Manual wafer thinning and peeling jig and method

Abstract

The application discloses a thin wafer manual peeling jig, which comprises a handle, and a storage tray is fixed at one end of the handle; and a detachable multi-hole slide is arranged on the storage tray. The application further discloses a method for peeling using the thin wafer manual peeling jig, which comprises the following steps: firstly, fixing the multi-hole slide and the thin wafer on the storage tray; secondly, placing the peeling jig with the fixed thin wafer into a peeling liquid for ultrasonic peeling, and further soaking, cleaning and water removing to obtain a peeled wafer; and finally, checking the peeled wafer through a microscope. The thin wafer manual peeling jig has the advantages of simple structure, convenient disassembly and assembly, compatibility with thin wafers of different sizes and regular or irregular shapes, and the ability to guarantee a better peeling effect without wafer breakage.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor wafer stripping technology, specifically relating to a manual wafer stripping fixture for thinning wafers, and also to a stripping method using the manual wafer stripping fixture for thinning wafers. Background Technology

[0002] As is well known, wafer lift-off is a crucial step in semiconductor wafer fabrication. For thinned wafers, vacuum spin-coating lift-off is commonly used, but this method has two drawbacks: high equipment cost and poor equipment versatility, only applicable to wafers of specific sizes. To reduce the cost of wafer lift-off, manual lift-off can be used. In manual lift-off, the lift-off fixture is critical; an unsuitable fixture often leads to wafer breakage or metal re-adhesion, resulting in poor lift-off performance. Therefore, there is an urgent need to design a manual wafer lift-off fixture that combines superior lift-off performance with high versatility. Summary of the Invention

[0003] The purpose of this invention is to provide a manual wafer stripping fixture for thinning wafers, which solves the problems of poor versatility and unsatisfactory stripping effect of existing manual wafer stripping fixtures.

[0004] Another object of the present invention is to provide a stripping method for the above-mentioned manual stripping fixture for thinning wafers.

[0005] The technical solution adopted in this invention is a wafer thinning manual stripping fixture, including a handle, a tray fixed to one end of the handle, and a detachable porous substrate on the tray.

[0006] Another technical solution adopted in this invention is a manual wafer thinning and peeling method, which uses the aforementioned manual wafer thinning and peeling fixture and specifically includes the following steps:

[0007] Step 1: Select a matching porous carrier according to the outer dimensions of the thinned wafer, align the edges of the porous carrier and the thinned wafer in sequence, place them on the tray, and fix them with bolts with soft washers through the nearest threaded holes.

[0008] Step 2: Slowly and vertically place the wafer stripping fixture, which has fixed the wafer to be stripped in Step 1, into the stripping solution and perform ultrasonic stripping to obtain wafer A.

[0009] Step 3: Immerse and clean wafer A from step 2 to obtain wafer B;

[0010] Step 4: Remove the bolts and transfer the porous carrier and wafer B to the oven to remove water, thus obtaining the stripped wafer;

[0011] Step 5: Examine the stripped wafer using a microscope.

[0012] The invention is further characterized in that,

[0013] The surface of the storage tray is marked with size markings, and the tray also has several threaded holes and several evenly distributed drainage holes.

[0014] The size markings include several concentric circles centered on the center of the tray, with diameters of 2 inches, 3 inches, 4 inches, 6 inches, 8 inches, and 12 inches.

[0015] The circular opening of the threaded hole is externally tangent to the scale line of the size mark, and the threaded hole is a threaded blind hole.

[0016] The storage tray also includes several bolts that mate with threaded holes. Each bolt is equipped with a soft washer. After the bolt is tightened with the threaded hole, there is a safe stopping distance, which is the distance between the end of the bolt head closest to the storage tray and the surface of the storage tray.

[0017] The dimensions of the porous substrate match the dimensions of the wafer to be stripped, and the thickness of the porous substrate is consistent with the safe stopping distance of the bolts.

[0018] The handle and tray are made of acid and alkali resistant and organic corrosion resistant materials, and the porous carrier is made of silicon carbide or ceramic.

[0019] The acid and alkali resistant and organic corrosion resistant material is any one of Teflon, nylon, polypropylene, polyvinylidene fluoride or polytetrafluoroethylene.

[0020] The ultrasonic stripping process in step 2 involves ultrasonic stripping in NMP stripping solution for 5-15 minutes, with an ultrasonic power of 300W and a current of 0.5-1.2A. The soaking and cleaning process in step 3 involves soaking and cleaning in isopropanol solution and deionized water for 5-10 minutes respectively. The dehydration process in step 4 involves dehydrating in a 70-100℃ oven purged with hot nitrogen for 5-10 minutes.

