Photoetching angle compensation method

Abstract

The invention relates to mask manufacturing, in particular to a photoetching angle compensation method, which comprises the following steps of: performing deviation angle detection on a first layer of a mask HTM by a photoetching machine to obtain a deviation angle detection result; determining a compensation angle according to a deviation angle detection result; driving the lens system to rotate according to the compensation angle, and enabling the to-be-photoetched mask to be at a zero-angle position relative to the lens system on the premise that an internal light path of the lens system is not changed; performing deviation angle detection on the second layer of the mask HTM by the photoetching machine to obtain a deviation angle detection result; s2 to S3 are repeated, so that the sleeving angle between the first layer and the second layer of the mask HTM is close to zero; according to the technical scheme provided by the invention, the defect that the deviation angle of the mask is difficult to accurately compensate in the prior art can be effectively overcome.

Description

Technical Field

[0001] The invention relates to mask manufacturing, and in particular to a photolithography angle compensation method. Background Art

[0002] In the production of mask, due to the large angle of the mask to be photolithography, the mask needs to be rotated to a certain angle to meet the photolithography conditions. The traditional rotation method is to rotate the mask through the pin column under the equipment, such as Figure 4 and Figure 5 As shown, the pin pillars rise, lifting the mask 1mm above the lithography machine. The mask is then held in place by vacuum holes in the pin pillars. The three pin pillars then rotate together to achieve lithography angle compensation. This traditional rotation method suffers from poor stability, large angular deflection, long rotation times, and low rotation accuracy. This is particularly problematic in reticle HTM production, where exposing the second layer is difficult and production efficiency is low.

[0003] At present, the production process of the mask HTM mainly includes: after the photolithography machine completes the writing of the first layer, it needs to be taken off the machine for development and etching, coating and gluing, etc., and then put back on the machine to write the second layer. The second layer is aligned and aimed according to the mark of the first layer. The angle of the entire graphic area relative to the photolithography machine can be measured through the mark. When the angle exceeds the specification requirements, it is necessary to transfer the plate through the pin column under the equipment, and then adjust the angle to within the specification requirements (the smaller the angle, the better).

[0004] However, due to the limitations of the angle adjustment capabilities of traditional rotation methods, it is difficult to achieve the angle within the specification requirements, and it is very time-consuming, greatly affecting the economic efficiency of production. At the same time, large angle deviations will also cause large deviations in the fitting angle between the two layers. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a photolithography angle compensation method, which can effectively overcome the defect of the prior art that it is difficult to accurately compensate for the deviation angle of the mask.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for photolithography angle compensation comprises the following steps:

[0010] S1. The photolithography machine performs deviation angle detection on the first layer of the mask HTM to obtain the deviation angle detection result;

[0011] S2. Determine the compensation angle according to the deviation angle detection result;

[0012] S3, driving the lens system to rotate according to the compensation angle, so that the mask to be photolithography is at a zero angle relative to the lens system under the premise that the optical path inside the lens system remains unchanged;

[0013] S4, the photolithography machine performs a deviation angle detection on the second layer of the mask HTM to obtain a deviation angle detection result;

[0014] S5. Repeat S2 to S3 to make the overlay angle between the first layer and the second layer of the mask HTM close to zero.

[0015] Preferably, the lithography machine in S1 performs deviation angle detection on the first layer of the mask HTM to obtain a deviation angle detection result, including:

[0016] The lithography machine uses a measuring probe to perform three-point position detection on the first layer of the mask HTM to obtain the corresponding deviation angle.

[0017] Preferably, in S3, driving the lens system to rotate according to the compensation angle so that the mask to be photolithography is at a zero angle relative to the lens system under the premise that the internal optical path of the lens system remains unchanged includes:

[0018] According to the compensation angle, the reflector and the lens unit are driven to rotate synchronously through the rotation mechanism to offset the deviation angle. Under the premise that the optical path inside the lens system remains unchanged, the mask to be photolithography is at a zero angle relative to the lens system.

[0019] The lens system includes a reflector and a lens unit.

[0020] Preferably, the step of driving the reflector and the lens unit to rotate synchronously by a rotation mechanism according to the compensation angle to offset the deviation angle comprises:

[0021] If the optical axis deviates from the center direction due to the tilt of the photolithography mask, the reflector and lens unit are driven to rotate synchronously around the horizontal or vertical axis through the rotation mechanism according to the compensation angle to adjust the direction of the optical axis so that the photolithography mask re-enters the center of the field of view to offset the deviation angle;

[0022] The optical axis is the axis perpendicular to the plane.

