Corrosion method and corrosion equipment for back cutting channel
By determining the total corrosion time and performing two corrosions in the back gold corrosion process of semiconductor devices, the wafer is flipped between the two corrosions, the corrosion uneven problem caused by poor flow of corrosion liquid is solved, and uniform corrosion of the back cutting channel is achieved.
Patent Information
- Application Number
- CN202411963654.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-05-13
AI Technical Summary
In the back gold corrosion process of semiconductor devices, deep grooves in the transverse cutting channel cause poor flow of corrosion liquid, resulting in uneven corrosion of the transverse cutting channel and the longitudinal cutting channel.
By determining the total corrosion time and placing the wafer in the corrosion groove, the positioning edges and positioning grooves are facing the bottom of the groove, flipped 80° to 100° after the first corrosion, and then performing a second corrosion, ensuring that the corrosion liquid flows fully through the cutting channel under the action of gravity.
The corrosion uniformity of the back cutting path is achieved, ensuring that both the transverse cutting path and the longitudinal cutting path are sufficiently corroded.
Smart Images
Figure CN119993914A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of semiconductor technology, and in particular relates to an etching method and an etching device for a backside scribe line. Background Art
[0002] Semiconductor devices are electronic devices that use the special electrical properties of semiconductor materials to perform specific functions.
[0003] In the related art, there is a process called back-gold etching in the preparation process of semiconductor devices. In the back-gold etching process, it is necessary to etch the back-side cutting paths, which include interlaced transverse cutting paths and longitudinal cutting paths, into which the etching liquid flows to etch the transverse cutting paths and the longitudinal cutting paths.
[0004] However, since the transverse cutting street has a deeper groove, the etching liquid cannot flow smoothly in the transverse cutting street, which may easily lead to uneven etching of the transverse cutting street and the longitudinal cutting street. Summary of the invention
[0005] The embodiment of the present disclosure provides a backside scribe line etching method and etching equipment, which can effectively ensure the etching uniformity of the backside scribe line. The technical solution is as follows:
[0006] In a first aspect, an embodiment of the present disclosure provides a backside scribe line etching method, the etching method comprising:
[0007] Determine the total corrosion time, wherein the total corrosion time is T minutes, T>0;
[0008] Placing the wafer into the etching groove so that the positioning edge and the positioning groove of the wafer face the bottom of the etching groove;
[0009] The wafer is etched for the first time, and the duration of the first etching is t 1 Minutes, t 1 >0;
[0010] Taking the diameter of the wafer as the turning axis, turning the wafer by 80° to 100°;
[0011] The wafer is etched for a second time, and the duration of the second etching is t 2 Minutes, t 2 >0, and t 1 +t 2 =T.
[0012] In one implementation of the present disclosure, determining the total corrosion time includes:
[0013] Determining the thickness of the wafer to be etched and the activity of the etching solution;
[0014] The total etching time is determined according to the thickness of the wafer to be etched and the activity of the etching solution.
[0015] In one implementation of the present disclosure, placing a wafer into an etching tank includes:
[0016] The wafer is placed on a rotating device in the etching tank so that the center of the wafer coincides with the rotation axis of the rotating device and the positioning edge and positioning groove of the wafer face the bottom of the etching tank.
[0017] In another implementation of the present disclosure, performing a first etching on the wafer includes:
[0018] Starting to supply the corrosive liquid and timing;
[0019] Rotating the wafer, wherein the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer;
[0020] Time to t 1 After 10 minutes, stop supplying the corrosive liquid.
[0021] In yet another implementation of the present disclosure, rotating the wafer includes:
[0022] The rotation speed of the wafer is set to 5-20 RPM.
[0023] In another implementation of the present disclosure, etching the wafer for a second time includes:
[0024] Starting to supply the corrosive liquid and timing;
[0025] Rotating the wafer, wherein the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer;
[0026] Time to t 2 After 10 minutes, stop supplying the corrosive liquid.
[0027] In yet another implementation of the present disclosure, rotating the wafer includes:
[0028] The rotation speed of the wafer is set to 5-20 RPM.
[0029] In another implementation of the present disclosure, the corrosion method further includes:
[0030] The duration of the first corrosion is the same as the duration of the second corrosion.
[0031] In another implementation of the present disclosure, after etching the wafer for the second time, the method includes:
[0032] taking the wafer out of the etching tank;
[0033] cleaning the wafer;
[0034] The wafer is dried.
