CN-121995714-A - Nanometer impression alignment control method

CN121995714ACN 121995714 ACN121995714 ACN 121995714ACN-121995714-A

Abstract

The invention relates to a nano-imprinting alignment control method, belonging to the technical field of micro-nano processing and nano-imprinting lithography. The invention takes the table with the reference mark group as the unified position intermediary, sequentially executes three core stages of master plate position calibration and soft film replication, imprint sheet alignment imprint and front and back layer alignment deviation compensation, and realizes the high-precision position alignment of the three stages through the position information transmission link of the master plate, the table, the soft film and the imprint sheet. According to the invention, the alignment marks do not need to be prefabricated on the wafer to be imprinted, the industrial pain point of the pure nano imprinting production line initial photo wafer without the alignment marks is solved, meanwhile, a complex transparent optical alignment module does not need to be integrated on the imprinting head, the equipment structure is greatly simplified, the production cost is reduced, and the continuous high-precision alignment of the front and rear layer structures of the whole production line can be realized through on-line offset data sharing and feedback compensation.

Inventors

ZENG PAN
JI RAN
WANG FENG
MA BINGQIAN
SUN JUNJIE

Assignees

青岛天仁微纳科技有限责任公司

Dates

Publication Date: 20260508
Application Date: 20260326

Claims (10)