[0023] Preferably, the step of driving the reflector and the lens unit to rotate synchronously around a horizontal or vertical axis by a rotation mechanism according to the compensation angle to adjust the direction of the optical axis includes:

[0024] According to the compensation angle, a high-precision linear servo motor or piezoelectric ceramic actuator is used, combined with a precision worm gear or flexible hinge structure, to drive the reflector and lens unit to rotate synchronously around the horizontal or vertical axis in micro-radians to adjust the direction of the optical axis.

[0025] Preferably, the step of driving the reflector and the lens unit to rotate synchronously around a horizontal or vertical axis by a rotation mechanism according to the compensation angle and adjusting the direction of the optical axis comprises:

[0026] Assume that the lens system rotates around the optical axis by an angle θ. Then, the pixel coordinates (x, y) on the plane of the photolithography mask will be transformed to new coordinates (x', y') under the action of the rotation matrix, that is, a new photolithography coordinate system is generated:

[0027]

[0028] Preferably, in S4, the lithography machine performs deviation angle detection on the second layer of the mask HTM to obtain a deviation angle detection result, including:

[0029] The lithography machine uses a measurement probe through the Mark recognition system to perform three-point position detection on the second layer of the mask HTM to obtain the corresponding deviation angle.

[0030] (3) Beneficial effects

[0031] Compared with the existing technology, the lithography angle compensation method provided by the present invention effectively saves the exposure preparation time of the lithography mask HTM, achieves the purpose of lithography angle compensation by rotating the lens system at one time, and greatly improves the economic efficiency of the mask HTM production; at the same time, the fitting accuracy between the two layers of the mask HTM is also fully improved, which is of great significance to enterprises producing high-precision masks. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0033] Figure 1 It is a schematic diagram of the process of the present invention;

[0034] Figure 2 Schematic diagram of the photolithography machine in the present invention performing deviation angle detection on the mask;

[0035] Figure 3 is a schematic diagram of driving the lens system to rotate according to the compensation angle in the present invention;

[0036] Figure 4 This is a structural diagram of the traditional rotation method of transferring the plate through the pin column under the device;

[0037] Figure 5 This is a schematic diagram of the effect of transferring the plate using the traditional rotation method using the pin column below the device. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] A method for photolithography angle compensation, such as Figure 1 As shown, S1, the lithography machine performs deviation angle detection on the first layer of the mask HTM and obtains the deviation angle detection result, such as Figure 2 As shown, specifically including:

[0040] The lithography machine uses a measuring probe to measure the three-point position of the first layer of the mask HTM ( Figure 2 The measurement positions 1, 2 and 3 in the figure are detected to obtain the corresponding deviation angles.

[0041] S2. Determine the compensation angle according to the deviation angle detection result.

[0042] S3, driving the lens system to rotate according to the compensation angle, under the premise that the internal optical path of the lens system remains unchanged, so that the mask to be photolithography is at a position with a zero angle relative to the lens system, such as Figure 3 As shown, specifically including:

[0043] According to the compensation angle, the reflector and the lens unit are driven to rotate synchronously through the rotation mechanism to offset the deviation angle. Under the premise that the optical path inside the lens system remains unchanged, the mask to be photolithography is at a zero angle relative to the lens system.

[0044] The lens system includes a reflector and a lens unit.

[0045] Specifically, the reflector and the lens unit are driven to rotate synchronously by a rotation mechanism according to the compensation angle to offset the deviation angle, including:

[0046] If the optical axis deviates from the center direction due to the tilt of the photolithography mask, the reflector and lens unit are driven to rotate synchronously around the horizontal or vertical axis through the rotation mechanism according to the compensation angle to adjust the direction of the optical axis so that the photolithography mask re-enters the center of the field of view to offset the deviation angle;

[0047] The optical axis is the axis perpendicular to the plane.

[0048] Specifically, the reflector and the lens unit are driven to rotate synchronously around the horizontal or vertical axis by a rotation mechanism according to the compensation angle to adjust the direction of the optical axis, including:

[0049] According to the compensation angle, a high-precision linear servo motor or piezoelectric ceramic actuator is used in conjunction with a precision worm gear or flexible hinge structure to drive the reflector and lens unit to rotate synchronously around the horizontal or vertical axis in micro-radians (for example, the top screw adjustment device, through pitch conversion, the M3 top screw rotates 0.004° per turn to achieve a fine-tuning accuracy of 0.001°) to adjust the direction of the optical axis.

