Control method of ultra-thin sheet planarization process and process machine table

Abstract

The invention provides a control method of an ultrathin wafer planarization process and a process machine, and relates to the technical field of semiconductor devices. Before the ultra-thin sheet is flattened, the ultra-thin sheet is temporarily bonded with the wafer level of the slide glass in the machine table, and the flattening process of the ultra-thin sheet is completed by using the slide glass as a structural bearing for process processing; and after the planarization is completed, decoupling of the processing sheet and the slide glass is realized in the machine table, and the processing sheet and the slide glass are conveyed back to respective crystal boxes after being cleaned and blow-dried respectively, so that the planarization of the ultrathin sheet is realized. Through temporary bonding and de-bonding of the ultrathin wafer and the slide glass, the breakage probability of the ultrathin wafer in the planarization process is reduced, and the processing efficiency and the yield of the ultrathin wafer planarization process are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a control method and a process machine for an ultra-thin sheet flattening process. Background Art

[0002] In the field of semiconductor manufacturing and advanced material processing, with the continuous advancement of technology and the emergence of special process processing needs, the surface flattening requirements for wafers and similar ultra-thin materials are becoming increasingly stringent. The traditional chemical mechanical polishing (CMP) process shows good stability and efficiency when processing wafers with a thickness greater than 700 microns, but when faced with ultra-thin wafers with a thickness below this critical value, the technical challenges increase significantly.

[0003] Ultra-thin wafers are prone to breakage during the grinding process due to reduced material strength and insufficient rigidity, which not only directly leads to a sharp increase in product scrap rate, but also contaminates the grinding pad and grinding head due to scattered debris, forcing the production line to be frequently interrupted for equipment cleaning and replacement, greatly affecting production efficiency and increasing production costs. In addition, tiny particles of debris may also be embedded in subsequent processed products, becoming a potential quality risk and affecting the overall performance and reliability of the product.

[0004] The planarization process of wafer-level optical sheets with high hardness and high brittleness, such as crystal, ceramic, optical glass, and sapphire, faces unprecedented challenges. These materials not only require extremely high surface finish and flatness to meet the requirements of optical performance, but their ultra-thin characteristics also increase the technical difficulty in the processing process. At present, there is a lack of CMP process solutions and special equipment designed specifically for ultra-thin sheets. Existing machines often find it difficult to strike a balance between processing accuracy and material protection, resulting in low processing efficiency and difficulty in improving the yield rate. Summary of the invention

[0005] The present invention provides a control method and a process machine for an ultra-thin sheet flattening process, which can reduce the probability of breakage of the ultra-thin sheet during the flattening process and improve the processing efficiency and yield rate of the ultra-thin sheet flattening process.

[0006] In the first aspect, the present invention provides a control method for an ultra-thin sheet flattening process, which is applied to a process machine, wherein the process machine includes a pre-processing area, a flattening area, and a post-processing area, and the control method includes: sucking a carrier from a wafer carrier box outside the process machine to the pre-processing area for alignment and lamination, thereby obtaining a carrier to be bonded with bonding glue attached thereto; sucking an ultra-thin sheet from an ultra-thin sheet crystal box outside the process machine to the pre-processing area for alignment, thereby obtaining an ultra-thin sheet to be bonded; bonding the carrier to be bonded and the ultra-thin sheet to be bonded in the pre-processing area to obtain a bonded ultra-thin sheet; transferring the bonded ultra-thin sheet to the flattening area for flattening to obtain a processed composite sheet; after the flattening, transferring the processed composite sheet to the post-processing area, debonding the processed composite sheet to obtain a carrier and a flattened ultra-thin sheet, and cleaning and drying them respectively; moving the carrier to the carrier crystal box, and moving the flattened ultra-thin sheet to the ultra-thin sheet crystal box to achieve flattening of the ultra-thin sheet.

[0007] In a possible implementation, the process machine also includes a front-end intelligent transfer FI robot and a transfer robot; the pre-processing area includes a wafer aligner, a wafer laminator, a wafer baker and a wafer bonder; after the carrier is sucked from the carrier crystal box outside the process machine to the pre-processing area for alignment and lamination, a carrier to be bonded with bonding glue attached thereto is obtained, including: controlling the FI robot to suck the carrier from the carrier crystal box to the wafer aligner; controlling the carrier alignment in the wafer aligner; controlling the transfer robot to transfer the carrier from the wafer aligner to the wafer laminator; in the wafer laminator, using a rotary coating method to apply bonding glue on the surface of the carrier to complete the lamination; controlling the transfer robot to transfer the carrier from the wafer laminator to the wafer baker; in the wafer baker, using a first set temperature to set the baking time for the laminated carrier to complete the baking; controlling the transfer robot to transfer the baked carrier from the wafer baker to the wafer bonder to obtain a carrier to be bonded with bonding glue attached thereto.