1. A nano-imprinting alignment control method is characterized in that the method is based on a table plate with an imprinting station, wherein a reference mark group is marked on the imprinting station; The reference Mark group comprises a notch Mark and a Mark; a notch mark is used as a C mark to determine the angle of the master plate; mark as B Mark to fix the mother board position; The master plate is provided with a notch corresponding to the notch mark; calibrating the set of belt reference marks at the master plate position at the imprinting station; The PET tooling is loaded with a soft film, the soft film is used for carrying out pattern transfer copying, and the stamping sheet is aligned and stamped; the table plate is provided with an X-axis translational degree of freedom, a Y-axis translational degree of freedom and a rotational theta degree of freedom around a Z-axis, and a fixed reference mark group is arranged on the surface of the table plate; A tooling alignment mark A mark is prefabricated on the PET tooling; the alignment control method specifically comprises the following steps: s1, calibrating the master plate position and copying a soft film; S2, aligning and embossing the embossing sheet; S3, aligning and compensating the front layer and the rear layer in an alignment way.
2. The nanoimprint alignment control method according to claim 1, wherein in S1, the vision camera is electrically connected to the control system; S11, placing the master with the target micro-nano graph at an imprinting station of a table, identifying a notch mark of the master and a reference mark group on the table through a visual camera, feeding back a position and angle deviation signal to a control system, driving the table by the control system to complete translation and rotation adjustment, realizing complete calibration of positions and angles of the master and the table reference mark group, and recording relative position parameters of the master and the table reference mark group at the moment; S12, carrying out alignment pre-calibration on the soft film, namely moving a PET tool carrying the soft film to the position right above a master plate, controlling the PET tool and the master plate to keep a set short-distance and non-contact state, identifying an A mark on the PET tool and a reference mark group on a table disc through a vision camera, and feeding back the A mark and the reference mark group to a control system to correct the position and the angle of the PET tool so as to realize alignment of the PET tool and the table disc reference mark group; S13, soft film copying and parameter recording, namely after pre-calibration is completed, a CLIV imprinting process is executed according to a preset imprinting program, a target micro-nano pattern on a master plate is copied to the surface of the soft film, the soft film copying is completed after demolding, and meanwhile, the alignment parameters of the PET tool A mark and the table disc reference mark group in the process are recorded and used as reference alignment data of a subsequent imprinting process.
3. The method for controlling nano imprinting alignment according to claim 2, wherein in S2, S21, the imprinting sheet is placed and position calibrated, namely, a wafer imprinting sheet to be imprinted is placed on the surface of a table, a notch mark of the imprinting sheet and a reference mark group on the table are identified through a visual camera, the notch mark and the reference mark group are fed back to a control system to drive the table to complete translation and rotation adjustment, and the position deviation and the angle deviation of the imprinting sheet are corrected, so that the position and the angle of the imprinting sheet after being placed are completely consistent with the position and the angle of a master plate in the step S11; S22, carrying out imprinting alignment pre-calibration, namely moving a PET tool carrying the copied soft film to the position right above an imprinting sheet, controlling the PET tool and the imprinting sheet to keep a close-range non-contact state, identifying an A mark on the PET tool through a vision camera, correcting the position and the angle of the PET tool by a control system according to the reference alignment data recorded in the step S13, compensating the deviation of the position and the angle, and realizing the accurate pre-alignment of the soft film and the imprinting sheet; S23, embossing forming and feedback control, namely executing an embossing process according to a preset embossing program after the pre-calibration is completed, transferring the micro-nano pattern on the soft film to the surface of an embossing sheet, and reading position deviation data of the embossing after the embossing is completed, wherein the position deviation data are used for closed loop feedback optimization of an alignment control system, and completing alignment embossing of single-round wafer-free marks after demolding.
4. The method of claim 3, wherein in S3, S31, the deviation data is shared by the processing equipment of the next layer structure of the current stamping sheet, and the position deviation data of the last layer stamping process is obtained through a production line online data sharing system; S32, performing alignment compensation and overlay imprinting, namely repeatedly executing the process of the steps S1 to S22, compensating the position deviation data of the previous layer of imprinting to the position and angle adjustment process of the PET tool until the pre-alignment step of the PET tool, performing the imprinting process after the pre-alignment is completed, and transferring the next layer of micro-nano pattern overlay to the surface of an imprinting sheet; And S33, overlay feedback control, namely reading position deviation data of the overlay imprint after the imprinting is finished, wherein the position deviation data are used for closed-loop feedback to optimize the overlay control, and the position deviation data are transmitted to next-layer processing equipment through an online data sharing system to realize the continuous overlay control of the full production line.
5. The method according to claim 4, wherein in steps S11 and S21, the vision camera includes at least two sets of alignment vision units, wherein the first vision unit is used for identifying the notch marks of the wafer or the master, the second vision unit is used for identifying the reference mark group on the platen, and the two sets of vision units synchronously acquire images and feed back the images to the control system.
6. The method of claim 5, wherein the set of fiducial marks on the platen comprises at least two sets of B marks and C marks symmetrically distributed on the surface of the platen, and the rotation angle deviation of the wafer or the master is calculated by the coordinate difference of the two sets of marks.
7. The method of claim 6, wherein in steps S12 and S22, the non-contact distance between the PET tooling and the master or between the PET tooling and the imprint sheet is controlled within a range of 50 μm to 200 μm.
8. The method of claim 7, wherein in steps S23 and S33, the post-imprinting positional deviation data is acquired by online detection by a post-imprinting vision system, and the positional deviation data includes an X-positional deviation, a Y-positional deviation, and a θ -direction angular deviation.
9. The method of claim 6, wherein the platen is an air-floating motion stage or a manipulator controlled motion stage, and the stage at the imprinting process adopts a vacuum adsorption station for fixing the master plate or the imprinting sheet.
10. The method of claim 7, wherein the imprinting process in steps S13 and S23 is an ultraviolet-curing nanoimprinting process; the stamping station is a circular area; a process groove positioned at two sides of the notch mark is arranged at one side of the circular area; The table disc has a swinging action, so that the notch Mark is positioned obliquely below the Mark; The swinging shaft of the table plate is horizontally perpendicular to the length direction of the process groove; A rotary base is arranged below the table plate and is used for realizing the rotation of the table plate; The rotary base is connected with the telescopic manipulator; the telescopic manipulator is provided with an inclined manipulator for driving the rotary base and the table plate to swing; An adjusting manipulator is arranged above the inclined station of the table plate, and a rotating finger is arranged below the adjusting manipulator and is used for rotating and rolling contact with the edge of the lower part of the object on the imprinting station in an inclined state; A conical finger is arranged below the adjusting manipulator and is used for rotating and rolling contact with the lower edge of the object on the imprinting station in an inclined state; The adjusting manipulator drives the adjusting manipulator to move along the inclined direction and roll to contact, so that the load is adjusted to a Mark and Mark determining area.

