A method for improving step coverage of an evaporation coating

Abstract

The present application relates to the technical field of electronic device preparation, and provides a method for improving step coverage of evaporation coating, which comprises the following steps: providing a three-dimensional structure substrate, the substrate comprising a forward coating surface and a lateral coating surface on adjacent different surfaces, and the substrate is further provided with a spacer, and a gap is formed between the spacer and the lateral coating surface; performing evaporation coating on the substrate, the incident direction of evaporation particles is towards the forward coating surface, the evaporation particles which are incident on the forward coating surface along the incident direction are deposited on the forward coating surface to form at least a first film, and the evaporation particles which are incident on the gap along the incident direction change the direction of movement in the gap and are deposited on the lateral coating surface to form a second film which is continuous with the first film. The present application forms a gap between the spacer and the surface to be coated by using the spacer, the evaporation particles change the direction of movement when passing through the gap, so that the film is formed on the surface which cannot deposit the film originally, thereby improving the step coverage of evaporation coating.

Description

Technical Field

[0001] This invention relates to the field of electronic device fabrication technology, and in particular to a method for improving step coverage in evaporation coatings. Background Technology

[0002] As a common method for metal fabrication, evaporation coating is widely used in the Microelectromechanical Systems (MEMS) industry. The principle of evaporation coating is as follows: when the metal is heated to a temperature higher than its evaporation temperature, metal vapor diffuses freely from the source to the substrate surface, thus forming a film. Evaporation coating has advantages such as low temperature, low stress, and weak diffraction effects, and is particularly suitable for lift-off processes compared to magnetron sputtering.

[0003] The principle of evaporation coating determines that its film formation has good directionality. However, on the other hand, good directionality means lower step coverage, where step coverage refers to the ratio of the film thickness on the sidewall of a step at a certain depth to the film thickness on the upper surface. For example... Figure 1 As shown in (a), when the trajectory of the metal particles is completely perpendicular to the upper surface of the substrate 1, the step sidewalls (1a and 1b) are theoretically unable to deposit the thin film 2; and so on. Figure 1 As shown in (b), if the incident direction of the metal particles is tilted relative to the upper surface of the substrate 1, a thin film 2 can be deposited on the first sidewall 1a facing the incident direction of the metal particles, but a thin film cannot be deposited on the second sidewall 1b in the other direction. Therefore, the aforementioned disadvantages of evaporation deposition limit its application on substrates with three-dimensional structures.

[0004] Therefore, it is necessary to provide a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a method for improving the step coverage of evaporation coatings, thereby solving the problem that existing evaporation coating preparation methods cannot effectively cover the sidewalls of three-dimensional substrates.

[0006] This invention provides a method for improving step coverage in evaporation coatings, comprising the following steps: Step 1: Provide a three-dimensional substrate, the substrate including a front coating surface and a side coating surface adjacent to the front coating surface, the front coating surface and the side coating surface are opposite surfaces, the substrate is also provided with spacers, and a gap is formed between the spacers and the side coating surface; Step 2: Evaporation coating is performed on the substrate. The incident direction of the evaporation particles is towards the forward coating surface. The evaporation particles that are incident on the forward coating surface are deposited on the forward coating surface to form at least a first film. The evaporation particles that are incident on the gap change their movement direction in the gap and are deposited on the lateral coating surface to form a second film that is continuous with the first film.

[0007] According to the method for improving step coverage of evaporation coating provided by the present invention, the spacer is detachably mounted on the substrate, the spacer includes a spacer member and a fixing member, and prior to step 1, the method further includes the following steps: Step 01: Align the spacer with the lateral coating surface to form a gap between the spacer and the lateral coating surface; Step 02: Use the fastener to fix the spacer to the substrate to limit the spacer.

[0008] According to the method for improving step coverage of evaporation coating provided by the present invention, the substrate has a first surface, the first surface is provided with a first groove, the forward coating surface includes the first surface corresponding to the outside of the first groove and a first bottom surface corresponding to the bottom of the first groove, the lateral coating surface is the sidewall of the first groove, the shape of the spacer matches the shape of the first groove, the height of the spacer is greater than or equal to the depth of the first groove, wherein step 01 includes: The spacer is placed into the first groove of the substrate, and the distance between the spacer and the side wall of the first groove is adjusted so that a gap is formed between the spacer and the side wall of the first groove.