[0008] In one possible implementation, an ultra-thin wafer is sucked from an ultra-thin wafer box outside a process machine to a pre-processing area for alignment to obtain an ultra-thin wafer to be bonded, including: controlling the FI robot to suck the ultra-thin wafer from the ultra-thin wafer box to a wafer aligner; controlling the alignment of the ultra-thin wafer on the wafer aligner; controlling the transfer robot to transfer the ultra-thin wafer from the wafer aligner to the wafer bonder to obtain an ultra-thin wafer to be bonded.

[0009] In one possible implementation, the carrier wafer to be bonded and the ultra-thin sheet to be bonded are bonded in a pre-processing area to obtain a bonded ultra-thin sheet, including: in a wafer bonder, using a second set temperature to bond the carrier wafer to be bonded and the ultra-thin sheet to obtain a bonded ultra-thin sheet.

[0010] In a possible implementation, the planarization processing area includes a grinding area and a wet environment cleaning and drying processing area, the grinding area includes a first wafer grinder, a first stop table, a second wafer grinder and a second stop table; the transfer robot includes a first transfer robot and a second transfer robot; the transfer of the bonded ultra-thin wafer to the planarization processing area for planarization to obtain a processed composite wafer includes: controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer bonder to the wafer aligner; controlling the bonded ultra-thin wafer to be aligned and cooled at the wafer aligner; controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer aligner to the stop table; the first wafer grinder grinding head Move to the first stop station to load the bonded ultra-thin wafer from the first stop station onto the grinding head of the first wafer grinder, and grind the bonded ultra-thin wafer once; the first wafer grinder grinding head transfers the bonded ultra-thin wafer from the first wafer grinder to the first stop station; the second wafer grinder grinding head moves to the first stop station to transfer the bonded ultra-thin wafer from the first stop station to the grinding head of the second wafer grinder, and grinds the bonded ultra-thin wafer twice; the second wafer grinder grinding head moves to the second stop station to unload the bonded ultra-thin wafer to the second stop station, and the second transfer robot is controlled to transfer the composite ultra-thin wafer from the second stop station to the wet environment cleaning and drying processing area for wet environment post-grinding cleaning processing.

[0011] In one possible implementation, the wet environment cleaning and drying processing area includes a wafer roller brush, a wafer cleaner, a wafer dryer and a wet environment transfer robot; the bonded ultra-thin wafer is transferred to the flattening processing area for flattening treatment to obtain a processed composite thin wafer, and also includes: controlling the wafer roller brush to perform roller brushing treatment on the bonded ultra-thin wafer; controlling the wet environment transfer robot to transfer the bonded ultra-thin wafer from the wafer roller brush to the wafer cleaner to clean the bonded ultra-thin wafer; controlling the wet environment transfer robot to transfer the bonded ultra-thin wafer from the wafer cleaner to the wafer dryer to dry the bonded ultra-thin wafer, thereby achieving post-flattening cleaning and drying treatment of the bonded ultra-thin wafer to obtain a processed composite thin wafer.

[0012] In one possible implementation, after the flattening treatment, the processed composite sheet is transferred to the post-processing area, and the processed composite sheet is debonded to obtain a carrier sheet and a flattened ultra-thin sheet, including: controlling the second transfer robot to transfer the processed composite sheet from the wafer dryer to the wafer debonder; in the wafer debonder, using a third set temperature, debonding the processed composite sheet to obtain a carrier sheet and a flattened ultra-thin sheet.

[0013] In the second aspect, an embodiment of the present invention provides an ultra-thin wafer flattening process machine, which includes: a pre-processing area, a flattening processing area, a post-processing area, a front-end intelligent transmission FI robot and a transmission robot; the pre-processing area includes a wafer aligner, a wafer laminator, a wafer baker and a wafer bonder; the post-processing area includes a wafer debonder; a wafer carrier box and an ultra-thin wafer box are arranged outside the process machine; the FI robot is adjacent to the wafer carrier box, the ultra-thin wafer box and the wafer aligner, and the FI robot respectively transmits the wafer in the wafer carrier box and the ultra-thin wafer in the ultra-thin wafer box to the wafer aligner for alignment; the transmission robot is adjacent to the wafer aligner, the wafer laminator, the wafer baker and the wafer bonder, and the transmission robot transmits the wafer to the wafer aligner, the wafer laminator, the wafer baker and the wafer bonder and wafer bonder, transfer the ultra-thin wafer to wafer aligner and wafer bonder; the wafer bonder bonds the carrier and the ultra-thin wafer to obtain a bonded ultra-thin wafer; the transfer robot transfers the bonded ultra-thin wafer to the flattening treatment area for flattening treatment to obtain a processed composite thin wafer; after the flattening is completed, the transfer robot transfers the processed composite thin wafer to the wafer debonder in the post-processing area for debonding treatment to obtain a carrier and a flattened ultra-thin wafer; the second transfer robot transfers the carrier to the wafer laminator for degumming, cleaning and drying, and after cleaning and drying, the FI robot transfers the flattened ultra-thin wafer to the ultra-thin wafer box, and the second transfer robot transfers the ultra-thin wafer to the wafer laminator again for degumming, cleaning and drying, and after cleaning and drying, the FI robot transfers the flattened ultra-thin wafer to the ultra-thin wafer box to achieve flattening of the ultra-thin wafer.

