extremely close to each other are S1 and S2. The stroke of the shielding plate is divided into n equal segments, each corresponding to a point on the substrate. to If we approximate the travel of the baffle within each segment as uniform motion, then the speeds of each of the n segments are as follows: V1 = (S1 - S0) / (t0 - t1), at this time L1 = 1 / 5R; V2 = (S2 - S1) / (t1 - t2), at this time L2 = 2 / 5R; ………… =( - ) / ( - ),at this time =n / 5R; After the shield is fully open, the holding time is: =T2 /

[0011] =T2 / V2 D2² / [D2²+(R- )²-2 D2 (R- ) cos(90+α)]²} =T2 / V2 D²² / [D²²+R²+2] D2 R cos(90+α)]²}; treat Afterwards, the barrier was quickly closed.

[0012] Beneficial effects: This application provides a high-uniformity tilt angle electron beam evaporation apparatus and method, including a vacuum chamber and an electron beam evaporation source; the substrate is tilted and disposed in the vacuum chamber, and the apparatus also includes a protective plate, a shielding plate and a controller. Through time-domain modulation and compensation strategies, the region of the substrate away from the evaporation source is exposed first, and the region of the substrate closer to the evaporation source is exposed later, thereby improving the film thickness uniformity. It has the advantages of effectively improving the uniformity of the substrate film thickness at the tilt angle, significantly reducing thickness differences, and being applicable to large-size substrates. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a high-uniformity tilt angle electron beam evaporation apparatus according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the compensation process of a high-uniformity tilt angle electron beam evaporation device according to an embodiment of the present invention; Figure 3This is a schematic diagram of the film thickness measurement of the substrate without compensation; Figure 4 This is a schematic diagram of substrate film thickness measurement after compensation using the device in an embodiment of the present invention; Figure label: 1. Substrate; 2. Protective plate; 21. Opening; 3. Shielding plate; 4. Crystal oscillator film thickness gauge; 5. Evaporation source. Detailed Implementation

[0014] Traditional tilted-angle electron beam evaporation technology, when depositing nanoscale thin films on large-size substrates 1, suffers from significant gradient non-uniformity in the deposition thickness due to the point source characteristics of the evaporation source 5 and the tilted placement of the substrate 1. This non-uniformity is particularly pronounced on large-size substrates 1, severely impacting the performance and yield of precision devices such as superconducting qubits. Existing solutions that involve adding baffles to the sample stage surface suffer from structural complexity, large cavity space requirements, and high implementation difficulty, making it difficult to effectively address the challenge of uniformity in tilted deposition on large-size substrates 1.

[0015] In this regard, combined with Figure 1 and Figure 2 As shown, this application proposes a high-uniformity tilt-angle electron beam evaporation apparatus. The apparatus includes a vacuum chamber and an electron beam evaporation source 5, wherein a substrate 1 is tilted and disposed within the vacuum chamber. Further, the apparatus includes a protective plate 2 fitted onto the emission side of the evaporation source 5, the protective plate 2 having an opening 21 facing the evaporation source 5 and coaxial with the center point of the substrate 1. In addition, a programmable linearly movable baffle plate 3 is disposed above the opening 21, its travel adapted to be horizontal, to temporally modulate the size of the evaporation beam passing through the opening 21 during the evaporation process. The apparatus also includes a controller for driving the baffle plate 3 to perform segmented opening according to a predetermined scan trajectory after the deposition rate stabilizes. The direction of travel of the predetermined scan trajectory is implemented according to a compensation strategy of exposing areas farther from the evaporation source 5 first and areas closer to the evaporation source 5 later.

[0016] For ease of understanding, the following explains some key terms in this embodiment: The protective plate 2 serves to initially constrain the evaporation beam emitted from the evaporation source 5, guiding it through a defined opening area 21. This protective plate 2 is typically made of a high-temperature resistant material and is fixed above the evaporation source 5 to ensure the initial directionality and range of the evaporation beam.

[0017] An opening 21 is disposed on the protective plate 2, positioned directly opposite the evaporation source 5 and coaxial with the center point of the substrate 1. The size and shape of this opening 21 determine the initial cross-section through which the evaporation beam can pass, and are the physical basis for realizing subsequent time-domain modulation.