[0009] According to the method for improving step coverage of evaporation coatings provided by the present invention, step 2 includes: An evaporation coating is performed on the substrate using a mask template. Evaporation particles are deposited in an incident direction perpendicular to the first surface. The evaporation particles that pass through the mask template and are incident on the first surface in the incident direction are deposited on the first surface to form a first thin film. A portion of the evaporation particles that pass through the mask template and are incident on the gap change their movement direction in the gap and are deposited on the sidewall of the first groove to form a second thin film. Another portion of the evaporation particles that pass through the mask template and are incident on the gap pass through the gap and are deposited on the first bottom surface to form a third thin film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern.

[0010] According to the method for improving step coverage of evaporation coating provided by the present invention, the substrate has a second surface and a third surface disposed opposite to each other, the substrate has a through hole extending from the second surface to the third surface, the forward coating surface includes the second surface and the sidewall of the through hole, the lateral coating surface is the third surface, wherein step 01 includes: The spacer is moved to the through hole on the side of the third surface of the substrate, so that the spacer extends from the position corresponding to the through hole in a direction parallel to the third surface to a preset position on the third surface, and the distance between the spacer and the third surface is adjusted so that a gap is formed between the spacer and the third surface.

[0011] According to the method for improving step coverage of evaporation coatings provided by the present invention, step 2 includes: An evaporation coating is performed on the substrate using a photomask. Evaporation particles are deposited at a predetermined angle to the second surface. The evaporation particles that pass through the photomask and are incident on the sidewall of the through hole along the incident direction are deposited on the sidewall of the through hole to form a first film. The evaporation particles that pass through the photomask and are incident on the through hole and are incident on the gap change their movement direction in the gap and are deposited on the third surface to form a second film. The evaporation particles that pass through the photomask and are incident on the second surface are deposited on the second surface to form a third film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern.

[0012] According to the method for improving step coverage of evaporation coatings provided by the present invention, after step 2, the method further includes the following steps: Remove the spacer and the fastener from the substrate.

[0013] According to the method for improving step coverage of evaporation coatings provided by the present invention, prior to step 1, the method further includes the following steps: The substrate has a fourth surface, and a second groove and a spacer located in the second groove and spaced apart from the sidewall of the second groove are formed on the fourth surface of the substrate by photolithography and etching processes. Wherein, the sidewall of the second groove is the lateral coating surface, the gap is formed between the spacer and the sidewall of the second groove, and the height of the spacer is greater than or equal to the depth of the second groove.

[0014] According to the method for improving step coverage of evaporation coating provided by the present invention, the forward coating surface includes the fourth surface corresponding to the second groove and the second bottom surface corresponding to the bottom of the second groove, and step 2 includes: An evaporation coating is performed on the substrate using a photomask. Evaporation particles are deposited in a direction perpendicular to the fourth surface. The evaporation particles that pass through the photomask and are incident on the fourth surface are deposited on the fourth surface to form a first film. A portion of the evaporation particles that pass through the photomask and are incident on the gap change their direction of movement in the gap and are deposited on the sidewall of the second groove to form a second film. Another portion of the evaporation particles that pass through the photomask and are incident on the gap pass through the gap and are deposited on the second bottom surface to form a third film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern; Following step 2, the method further includes the following steps: The spacers are removed using an etching process.

[0015] According to the method for improving step coverage of evaporation coating provided by the present invention, the width of the gap is between 5 micrometers and 30 micrometers.

[0016] The above-described technical solution of the present invention has the following beneficial effects: This invention provides a method for improving step coverage in evaporation coating. The three-dimensional substrate includes a front coating surface and a side coating surface. The front coating surface is defined as the surface to which evaporation particles are directly incident along the incident direction, and the side coating surface is defined as the surface to which evaporation particles cannot be directly incident along the incident direction. The side coating surface is adjacent to and opposite to the front coating surface. This invention provides spacers on the substrate, creating gaps between the spacers and the side coating surface. During evaporation coating of the substrate, the incident direction of the evaporation particles is towards the front coating surface. Evaporation particles incident along the incident direction towards the front coating surface are deposited on the front coating surface to form at least a first thin film. Evaporation particles incident along the incident direction towards the gap change their movement direction in the gap and are deposited on the side coating surface to form a second thin film continuous with the first thin film. This invention utilizes the gap formed between the spacer and the surface to be coated (lateral coating surface). When the vapor-deposited particles pass through the gap, they change their direction of movement, causing a thin film to form on the surface (lateral coating surface) that could not originally deposit a thin film, thereby improving the step coverage of the vapor-deposited film. Attached Figure Description