[0014] In a possible implementation, the planarization processing area includes a grinding area and a wet environment cleaning and drying processing area; the transfer robot includes a first transfer robot and a second transfer robot; the grinding area includes a first wafer grinder, a second wafer grinder and a first stop table, and a second stop table; the first transfer robot is adjacent to the pre-processing area and the grinding area, and transfers the bonded ultra-thin wafer from the wafer aligner to the first stop table; the first wafer grinder grinding head moves to the first stop table to load the bonded ultra-thin wafer from the first stop table to the first wafer grinder for one grinding; the first wafer grinder grinding head transfers the bonded ultra-thin wafer from the first wafer grinder to the first stop table; the second transfer robot is adjacent to the grinding area and the wet environment cleaning and drying processing area, and transfers the bonded ultra-thin wafer from the second stop table to the wet environment cleaning and drying processing area for wet environment cleaning and drying processing.

[0015] In one possible implementation, the wet environment cleaning and drying processing area includes a wafer roller brush, a wafer cleaner, a wafer dryer and a wet environment transfer robot; the wafer roller brush performs roller brushing on the bonded ultra-thin wafers; the wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer roller brush to the wafer cleaner for cleaning; the wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer cleaner to the wafer dryer for drying.

[0016] The present invention provides a control method and a process machine for an ultra-thin sheet flattening process. Before flattening the ultra-thin sheet, the present invention temporarily bonds the ultra-thin sheet to a carrier at the wafer level inside the machine, and uses the carrier as a structural support for process processing to complete the ultra-thin sheet flattening process; after the flattening is completed, the processing sheet and the carrier are decoupled inside the machine, and after each is cleaned and dried, they are transferred back to their respective crystal boxes, thereby achieving ultra-thin sheet flattening. The present invention reduces the probability of breakage during the ultra-thin sheet flattening process by temporarily bonding and debonding the ultra-thin sheet to the carrier, and improves the processing efficiency and yield rate of the ultra-thin sheet flattening process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a structural schematic diagram of an ultra-thin sheet flattening process machine provided by an embodiment of the present invention;

[0019] Figure 2 It is a flow chart of a control method of an ultra-thin sheet flattening process provided by an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of a process flow of an ultra-thin sheet flattening process provided by an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of a process of ultra-thin sheet bonding provided by an embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of a process of ultra-thin sheet flattening provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0024] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0025] In addition, the terms "including" and "having" and any variations thereof mentioned in the description of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or modules, but may optionally include other steps or modules that are not listed, or may optionally include other steps or modules that are inherent to these processes, methods, products or devices.

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following will be described through specific embodiments in conjunction with the accompanying drawings of the present invention.

[0027] To facilitate the description of the technical solution of the present invention, the technical terms involved in the specific process and principles of the present invention are explained as follows.

[0028] Carrier: Carrier

[0029] Device: Ultra-thin sheet to be processed

[0030] EFEM:Equipment front end module

[0031] FI Robot: Front intelligent robot

[0032] Transfer Robot: Transfer Robot

[0033] WET Robot: Wet Environment Transport Robot

[0034] Aligner: Wafer alignment

[0035] Cooler: Wafer cooling

[0036] Bonder: Wafer bonding

[0037] Baker: Wafer baking

[0038] Coater: Wafer coating

[0039] Cleaner: Wafer cleaning

[0040] Debonder: Wafer debonding

[0041] Dryer: Wafer drying

[0042] Brush: Wafer roller brush

[0043] Pencil: Wafer cleaning wipe

[0044] Polisher: Wafer polisher

[0045] Platen: Wafer grinding plate

[0046] Load port: crystal box loading position

[0047] Wafer Station: Wafer station

[0048] Head: Flattening process grinding head

[0049] DHF: Diluted HF

[0050] SC1: Standard Chemical-1

[0051] SC2: Standard Chemical-2

[0052] TBDB:Temporary Bonding and Debonding

[0053] As described in the background technology, there is a need for planarization of ultra-thin wafers in some wafer-level processing, such as polishing of wafer-level optical wafers such as crystal, ceramic, optical glass, and sapphire. When the wafer thickness processed by the current chemical mechanical planarization process is less than 700um, it is difficult to achieve complete processing during the wafer grinding process due to the wafer thickness being too thin. During the grinding process, the wafer is prone to fragmentation, which causes the grinding pad and grinding head to be contaminated and need to be replaced, forcing the process to be terminated and wasting consumables.