[0018] A baffle plate 3, positioned above the opening 21, is capable of programmable linear movement. This baffle plate 3 dynamically alters the effective flux area of ​​the opening 21 through its movement, thereby enabling precise time-domain control of the size of the evaporation beam passing through the opening 21. Its travel is designed to be horizontal to accommodate the geometry of the evaporation beam.

[0019] The controller, as the core of the entire device, receives and processes various input signals. Based on a preset compensation program, the controller precisely drives the baffle 3 to move along a specific predetermined scanning trajectory, thereby achieving differentiated control of the deposition time in different areas of the substrate 1.

[0020] Temporal modulation refers to the precise control of the deposition amount in different regions of substrate 1 over time by dynamically changing the effective flux of the evaporation beam. By controlling the opening and closing time of the baffle 3, fine adjustment of the deposition thickness at each point on substrate 1 can be achieved.

[0021] The compensation strategy refers to controlling the movement of the shielding plate 3 during the deposition process so that areas on the substrate 1 farther from the evaporation source 5 are exposed to the evaporation beam before areas closer to the evaporation source 5. This strategy aims to counteract the thickness non-uniformity caused by the tilt of the substrate 1 and the point source effect, thereby achieving highly uniform film deposition across the entire substrate 1.

[0022] This embodiment provides a high-uniformity tilt-angle electron beam evaporation apparatus. The apparatus is typically housed within a vacuum chamber to provide a clean deposition environment. Inside the vacuum chamber, an electron beam evaporation source 5 is configured to generate a vapor flow for the evaporating material. A substrate 1 is tilted within the vacuum chamber to accommodate specific thin film growth requirements. For example, the substrate 1 can be fixed to an adjustable-angle sample stage and positioned using a robotic arm or rotating mechanism.

[0023] To initially constrain the evaporation beam, a protective plate 2 is fitted onto the exit side of the evaporation source 5. Above the opening 21, a programmable linearly movable baffle 3 is provided. The travel of the baffle 3 is designed to be horizontal to modulate the size of the evaporation beam passing through the opening 21 in the time domain during evaporation. For example, the baffle 3 can be made of a thin metal sheet and moved precisely by a linear guide driven by a stepper motor or servo motor. By controlling the moving speed and position of the baffle 3, the effective area of ​​the opening 21 can be dynamically changed, thereby controlling the evaporation flux reaching different regions on the substrate 1.

[0024] The device also includes a controller for automating and precisely controlling the entire deposition process. After detecting a stable deposition rate, the controller drives the shielding plate 3 to perform a segmented opening operation according to a predetermined scanning trajectory. The direction of travel of this predetermined scanning trajectory is programmed to implement a compensation strategy of exposing areas farther from the evaporation source 5 first and areas closer to the evaporation source 5 later. For example, the controller can be a programmable logic controller (PLC) or an embedded system, internally storing preset compensation algorithms and scanning paths. At the start of deposition, the controller calculates the dwell time or moving speed of the shielding plate 3 at different positions based on the algorithm and precisely controls the linear actuator of the shielding plate 3 to ensure that each area on the substrate 1 achieves a uniform deposition thickness.

[0025] The high-uniformity tilt angle electron beam evaporation apparatus provided in this embodiment achieves time-domain modulation of the evaporation beam by introducing a protective plate 2 and an opening 21 sleeved on the emission side of the evaporation source 5, combined with a programmable linearly movable shielding plate 3 positioned above the opening 21. The controller drives the shielding plate 3 to open segment by segment according to a compensation strategy that exposes areas farther from the evaporation source 5 first and areas closer to the evaporation source 5 later, effectively offsetting the non-uniformity of deposition thickness on the tilted substrate 1 caused by differences in distance and angle. This scheme has a relatively simple structure and can achieve highly uniform deposition of nanoscale thin films on large-size substrates 1, thereby improving the performance consistency and chip yield of precision devices such as superconducting quantum bits.

[0026] In the tilted electron beam evaporation process, precise temporal modulation of the evaporation beam is required to achieve high uniformity deposition. However, if the evaporation beam emitted from the evaporation source 5 is not effectively constrained and shaped before entering the modulation region, it may cause the edges of the evaporation beam to become blurred or diffused, thereby increasing the difficulty of subsequent compensation modulation by the shielding plate 3 and affecting the uniformity of the final film thickness. Especially when the substrate 1 is tilted, the geometric path of the evaporation beam is complex, making the control of the initial beam current particularly important.

