CN217134323U

CN217134323U - Localized wet etching fence assembly

Info

Publication number: CN217134323U
Application number: CN202220537967.3U
Authority: CN
Inventors: 何光泽; 林于腾; 方军捷; 黄益沧
Original assignee: Hongkang Technology Testing Shanghai Co ltd
Current assignee: Hongkang Technology Testing Shanghai Co ltd
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2022-08-05
Anticipated expiration: 2032-03-11

Abstract

The application relates to the technical field of wet etching, in particular to a localized wet etching fence assembly, which comprises a fence in a closed loop arrangement, wherein the bottom end of the fence is fixedly connected to a region to be etched on the surface of a wafer, and etching solution is injected into the inner side of the fence. The wafer thinning efficiency can be improved, and the wafer thinning cost is reduced.

Description

Localized wet etching fence assembly

Technical Field

The present disclosure relates to wet etching, and particularly to a localized wet etching fence assembly.

Background

In wafer Failure Analysis (FA), there is often a need to reduce the thickness of the wafer (back thinning) in order to sample the defect area and observe it in the form of an SEM or TEM image after FIB trimming. At present, for thinning the wafer thickness, a whole grinding mode is often adopted.

In view of the above-mentioned related technologies, the inventor believes that the thinning method of the overall grinding of the wafer requires a grinding machine, which is relatively expensive in use and time-consuming in operation, and the thinning method of the overall grinding of the wafer has the defects of time and labor waste and relatively high cost.

SUMMERY OF THE UTILITY MODEL

To improve the efficiency and reduce the cost of wafer thinning, the present application provides a localized wet etch fence assembly.

The application provides a localized wet etching rail subassembly adopts following technical scheme:

a localized wet etching fence assembly comprises a fence which is arranged in a closed loop, the bottom end of the fence is fixedly connected to a region to be etched on the surface of a wafer, and etching solution is injected into the inner side of the fence.

Through adopting above-mentioned technical scheme, frame specific etching region at the wafer surface through the rail to local etching has been reduced the influence of etching operation to other regions of wafer, compares in the wafer attenuate mode of grinding, adopts the wet etching mode simple operation of etching solution, has faster wafer attenuate speed, and the cost is lower, thereby has effectively improved the efficiency of wafer attenuate and has reduced the cost of wafer attenuate.

Preferably, the enclosure is made of ceramic or acid resistant material.

By adopting the technical scheme, the fence made of the ceramic or acid-resistant material can weaken the corrosion of the etching solution to the fence, so that the service life of the fence is prolonged.

Preferably, the bottom end of the fence is fixedly connected with a connecting folding edge, the connecting folding edge is positioned on the outer side of the fence, and the connecting folding edge is fixedly connected to the surface of the wafer.

Through adopting above-mentioned technical scheme, the setting of connecting the hem has increased the area of contact between rail and wafer surface to the stability of being connected between rail and wafer has been improved.

Preferably, the connecting folding edge is made of transparent materials, and a UV adhesive layer is arranged between the connecting folding edge and the surface of the wafer.

Through adopting above-mentioned technical scheme, it is fixed through the UV glue film to connect between hem and wafer, and the UV glue film solidifies after the ultraviolet ray shines to realize connecting the fixed connection between hem and wafer, the connection hem made by transparent material is convenient for ultraviolet ray shines in the UV glue film.

Preferably, the localized wet etch pen assembly further comprises a liquid transfer member for withdrawing liquid from the inside of the pen.

By adopting the technical scheme, in the etching operation, acid adding and acid discharging are required to be repeated for a plurality of times to the inner side of the fence, acid with higher concentration is injected into the inner side of the fence, acid with lower concentration is discharged from the inner side of the fence through the liquid transfer assembly after a proper time, the acid adding and acid discharging processes are repeated until the etching target depth is reached, and after the etching operation is completed, the liquid transfer component is also used for injecting clear water into the inner side of the fence to dilute the acid remained on the surface of the wafer, and the cleaning operation of the surface of the etching area and the liquid transfer component is completed for a plurality of times.

Preferably, the liquid transfer component comprises a water pumping ball, two ends of the water pumping ball are respectively communicated with a hose, and the water pumping ball and the hose are both made of acid and alkali resistant materials.

By adopting the technical scheme, the working personnel use the water pumping ball and the hose to transfer liquid on the inner side and the outer side of the fence, and the water pumping ball and the hose made of acid and alkali resistant materials can reduce the corrosion of the etching solution to the water pumping ball and the hose.

Preferably, the inner side wall of the fence is slidably provided with a lining tube, the sliding direction of the lining tube is perpendicular to the surface of the wafer, and the bottom end of the lining tube abuts against the wafer.