[0054] Since there was less demand for ultra-thin sheet processing in the early days and the technology was quite difficult, there are currently almost no technical solutions or machines that can achieve flattening processing for ultra-thin sheets.

[0055] To solve the above technical problems, Figure 1 As shown, an embodiment of the present invention provides an ultra-thin sheet flattening process machine, which includes a pre-processing area, a flattening processing area, a post-processing area, a front intelligent transfer robot (FI robot) and a transfer robot.

[0056] Exemplarily, in the present invention, the FI Robot and the Transfer Robot: adopt a Bernoulli structure to avoid direct contact with the wafer.

[0057] The pre-processing area includes a wafer aligner (Aligner & cooler), a wafer coater (Coater & cleaner), a wafer baker (Baker) and a wafer bonder (Bonder); the post-processing area includes a wafer debonder (Debonder).

[0058] Exemplarily, the wafer aligner (Aligner & cooler) in the present invention integrates alignment and cooling together to save machine space.

[0059] Exemplarily, the wafer coater & cleaner in the present invention integrates wafer coating and wafer post-debonding cleaning into one, saving machine space; post-debonding cleaning adopts acetone (ACE) / isopropyl alcohol (IPA) or propylene glycol monomethyl ether acetate (PMA) / methyl pyrrolidone (NMP).

[0060] Exemplarily, in the present invention, the wafer baker Baker has a wafer baking temperature range of 100 to 200° C. and a baking time of 1 to 5 minutes.

[0061] Exemplarily, in the present invention, the wafer bonder Bonder has different wafer bonding temperatures according to different bonding adhesive materials, and the bonding temperature is 110 to 250°C.

[0062] Exemplarily, the wafer debonder in the present invention has slightly different wafer debonding temperatures according to different bonding adhesive materials, and the debonding temperature is 150-300° C. After heating to the debonding temperature, the debonding is completed by thermal slide.

[0063] A carrier crystal box and a device crystal box are arranged outside the process machine.

[0064] Exemplarily, the present invention uses four crystal box loading positions (load ports) in the equipment front end module (EFEM); one load port is specifically used to place the wafer carrier crystal box, and the remaining three are used to place the processed wafer boxes, that is, the ultra-thin wafer boxes, or the settings can be changed according to actual needs.

[0065] The FI robot is adjacent to the wafer carrier cassette, the ultra-thin wafer cassette and the wafer aligner. The FI robot transfers the wafer in the wafer carrier cassette and the ultra-thin wafer in the ultra-thin wafer cassette to the wafer aligner for alignment.

[0066] The transfer robot is adjacent to the wafer aligner, wafer laminator, wafer baker and wafer bonder. The transfer robot transfers the carrier to the wafer aligner, wafer laminator, wafer baker and wafer bonder, and transfers the ultra-thin wafer to the wafer aligner and wafer bonder.

[0067] The wafer bonder bonds the carrier wafer and the ultra-thin wafer to obtain a bonded ultra-thin wafer.

[0068] The transfer robot transfers the bonded ultra-thin sheet to the flattening treatment area for flattening treatment to obtain a processed composite sheet.

[0069] After the planarization is completed, the transfer robot transfers the processed composite wafer to the wafer debonder in the post-processing area for debonding to obtain a carrier wafer and a flattened ultra-thin wafer.

[0070] The second transfer robot transfers the carrier to the wafer laminator for degumming, cleaning and drying. After cleaning and drying, the FI robot transfers the carrier to the carrier crystal box. The second transfer robot again transfers the ultra-thin sheet to the wafer laminator for degumming, cleaning and drying. After cleaning and drying, the FI robot transfers the flattened ultra-thin sheet to the ultra-thin sheet crystal box to achieve flattening of the ultra-thin sheet.

[0071] It should be noted that the carrier, as a carrier for carrying ultra-thin sheets for processing and cleaning, has high mechanical rigidity and strength, stable physical and chemical properties, small thermal expansion coefficient and high thickness uniformity within the sheet to ensure the safety of the ultra-thin sheet and avoid warping and cracking of the ultra-thin sheet due to its own thin mechanical thickness. Generally, the shape and size of the carrier are consistent with the ultra-thin sheet to be processed; its thickness is a safe thickness or above to ensure the mechanical strength and rigidity of the carrier.

[0072] In some embodiments, the planarization processing area includes a grinding area and a wet environment cleaning and drying processing area; the transfer robot includes a first transfer robot (Transfer Robot-1) and a second transfer robot (Transfer Robot-2); the grinding area includes a first wafer grinder (Polisher-1), a second wafer grinder (Polisher-1) and a first stop station (Wafer Station-1) and a second stop station (Wafer Station-2).

[0073] For example, the polisher: planarization process module in the present invention adopts a two-platen layout to save machine space. A sliding polishing head is equipped above each platen, which can adsorb the wafer from the wafer station to the polishing head and unload the wafer to the wafer station after the planarization process is completed.