[0035] In a second aspect, an embodiment of the present disclosure provides an etching device for backside scribing, which is applicable to the etching method described in the first aspect, and the etching device comprises: an etching tank, a turning device and a rotating device;
[0036] The flipping device and the rotating device are respectively located in the corrosion groove, one end of the flipping device is connected to the inner wall of the corrosion groove, and the other end of the flipping device is connected to the rotating device, and the flipping axis of the flipping device is perpendicular to the rotating axis of the rotating device.
[0037] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:
[0038] In the process of etching the backside cutting path by the etching method provided by the embodiment of the present disclosure, the total etching time is first determined to ensure that the subsequent first etching and second etching can have sufficient etching time. Then, the wafer is placed in the etching groove, so that the positioning edge and the positioning groove of the wafer face the bottom of the etching groove, and the wafer is in a vertical posture, so that the positioning edge and the positioning groove ensure the correct position of the wafer in the etching groove, and prepare for the subsequent first etching and second etching. The wafer is etched for the first time, and the duration of the first etching is t 1 Minutes. Through the first etching, the etching liquid can initially act on the transverse cutting path and the longitudinal cutting path. Then, with the diameter of the wafer as the turning axis, the wafer is turned 80° to 100°, so that the wafer changes from a vertical posture to a horizontal posture. The wafer is etched for a second time, and the duration of the second etching is t 2 minutes, and t 1 +t 2 = T. After the wafer is flipped and turned into a horizontal posture, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road under the action of its own gravity, so that the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of corrosion.
[0039] That is to say, by performing the first etching and the second etching separately and flipping the wafer between the two etchings, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road, so that both the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of etching. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0041] Figure 1 is a flow chart of a backside scribe line etching method provided by an embodiment of the present disclosure;
[0042] Figure 2 is a flow chart of another backside scribe line etching method provided by an embodiment of the present disclosure;
[0043] Figure 3 It is a schematic structural diagram of a back-side cutting road etching device provided in an embodiment of the present disclosure.
[0044] Meaning of the figures:
[0045] 10. Corrosion tank;
[0046] 20. Flipping device;
[0047] 30. Rotating device;
[0048] 100. Wafer.
[0049] The above drawings show clear embodiments of the present disclosure, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present disclosure in any way, but to illustrate the concepts of the present disclosure to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION
[0050] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.
[0051] The present disclosure provides a backside scribe line etching method. Figure 1 For a flow chart of the corrosion method, see Figure 1 In this embodiment, the preparation method comprises:
[0052] Step 101: Determine the total corrosion time.
[0053] Among them, the total corrosion time is T minutes, T>0.
[0054] Step 102: Place the wafer into the etching groove so that the positioning edge and positioning groove of the wafer face the bottom of the etching groove.
[0055] Step 103: Perform the first etching on the wafer.
[0056] Among them, the duration of the first corrosion is t 1 Minutes, t 1 >0.
[0057] Step 104: Using the diameter of the wafer as the turning axis, turn the wafer by 80° to 100°.
[0058] Step 105: Perform a second etching on the wafer.
[0059] Among them, the duration of the second corrosion is t 2 Minutes, t 2 >0, and t 1 +t 2 =T.
[0060] In the process of etching the backside cutting path by the etching method provided by the embodiment of the present disclosure, the total etching time is first determined to ensure that the subsequent first etching and second etching can have sufficient etching time. Then the wafer is placed in the etching groove, so that the positioning edge and the positioning groove of the wafer face the bottom of the etching groove, and the wafer is in a vertical posture, so that the positioning edge and the positioning groove ensure the correct position of the wafer in the etching groove, and prepare for the subsequent first etching and second etching. The wafer is etched for the first time, and the duration of the first etching is t 1 Minutes. Through the first etching, the etching liquid can initially act on the horizontal and vertical cutting paths. Then, with the diameter of the wafer as the flipping axis, the wafer is flipped 80° to 100°, so that the wafer changes from a vertical posture to a horizontal posture. The wafer is etched for the second time, and the duration of the second etching is t 2 minutes, and t 1 +t 2 = T. After the wafer is flipped and turned into a horizontal posture, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road under the action of its own gravity, so that the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of corrosion.
[0061] That is to say, by performing the first etching and the second etching separately and flipping the wafer between the two etchings, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road, so that both the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of etching.