[0027] In one embodiment, the protective plate 2 is configured as a convex barrel-shaped structure with an opening 21, the diameter of which is smaller than the diameter of the substrate 1. Specifically, the protective plate 2 can be made of a high-temperature resistant, low-outgas-rate material, such as 316L stainless steel, and its surface needs to be sandblasted, especially in areas where thin films may be deposited, typically choosing a large particle roughness, such as Ra3.2. The protective plate 2 can be designed as a truncated cone with an open bottom and a converging top, or a barrel-shaped structure with arc-shaped sidewalls and an opening 21 at the top. This convex barrel-shaped structure can effectively confine the vapor flow emitted by the evaporation source 5 within a small solid angle, reducing vapor scattering within the vacuum chamber and ensuring that the evaporation beam passes through the opening 21 in a concentrated manner. At the same time, the diameter of the opening 21 is smaller than the diameter of the substrate 1, ensuring that the cross-sectional size of the evaporation beam is smaller than that of the substrate 1 when passing through the opening 21, thereby preventing the evaporation material from being directly deposited outside the edge of the substrate 1 and providing more controlled initial conditions for the subsequent fine modulation of the shielding plate 3.

[0028] Based on this, when determining the size of the opening 21, it is necessary to determine the maximum size of the substrate to be deposited, such as 8 inches. Then, according to the point evaporation model, the distance from the evaporation source to the center point of the substrate is determined (for example, the evaporation distance for an 8-inch substrate is 700~800mm, for a 6-inch substrate it is 600~700mm, and for a 4-inch substrate it is 500~600mm). Then, the diameter of the opening 21 is calculated based on the evaporation distance. The calculation principle is as follows: taking an 8-inch substrate as an example, when the substrate is flat (not tilted), the evaporation radius at 750mm is 1~2 inches greater than the radius of the 8-inch substrate. At this time, any substrate < 8 inches can obtain a highly uniform deposited film through a compensation scheme.

[0029] In this embodiment, the device further includes at least one crystal oscillator film thickness gauge 4 connected to the controller. The crystal oscillator film thickness gauge 4 is a precision instrument that uses the frequency change of a quartz crystal oscillator to measure film thickness and deposition rate. Its working principle is based on the piezoelectric effect of quartz crystals; when film material is deposited on the crystal surface, the crystal mass increases, causing its resonant frequency to decrease. By monitoring the frequency change, the deposition rate and film thickness can be calculated accurately in real time. The crystal oscillator film thickness gauge 4 can detect the deposition rate. Before formally starting film deposition, the evaporation rate of the evaporation source 5 can be pre-detected using the crystal oscillator film thickness gauge 4, ensuring the stability of the evaporation process and obtaining accurate rate data under the current evaporation conditions. This detected deposition rate will be used as an input to the controller. After receiving the real-time or preset deposition rate data provided by the crystal oscillator film thickness gauge 4, the controller can dynamically adjust the scanning trajectory of the baffle 3, the timing of its segmented opening, and the dwell time in each segment according to this input. For example, the controller can accurately calculate the opening and closing times of the shielding plate 3 in different regions based on the actual detected deposition rate and the preset film thickness target, in order to compensate for the impact of rate fluctuations on film thickness uniformity.

[0030] Specifically, let D1 be the distance between the crystal oscillator and the evaporation source 5, D2 be the distance between the center of the substrate 1 and the evaporation source 5, V1 be the deposition rate on the crystal oscillator, V2 be the deposition rate at the center of the substrate 1, and α be the tilt angle of the substrate 1. The tooling value is set into the recipe, and the recipe is downloaded to the film thickness gauge in automatic mode to control the coating rate. At this time, the coating rate displayed on the film thickness gauge is the actual coating rate on substrate 1. By first writing the tooling value into the overall process recipe, the crystal oscillator film thickness gauge 4 will load the tooling value from the overall recipe, thus facilitating coating control.