[0021] The beneficial effects of this invention are:

[0022] (1) The thinning wafer manual stripping fixture of the present invention has a simple structure and is easy to disassemble and assemble. It uses multiple sets of threaded holes and bolts with soft washers to fix the thinning wafer, which can prevent the thinning wafer from falling off during the stripping process and avoid hard damage to the surface of the thinning wafer.

[0023] (2) The thinning wafer manual stripping fixture of the present invention is provided with multiple threaded holes at different sizes, so that the stripping fixture can fix the thinning wafer nearby, thereby being compatible with regular or irregular thinning wafers of different sizes, and thus improving the versatility of the stripping fixture.

[0024] (3) The thinning wafer manual stripping fixture of the present invention can ensure a better stripping effect without breaking the thinning wafer. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the manual wafer thinning and peeling fixture of the present invention;

[0026] Figure 2 This is a process flow diagram of the manual wafer thinning and peeling method of the present invention;

[0027] Figure 3 This is a microscopic image of the wafer stripped in Embodiment 1 of the present invention.

[0028] In the diagram: 1. Handle, 2. Storage tray, 2-1. Size marking, 2-2. Threaded hole, 2-3. Drain hole, 2-4. Bolt, 2-41. Soft washer. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] The structure of the manual wafer thinning lift fixture of this invention is as follows: Figure 1 As shown, the device includes a handle 1, with a tray 2 fixed to one end of the handle 1. The tray 2 has a removable porous carrier plate. Both the handle 1 and the tray 2 are made of acid- and alkali-resistant and organic corrosion-resistant materials, preferably any one of Teflon, nylon, polypropylene, polyvinylidene fluoride, or polytetrafluoroethylene; the porous carrier plate is made of silicon carbide or ceramic.

[0031] The surface of the storage tray 2 is provided with size markings 2-1, which include several scale lines arranged in concentric circles with the center of the storage tray 2 as the center. The diameters of the scale lines are 2 inches, 3 inches, 4 inches, 6 inches, 8 inches and 12 inches, so as to accommodate the stripping operation of wafers of different sizes.

[0032] The tray 2 is also provided with several threaded holes 2-2 and several bolts 2-4 that mate with the threaded holes 2-2. Each bolt 2-4 is equipped with a soft washer 2-41. The circular opening of the threaded hole 2-2 is externally tangent to the scale line of the size mark 2-1. This ensures that after the threaded hole 2-2 and the bolt 2-4 are tightened, the head of the bolt 2-4 can be fixed to the porous carrier and the thinned wafer by snap-fit. This ensures that the thinned wafer is peeled off in a vertical position. At the same time, since the tray 2 is provided with multiple externally tangent threaded holes 2-2 at different scale line positions, the peeling fixture can select the nearest threaded hole 2-2 to fix the porous carrier and the thinned wafer, thereby being compatible with regular or irregular thinned wafers of different sizes and improving the versatility of the peeling fixture. In addition, the present invention uses the deformation of the soft washer 2-41 to fix the thinned wafer, which on the one hand ensures that the thinned wafer does not fall off during the stripping operation, and on the other hand avoids hard contact between the thinned wafer and the bolt 2-4, effectively preventing damage or even breakage of the thinned wafer during the stripping operation; in addition, the threaded hole 2-2 of the stripping fixture is a threaded blind hole, and when the bolt 2-4 is tightened in conjunction with the threaded hole 2-2, there is a safe stopping distance between the end of the bolt 2-4 near the storage tray 2 and the surface of the storage tray 2.

[0033] Considering the strong adsorption between the porous wafer and the storage tray 2 during the stripping operation, which increases the difficulty of removing the porous wafer and the thinned wafer, and may even cause damage or breakage of the thinned wafer due to improper operation during the removal process, the storage tray 2 of the present invention is also provided with several evenly distributed water-permeable holes 2-3. The water-permeable holes 2-3 allow air to circulate, which facilitates the subsequent removal of the porous wafer and the thinned wafer from the storage tray 2 intact and smoothly.

[0034] Thinned wafers are relatively thin, and when directly fixed to the stripping fixture and stripped in the stripping solution, their sides are prone to breakage due to solution pressure. To reduce the impact of solution pressure on the thinned wafers, this invention incorporates a porous carrier to support them. The carrier's dimensions match the wafer's dimensions. Simultaneously, the porous carrier prevents the wafer from breaking due to water adsorption during subsequent removal when directly fixed to the tray 2. Furthermore, the porous nature of the carrier facilitates faster evaporation of moisture from the side of the wafer in contact with it during subsequent dehydration. Additionally, the thickness of the porous carrier matches the safe stopping distance of bolts 2-4, reducing operator error and preventing damage to the wafer due to overtightening or detachment of the carrier and wafer from the fixture during stripping. This facilitates the standardized application of thinned wafer stripping procedures.