[0062] Figure 2 A flowchart of another backside scribe line etching method provided in an embodiment of the present disclosure is shown in FIG. Figure 2 In this embodiment, the corrosion method includes:
[0063] Step 201: Determine the total corrosion time.
[0064] Among them, the total corrosion time is T minutes, T>0.
[0065] In the above implementation, by determining the total corrosion time, a basis can be provided for determining the duration of the first corrosion and the duration of the second corrosion in the subsequent steps. In addition, by determining the total corrosion time, the total corrosion degree can be grasped to ensure that the corrosion degree meets the requirements.
[0066] Exemplarily, step 201 is performed by the following steps:
[0067] First, determine the thickness of the wafer to be etched and the activity of the etching solution.
[0068] Then, the total etching time is determined according to the thickness of the wafer to be etched and the activity of the etching solution.
[0069] In the above implementation, the greater the thickness of the wafer to be etched, the longer the total etching time, and vice versa, the smaller the thickness of the wafer to be etched, the shorter the total etching time. The stronger the activity of the etching solution, the shorter the total etching time, and vice versa, the weaker the activity of the etching solution, the longer the total etching time.
[0070] In this embodiment, the total corrosion time is an artificially set value, which can be set according to actual conditions, and the present disclosure does not impose any restrictions on this.
[0071] Step 202: Place the wafer into the etching groove so that the positioning edge and positioning groove of the wafer face the bottom of the etching groove.
[0072] In the above implementation, the positioning edge and positioning groove of the wafer are directed toward the bottom of the etching groove, so that the positioning edge and positioning groove are used to ensure the correct position of the wafer in the etching groove, preparing for the subsequent first etching and second etching.
[0073] It is worth noting that the wafer flat is a flat edge at the outer edge of the wafer, which is used to position the wafer. The wafer notch is a notch at the outer edge of the wafer, which is used to position the wafer.
[0074] Exemplarily, step 202 is performed by the following steps:
[0075] The wafer is placed on a rotating device in the etching tank so that the center of the wafer coincides with the rotation axis of the rotating device and the positioning edge and positioning groove of the wafer face the bottom of the etching tank.
[0076] In the above implementation, the rotating device is located inside the etching tank and can rotate itself, thereby driving the wafer placed thereon to rotate. In this way, it is beneficial for the etching solution to fully and evenly infiltrate the back cutting channels on the wafer during the subsequent first etching and second etching processes.
[0077] Step 203: Perform the first etching on the wafer.
[0078] Among them, the duration of the first etching is t 1 minutes, and t 1 > 0.
[0079] It is easy to understand that t 1 < T, that is, the duration of the first etching should be less than the total etching time, so as to reserve time for the second etching.
[0080] Exemplarily, in step 203, it is executed through the following steps:
[0081] First, start supplying the etching solution and start timing.
[0082] At the same time as starting to supply the etching solution, start timing, so as to ensure the accuracy of t 1 .
[0083] Then, rotate the wafer, and the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer.
[0084] In the above implementation, the rotating device in the etching tank drives the wafer to rotate. Since the center of the wafer coincides with the rotation axis of the rotating device, the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer.
[0085] By rotating the wafer, it is possible to promote good flow and replacement (replacement between the old etching solution and the new etching solution) effects of the etching solution in the longitudinal cutting channels and the transverse cutting channels, thereby further ensuring etching uniformity.
[0086] Exemplarily, set the rotation speed of the wafer to 5 - 20 RPM.
[0087] Setting the rotation speed of the wafer within the above range can, on the one hand, ensure good promotion of the flow and replacement effects of the etching solution, and on the other hand, can also avoid the difficulty in controlling the etching process due to too fast a flow rate.
[0088] Finally, after timing to t 1 minutes, stop supplying the etching solution.
[0089] Step 204: Flip the wafer by 80° - 100° with the diameter of the wafer as the flipping axis.
[0090] In the above implementation, the flipping device in the etching tank drives the wafer to flip. During the first etching process, if the etching tank is arranged horizontally, the wafer is arranged vertically perpendicular to the horizontal plane, and the wafer is in a vertical posture. After the wafer is flipped 80° to 100°, the wafer is arranged approximately parallel to the horizontal plane, and the wafer is in a horizontal posture. In this way, preparations can be made for the second etching.