Description

Nanometer impression alignment control method Technical Field The invention relates to a nano-imprint alignment control method, in particular to a nano-imprint alignment control method without wafer alignment marks. Background The nanoimprint technology is used as a new generation of micro-nano patterning technology, and is widely researched and applied in the fields of semiconductor chips, optoelectronic devices, biochips, super-surface optics and the like by virtue of the advantages of ultrahigh resolution, low cost, compatibility with CMOS (complementary metal oxide semiconductor) process and the like. The nano-imprinting is a contact pattern transfer process, and the alignment accuracy in the imprinting process directly determines the processing yield and performance of the device, so that the alignment method and the control technology thereof are one of the core barriers for preventing the large-scale mass production application of the nano-imprinting technology. Currently, the main stream of step-by-step nano imprinting alignment technology in the industry relies on a transparent optical alignment module integrated on an imprinting head, and accurate alignment in the imprinting process is realized by synchronously identifying an alignment mark prefabricated on a stamp and a wafer. The technical scheme has the inherent defects that a high-precision large-view-field transparent optical alignment system is integrated on an imprinting head, the structural design of equipment is complex, the manufacturing cost and the maintenance cost of the equipment are extremely high, the alignment process is long in alignment process, the production efficiency and the yield are low, large-scale modulus production requirements are difficult to adapt, and the alignment operation can be realized only by relying on the prefabricated alignment marks on the wafer. For the wafer-level nanoimprint technology with lower cost and larger mass production potential, a mature and stable alignment control scheme is not formed in the industry at present due to the obvious difference between the process principle and the traditional photoetching technology. Particularly for a pure nano-imprinting mass production line, no prefabricated alignment mark exists on the surface of an initial wafer to be processed, and alignment cannot be realized through a traditional mark recognition scheme, so that how to realize accurate alignment of an imprinting pattern on a polished wafer without any wafer alignment mark and alignment of a full-production line multi-process front-rear layer structure are the primary technical problems to be solved in mass production of the pure nano-imprinting process. Disclosure of Invention The invention aims to overcome the defects in the prior art, and provides a nano-imprinting alignment control method without wafer alignment marks, which solves the alignment problem that an initial wafer in a pure nano-imprinting production line has no alignment marks, simplifies the structural design of nano-imprinting alignment equipment, reduces the equipment and mass production cost, improves the production efficiency, can realize high-precision continuous alignment of the front and rear layer structures of the whole production line, and is suitable for large-scale mass production application of the nano-imprinting technology. In order to solve the problems, the invention adopts the following technical scheme: A nanoimprint alignment control method without wafer alignment marks uses a table disc with a reference mark group as a position reference medium, and completes nanoimprint high-precision alignment control without wafer alignment marks through three core stages of master plate position calibration and soft film replication, imprint sheet alignment imprinting and front and back layer alignment deviation compensation; The table plate is provided with X-axis and Y-axis translational degrees of freedom and a rotation theta degree of freedom around a Z axis, a fixed reference mark group is arranged on the surface of the table plate, The reference mark group comprises a B mark used for position deviation calibration and a C mark used for angle deviation calibration, a soft film used for pattern transfer is fixed on the surface of a PET tool, and a tool alignment mark A mark is prefabricated on the PET tool. The alignment control method specifically comprises the following steps: s1, calibrating the master plate position and copying a soft film; s11, master set placement and position calibration: Placing a master plate with a target micro-nano graph on the surface of a table plate, identifying a notch mark of the master plate and a reference mark group on the table plate through a visual camera, feeding back a position and angle deviation signal to a control system, driving the table plate by the control system to finish translational and rotational adjustment, realizing the complete calibration of the positions and angles of