[0035] In summary, the manual wafer stripping fixture of the present invention has a simple structure, is easy to assemble and disassemble, can be compatible with wafers of different sizes, whether regular or irregular, and can ensure a better stripping effect without breaking the wafer.

[0036] The peeling method using the above-mentioned manual wafer thinning peeling fixture, such as Figure 2 As shown, the specific steps include:

[0037] Step 1: Select a matching porous carrier according to the outer dimensions of the thinned wafer, align the edges of the porous carrier and the thinned wafer in sequence, place them on the tray 2, and fix them with bolts 2-4 with soft washers 2-41 through the nearest multiple threaded holes 2-2.

[0038] Step 2: Slowly and vertically place the stripping jig with the thinned wafer fixed in Step 1 into the NMP stripping solution and perform ultrasonic stripping for 5-15 minutes to obtain wafer A, wherein the ultrasonic power is 300W and the current is 0.5-1.2A.

[0039] Step 3: Immerse and clean wafer A from step 2 in isopropanol solution and deionized water for 5-10 minutes respectively to obtain wafer B;

[0040] Step 4: Remove bolts 2-4, transfer the porous substrate and wafer B to a 70-100℃ oven purged with hot nitrogen to remove moisture for 5-10 minutes, and obtain the stripped wafer;

[0041] Step 5: Examine the stripped wafer using a microscope.

[0042] Using the wafer thinning manual stripping fixture of the present invention, and through the stripping method described above, the wafer thinning stripping operation can be completed conveniently and effectively.

[0043] Example 1

[0044] The present invention provides a manual wafer thinning stripping fixture comprising a handle 1, a tray 2 fixed to one end of the handle 1, and a detachable porous substrate on the tray 2. The handle 1 and the tray 2 are both made of Teflon, and the porous substrate is made of silicon carbide.

[0045] The above-described manual wafer stripping fixture is used to strip irregularly thinned wafers with a diameter of 6 inches. The specific steps include:

[0046] Step 1: Select a porous substrate with the same dimensions as the thinned wafer. Place the porous substrate and the thinned wafer on the tray 2 with their edges aligned. Secure them by multiple threaded holes 2-2 on the tray 2 that are tangent to the 2-6 inch scale lines and close to the edge of the thinned wafer, and by bolts 2-4 with soft washers 2-41 that mate with them.

[0047] Step 2: Slowly and vertically place the stripping jig with the thinned wafer fixed in Step 1 into the NMP stripping solution and perform ultrasonic stripping for 10 minutes to obtain wafer A, wherein the ultrasonic power is 300W and the current is 0.7A.

[0048] Step 3: Immerse and clean wafer A from step 2 in isopropanol solution and deionized water for 7 minutes each to obtain wafer B;

[0049] Step 4: Remove bolts 2-4, transfer the porous substrate and wafer B to an 85°C oven purged with hot nitrogen to remove moisture for 7 minutes, and obtain the stripped wafer;

[0050] Step 5: Examine the stripped wafer using a microscope.

[0051] The microscopic image of the wafer after peeling in this embodiment is shown below. Figure 3 As shown in the figure, the 6-inch irregular thinned wafer was effectively peeled off without breaking the wafer, and there was no metal re-adhesion phenomenon in the peeled wafer.

[0052] Example 2

[0053] The present invention provides a manual wafer thinning stripping fixture comprising a handle 1, a tray 2 fixed to one end of the handle 1, and a detachable porous carrier plate disposed on the tray 2. The handle 1 is made of nylon, the tray 2 is made of polypropylene, and the porous carrier plate is made of ceramic.

[0054] The above-described manual wafer stripping fixture is used to strip a regular 2-inch diameter thinned wafer, specifically including the following steps:

[0055] Step 1: Select a porous substrate with the same dimensions as the thinned wafer. Place the porous substrate and the thinned wafer on the tray 2 with their edges aligned. Secure them with multiple threaded holes 2-2 on the tray 2 that are externally tangent to the 2-inch mark and bolts 2-4 with soft washers 2-41 that mate with them.

[0056] Step 2: Slowly and vertically place the stripping jig with the thinned wafer fixed in Step 1 into the NMP stripping solution and perform ultrasonic stripping for 5 minutes to obtain wafer A, wherein the ultrasonic power is 300W and the current is 1.2A.