[0091] In this embodiment, the wafer is flipped 90° with the diameter of the wafer as the flipping axis.
[0092] Such a design allows the wafer to change from a vertical posture to a horizontal posture after flipping, that is, the wafer is arranged parallel to the horizontal plane. Of course, in other embodiments, the flip angle of the wafer can also be other values within the above range, and the present disclosure does not limit this.
[0093] Step 205: performing a second etching on the wafer.
[0094] Among them, the duration of the second corrosion is t 2 Minutes, t 2 >0, and t 1 +t 2 =T.
[0095] Exemplarily, step 205 is performed by the following steps:
[0096] First, start supplying the corrosive fluid and start the timer.
[0097] When the corrosive liquid is supplied, the timing starts, so as to ensure that t 2 accuracy.
[0098] Then, the wafer is rotated, with the rotation axis of the wafer being perpendicular to the wafer and passing through the center of the wafer.
[0099] In the above implementation, the rotating device in the etching tank drives the wafer to rotate. Since the center of the wafer coincides with the rotation axis of the rotating device, the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer.
[0100] By rotating the wafer, the etching liquid can be encouraged to form a good flow and replacement (replacement between old etching liquid and new etching liquid) effect in the longitudinal cutting lanes and the transverse cutting lanes, thereby further ensuring the uniformity of etching.
[0101] Exemplarily, the rotation speed of the wafer is set to 5-20 RPM.
[0102] Setting the rotation speed of the wafer to the above range can ensure good promotion of the flow and replacement effect of the etching liquid on the one hand, and can also avoid the corrosion process being difficult to control due to too fast flow rate on the other hand.
[0103] Since the wafer has been flipped to a horizontal position in step 204, the etching liquid can fully flow through the transverse cutting lanes and the longitudinal cutting lanes under the action of its own gravity, so that both the transverse cutting lanes and the longitudinal cutting lanes can be fully corroded, ensuring the uniformity of etching.
[0104] Finally, the time is counted to t 2 After 10 minutes, stop supplying the corrosive liquid.
[0105] In this embodiment, the duration of the first etching is the same as the duration of the second etching, that is, t 1 =t 2 .
[0106] By designing the duration of the first corrosion and the duration of the second corrosion in this way, it can be ensured that both corrosions are fully carried out.
[0107] Of course, in other embodiments, the duration of the first corrosion and the duration of the second corrosion can be adjusted according to actual needs, as long as t 1 +t 2 =T.
[0108] Step 206: Take the wafer out of the etching tank, clean the wafer, and dry the wafer.
[0109] In step 206, the etching solution remaining on the surface of the wafer is cleaned and the wafer is dried to dry the wafer.
[0110] At this point, the etching process for the sawing line on the back side of the wafer is completed, and the process of preparing other semiconductor devices is waiting.
[0111] In the process of etching the backside cutting path by the etching method provided by the embodiment of the present disclosure, the total etching time is first determined to ensure that the subsequent first etching and second etching can have sufficient etching time. Then the wafer is placed in the etching groove, so that the positioning edge and the positioning groove of the wafer face the bottom of the etching groove, and the wafer is in a vertical posture, so that the positioning edge and the positioning groove ensure the correct position of the wafer in the etching groove, and prepare for the subsequent first etching and second etching. The wafer is etched for the first time, and the duration of the first etching is t 1 Minutes. Through the first etching, the etching liquid can initially act on the horizontal and vertical cutting paths. Then, with the diameter of the wafer as the flipping axis, the wafer is flipped 80° to 100°, so that the wafer changes from a vertical posture to a horizontal posture. The wafer is etched for the second time, and the duration of the second etching is t 2 minutes, and t 1 +t 2= T. After the wafer is flipped and turned into a horizontal posture, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road under the action of its own gravity, so that the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of corrosion.
[0112] That is to say, by performing the first etching and the second etching separately and flipping the wafer between the two etchings, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road, so that both the transverse cutting road and the longitudinal cutting road can be fully corroded, ensuring the uniformity of etching.
[0113] Figure 3 A schematic diagram of a backside cutting road etching device provided in an embodiment of the present disclosure, combined with Figure 3 In this embodiment, the etching device includes: an etching tank 10, a turning device 20 and a rotating device 30.