[0031] By introducing a crystal oscillator film thickness gauge 4 into the tilted electron beam evaporation process and using its detected deposition rate as the input to the controller, the control of the entire deposition process becomes more intelligent and adaptive. The controller no longer relies solely on preset fixed parameters but can adjust in real-time or in advance based on the actual evaporation rate. This effectively solves the challenge posed by evaporation rate fluctuations to the film thickness uniformity control accuracy, ensuring that the time-domain modulation of the shielding plate 3 can more accurately match the actual deposition requirements. Therefore, even with certain rate fluctuations in the evaporation source 5, the uniformity of the film thickness on the substrate 1 can be significantly improved. Especially in complex scenarios such as tilted deposition where inherent film thickness distribution is uneven, this solution can more effectively achieve high-uniformity coating, improving the stability and reliability of the device.

[0032] Example 2 Combination Figure 2As shown, this embodiment discloses a method for controlling high-uniformity tilt-angle electron beam evaporation. Using the aforementioned high-uniformity tilt-angle electron beam evaporation apparatus, the steps are as follows: S1. The substrate 1 is arranged relative to the evaporation source 5 at a preset tilt angle α. Before evaporation, the evaporation material is melted to a stable state. After the crystal oscillator film thickness gauge 4 shows that the evaporation rate is stable at the set value, the compensation program is started. S2. Divide the stroke S of the shielding plate 3 from fully open to fully closed into N segments (N≥1) to correspond to the corresponding segments on the substrate 1. Move the shielding plate 3 in parallel to open the opening 21 segment by segment and control the time of the corresponding evaporation beam. Expose the substrate 1 in the area away from the evaporation source 5 first and then expose it in the area closer to the evaporation source 5. Control the dwell time of the shielding plate 3 in each segment to control the deposition time of the substrate 1 in each corresponding segment, so that the film thickness at any point on the axis of the substrate 1 is close to the center film thickness. The required dwell time of the shield 3 at any point within each segment is: t=T2 / V2 D2² / [D2²+(RL)²-2 D2 (RL) cos(90+α)]²}, Where T2 is the target film thickness at the center of substrate 1, V2 is the deposition rate at the center of substrate 1, which is measured by a crystal oscillator film thickness sensor, D2 is the distance from the center of substrate 1 to the evaporation source 5, R is the radius of substrate 1, and L is the distance from any point on the axis of substrate 1 to the left end of substrate 1. S3. After the baffle 3 reaches the fully open position, keep it fully open. At the end, quickly close the baffle 3 to complete the deposition.

[0033] It is important to note that if the partition is divided into one section, the baffle will slowly open from left to right at a constant speed; if it is divided into two or more sections, the baffle will move at different speeds in several ranges. The specific number of sections is set according to the uniformity requirements. For example, if a high degree of uniformity is required, it can be divided into multiple sections.

[0034] The core innovation of this embodiment lies in combining a programmable linearly moving shield 3 with a time-domain modulation strategy to compensate for the exposure of regions farther from the evaporation source 5 first and closer to the evaporation source 5 later. This dynamically adjusts the exposure time of different regions of the substrate 1 during the evaporation process, offsetting the deposition rate differences caused by the tilt of the substrate 1 and the point source effect, thus achieving highly uniform deposition of nanoscale thin films on a large-size substrate 1. Specifically, this method accurately calculates the dwell time of the shield 3 in each segment based on a deposition rate model, ensuring that the film thickness at any point on the axis of the substrate 1 is close to the center film thickness, effectively solving the problem of uniformity differences of 20%-30% in traditional solutions. Through the above technical solution, the uniformity of tilted deposition can be optimized from RU > 20% to Ru < 5%, significantly improving the performance consistency and yield of superconducting quantum chips.