[0074] The first transfer robot is adjacent to the pre-processing area and the grinding area, and transfers the bonded ultra-thin wafer from the wafer aligner to the first stop station; the first wafer grinder grinding head moves to the first stop station to load the bonded ultra-thin wafer from the first stop station to the first wafer grinder for one grinding; the first wafer grinder grinding head transfers the bonded ultra-thin wafer from the first wafer grinder to the first stop station.

[0075] The second transfer robot is adjacent to the wet environment cleaning and drying processing area and the post-processing area, and transfers the composite ultra-thin sheet from the wafer dryer to the debonder; and transfers the debonded carrier and ultra-thin sheet to the wafer coating cleaner for cleaning and drying.

[0076] In some embodiments, the wet environment cleaning and drying processing area includes a wafer roller brush (Brush), a wafer cleaner (Pencil), a wafer dryer (Dryer) and a wet environment transfer robot (WET Robot).

[0077] Exemplarily, in the Cleaner of the present invention, the WET Robot transfers the wafers into the cleaning module after the planarization process, the chemicals used for wafer cleaning include ammonia, DHF, SC1, SC2, etc., the rotation speed of the wafer roller brush (Brush) is 100 to 800 rpm, the rotation speed of the wafer cleaning wipe (Pencil) is 50 to 400 rpm, and the wafer drying (Dryer) uses nitrogen and isopropyl alcohol (IPA).

[0078] The wafer roller brushes the bonded ultra-thin wafers.

[0079] The wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer roller to the wafer cleaner for cleaning.

[0080] The wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer cleaner to the wafer dryer for drying.

[0081] based on Figure 1 The process machines shown are Figure 2 As shown, an embodiment of the present invention provides a control method for an ultra-thin sheet planarization process, and the control method includes steps S11-S16.

[0082] S11, sucking the wafer from the wafer box outside the process machine to the pre-processing area for alignment and lamination, and obtaining the wafer to be bonded with bonding glue attached thereto.

[0083] In some embodiments, the process machine further includes a front intelligent robot (FI robot) and a transfer robot; the pre-processing area includes a wafer aligner, a wafer laminator, a wafer baker and a wafer bonder.

[0084] As a possible implementation, Figure 3 and Figure 4 As shown, step S11 can be specifically implemented as steps S111-S117.

[0085] S111, control the FI robot to take the wafer from the wafer cassette to the wafer aligner.

[0086] S112, controlling the alignment of the wafer carrier on the wafer aligner.

[0087] S113, controlling the transfer robot to transfer the carrier from the wafer aligner to the wafer laminator.

[0088] S114. In the wafer laminator, a spin coating method is used to apply bonding glue on the surface of the carrier to complete the lamination.

[0089] S115, controlling the transfer robot to transfer the wafer from the wafer laminator to the wafer baker.

[0090] S116. In a wafer baker, the coated wafer is baked at a first set temperature for a set time to complete the baking.

[0091] S117, controlling the transfer robot to transfer the baked carrier from the wafer baker to the wafer bonder to obtain the carrier to be bonded with bonding glue attached thereto.

[0092] For example, the wafer bonding pre-processing process: the wafer is the carrier for the ultra-thin wafer, which is first transferred to the Aligner by the FI Robot for alignment before wafer bonding. After alignment, it is transferred to the Coater by the Transfer Robot for cleaning and a layer of bonding glue is applied on the surface of the wafer by spin coating. Then, it is transferred to the Baker by the Transfer Robot for baking to adjust the moisture content of the bonding glue, and then transferred to the Bonder by the Transfer Robot to wait for the ultra-thin wafer to be bonded.

[0093] S12, the ultra-thin wafer is sucked from the ultra-thin wafer box outside the process machine to the pre-processing area for alignment to obtain the ultra-thin wafer to be bonded.

[0094] As a possible implementation, Figure 3 and Figure 4 As shown, step S12 can be specifically implemented as steps S121-S123.

[0095] S121, control the FI robot to suck the ultra-thin wafer from the ultra-thin wafer box to the wafer aligner.

[0096] S122, controlling the alignment of the ultra-thin sheet on a wafer aligner.

[0097] S123, controlling the transfer robot to transfer the ultra-thin sheet from the wafer aligner to the wafer bonder to obtain the ultra-thin sheet to be bonded.

[0098] Exemplary, ultra-thin sheet bonding and pre-processing process: the ultra-thin sheet is sent to the Aligner for alignment via the FI Robot, and after alignment, it is sent to the Bonder via the Transfer Robot for bonding with the carrier.

[0099] S13, bonding the carrier wafer to be bonded and the ultra-thin sheet to be bonded in the pre-treatment area to obtain a bonded ultra-thin sheet.

