A mask alignment and fixing method and device

Abstract

The present invention discloses a mask alignment and fixing method and device, comprising an alignment mechanism, wherein a substrate chuck is installed above the alignment mechanism, a substrate is adsorbed on the substrate chuck, an outer ring of the substrate chuck is sleeved with a substrate clamping ring, a mask leveling bracket is provided on the substrate, a Z-axis displacement stage is installed on one side of the mask leveling bracket, a pillar is fixedly installed above the alignment mechanism, a movably adjustable alignment objective lens is provided on the pillar, a mask clamping ring is provided directly below the alignment objective lens, a mask is installed below the mask clamping ring, and a computer is electrically connected to the alignment mechanism; on the basis of taking into account high-precision visual measurement and motion control, the separation of the mask-substrate and its clamping ring from the alignment system is cleverly achieved so that they can be independently transferred to subsequent thin film deposition process equipment.

Description

Technical Field

[0001] The invention relates to a mask alignment and fixing method and device, and belongs to the field of thin film deposition. Background Art

[0002] In the field of thin film deposition, masks are a commonly used method to achieve patterned deposition. From primary pattern generation without specific alignment, to low-precision secondary pattern deposition using some mechanical self-alignment, to precise secondary pattern deposition using high-precision vision systems and motion control systems, the patterning accuracy that can be achieved using masks has gradually increased. When the technology develops to the stage of combining vision systems and motion control systems to achieve high-precision patterned deposition using masks, it becomes increasingly difficult to unify high-precision alignment structures and simple, separable mask-substrate clamping mechanisms into the same system design.

[0003] In order to achieve high-precision alignment, the clamping mechanism is often complex and difficult to separate from the alignment platform; the alignment mechanism of the independently operable alignment-clamping mechanism is relatively compact, making it difficult to achieve high-precision automated alignment. At the same time, the former technical route means that the entire set of alignment and fixing mechanisms must be integrated with the subsequent deposition equipment, which increases the equipment cost and reduces the operating efficiency of the alignment platform. The latter technical route means that the compact and precise alignment control mechanism needs to experience a harsh film deposition environment and is prone to damage. Summary of the invention

[0004] The invention provides a mask alignment and fixing method and device for overcoming the defect that a substrate clamping mechanism of a mask in the prior art is difficult to realize high-precision automatic alignment.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] The present invention discloses a mask alignment and fixing method and device, comprising an alignment mechanism, a substrate chuck is installed above the alignment mechanism, a substrate is adsorbed on the substrate chuck, an outer ring of the substrate chuck is sleeved with a substrate clamping ring, a mask leveling bracket is provided above the substrate, a Z-axis displacement stage is installed on one side of the mask leveling bracket, a pillar is also fixedly installed on the alignment mechanism, a movable and adjustable alignment objective lens is arranged on the pillar, a mask clamping ring is provided directly below the alignment objective lens, a mask is installed below the mask clamping ring, and a computer is electrically connected to the alignment mechanism.

[0007] Mask alignment and fixing method:

[0008] 1) The mask is fixed to the mask clamping ring, and the substrate is adsorbed on the substrate chuck, and the outer ring of the substrate chuck is covered with the substrate clamping ring;

[0009] 11) The substrate clamping ring is provided with a threaded hole matched with the fastening screw, and the mask clamping ring is provided with a through hole with a hole diameter greater than the outer diameter of the fastening screw, so as to ensure that when the fastening screw tightens the two clamping rings, the mask clamping ring has a movable margin for precise position adjustment relative to the substrate clamping ring;

[0010] 12) The mask clamping ring is fixed to the mask leveling bracket by a leveling screw padded with a leveling spring, and the through hole between the leveling screw and the mask leveling bracket also retains a movable margin to ensure the allowable tilt angle of the mask clamping ring relative to the mask leveling bracket;

[0011] 2) After the mask and substrate are loaded, the position of the Z-axis translation stage is adjusted to gradually bring the mask closer to the substrate so that both fall within the depth of field of the alignment lens at the same time, and then the position of the alignment lens is controlled to search for the alignment mark on the mask;

[0012] 21) The computer automatically extracts the coordinates of the alignment marks on the mask and the substrate based on the image information transmitted from the alignment lens, for example, by using a feature recognition algorithm, and calculates the position deviation, and then compensates for the position deviation by manipulating the movement of the alignment mechanism. The computer repeats the above process until the deviation of the alignment mark meets the set requirements;

[0013] 3) When the computer confirms the alignment of the mask and the substrate through the overlap of the alignment marks, the height of the mask is further lowered by the Z-axis translation stage for pre-compression. The leveling spring in the mask clamping ring can automatically compensate for the non-parallelism between the substrate chuck and the mask leveling frame during the pre-compression process;

[0014] 4) After the pre-tightening is completed, tighten the fixing screws so that the substrate clamping ring and the mask clamping ring clamp the substrate and the mask;

[0015] 5) Remove the leveling screws and leveling springs to separate the mask clamping ring from the mask leveling frame, disconnect the temporary adsorption of the substrate by the substrate chuck, and remove the mask and substrate.