[0035] It is important to note that the baffle plate 3 is positioned close to and parallel to the evaporation source 5, achieving tilted deposition by changing the tilt angle of the substrate 1. This tilted deposition, achieved by changing the tilt angle of the substrate 1 relative to the evaporation source 5, means that the tilt angle α of the substrate 1 relative to the evaporation source 5 is adjusted by changing the orientation of the substrate 1 itself. Before deposition, the operator can input a command through the controller to adjust the substrate 1 to the preset tilt angle α according to the desired tilt angle. This adjustment mechanism needs to possess high precision and good stability to ensure that the tilt angle of the substrate 1 remains constant throughout the deposition process. By positioning the baffle plate 3 close to and parallel to the evaporation source 5, the baffle plate 3's blocking and opening effects on the evaporation beam are made more direct and precise. This close and parallel arrangement effectively reduces the blurring effect caused by diffusion or scattering of the evaporation beam in the early stages of propagation, thereby improving the clarity and predictability of the baffle plate 3's modulation effect on the evaporation beam. This provides a more stable geometric basis for subsequent time-domain modulation via the linear movement of the shielding plate 3. In step S2, the shielding plate 3 is opened segment by segment, and the timing of the corresponding evaporation beams is controlled. This allows the compensation strategy of exposing the substrate 1 in areas away from the evaporation source 5 first and then in areas closer to the evaporation source 5 later to achieve better results. This results in more precise control of the film thickness at any point on the axis of the substrate 1, ensuring it is close to the center film thickness. Simultaneously, by changing the tilt angle of the substrate 1 to achieve tilted deposition, rather than adjusting the angle of the evaporation source 5 or the shielding plate 3, the stability of the relative positions between the evaporation source 5 and the shielding plate 3 is maintained, simplifying the complexity of the compensation algorithm. The flexible adjustment of the substrate 1 tilt angle combined with the precise modulation of the shielding plate 3 can more effectively compensate for the inherent film thickness non-uniformity of tilted deposition, ensuring highly uniform films at different tilt angles.

[0036] In the above-mentioned method of high uniformity tilt angle electron beam evaporation, although the film thickness of different regions of substrate 1 can be compensated by segmenting the stroke of the shielding plate 3 and controlling the dwell time of each segment, if the number of segments is insufficient or the moving speed of the shielding plate 3 is not controlled precisely enough, the film thickness uniformity compensation effect may be unsatisfactory. Especially in application scenarios that require high-precision film thickness control, it is difficult to ensure that the film thickness at any point on the axis of substrate 1 can be accurately close to the center film thickness.

[0037] Therefore, in a preferred embodiment, the full stroke of the shielding plate 3 is set to S. Then, the positions of the shielding plate 3 at any two points that are very close to each other are S1 and S2. The stroke of the shielding plate 3 is divided into n segments (n≥10), which correspond to the positions on the substrate 1. (All closed) to (Fully open), at this time, if we approximate the travel of the baffle 3 within each segment as uniform motion, then the speeds of each segment within n segments are as follows: V1 = (S1 - S0) / (t0 - t1), at this time L1 = 1 / 5R; V2 = (S2 - S1) / (t1 - t2), at this time L2 = 2 / 5R; ………… =( - ) / ( - ),at this time =n / 5R; After the shield is fully open, the holding time is: =T2 /

[0038] =T2 / V2 D2² / [D2²+(R- )²-2 D2 (R- ) cos(90+α)]²} =T2 / {V2 D²² / [D²²+R²+2] D2 R cos(90+α)]²};After tn ends, the shield 3 closes quickly.

[0039] Dividing the entire stroke S of the baffle 3 into at least 10 smaller segments allows for more precise control over the time-domain modulation of the evaporation beam passing through the opening 21. Each segment corresponds to a specific region on the axis of the substrate 1. to This means that the deposition time at different locations on substrate 1 can be independently and precisely controlled, thereby improving the uniformity of film thickness. The controller can pre-calculate and store the start and end positions of each segment, and drive the linear movement mechanism of the baffle 3 (e.g., a stepper motor or a servo motor) to move segment by segment along the predetermined segment path. The number of segments n≥10 ensures sufficient precision to cope with the complex uneven film thickness distribution caused by tilted evaporation.

[0040] Meanwhile, the travel of the shielding plate 3 within each segment is approximated as uniform motion. This approximation simplifies the motion control and calculation of the shielding plate 3 within each segment. In actual operation, the speed of the shielding plate 3 may fluctuate slightly when moving from the starting point to the ending point of a segment. Approximating it as uniform motion simplifies the complexity of the control algorithm and real-time calculation while ensuring sufficient accuracy, thereby improving the system's response speed and stability. When the controller drives the shielding plate 3 to move, it sets a target speed for each segment and uses closed-loop control to try to keep the shielding plate 3 moving at a near-constant speed within each segment. When the number of segments is sufficiently small (n≥10), the impact of this approximation on the final film thickness uniformity can be ignored.