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

[0018] Figure 1 This is a schematic diagram of the structure of a substrate prepared using a traditional evaporation coating process; Figure 2 A flowchart illustrating a method for improving step coverage in evaporation coatings according to an embodiment of the present invention; Figure 3 One of the schematic diagrams is shown below, illustrating the preparation of a substrate using the improved step coverage method for evaporation coating provided in Embodiment 1 of the present invention. Figure 4 This is a second schematic diagram of a substrate prepared using the improved step coverage method for evaporation coating provided in Embodiment 1 of the present invention. Figure 5 A schematic diagram of a substrate prepared using the improved step coverage method for evaporation coating provided in Embodiment 2 of the present invention; Figure 6 A schematic diagram of a substrate prepared using the improved step coverage method for evaporation coating provided in Embodiment 3 of the present invention; Figure 7 This is a top view of a substrate prepared using the improved step coverage method for evaporation coating provided in Embodiment 1 or Embodiment 3 of the present invention; Figure 8 This is a cross-sectional view of a substrate prepared using the improved step coverage method for evaporation coating provided in Embodiment 1 or Embodiment 3 of the present invention.

[0019] Figure label: 1. Substrate; 1a. First sidewall; 1b. Second sidewall; 2. Film; 10. First substrate; 10a. First surface; 10b. Sidewall of the first groove; 10c. First bottom surface; 101. First groove; 100. First mask; 20. Second substrate; 20a. Second surface; 20b. Third surface; 20c. Sidewall of the through hole; 201. Through hole; 30. Third substrate; 30a. Fourth surface; 30b. Sidewall of the second groove; 30c. Second bottom surface Surface; 301, second groove; 40, first electrode; 50, second electrode; 60, third electrode; 100, first mask template; 200, second mask template; 300, third mask template; 400, first spacer; 401, first spacer; 402, first fixing member; 500, second spacer; 501, second spacer; 502, second fixing member; 600, third spacer; 700, first film; 800, second film; 900, third film. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] Evaporation coating, as a common method for preparing metal thin films, is increasingly widely used in the MEMS industry. With the development of the MEMS industry, the demand for preparing metal thin films on substrates with three-dimensional structures is becoming increasingly urgent. This invention provides a method for improving step coverage in evaporation coatings, which effectively solves the problem that existing evaporation coating methods cannot effectively cover sidewalls or steps on three-dimensional substrates.

[0022] It should be noted that when using the method of improving the step coverage of evaporation coating of the present invention to perform evaporation coating on a three-dimensional structure substrate, a corresponding mask can be used to perform evaporation coating on the top of the three-dimensional structure substrate, or a mask can be omitted; the evaporation source can be a corresponding metal particle, such as copper particles or aluminum particles, according to the actual process requirements; when a mask is used, the evaporation particles generated by the evaporation source can pass through the opening of the preset pattern on the mask and be deposited on the corresponding coating surface of the three-dimensional structure substrate, so as to form a metal electrode on the three-dimensional structure substrate with the same shape as the preset pattern on the mask.

[0023] The three-dimensional structure substrate provided by this invention includes a front coating surface and a side coating surface. The front coating surface is defined as the surface that vapor-deposited particles can directly strike along the incident direction, and the side coating surface is defined as the surface that vapor-deposited particles cannot directly strike along the incident direction. The side coating surface is adjacent to the front coating surface but not on the same plane. For example, the side coating surface is a surface parallel to the incident direction of the vapor-deposited particles, or a surface that is blocked by the front coating surface and on which vapor-deposited particles cannot form a film along the incident direction.

[0024] The following is combined Figures 2-8 The method for improving step coverage of evaporation coating according to the present invention will be described in detail with reference to different embodiments.