[0100] As a possible implementation, the embodiment of the present invention can use a second set temperature on a wafer bonder in a pre-processing area to bond a carrier wafer to be bonded and an ultra-thin sheet to be bonded to obtain a bonded ultra-thin sheet.

[0101] S14, transferring the bonded ultra-thin sheet to a planarization treatment area for planarization treatment to obtain a processed composite sheet.

[0102] In some embodiments, the planarization processing area includes a grinding area and a wet environment cleaning and drying processing area, the grinding area includes a first wafer grinder, a second wafer grinder and two stop stations; the transfer robot includes a first transfer robot and a second transfer robot.

[0103] Correspondingly, such as Figure 3 and Figure 5 As shown, step S14 can be specifically implemented as steps S141-S147.1.

[0104] S141, controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer bonder to the wafer aligner; and controlling the alignment and cooling of the bonded ultra-thin wafer in the wafer aligner.

[0105] S142, controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer aligner to the first stop station.

[0106] S143, controlling the first wafer grinder grinding head to move to the first stop position to load the bonded ultra-thin wafer from the first stop position to the first wafer grinder grinding head, and grinding the bonded ultra-thin wafer once.

[0107] S144, controlling the first wafer grinder grinding head to transfer the bonded ultra-thin wafer from the first wafer grinder to the first stop station.

[0108] S145, controlling the grinding head of the second wafer grinder to move to the first stop position to move the bonded ultra-thin wafer from the first stop position to the grinding head of the second wafer grinder, and performing secondary grinding on the bonded ultra-thin wafer.

[0109] S146, control the second wafer grinder grinding head to move to the second stop station to unload the bonded ultra-thin wafer to the second stop station, and control the second transfer robot to transfer the composite ultra-thin wafer from the second stop station to the wet environment cleaning and drying treatment area for wet environment post-grinding cleaning.

[0110] S147.1. Control the wet environment transfer robot to transfer from the second stop station to the wafer roller in the wet environment cleaning and drying processing area for post-cleaning and drying processing.

[0111] In some embodiments, the wet environment cleaning and drying processing area includes a wafer roller brush, a wafer cleaner, a wafer dryer, and a wet environment transfer robot.

[0112] Correspondingly, such as Figure 3 and Figure 5 As shown, step S14 can be specifically implemented as steps S147.2-S149.

[0113] S147.2. Control the wafer roller to perform roller brushing on the bonded ultra-thin wafer.

[0114] S148, controlling the wet environment transfer robot to transfer the bonded ultra-thin wafer from the wafer roller brush to the wafer cleaner to clean the bonded ultra-thin wafer.

[0115] S149, controlling the wet environment transfer robot to transfer the bonded ultra-thin wafer from the wafer cleaner to the wafer dryer, performing drying treatment on the bonded ultra-thin wafer, achieving post-planarization cleaning and drying treatment of the bonded ultra-thin wafer, and obtaining a processed composite wafer.

[0116] S15, after the planarization treatment, the processed composite sheet is transferred to the post-processing area, and the processed composite sheet is debonded to obtain a carrier sheet and a planarized ultra-thin sheet.

[0117] As a possible implementation manner, step S15 can be specifically implemented as steps S151-S152.

[0118] S151, controlling the second transfer robot to transfer the processed composite sheet from the wafer dryer to the wafer debonder.

[0119] S152. In a wafer debonder, use a third set temperature to debond the processed composite wafer to obtain a carrier wafer and a flattened ultra-thin wafer.

[0120] For example, after the ultra-thin wafer is bonded to the carrier wafer, it is flattened (Polisher) and cleaned (Cleaner) before being transferred to the debonder. After debonding, the carrier wafer and the ultra-thin wafer are separated and respectively transferred to the Coater & Cleaner by the Transfer Robot for post-debonding cleaning. After cleaning and drying, they are transferred to the Aligner by the Transfer Robot and then transferred back to their respective wafer boxes by the FI Robot.

[0121] S16, moving the wafer carrier to a wafer carrier box, and moving the flattened ultra-thin sheet to an ultra-thin sheet box to achieve flattening of the ultra-thin sheet.

[0122] The present invention provides a control method for an ultra-thin sheet flattening process. Before the ultra-thin sheet is flattened, the ultra-thin sheet is temporarily bonded to a carrier at the wafer level inside a machine, and the carrier is used as a structural support for process processing to complete the ultra-thin sheet flattening process; after the flattening is completed, the processing sheet and the carrier are decoupled inside the machine, and after each is cleaned and dried, they are transferred back to their respective wafer boxes, thereby achieving ultra-thin sheet flattening. The present invention reduces the probability of breakage during the ultra-thin sheet flattening process by temporarily bonding and debonding the ultra-thin sheet and the carrier, and improves the processing efficiency and yield rate of the ultra-thin sheet flattening process.

[0123] The process machine provided by the present invention can realize the chemical mechanical planarization process for ultra-thin wafers, especially the planarization process for ultra-thin wafers below 700um, and innovatively integrates process modules such as alignment and cooling, coating and cleaning, baking, bonding, debonding, and planarization.