[0041] Furthermore, the above formula defines the moving speed of the shielding plate 3 within each specific segment. By precisely calculating and controlling these speeds, the exposure time of different regions on the substrate 1 can be accurately regulated. Here, L1=1 / 5R, L2=2 / 5R, ..., Ln=n / 5R represent specific positions on the axis of the substrate 1 corresponding to different segments of the shielding plate 3. These positions are proportionally divided according to the substrate radius R, aiming to more accurately match the characteristics of the film thickness distribution on the substrate 1, thereby achieving a more optimized compensation effect. Before the compensation program begins, the controller calculates the speed of the shielding plate 3 based on the preset substrate radius R and the number of segments n. arrive The specific location. Then, combining the travel S of the shield 3 and the start and end times of each segment, the exact location is calculated. arrive The controller calculates these rate values ​​and precisely drives the baffle 3 to move at the corresponding speed in each segment based on these calculated rate values ​​during execution.

[0042] After the shielding plate 3 is fully opened, in order to ensure that the central area of ​​the substrate 1 reaches the target film thickness T2, it needs to be kept in the fully open state for a specific period of time. .this The calculation formula is based on parameters such as the target film thickness T2 at the center of substrate 1, the deposition rate V2 at the center of substrate 1, the distance D2 from the center of substrate 1 to the evaporation source 5, the substrate radius R, and the tilt angle α. This ensures that the central region of substrate 1 can obtain an accurate film thickness after the entire compensation process. The rapid closure of the shielding plate 3 avoids unnecessary additional deposition and ensures the accurate termination of the deposition process. Before the compensation program begins, the controller calculates the film thickness based on the stable deposition rate V2 measured by the crystal oscillator film thickness gauge 4, as well as preset parameters such as T2, D2, R, and α. The specific value. When the baffle 3 moves to the fully open position, the controller will start the timer and keep the baffle 3 in that position. Duration. After the timer ends, the controller will immediately drive the baffle 3 to move at its maximum speed or a preset fast closing speed, causing it to close quickly, thus completing the entire deposition process.

[0043] By employing the aforementioned technical solution, the stroke S of the baffle plate 3 is subdivided into at least n (n≥10) segments, and the baffle plate 3 moves at approximately a constant speed within each segment. This application enables more precise and accurate control over the time-domain modulation of the evaporation beam passing through the opening 21. This precise segmentation and approximate constant speed movement allow for more precise control of the time-domain modulation of the evaporation beam along the axis of the substrate 1. to Each corresponding region can obtain a more precise deposition time, thus effectively compensating for the film thickness unevenness caused by evaporation at the tilt angle. Furthermore, by accurately calculating the holding time after the shielding plate 3 is fully open... By combining the target film thickness T2 at the center of substrate 1, the deposition rate V2, and geometric parameters, the desired film thickness in the central region of substrate 1 was ensured, while over-deposition was avoided. This combination of segmented rate control and precise holding time significantly improved the uniformity of film thickness during tilted-angle electron beam evaporation, allowing the film thickness at any point on substrate 1 to more closely approximate the central film thickness, thus meeting the requirements for high-precision film thickness control.

[0044] Through the above steps, approximately the same film thickness can be deposited at every point along the axis of substrate 1; however, when the shielding plate 3 is not compensated, substrate 1 exhibits a gradient distribution along the axis, and it can be approximated that the interior of each gradient is relatively uniform (e.g., Figure 3 As shown, before compensation (substrate tilted 45° - 130nm AI film - masking plate - 6inch - EE5mm - Ru = 23.20%, 1σ = 13.78%), specifically, before compensation, a 130nm thick aluminum film is deposited on a 6-inch substrate tilted at 45°. The measurement range is within 5mm of the 6-inch edge. The sheet resistance uniformity Ru is 23.2%, and the sheet resistance uniformity 1σ is 13.78%. After compensation by the masking plate 3, each gradient can be made close to the center film thickness, so the film thickness of the entire substrate 1 is close to the center film thickness (e.g., Figure 4 As shown, with a substrate tilted at 45°, a 130nm thick aluminum film is deposited on a 6-inch substrate at a 45° tilt. The measurement range is within 5mm of the 6-inch edge. The sheet resistance uniformity (Ru) is 3.58%, and the sheet resistance uniformity (1σ) is 2.14%. Figure 3 and Figure 4 The graph shows the sheet resistance uniformity parameters measured using a four-probe array. By comparing the test data, it can be concluded that the uniformity of the compensated substrate is significantly improved.