[0025] Please see Figures 2-4 Embodiment 1 of the present invention provides a method for improving step coverage of evaporation coatings, comprising the following steps: Step 1: Provide a three-dimensional substrate, which includes a front coating surface and a side coating surface adjacent to the front coating surface. The front coating surface and the side coating surface are opposite surfaces. The substrate is also provided with spacers, and gaps are formed between the spacers and the side coating surface.

[0026] Specifically, such as Figure 3 and Figure 4 As shown, the three-dimensional structure substrate provided in this embodiment is a first substrate 10. The first substrate 10 has a first surface 10a, on which a first groove 101 is provided. Exemplarily, the first groove 101 is a circular groove with a diameter of 100 μm and a depth of 100 μm, but it is not limited thereto. It is understood that in other embodiments of the present invention, the shape of the first groove 101 can also be rectangular or trapezoidal or other shapes, and the diameter and depth of the first groove 101 can be set according to the actual situation.

[0027] In the evaporation coating process of this embodiment, a metal thin film needs to be formed on the first surface 10a of the bottom, sidewall and top of the first groove 101 to realize the conduction between the top and bottom of the first groove 101.

[0028] Therefore, this embodiment requires a first spacer 400 to be provided on the first substrate 10. The first spacer 400 is detachably installed on the first substrate 10. The first spacer 400 includes a first spacer 401 and a first fixing member 402. The shape of the first spacer 401 matches the shape of the first groove 101, and the diameter of the first spacer 401 is smaller than the diameter of the first groove 101. The height of the first spacer 401 is greater than or equal to the depth of the first groove 101. The function of the first spacer 401 is to form a small gap with the sidewall of the first groove 101, and the function of the first fixing member 402 is to fix and limit the first spacer 401.

[0029] The material of the first spacer 400 can be metal, silicone, plastic, or other materials; there are no restrictions here.

[0030] In the evaporation coating process, a first mask 100 is used to mask the first substrate 10, and the incident direction of the evaporation particles is perpendicular to the first surface 10a of the first substrate 10 for evaporation coating. Therefore, in this embodiment, the forward coating surface of the first substrate 10 includes the first surface 10a corresponding to the first groove 101 and the first bottom surface 10c corresponding to the bottom of the first groove 101, and the lateral coating surface is the sidewall 10b of the first groove.

[0031] Prior to step 1 above, the method further includes the following steps: Step 01: Align the spacer with the side coating surface to form a gap between the spacer and the side coating surface.

[0032] Specifically, such as Figure 3 and Figure 4 As shown, step 01 includes: The first spacer 401 is placed into the first groove 101 of the first substrate 10, and the distance between the first spacer 401 and the side wall 10b of the first groove is adjusted so that a gap is formed between the first spacer 401 and the side wall 10b of the first groove.

[0033] Step 02, as follows Figure 3 and Figure 4 As shown, the first spacer 401 is fixed to the first substrate 10 by the first fastener 402 to limit the position of the first spacer 401.

[0034] Specifically, the first spacer 401 can be fixed on the first fixing member 402. The first fixing member 402 is marked, and the first fixing member 402 is aligned and fixed with the first substrate 10 through the mark on the first fixing member 402, so that the relative position of the first spacer 401 and the first groove 101 is accurate and fixed.

[0035] In one embodiment, the width of the formed slit is between 5 micrometers and 30 micrometers. For example, the width of the slit can be 5 micrometers, 10 micrometers, 15 micrometers, 20 micrometers, 25 micrometers, or 30 micrometers.

[0036] In this embodiment, the width of the slit is 15 micrometers.

[0037] In one embodiment, the first spacer 401 is a thin-walled annular structure, but is not limited thereto.

[0038] Step 2: Evaporation coating is performed on the substrate. The incident direction of the vaporized particles is towards the front coating surface. The vaporized particles that are incident on the front coating surface are deposited on the front coating surface to form at least a first thin film. The vaporized particles that are incident on the gap change their movement direction in the gap and are deposited on the side coating surface to form a second thin film that is continuous with the first thin film.