[0057] Step 3: Immerse and clean wafer A from step 2 in isopropanol solution and deionized water for 5 minutes each to obtain wafer B;

[0058] Step 4: Remove bolts 2-4, transfer the porous substrate and wafer B to a 70°C oven purged with hot nitrogen to remove moisture for 10 minutes, and obtain the stripped wafer;

[0059] Step 5: Examine the stripped wafer using a microscope.

[0060] Example 3

[0061] The present invention provides a manual wafer stripping fixture for thinning wafers, comprising a handle 1, a tray 2 fixed to one end of the handle 1, and a detachable porous carrier plate on the tray 2. The handle 1 is made of polyvinylidene fluoride, the tray 2 is made of polytetrafluoroethylene, and the porous carrier plate is made of silicon carbide.

[0062] The above-described manual wafer stripping fixture is used to strip a regular 12-inch diameter wafer, specifically including the following steps:

[0063] Step 1: Select a porous carrier with the same shape and size as the wafer to be thinned. Place the porous carrier and the wafer to be stripped on the tray 2 with their edges aligned. Secure them with multiple threaded holes 2-2 on the tray 2 that are externally tangent to the 12-inch mark and bolts 2-4 with soft washers 2-41 that mate with them.

[0064] Step 2: Slowly and vertically place the stripping jig that fixed the thinned wafer in Step 1 into the NMP stripping solution and perform ultrasonic stripping for 15 minutes to obtain wafer A. The ultrasonic power is 300W and the current is 0.5A.

[0065] Step 3: Immerse and clean wafer A from step 2 in isopropanol solution and deionized water for 10 minutes each to obtain wafer B;

[0066] Step 4: Remove bolts 2-4, transfer the porous substrate and wafer B to a 100°C oven purged with hot nitrogen to remove moisture for 5 minutes, and obtain the stripped wafer;

[0067] Step 5: Examine the stripped wafer using a microscope.

Claims

1. A manual wafer stripping method for thinning wafers, characterized in that, The manual wafer stripping fixture used for thinning wafers includes the following steps: Step 1: Select a matching porous substrate according to the outer dimensions of the thinned wafer, align the edges of the porous substrate and the thinned wafer in sequence, place them on the tray (2), and fix them by using the nearest multiple threaded holes (2-2) and bolts (2-4) with soft washers (2-41); Step 2: Slowly and vertically place the wafer stripping fixture, which has fixed the wafer to be stripped in Step 1, into the stripping solution and perform ultrasonic stripping to obtain wafer A. The ultrasonic stripping process specifically involves ultrasonic stripping in NMP stripping solution for 5-15 minutes, wherein the ultrasonic power is 300W and the current is 0.5-1.2A. Step 3: Immerse and clean wafer A from step 2 to obtain wafer B; The soaking and cleaning process described in step 3 specifically involves soaking and cleaning in isopropanol solution and deionized water for 5-10 minutes respectively. Step 4: Remove bolts (2-4), transfer the porous carrier and wafer B to the oven to remove water, and obtain the stripped wafer; The water removal process described in step 4 specifically involves removing water in a 70-100℃ oven purged with hot nitrogen for 5-10 minutes. Step 5: Inspect the removed wafer using a microscope; The thinning wafer manual stripping fixture includes a handle (1), one end of which is fixed with a tray (2), and the tray (2) is provided with a detachable porous substrate. The surface of the storage tray (2) is provided with size markings (2-1), and the storage tray (2) is also provided with a number of threaded holes (2-2) and a number of evenly distributed water-permeable holes (2-3). The size markings (2-1) include several scale lines arranged in concentric circles with the center of the tray (2) as the center, and the diameters of the scale lines are 2 inches, 3 inches, 4 inches, 6 inches, 8 inches and 12 inches respectively; The circular opening of the threaded hole (2-2) is externally tangent to the scale line of the dimension mark (2-1), and the threaded hole (2-2) is a threaded blind hole; The storage tray (2) also includes a number of bolts (2-4) that mate with the threaded holes (2-2). Each bolt (2-4) is equipped with a soft washer (2-41). After the bolt (2-4) is tightened in conjunction with the threaded holes (2-2), it has a safe stopping distance. The safe stopping distance is the distance between the end of the bolt (2-4) head that is close to the storage tray (2) and the surface of the storage tray (2). The dimensions of the porous carrier are matched with the dimensions of the wafer to be stripped, and the thickness of the porous carrier is consistent with the safe stopping distance of the bolts (2-4). The handle (1) and the tray (2) are both made of acid and alkali resistant and organic corrosion resistant materials, and the porous carrier is made of silicon carbide or ceramic. The acid and alkali resistant and organic corrosion resistant material is any one of Teflon, nylon, polypropylene, polyvinylidene fluoride or polytetrafluoroethylene.

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