By adopting the technical scheme, when the wafer is etched by the etching solution successively, the depth of the etching area is gradually increased, the worker can gradually slide the inner bushing towards the bottom of the etching area, and the inner bushing is abutted against the bottom of the etching area before each etching to protect the peripheral side of the etching area, reduce the etching of the etching solution to the peripheral side of the etching area, and can guide the etching solution to etch the wafer towards the depth direction of the etching area.

Preferably, the height of the lining cylinder is greater than that of the rail, the difference between the heights of the rail and the lining cylinder is equal to the target depth of the etching area, one end of the lining cylinder, which is far away from the wafer, is provided with a positioning folded edge, and when the bottom end of the lining cylinder extends to the target depth of the etching area, the positioning folded edge abuts against the top end of the rail.

By adopting the technical scheme, the height of the lining barrel is greater than that of the fence, the difference value is equal to the target depth of the etching area, and when the etching depth of the etching area reaches the target depth, the positioning folding edge abuts against the top end of the fence, so that a worker can timely obtain the information of the etching target depth.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the specific etching area is framed on the surface of the wafer through the fence so as to facilitate local etching, thereby reducing the influence of etching operation on other areas of the wafer, compared with a grinding wafer thinning mode, the wet etching mode adopting the etching solution is simple to operate, has higher wafer thinning speed and lower cost, thereby effectively improving the wafer thinning efficiency and reducing the wafer thinning cost;

2. the arrangement of the connecting folding edge increases the contact area between the rail and the surface of the wafer, thereby improving the connection stability between the rail and the wafer;

3. when the etching solution etches the wafer successively, the depth of the etching area is increased gradually, and workers can slide the inner lining sleeve towards the bottom of the etching area gradually, and the inner lining sleeve is abutted against the bottom of the etching area before each etching so as to protect the peripheral side of the etching area, reduce the etching of the etching solution on the peripheral side of the etching area, and can guide the etching solution to etch the wafer towards the depth direction of the etching area.

Drawings

FIG. 1 is a schematic view of the overall structure of embodiment 1;

FIG. 2 is a cross-sectional view at the fence of example 2 to show the position and structure of the inner liner.

Reference numerals: 0. a wafer; 1. a fence; 2. connecting and folding edges; 3. a UV adhesive layer; 4. a liquid transfer member; 41. a water pumping ball; 42. a hose; 5. a liquid storage barrel; 6. a liner barrel; 61. and (6) positioning and folding edges.

Detailed Description

The present application is described in further detail below with reference to fig. 1-2.

The embodiment of the application discloses a localized wet etching fence component.

Example 1:

referring to fig. 1, the localized wet etching fence assembly includes a fence 1 disposed on the wafer backside of a wafer 0, wherein the wafer 0 is disposed in a rectangular sheet shape and horizontally disposed with the wafer backside facing upward. In the embodiment of the present application, the fence 1 is set to be rectangular frame-shaped, and the height direction of the fence 1 is vertical.

The bottom of rail 1 is provided with connects hem 2, connects 2 levels of hem and sets up to the lateral wall of establishing in rail 1 bottom, rail 1's bottom fixed connection is in connecting hem 2.

Referring to fig. 1, a UV adhesive layer 3 is disposed between the connection flange 2 and the surface of the wafer 0, and the connection flange 2 is made of a transparent material, in the embodiment of the present application, the connection flange 2 is made of organic glass. The staff coats the bottom at connection hem 2 with UV glue to connect hem 2 and set up on the area of treating the etching on wafer 0 surface, use ultraviolet ray irradiation UV glue film 3, so that UV glue film 3 solidifies, in order to realize the firm setting of rail 1 on wafer 0.

The arrangement of the connecting folding edge 2 increases the contact area between the rail 1 and the wafer 0, and can improve the connection stability between the rail 1 and the wafer 0.

The inner side of the fence 1 is filled with an etching solution, and the wafer 0 back side in the etching area defined by the fence 1 is wet-etched by the etching solution. Compared with the grinding 0 wafer thinning mode, the wet etching 0 wafer thinning mode has simple operation, higher 0 wafer thinning speed and lower cost, thereby effectively improving the 0 wafer thinning efficiency and reducing the 0 wafer thinning cost.

The enclosure 1 is made of ceramic or acid-resistant material. The fence 1 made of ceramic or acid-resistant material can reduce corrosion of the fence 1 by etching solution to improve the service life of the fence 1.

Referring to fig. 1, a liquid transferring member 4 is further disposed on one side of the enclosure 1, and a liquid storage barrel 5 is disposed on one side of the liquid transferring member 4 away from the enclosure 1. The liquid transfer component 4 comprises a water pumping ball 41 and two hoses 42, wherein two hoses 42 are arranged, two ends of one hose 42 are respectively communicated to the inside of the water pumping ball 41 and the inner side of the fence 1, and two ends of the other hose 42 are respectively communicated to the inside of the water pumping ball 41 and the inside of the liquid storage barrel 5. The water pumping ball 41 and the hose 42 are made of acid and alkali resistant materials to reduce corrosion of the water pumping ball 41 and the hose 42 by the etching solution, and in the embodiment of the present invention, the water pumping ball 41 is made of teflon (polytetrafluoroethylene).