[0114] The flipping device 20 and the rotating device 30 are respectively located in the corrosion groove 10, one end of the flipping device 20 is connected to the inner wall of the corrosion groove 10, and the other end of the flipping device 20 is connected to the rotating device 30, and the flipping axis of the flipping device 20 is perpendicular to the rotation axis of the rotating device 30.
[0115] In the above implementation, the etching tank 10 is used to contain the etching liquid and provide a stable etching environment for the wafer 100 .
[0116] The rotating device 30 is used to carry the wafer 100 and can drive the wafer 100 to rotate, and the rotation axis of the wafer 100 is perpendicular to the wafer 100 and passes through the center of the wafer 100. The rotating device 30 can drive the wafer 100 to rotate during the first etching and the second etching process, thereby promoting the etching liquid to form a good flow and replacement (replacement between old etching liquid and new etching liquid) effect in the longitudinal cutting road and the transverse cutting road, thereby further ensuring the etching uniformity.
[0117] The flipping device 20 is connected to the rotating device 30, and can drive the rotating device 30 to flip, thereby driving the wafer 100 to flip, and the flipping axis of the wafer 100 is the diameter of the wafer 100. Through the flipping device 20, the posture of the wafer 100 can be changed during the interval between the first etching and the second etching, so that the wafer 100 is changed from a vertical posture to a horizontal posture, so that during the second etching process, the etching liquid can fully flow through the transverse cutting road and the longitudinal cutting road under the action of its own gravity, so that the transverse cutting road and the longitudinal cutting road can be fully etched, ensuring the uniformity of etching.
[0118] Exemplarily, both the rotating device 30 and the flipping device 20 are driven by motors.
[0119] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0120] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.
Claims
1. A backside scribe line etching method, characterized in that: The corrosion method comprises: Determine the total corrosion time, wherein the total corrosion time is T minutes, T>0; Placing the wafer into the etching groove so that the positioning edge and the positioning groove of the wafer face the bottom of the etching groove; The wafer is subjected to a first etching, and the duration of the first etching is t1 minutes, where t1>0; Taking the diameter of the wafer as the turning axis, turning the wafer by 80° to 100°; The wafer is subjected to a second etching, and the duration of the second etching is t2 minutes, t2>0, and t1+t2=T.
2. The etching method according to claim 1, characterized in that: Determine the total corrosion time, including: Determining the thickness of the wafer to be etched and the activity of the etching solution; The total etching time is determined according to the thickness of the wafer to be etched and the activity of the etching solution.
3. The etching method according to claim 1, characterized in that: Place the wafer into the etching tank, including: The wafer is placed on a rotating device in the etching tank so that the center of the wafer coincides with the rotation axis of the rotating device and the positioning edge and positioning groove of the wafer face the bottom of the etching tank.
4. The etching method according to claim 2, characterized in that: The wafer is subjected to a first etching, comprising: Starting to supply the corrosive liquid and timing; Rotating the wafer, wherein the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer; After the timing reaches t1 minute, stop supplying the corrosive liquid.
5. The etching method according to claim 4, characterized in that: Rotating the wafer, comprising: The rotation speed of the wafer is set to 5-20 RPM.
6. The etching method according to claim 2, characterized in that: The wafer is subjected to a second etching, comprising: Starting to supply the corrosive liquid and timing; Rotating the wafer, wherein the rotation axis of the wafer is perpendicular to the wafer and passes through the center of the wafer; After the timing reaches t2 minutes, stop supplying the corrosive liquid.
7. The etching method according to claim 6, characterized in that: Rotating the wafer, comprising: The rotation speed of the wafer is set to 5-20 RPM.
8. The etching method according to claim 1, characterized in that: The corrosion method further comprises: The duration of the first corrosion is the same as the duration of the second corrosion.
9. The etching method according to claim 1, characterized in that: After the wafer is subjected to a second etching, the method further comprises: taking the wafer out of the etching tank; cleaning the wafer; The wafer is dried.
10. A backside scribe line etching device, characterized in that: The etching method according to any one of claims 1 to 9, wherein the etching equipment comprises: an etching tank (10), a turning device (20) and a rotating device (30); The flipping device (20) and the rotating device (30) are respectively located in the corrosion groove (10); one end of the flipping device (20) is connected to the inner wall of the corrosion groove (10); the other end of the flipping device (20) is connected to the rotating device (30); and the flipping axis of the flipping device (20) and the rotating axis of the rotating device (30) are perpendicular to each other.