[0016] Furthermore, the alignment mechanism includes a rotation translation stage, a Y-axis translation stage and an X-axis translation stage which are arranged in sequence from top to bottom.

[0017] Furthermore, a magnetic attraction plate is attached behind the substrate and cooperated with a ferromagnetic mask to achieve high-precision patterned thin film deposition, and the mask is further pressed against the substrate to prevent the thin film from being deposited in the gap between the two.

[0018] Furthermore, the mask is fixed to the mask clamping ring by means of screw compression, gluing or vacuum adsorption; and the substrate is adsorbed on the substrate chuck by means of vacuum or electrostatic adsorption.

[0019] The beneficial effect achieved by the present invention is that, on the basis of taking into account high-precision visual measurement and motion control, the mask-substrate and its clamping ring are cleverly separated from the alignment system so as to be independently transferred to the subsequent thin film deposition process equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the magnetic attraction plate of the present invention;

[0023] Figure 3 It is an operation flow chart of the present invention.

[0024] In the figure: 1. mask; 2. substrate; 3. mask clamping ring; 4. substrate chuck; 5. substrate clamping ring; 6. mask leveling bracket; 7. Z-axis translation stage; 8. alignment objective lens; 9. X-axis translation stage; 10. Y-axis translation stage; 11. rotation translation stage; 12. computer; 13. magnetic plate. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0026] Example 1

[0027] like Figure 1-3 As shown, a mask device includes an alignment mechanism, a substrate chuck 4 is installed above the alignment mechanism, a substrate 2 is adsorbed on the substrate chuck 4, an outer ring of the substrate chuck 4 is sleeved with a substrate clamping ring 5, a mask leveling bracket 6 is provided above the substrate 2, a Z-axis translation stage 7 is installed on one side of the mask leveling bracket 6, a pillar is also fixedly installed on the alignment mechanism, a movable and adjustable alignment lens 8 is provided on the pillar, a mask clamping ring 3 is provided directly below the alignment lens 8, a mask 1 is installed below the mask clamping ring 3, and a computer 12 is electrically connected to the alignment mechanism.

[0028] The alignment mechanism includes a rotational translation stage 11, a Y-axis translation stage 10 and an X-axis translation stage 9 which are arranged in sequence from top to bottom.

[0029] Mask alignment and fixation methods include:

[0030] 1) The mask 1 is fixed to the mask clamping ring 3 by screw compression, gluing or vacuum adsorption, and the substrate 2 is temporarily adsorbed on the substrate chuck 4 by vacuum or static electricity, and the outer ring of the substrate chuck 4 is covered with a substrate clamping ring 5;

[0031] 11) The substrate clamping ring 5 is provided with a threaded hole matched with the fastening screw, and the mask clamping ring 3 is provided with a through hole with a hole diameter greater than the outer diameter of the fastening screw, so as to ensure that when the fastening screw tightens the two clamping rings, the mask clamping ring 3 has a certain amount of free space relative to the substrate clamping ring 5 for precise position adjustment;

[0032] 12) The mask clamping ring 3 is fixed to the mask leveling bracket 6 through a set of leveling screws padded with leveling springs, and the through holes between the leveling screws and the mask leveling bracket 6 also retain a certain amount of margin to ensure the inclination angle of the mask clamping ring 3 relative to the mask leveling bracket 6;

[0033] 2) After the mask 1 and the substrate 2 are loaded, the position of the Z-axis translation stage 7 is adjusted so that the mask 1 gradually approaches the substrate 2 so that both fall within the depth of field of the alignment lens 8 at the same time, and then the position of the alignment lens 8 is controlled to search for the alignment mark on the mask 1;

[0034] 21) The computer 12 automatically extracts the coordinates of the alignment marks on the mask 1 and the substrate 2 according to the image information transmitted from the alignment lens 8, for example, by using a feature recognition algorithm, and calculates the position deviation, and then compensates for the position deviation by manipulating the movement of the alignment mechanism. The computer 12 repeats the above process until the deviation of the alignment mark meets the set requirement;