The implementation principle of the embodiment 1 is as follows:

and coating UV glue at the bottom of the connecting flange 2, and irradiating the UV glue layer 3 by using ultraviolet light after the position of the fence 1 is determined so as to solidify the UV glue.

Since the etching effect is easily saturated by a trace amount of acid solution, the wet etching operation is performed in multiple steps.

In each step of wet etching operation, an etching solution with a higher concentration is injected into the inner side of the rail 1 for wet etching. After a suitable time, the etching solution with a lower concentration is pumped out of the inside of the enclosure 1 through the water pumping ball 41 and the hose 42 and discharged into the liquid storage barrel 5.

And repeating the steps until the etching depth of the etching area reaches the target depth.

Clean water is then injected into the enclosure 1 to dilute the residual acid on the surface of the wafer 0, and this process is repeated several times to complete the cleaning of the etched area surface and the water-pumping ball 41 and hose 42.

The enclosure 1 is removed from the wafer 0 by means of a heat treatment.

Example 2:

referring to fig. 2, the difference between the embodiment and the embodiment 1 is that the inner sidewall of the fence 1 is slidably provided with a lining tube 6, the lining tube 6 is disposed in a square tube shape, and the sliding direction of the lining tube 6 is perpendicular to the surface of the wafer 0. The height of the lining cylinder 6 is larger than that of the fence 1, and the difference between the height of the lining cylinder 6 and the height of the fence 1 is equal to the target depth of the etching area. The top end of the lining tube 6 extends outwards to form a positioning folding edge 61, and the positioning folding edge 61 is integrally arranged at the top end of the lining tube 6.

The implementation principle of the embodiment 2 is as follows:

In each step of wet etching operation, an etching solution with a higher concentration is injected into the inner side of the rail 1 for wet etching. After a suitable time, the etching solution with a lower concentration is pumped out of the inside of the enclosure 1 through the water pumping ball 41 and the hose 42 and discharged into the liquid storage barrel 5. At this time, the etching depth of the etching region is further increased, the liner 6 is slid downward, and the bottom end of the liner 6 abuts against the bottom of the etching region to protect the periphery of the etching region, thereby reducing the etching of the etching solution to the periphery of the etching region, and guiding the etching solution to etch the wafer 0 in the depth direction of the etching region.

And repeating the steps until the etching depth of the etching area reaches the target depth. At this time, the positioning flange 61 abuts against the top end of the fence 1, so that the worker can timely obtain the information that the etching target depth has been reached.

The enclosure 1 is removed from the wafer 0 by means of a heat treatment.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The localized wet etching fence assembly is characterized by comprising a fence (1) which is arranged in a closed loop, wherein the bottom end of the fence (1) is fixedly connected to a region to be etched on the surface of a wafer (0), and an etching solution is injected into the inner side of the fence (1).

2. A localized wet etching fence assembly as claimed in claim 1, wherein the fence (1) is made of ceramic or acid resistant material.

3. A localized wet etching fence assembly as claimed in claim 1, characterized in that the bottom end of the fence (1) is fixedly connected with a connecting flange (2), and the connecting flange (2) is located at the outer side of the fence (1), and the connecting flange (2) is fixedly connected to the surface of the wafer (0).

4. A localized wet etching fence assembly as claimed in claim 3, characterized in that said attachment flange (2) is made of transparent material and a layer of UV glue (3) is provided between said attachment flange (2) and the surface of said wafer (0).

5. A localized wet etching fence assembly as claimed in claim 1, characterized in that the localized wet etching fence (1) assembly further comprises a liquid transfer means (4) for withdrawing liquid from the inside of the fence (1).

6. A localized wet etching fence assembly as claimed in claim 5, characterized in that said liquid transfer member (4) comprises a water pumping ball (41), both ends of said water pumping ball (41) are connected with a hose (42), and both said water pumping ball (41) and said hose (42) are made of acid and alkali resistant material.

7. A localized wet etching fence assembly as claimed in claim 1, wherein the inner side wall of the fence (1) is slidably provided with a lining cylinder (6), the sliding direction of the lining cylinder (6) is perpendicular to the surface of the wafer (0), and the bottom end of the lining cylinder (6) abuts against the wafer (0).

8. A localized wet etching fence assembly as claimed in claim 7, wherein the height of the inner liner (6) is greater than the height of the fence (1), and the difference between the heights of the fence (1) and the inner liner (6) is equal to the target depth of the etching area, and one end of the inner liner (6) away from the wafer (0) is provided with a positioning flange (61), and when the bottom end of the inner liner (6) extends to the target depth of the etching area, the positioning flange (61) abuts against the top end of the fence (1).