[0045] Therefore, in the above embodiments, by customizing a special protective plate 2, the point evaporation source 5 is constrained, causing it to evaporate onto the substrate 1 through a circular hole of a specific diameter. Then, a baffle of a specific shape is customized above the protective plate 2 for scanning compensation, thereby achieving high uniformity under tilted conditions. Secondly, a compensation program for the baffle plate 3 is developed to ensure that the baffle plate 3 compensates according to a preset path, allowing areas farther from the evaporation source 5 to deposit first, and areas closer to the evaporation source 5 to deposit later. This results in high coating uniformity, a simple structure, and applicability to large-size wafer solutions, providing a high-quality solution for large-size quantum chip applications.

[0046] It should be understood that the above are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention.

[0047] The accompanying drawings used in the above description of the embodiments only illustrate certain embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

Claims

1. A high-uniformity tilt angle electron beam evaporation apparatus, comprising a vacuum chamber and an electron beam evaporation source; The substrate is tilted within the vacuum cavity, characterized in that it further includes: A protective plate is fitted onto the emission side of the evaporation source, and the protective plate is provided with an opening facing the evaporation source and coaxial with the center point of the substrate; A baffle plate, which is set above the opening and can be programmably linearly moved, has a travel adapted to be set in the horizontal direction to modulate the size of the evaporation beam passing through the opening in the time domain during the evaporation process. The controller is used to drive the shield to open segment by segment according to a predetermined scanning trajectory after the deposition rate stabilizes. The direction of travel of the predetermined scanning trajectory is implemented according to a compensation strategy of exposing areas away from the evaporation source first and areas closer to the evaporation source later.

2. The high-uniformity tilted-angle electron beam evaporation apparatus according to claim 1, characterized in that, The protective plate is configured as a convex barrel-shaped structure with openings, and the diameter of the openings is smaller than the diameter of the substrate.

3. The high-uniformity tilt angle electron beam evaporation apparatus according to claim 1, characterized in that, It also includes at least one crystal film thickness gauge connected to the controller for detecting the deposition rate before deposition and serving as an input to the controller.

4. A method for controlling electron beam evaporation with a high uniformity tilt angle, characterized in that, Using the high-uniformity tilt-angle electron beam evaporation apparatus according to any one of claims 1-3, the steps are as follows: S1. The substrate is arranged relative to the evaporation source at a preset tilt angle α. Before evaporation, the evaporation material is melted to a stable state. After the crystal oscillator film thickness gauge shows that the evaporation rate is stable at the set value, the compensation program is started. S2. Divide the stroke S of the shield from fully open to fully closed into N segments (N≥1) to correspond to the corresponding segments on the substrate. Move the shield parallel to open the openings segment by segment and control the time of the corresponding evaporation beam. Expose the substrate away from the evaporation source area first and then expose it closer to the evaporation source area. Control the dwell time of the shield in each segment to control the deposition time of the substrate on each corresponding segment, so that the film thickness at any point on the substrate axis is close to the center film thickness. The required dwell time of the barrier at any point within each segment is: Where T2 is the target film thickness deposited at the center of the substrate. The deposition rate at the center of the substrate is measured by a crystal oscillator film thickness sensor; D2 is the distance from the center of the substrate to the evaporation source; R is the substrate radius; and L is the distance from any point on the substrate axis to the left end of the substrate. S3. After the baffle reaches the fully open position, keep it fully open. At the end, quickly close the baffle to complete the deposition.

5. The method for controlling high-uniformity tilt angle electron beam evaporation according to claim 4, characterized in that, Let the full-scale travel of the shielding plate be S. Then, the positions of the shielding plate at any two points that are extremely close to each other are S1 and S2. Divide the travel of the shielding plate into n equal segments, each corresponding to a point on the substrate. to If we approximate the travel of the baffle within each segment as uniform motion, then the speeds of each of the n segments are as follows: V1 = (S1 - S0) / (t0 - t1), at this time L1 = 1 / 5R; V2 = (S2 - S1) / (t1 - t2), at this time L2 = 2 / 5R; ………… =( - ) / ( - ),at this time =n / 5R; After the shield is fully open, the holding time is: =T2 / =T2 / V2 D2² / [D2²+(R- )²-2 D2 (R- ) cos(90+α)]²} =T2 / V2 D2² / [D2²+R²+2 D2 R cos(90+α)]²}; treat Afterwards, the barrier was quickly closed.

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