[0035] 3) When the computer 12 confirms the alignment of the mask 1 and the substrate 2 by the overlap of the alignment marks, the height of the mask 1 can be further lowered by the Z-axis translation stage 7 for pre-compression, and the leveling spring in the mask clamping ring 3 can automatically compensate for the non-parallelism between the substrate chuck 4 and the mask leveling frame 6 during the pre-compression process;

[0036] 4) After the pre-tightening is completed, tighten the fixing screws so that the substrate clamping ring 5 and the mask clamping ring 3 clamp the substrate 2 and the mask 1;

[0037] 5) Remove the leveling screws and the leveling spring to separate the mask clamping ring 3 from the mask leveling frame 6, disconnect the temporary adsorption of the substrate 2 by the substrate chuck 4, and remove the mask 1 and the substrate 2;

[0038] 6) For high-precision patterned thin film deposition requirements, the mask 1 needs to be further attached to the substrate 2 to prevent the thin film from being deposited in the gap between the two. This is achieved by attaching a magnetic attraction plate 13 behind the substrate 2 and using a ferromagnetic mask.

[0039] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mask alignment device, comprising an alignment mechanism, a substrate chuck is mounted above the alignment mechanism, a substrate is adsorbed on the substrate chuck, an outer ring of the substrate chuck is sleeved with a substrate clamping ring, a mask leveling bracket is arranged above the substrate, a Z-axis displacement stage is mounted on one side of the mask leveling bracket, a pillar is fixedly mounted on the alignment mechanism, The pillar is provided with a movable and adjustable alignment lens, a mask clamping ring is provided directly below the alignment lens, a mask is installed below the mask clamping ring, and a computer is electrically connected to the alignment mechanism; It is characterized in that The mask alignment and fixation method is: 1) The mask is fixed to the mask clamping ring, and the substrate is adsorbed on the substrate chuck, and the outer ring of the substrate chuck is covered with the substrate clamping ring; 11) The substrate clamping ring is provided with a threaded hole matched with the fastening screw, and the mask clamping ring is provided with a through hole with a hole diameter greater than the outer diameter of the fastening screw, so as to ensure that when the fastening screw tightens the two clamping rings, the mask clamping ring has a movable margin for precise position adjustment relative to the substrate clamping ring; 12) The mask clamping ring is fixed to the mask leveling bracket by a leveling screw padded with a leveling spring, and the through hole between the leveling screw and the mask leveling bracket also retains a movable margin to ensure the allowable tilt angle of the mask clamping ring relative to the mask leveling bracket; 2) After the mask and substrate are loaded, the position of the Z-axis translation stage is adjusted to gradually bring the mask closer to the substrate so that both fall within the depth of field of the alignment lens at the same time, and then the position of the alignment lens is controlled to search for the alignment mark on the mask; 21) The computer automatically extracts the coordinates of the alignment marks on the mask and substrate based on the image information transmitted from the alignment lens and uses a feature recognition algorithm to calculate the position deviation, and then compensates for the position deviation by manipulating the movement of the alignment mechanism. The computer repeats the above process until the deviation of the alignment mark meets the set requirements; 3) When the computer confirms the alignment of the mask and the substrate through the overlap of the alignment marks, the height of the mask is further lowered by the Z-axis translation stage for pre-compression. The leveling spring in the mask clamping ring can automatically compensate for the non-parallelism between the substrate chuck and the mask leveling bracket during the pre-compression process; 4) After the pre-tightening is completed, tighten the fixing screws so that the substrate clamping ring and the mask clamping ring clamp the substrate and the mask; 5) Remove the leveling screws and leveling springs to separate the mask clamping ring from the mask leveling bracket, disconnect the temporary adsorption of the substrate by the substrate chuck, and remove the mask and substrate.

2. The mask alignment device according to claim 1, characterized in that: The alignment mechanism comprises a rotation translation stage, a Y-axis translation stage and an X-axis translation stage which are arranged in sequence from top to bottom.

3. The mask alignment device according to claim 1, characterized in that: A magnetic attraction plate is attached behind the substrate and cooperated with a ferromagnetic mask to realize high-precision patterned thin film deposition, and the mask is further attached to the substrate to prevent the thin film from being deposited in the gap between the two.

4. The mask alignment device according to claim 1, characterized in that: The mask is fixed to the mask clamping ring by means of screw compression, adhesive bonding or vacuum adsorption; the substrate is adsorbed on the substrate chuck by means of vacuum or electrostatic adsorption.

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