[0039] Please see Figure 3 , Figure 4 , Figure 7 and Figure 8 Specifically, step 2 above includes: The first substrate 10 is vapor-deposited using a first mask 100. The vapor-deposited particles are vapor-deposited in an incident direction perpendicular to the first surface 10a. The vapor-deposited particles that pass through the first mask 100 and are incident on the first surface 10a are deposited on the first surface 10a to form a first thin film 700. A portion of the vapor-deposited particles that pass through the first mask 100 and are incident on the gap change their direction of movement in the gap and are deposited on the side wall 10b of the first groove to form a second thin film 800. Another portion of the vapor-deposited particles that pass through the first mask 100 and are incident on the gap pass through the gap and are deposited on the first bottom surface 10c to form a third thin film 900.

[0040] The first thin film 700, the second thin film 800 and the third thin film 900 are interconnected to form a first electrode 40 (such as a copper electrode) with a preset pattern, thereby enabling the top and bottom of the first groove 101 to be connected.

[0041] Following step 2 above, the method further includes the following steps: Remove the first spacer and the first fastener from the first substrate.

[0042] The above steps allow for the formation of a first electrode 40 with a thickness of 0.3 μm on the first substrate 10. It should be noted that the film thickness formed on the substrate using the above method can be adjusted according to actual conditions and is not limited here.

[0043] Please see Figure 2 and Figure 5 Embodiment 2 of the present invention provides a method for improving step coverage of evaporation coating, comprising the following steps: Step 1: Provide a three-dimensional substrate, which includes a front coating surface and a side coating surface adjacent to the front coating surface. The front coating surface and the side coating surface are opposite surfaces. The substrate is also provided with spacers, and gaps are formed between the spacers and the side coating surface.

[0044] Specifically, such as Figure 5 As shown, the three-dimensional structure substrate provided in this embodiment is a second substrate 20. The second substrate 20 has a second surface 20a and a third surface 20b disposed opposite to each other. A through hole 201 is provided on the second substrate 20, extending from the second surface 20a to the third surface 20b. For example, the diameter of the through hole 201 is 200 μm and the depth is 100 μm. The through hole 201 can be a circular hole, a rectangular hole, or a hole of other shapes, but is not limited thereto. It is understood that in other embodiments of the present invention, the diameter and depth of the through hole 201 can be set according to actual conditions.

[0045] In the evaporation coating process of this embodiment, a metal thin film needs to be formed on the second surface 20a, the third surface 20b and the sidewall 20c of the through hole of the second substrate 20, so that the metal thin films on the second surface 20a and the third surface 20b of the second substrate 20 can be connected through the metal thin film on the sidewall 20c of the through hole.

[0046] Therefore, in this embodiment, a second spacer 500 needs to be provided on the second substrate 20. The second spacer 500 is detachably installed on the second substrate 20. The second spacer 500 includes a second spacer 501 and a second fixing member 502. The function of the second spacer 501 is to form a small gap with the third surface 20b, and the function of the second fixing member 502 is to fix and limit the second spacer 501.

[0047] The material of the second spacer 500 can be metal, silicone, plastic, or other materials; there are no restrictions here.

[0048] In the evaporation deposition process of this embodiment, a second mask 200 is used to mask the second substrate 20. The incident direction of the evaporation particles is at a preset tilt angle to the second surface 20a (e.g., 45° to the second surface 20a). In this way, the evaporation particles can be directly deposited on the second surface 20a and the sidewall 20c of the through hole along the incident direction. Therefore, in this embodiment, the forward deposition surface of the second substrate 20 includes the second surface 20a and the sidewall 20c of the through hole, and the lateral deposition surface is the third surface 20b.

[0049] Prior to step 1 above, the method further includes the following steps: Step 01: Align the spacer with the side coating surface to form a gap between the spacer and the side coating surface.

[0050] Specifically, step 01 includes: The second spacer 501 is moved to the through hole 201 on the side of the third surface 20b of the second substrate 20, so that the second spacer 501 extends from the position corresponding to the through hole 201 in a direction parallel to the third surface 20b to a preset position of the third surface 20b, and the distance between the second spacer 501 and the third surface 20b is adjusted so that a gap is formed between the second spacer 501 and the third surface 20b.

[0051] Step 02: The second spacer 501 is fixed to the second substrate 20 using the second fastener 502 to limit the position of the second spacer 501.

[0052] Specifically, the second spacer 501 can be fixed on the second fixing member 502. The second fixing member 502 is marked, and the alignment and fixing with the second substrate 20 are achieved through the marking on the second fixing member 502, so that the relative position of the second spacer 501 with the through hole 201 and the preset position of the third surface 20b is accurate and fixed.