[0050] Specifically, according to the compensation angle, the reflector and the lens unit are driven to rotate synchronously around the horizontal or vertical axis through the rotation mechanism, and the direction of the optical axis is adjusted, including:

[0051] Assume that the lens system rotates around the optical axis by an angle θ. Then, the pixel coordinates (x, y) on the plane of the photolithography mask will be transformed to new coordinates (x', y') under the action of the rotation matrix, that is, a new photolithography coordinate system is generated:

[0052]

[0053] S4. The lithography machine performs deviation angle detection on the second layer of the mask HTM to obtain the deviation angle detection result, which specifically includes:

[0054] The lithography machine uses a measurement probe through the Mark recognition system to perform three-point position detection on the second layer of the mask HTM to obtain the corresponding deviation angle.

[0055] S5. Repeat S2 to S3 to make the overlay angle between the first layer and the second layer of the mask HTM close to zero.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for photolithography angle compensation, characterized in that: The following steps are involved: S1. The photolithography machine performs deviation angle detection on the first layer of the mask HTM to obtain the deviation angle detection result; S2. Determine the compensation angle according to the deviation angle detection result; S3, driving the lens system to rotate according to the compensation angle, so that the mask to be photolithography is at a zero angle relative to the lens system under the premise that the optical path inside the lens system remains unchanged; S4, the photolithography machine performs a deviation angle detection on the second layer of the mask HTM to obtain a deviation angle detection result; S5. Repeat S2 to S3 to make the overlay angle between the first layer and the second layer of the mask HTM close to zero.

2. The lithography angle compensation method according to claim 1, wherein: In S1, the lithography machine performs deviation angle detection on the first layer of the mask HTM and obtains the deviation angle detection results, including: The lithography machine uses a measuring probe to perform three-point position detection on the first layer of the mask HTM to obtain the corresponding deviation angle.

3. The lithography angle compensation method according to claim 1, wherein: In S3, the lens system is driven to rotate according to the compensation angle, so that the mask to be photolithography is at a zero angle relative to the lens system under the premise that the optical path inside the lens system remains unchanged, including: According to the compensation angle, the reflector and the lens unit are driven to rotate synchronously through the rotation mechanism to offset the deviation angle. Under the premise that the optical path inside the lens system remains unchanged, the mask to be photolithography is at a zero angle relative to the lens system. The lens system includes a reflector and a lens unit.

4. The lithography angle compensation method according to claim 3, wherein: The method of driving the reflector and the lens unit to rotate synchronously through a rotation mechanism according to the compensation angle to offset the deviation angle includes: If the optical axis deviates from the center direction due to the tilt of the photolithography mask, the reflector and lens unit are driven to rotate synchronously around the horizontal or vertical axis through the rotation mechanism according to the compensation angle to adjust the direction of the optical axis so that the photolithography mask re-enters the center of the field of view to offset the deviation angle; The optical axis is the axis perpendicular to the plane.

5. The lithography angle compensation method according to claim 4, wherein: The method of driving the reflector and the lens unit to rotate synchronously around the horizontal or vertical axis by a rotation mechanism according to the compensation angle to adjust the direction of the optical axis includes: According to the compensation angle, a high-precision linear servo motor or piezoelectric ceramic actuator is used, combined with a precision worm gear or flexible hinge structure, to drive the reflector and lens unit to rotate synchronously around the horizontal or vertical axis in micro-radians to adjust the direction of the optical axis.

6. The lithography angle compensation method according to claim 5, wherein: The method comprises: driving the reflector and the lens unit to rotate synchronously around the horizontal or vertical axis through the rotation mechanism according to the compensation angle, and adjusting the direction of the optical axis, comprising: Assume that the lens system rotates around the optical axis by an angle θ. Then, the pixel coordinates (x, y) on the plane of the photolithography mask will be transformed to the new coordinates (x', y') under the action of the rotation matrix, that is, a new photolithography coordinate system is generated:

7. The lithography angle compensation method according to claim 1, wherein: In S4, the lithography machine performs deviation angle detection on the second layer of the mask HTM and obtains the deviation angle detection results, including: The lithography machine uses a measurement probe through the Mark recognition system to perform three-point position detection on the second layer of the mask HTM to obtain the corresponding deviation angle.

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