[0124] The process machine of the present invention has a compact layout structure, saves space, fills the gap in the industry, and is the first in the industry. The process machine of the present invention integrates multiple process modules. The process machine not only includes chemical mechanical planarization process (CMP), but also temporary bonding and debonding process (TBDB), so that one machine can be used for multiple purposes.

[0125] The embodiments described above 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A control method for an ultra-thin sheet flattening process, characterized in that: Applied to a process machine, the process machine includes a pre-processing area, a flattening processing area, and a post-processing area, and the control method includes: After the wafer carrier is sucked from the wafer carrier box outside the process machine to the pre-processing area for alignment and lamination, the wafer carrier to be bonded with bonding glue attached thereto is obtained; after the ultra-thin wafer is sucked from the ultra-thin wafer carrier box outside the process machine to the pre-processing area for alignment, the ultra-thin wafer to be bonded is obtained; Bonding the carrier wafer to be bonded and the ultra-thin sheet to be bonded in the pre-treatment area to obtain a bonded ultra-thin sheet; Transferring the bonded ultra-thin sheet to a flattening treatment area for flattening treatment to obtain a processed composite sheet; After the flattening treatment, the processed composite thin sheet is transferred to the post-processing area, and the processed composite thin sheet is debonded to obtain a carrier sheet and a flattened ultra-thin sheet; the carrier sheet is moved to a carrier crystal box, and the flattened ultra-thin sheet is moved to an ultra-thin sheet crystal box to achieve flattening of the ultra-thin sheet.

2. The control method for ultra-thin sheet flattening process according to claim 1, characterized in that: The process machine also includes a front-end intelligent transfer FI robot and a transfer robot; the pre-processing area includes a wafer aligner, a wafer laminator, a wafer baker and a wafer bonder; The method of sucking the wafer from the wafer carrier box outside the process machine to the pre-processing area for alignment and lamination to obtain the wafer to be bonded with bonding glue attached thereto comprises: Control the FI robot to pick up the wafer from the wafer cassette and transfer it to the wafer aligner; Controlling the alignment of the carrier at the wafer aligner; Control the transfer robot to transfer the carrier from the wafer aligner to the wafer laminator; In the wafer laminator, a bonding adhesive is applied to the surface of the carrier wafer by a spin coating method to complete the lamination; Control the transfer robot to transfer the wafer from the wafer laminator to the wafer baker; In the wafer baker, the coated carrier is baked at a first set temperature for a set time to complete the baking; The transfer robot is controlled to transfer the baked carrier from the wafer baker to the wafer bonder to obtain the carrier to be bonded with bonding glue.

3. The control method for ultra-thin sheet flattening process according to claim 2, characterized in that: The method of sucking the ultra-thin wafer from the ultra-thin wafer box outside the process machine to the pre-processing area for alignment to obtain the ultra-thin wafer to be bonded comprises: Control the FI robot to pick up ultra-thin wafers from the ultra-thin wafer box to the wafer aligner; Controlling alignment of the ultra-thin wafer in the wafer aligner; The transfer robot is controlled to transfer the ultra-thin sheet from the wafer aligner to the wafer bonder to obtain the ultra-thin sheet to be bonded.

4. The control method for ultra-thin sheet flattening process according to claim 2, characterized in that: The step of bonding the carrier wafer to be bonded and the ultra-thin sheet to be bonded in the pre-processing area to obtain a bonded ultra-thin sheet comprises: In the wafer bonder, the second set temperature is used to bond the carrier wafer to be bonded and the ultra-thin sheet to be bonded to obtain a bonded ultra-thin sheet.

5. The control method for ultra-thin sheet flattening process according to claim 2, characterized in that: The planarization processing area includes a grinding area and a wet environment cleaning and drying processing area, the grinding area includes a first wafer grinder, a first stop stage, a second wafer grinder and a second stop stage; the transfer robot includes a first transfer robot and a second transfer robot; The method of transferring the bonded ultra-thin sheet to a flattening treatment area for flattening to obtain a processed composite sheet includes: Controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer bonder to the wafer aligner; The wafer aligner controls the alignment and cooling of the bonded ultra-thin wafers; Controlling the first transfer robot to transfer the bonded ultra-thin wafer from the wafer aligner to the stop station; The first wafer grinder grinding head moves to the first stop position platform to load the bonded ultra-thin wafer from the first stop position platform onto the first wafer grinder grinding head, and grinds the bonded ultra-thin wafer once; The first wafer grinder grinding head transfers the bonded ultra-thin wafer from the first wafer grinder to the first stop station; The second wafer grinder grinding head moves to the first stop position to move the bonded ultra-thin wafer from the first stop position to the second wafer grinder grinding head to perform secondary grinding on the bonded ultra-thin wafer; The grinding head of the second wafer grinder moves to the second stop position to unload the bonded ultra-thin wafer to the second stop position, and the second transfer robot is controlled to transfer the composite ultra-thin wafer from the second stop position to the wet environment cleaning and drying processing area for wet environment post-grinding cleaning processing.