[0053] In this embodiment, the width of the gap is 10 micrometers, but it can be adjusted according to actual usage.

[0054] Step 2: Evaporation coating is performed on the substrate. The incident direction of the vaporized particles is towards the front coating surface. The vaporized particles that are incident on the front coating surface are deposited on the front coating surface to form at least a first thin film. The vaporized particles that are incident on the gap change their movement direction in the gap and are deposited on the side coating surface to form a second thin film that is continuous with the first thin film.

[0055] Please see Figure 5 Specifically, step 2 above includes: The second substrate 20 is vapor-deposited using a second mask 200. The vapor-deposited particles are incident at a 45° angle to the second surface 20a. The vapor-deposited particles that pass through the second mask 200 and are incident along the incident direction are deposited on the sidewall 20c of the through hole to form a first thin film 700. The vapor-deposited particles that pass through the second mask 200 and are incident along the incident direction through the through hole 201 and are incident on the gap change their movement direction in the gap and are deposited on the third surface 20b to form a second thin film 800. The vapor-deposited particles that pass through the second mask 200 and are incident along the incident direction are deposited on the second surface 20a to form a third thin film 900.

[0056] After fabrication, a second thin film 800 can be observed on the third surface 20b, and the thickness of the second thin film 800 is approximately 5% to 10% of the thickness of the first thin film 700. The first thin film 700, the second thin film 800, and the third thin film 900 are interconnected to form a second electrode 50 with a preset pattern, thereby enabling the metal thin films on the second surface 20a and the third surface 20b to conduct through the metal thin film on the sidewall 20c of the through hole.

[0057] Following step 2 above, the method further includes the following steps: Remove the second spacer 501 and the second fastener 502 from the second substrate 20.

[0058] Please see Figure 2 and Figure 6 Embodiment 3 of the present invention provides a method for improving step coverage of evaporation coating, comprising the following steps: Step 1: Provide a three-dimensional substrate, which includes a front coating surface and a side coating surface adjacent to the front coating surface. The front coating surface and the side coating surface are opposite surfaces. The substrate is also provided with spacers, and gaps are formed between the spacers and the side coating surface.

[0059] Specifically, such as Figure 6 As shown, the three-dimensional structure substrate provided in this embodiment is a third substrate 30. The third substrate 30 has a fourth surface 30a, on which a second groove 301 is provided. The structure of the second groove 301 can be the same as the structure of the first groove in Embodiment 1, and will not be described again here. The difference between the third substrate 30 of this embodiment and the first substrate of Embodiment 1 is that a third spacer 600 is prepared inside the second groove 301 of the third substrate 30 of this embodiment, and the height of the third spacer 600 is greater than or equal to the depth of the second groove 301, forming a gap between the third spacer 600 and the sidewall 30b of the second groove. That is, this embodiment does not require the use of a temporary additional external spacer similar to that in Embodiment 1, but instead directly fabricates the third spacer 600, which can be subsequently etched away, on the third substrate 30 during its fabrication.

[0060] Specifically, prior to step 1 above, the method further includes the following steps: A second groove 301 and a third spacer 600 located within the second groove 301 and spaced apart from the sidewall 30b of the second groove are formed on the fourth surface 30a of the third substrate 30 using photolithography and etching processes.

[0061] The third spacer 600 and the second groove 301 can be formed simultaneously in the same photolithography and etching process, or they can be formed separately in different photolithography and etching processes.

[0062] The third spacer 600 can be a ring structure, but is not limited to this.

[0063] In the evaporation coating process of this embodiment, a metal thin film needs to be formed on the fourth surface 30a of the bottom, sidewall and top of the second groove 301 to achieve the conduction between the top and bottom of the second groove 301.

[0064] In the evaporation deposition process of this embodiment, a third mask 300 is used to mask the third substrate 30. The incident direction of the evaporation particles is perpendicular to the fourth surface 30a of the third substrate 30, so that the evaporation particles can be directly deposited on the fourth surface 30a and the second bottom surface 30c at the bottom of the second groove 301 along the incident direction. Therefore, in this embodiment, the forward deposition surface of the third substrate 30 includes the fourth surface 30a and the second bottom surface 30c corresponding to the second groove 301, and the lateral deposition surface is the sidewall 30b of the second groove.

[0065] In one embodiment, the third spacer 600 is a thin-walled annular structure, but is not limited thereto.

[0066] Step 2: Evaporation coating is performed on the substrate. The incident direction of the vaporized particles is towards the front coating surface. The vaporized particles that are incident on the front coating surface are deposited on the front coating surface to form at least a first thin film. The vaporized particles that are incident on the gap change their movement direction in the gap and are deposited on the side coating surface to form a second thin film that is continuous with the first thin film.

[0067] Please see Figure 6 , Figure 7 and Figure 8 Specifically, step 2 above includes: A third substrate 30 is vapor-deposited using a third mask 300. Vapor-deposited particles are deposited in a direction perpendicular to the fourth surface 30a of the third substrate 30. Vapor-deposited particles that pass through the third mask 300 and are incident on the fourth surface 30a of the third substrate 30 are deposited on the fourth surface 30a to form a first thin film 700. A portion of vapor-deposited particles that pass through the third mask 300 and are incident on the gap change their direction of movement in the gap and are deposited on the side wall 30b of the second groove to form a second thin film 800. Another portion of vapor-deposited particles that pass through the third mask 300 and are incident on the gap pass through the gap and are deposited on the second bottom surface 30c to form a third thin film 900.

[0068] The first thin film 700, the second thin film 800 and the third thin film 900 are interconnected to form a third electrode 60 with a preset pattern, thereby enabling the top and bottom of the second groove to be connected.

[0069] Following step 2, the method further includes the following steps: The third spacer 600 was removed using an etching process.

[0070] The materials of the third spacer 600 and the third substrate 30 may be the same or different.

[0071] In this embodiment, during the process of preparing the second groove 301 on the third substrate 30, the third spacer 600 is simultaneously prepared in the second groove 301. Therefore, this embodiment does not require additional processing of the spacer with a metal structure, and it does not require fixing and aligning the spacer during use.

[0072] In another embodiment of the present invention, the copper electrode in Example 1 can be replaced with an aluminum electrode, with all other conditions remaining unchanged, and the result is the same.

[0073] In summary, the present invention provides a method for improving step coverage in evaporation coating. The three-dimensional substrate includes a front coating surface and a side coating surface. The front coating surface is defined as the surface to which evaporation particles are directly incident along the incident direction, and the side coating surface is defined as the surface to which evaporation particles cannot be directly incident along the incident direction. The side coating surface is adjacent to and opposite to the front coating surface. The present invention provides spacers on the substrate, forming gaps between the spacers and the side coating surface. When evaporation coating is performed on the substrate, the incident direction of the evaporation particles is towards the front coating surface. Evaporation particles incident along the incident direction towards the front coating surface are deposited on the front coating surface to form at least a first thin film. Evaporation particles incident along the incident direction towards the gap change their movement direction in the gap and are deposited on the side coating surface to form a second thin film continuous with the first thin film. This invention utilizes the gap formed between the spacer and the surface to be coated (lateral coating surface). When the vapor-deposited particles pass through the gap, they change their direction of movement, causing a thin film to form on the surface (lateral coating surface) that originally could not deposit a thin film, thereby improving the step coverage of the vapor-deposited film and achieving a better deposition effect.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for improving step coverage in evaporation coatings, characterized in that, Includes the following steps: Step 1: Provide a three-dimensional substrate, the substrate including a front coating surface and a side coating surface adjacent to the front coating surface, the front coating surface and the side coating surface are opposite surfaces, the substrate is also provided with spacers, and a gap is formed between the spacers and the side coating surface; Step 2: Evaporation coating is performed on the substrate. The incident direction of the evaporation particles is towards the forward coating surface. The evaporation particles that are incident on the forward coating surface are deposited on the forward coating surface to form at least a first film. The evaporation particles that are incident on the gap change their movement direction in the gap and are deposited on the lateral coating surface to form a second film that is continuous with the first film. The spacer is detachably mounted on the substrate. The spacer includes a spacer and a fixing member. The substrate has a first surface with a first groove. The forward coating surface includes the first surface outside the first groove and a first bottom surface corresponding to the bottom of the first groove. The lateral coating surface is the sidewall of the first groove. The shape of the spacer matches the shape of the first groove. The height of the spacer is greater than or equal to the depth of the first groove. The spacer is located in the first groove and forms a gap with the sidewall of the first groove.