6. The control method for ultra-thin sheet flattening process according to claim 5, characterized in that: The wet environment cleaning and drying processing area includes a wafer rolling brush, a wafer cleaner, a wafer dryer and a wet environment transfer robot; the bonding ultra-thin wafer is transferred to the flattening processing area for flattening to obtain a processed composite wafer, and further includes: Control the wafer roller to perform roller brushing on the bonded ultra-thin wafers; Control the wet environment transfer robot to transfer the bonded ultra-thin wafers from the wafer roller brush to the wafer cleaner to clean the bonded ultra-thin wafers; The wet environment transfer robot is controlled to transfer the bonded ultra-thin wafer from the wafer cleaner to the wafer dryer, and the bonded ultra-thin wafer is dried to achieve post-planarization cleaning and drying of the bonded ultra-thin wafer to obtain a processed composite wafer.

7. The control method for ultra-thin sheet flattening process according to claim 1, characterized in that: After the flattening treatment, the treated composite sheet is transferred to a post-processing area, and the treated composite sheet is debonded to obtain a carrier sheet and a flattened ultra-thin sheet, including: Controlling the second transfer robot to transfer the processed composite sheet from the wafer dryer to the wafer debonder; In the wafer debonder, the third set temperature is used to debond the processed composite wafer to obtain a carrier wafer and a flattened ultra-thin wafer.

8. An ultra-thin sheet flattening process machine, characterized in that: The process machine includes a pre-processing area, a flattening processing area, a post-processing area, a front-end intelligent conveying FI robot and a conveying robot; the pre-processing area includes a wafer aligner, a wafer laminator, a wafer baker and a wafer bonder; the post-processing area includes a wafer debonder; a wafer carrier box and an ultra-thin wafer box are arranged outside the process machine; The FI robot is adjacent to the wafer carrier cassette, the ultra-thin wafer cassette and the wafer aligner. The FI robot transfers the wafer in the wafer carrier cassette and the ultra-thin wafer in the ultra-thin wafer cassette to the wafer aligner for alignment. The transfer robot is adjacent to the wafer aligner, the wafer laminator, the wafer baker and the wafer bonder, and the transfer robot transfers the carrier to the wafer aligner, the wafer laminator, the wafer baker and the wafer bonder, and transfers the ultra-thin wafer to the wafer aligner and the wafer bonder; The wafer bonder bonds the carrier wafer and the ultra-thin wafer to obtain a bonded ultra-thin wafer; The transfer robot transfers the bonded ultra-thin sheet to the flattening treatment area for flattening treatment to obtain a processed composite sheet; After the planarization is completed, the transfer robot transfers the processed composite wafer to the wafer debonder in the post-processing area for debonding to obtain a carrier wafer and a planarized ultra-thin wafer; The second transfer robot transfers the carrier to the wafer laminator for degumming, cleaning and drying. After cleaning and drying, the FI robot transfers the carrier to the carrier crystal box. The second transfer robot again transfers the ultra-thin sheet to the wafer laminator for degumming, cleaning and drying. After cleaning and drying, the FI robot transfers the flattened ultra-thin sheet to the ultra-thin sheet crystal box to achieve flattening of the ultra-thin sheet.

9. The ultra-thin sheet flattening process machine according to claim 8, characterized in that: The planarization processing area includes a grinding area and a wet environment cleaning and drying processing area; the transfer robot includes a first transfer robot and a second transfer robot; the grinding area includes a first wafer grinder, a second wafer grinder and a first stop position platform and a second stop position platform; The first transfer robot is adjacent to the pre-processing area and the grinding area, and transfers the bonded ultra-thin wafer from the wafer aligner to the first stop station; the first wafer grinder grinding head moves to the first stop station to load the bonded ultra-thin wafer from the first stop station to the first wafer grinder for one grinding; the first wafer grinder grinding head transfers the bonded ultra-thin wafer from the first wafer grinder to the first stop station; The second transfer robot is adjacent to the grinding area and the wet environment cleaning and drying processing area, and transfers the bonded ultra-thin wafer from the second stop position to the wet environment cleaning and drying processing area for wet environment cleaning and drying processing.

10. The ultra-thin sheet flattening process machine according to claim 8, characterized in that: The wet environment cleaning and drying processing area includes a wafer rolling brush, a wafer cleaner, a wafer dryer and a wet environment transfer robot; The wafer roller brushes the bonded ultra-thin wafers; The wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer roller to the wafer cleaner for cleaning; The wet environment transfer robot transfers the bonded ultra-thin wafers from the wafer cleaner to the wafer dryer for drying.

Images