2. The method for improving step coverage of evaporation coating according to claim 1, characterized in that, Prior to step 1, the method further includes the following steps: Step 01: Align the spacer with the lateral coating surface to form a gap between the spacer and the lateral coating surface; Step 02: Use the fastener to fix the spacer to the substrate to limit the spacer.

3. The method for improving step coverage of evaporation coating according to claim 2, characterized in that, in, Step 01 includes: The spacer is placed into the first groove of the substrate, and the distance between the spacer and the side wall of the first groove is adjusted so that a gap is formed between the spacer and the side wall of the first groove.

4. The method for improving step coverage of evaporation coating according to claim 3, characterized in that, Step 2 includes: An evaporation coating is performed on the substrate using a mask template. Evaporation particles are deposited in an incident direction perpendicular to the first surface. The evaporation particles that pass through the mask template and are incident on the first surface in the incident direction are deposited on the first surface to form a first thin film. A portion of the evaporation particles that pass through the mask template and are incident on the gap change their movement direction in the gap and are deposited on the sidewall of the first groove to form a second thin film. Another portion of the evaporation particles that pass through the mask template and are incident on the gap pass through the gap and are deposited on the first bottom surface to form a third thin film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern.

5. The method for improving step coverage of evaporation coating according to claim 2, characterized in that, The substrate has a second surface and a third surface disposed opposite to each other. A through-hole is provided on the substrate, extending from the second surface to the third surface. The forward coating surface includes the second surface and the sidewall of the through-hole. The lateral coating surface is the third surface. Step 01 includes: The spacer is moved to the through hole on the side of the third surface of the substrate, so that the spacer extends from the position corresponding to the through hole in a direction parallel to the third surface to a preset position on the third surface, and the distance between the spacer and the third surface is adjusted so that a gap is formed between the spacer and the third surface.

6. The method for improving step coverage of evaporation coating according to claim 5, characterized in that, Step 2 includes: An evaporation coating is performed on the substrate using a photomask. Evaporation particles are deposited at a predetermined angle to the second surface. The evaporation particles that pass through the photomask and are incident on the sidewall of the through hole along the incident direction are deposited on the sidewall of the through hole to form a first film. The evaporation particles that pass through the photomask and are incident on the through hole and are incident on the gap change their movement direction in the gap and are deposited on the third surface to form a second film. The evaporation particles that pass through the photomask and are incident on the second surface are deposited on the second surface to form a third film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern.

7. The method for improving step coverage of evaporation coatings according to claim 4 or 6, characterized in that, Following step 2, the method further includes the following steps: Remove the spacer and the fastener from the substrate.

8. The method for improving step coverage of evaporation coating according to claim 1, characterized in that, Prior to step 1, the method further includes the following steps: The substrate has a fourth surface, and a second groove and a spacer located in the second groove and spaced apart from the sidewall of the second groove are formed on the fourth surface of the substrate by photolithography and etching processes. Wherein, the sidewall of the second groove is the lateral coating surface, the gap is formed between the spacer and the sidewall of the second groove, and the height of the spacer is greater than or equal to the depth of the second groove.

9. The method for improving step coverage of evaporation coating according to claim 8, characterized in that, The forward coating surface includes the fourth surface corresponding to the second groove and the second bottom surface corresponding to the bottom of the second groove. Step 2 includes: An evaporation coating is performed on the substrate using a photomask. Evaporation particles are deposited in a direction perpendicular to the fourth surface. The evaporation particles that pass through the photomask and are incident on the fourth surface are deposited on the fourth surface to form a first film. A portion of the evaporation particles that pass through the photomask and are incident on the gap change their direction of movement in the gap and are deposited on the sidewall of the second groove to form a second film. Another portion of the evaporation particles that pass through the photomask and are incident on the gap pass through the gap and are deposited on the second bottom surface to form a third film. The first film, the second film, and the third film are interconnected to form electrodes with a preset pattern; Following step 2, the method further includes the following steps: The spacers are removed using an etching process.

10. The method for improving step coverage of evaporation coating according to claim 1, characterized in that, The width of the slit ranges from 5 micrometers to 30 micrometers.

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