Method of manually machining a notch at the edge of a silicon wafer

Abstract

The present application relates to a kind of operation methods for manually processing notch to silicon wafer edge, semiconductor processing technical field, including the following operating steps: first, thickness detection is carried out to silicon wafer on laser thickness measuring equipment.Thickness slotting grinding wheel assembly is selected according to the thickness of silicon wafer.Then the silicon wafer without notch is placed in the test piece clamping groove of clamping groove detection area.Then select the rough grinding unit to move, and the silicon wafer without notch is sucked on the grinding table.Then select the manual operation mode of chamfering machine, and the four orientation movements of grinding table are dynamic.The grinding bin door is closed, the grinding wheel cooling water is opened, the main shaft rotation of chamfering machine is started, and the silicon wafer without notch is grooved and chamfered.Then the mode of groove shape is modified by changing the way of machine table receiving silicon wafer, and the silicon wafer is coarsely chamfered and finely chamfered.It has the characteristics of convenient operation, time and labor saving and good running stability.Silicon wafers with different orientation crystal directions are realized under the same process processing condition, and various technical effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and more specifically to a method for manually machining notches on the edges of silicon wafers. Background Technology

[0002] Currently, after semiconductor crystal rods are pulled, they need to undergo processes such as outer diameter grinding, V-groove treatment, slicing, chamfering, grinding, etching, and polishing before the crystal's original defects are inspected.

[0003] In the current process, after the crystal rod is rolled, a row of notches is made on the surface of the crystal rod along a fixed crystal orientation. After slicing, these notches on the edges of the silicon wafers will serve as important positioning references during processing and inspection, and will also indicate the type and crystal orientation of the silicon wafers. Moreover, the accuracy of the notch positioning has a significant impact on the yield of subsequent processing and the performance of the final product.

[0004] The existing Notch locations are mainly: <100> <110> Crystal orientation: If these positions are fixed, the notched silicon wafer cannot be used for other crystal orientation requirements. However, the existing process has obvious drawbacks in implementation. Once the crystal orientation of the ingot is determined and the notch is cut, the intended use is fixed. If a defect does exist in the ingot, it cannot be used for other crystal orientation requirements and must be discarded. Summary of the Invention

[0005] This invention primarily addresses the shortcomings of existing technologies by providing a method for manually machining notches on the edges of silicon wafers. This method is characterized by its ease of operation, time and labor savings, and high operational stability. It also enables the production of silicon wafers with different crystal orientations under the same processing conditions, achieving multiple technical benefits.

[0006] The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions:

[0007] A method for manually machining notches on the edges of silicon wafers includes the following steps:

[0008] Step 1: When selecting the chamfering machine, first measure the thickness of the silicon wafer on the laser thickness measuring device. Place the silicon wafer on the suction cup of the measuring table. While the rotating motor drives the silicon wafer to rotate, the laser thickness measuring instrument on the laser thickness measuring bracket melts off the ultra-thick silicon wafer.

[0009] Step 2: Select the grooving grinding wheel assembly based on the thickness of the silicon wafer.

[0010] Step 3: After the silicon wafer thickness is detected, enter the chamfering machine processing conditions interface, modify the reference wafer thickness to the wafer thickness that needs to be slotted, and at the same time change the machine's wafer acceptance mode to round shape mode.

[0011] Step 4: Place the unnotched silicon wafer in the test wafer slot of the slot detection area. After placing the unnotched silicon wafer in the slot, click <Move the main wafer to the grinding table position>. Move it to the designated grinding table for suction and alignment through the chamfering machine's set action. At this time, the eccentricity in the X and Y directions must not exceed 10μm respectively.

[0012] Step 5: Select the notch rough grinding unit and move it. The silicon wafer without notches is held on the grinding table. The X, Y, Z and ∅ axis routes are planned by the chamfering machine. The silicon wafer is brought close to the grooving grinding wheel assembly. The position of the silicon wafer at the bottom of the groove of the grooving grinding wheel assembly is adjusted so that the silicon wafer reaches the center position of the groove of the grooving grinding wheel assembly.

[0013] Step 6: Select the manual operation mode of the chamfering machine, simulate the four-way movement of the grinding table, select the Y-axis stepper motor movement of the grinding table, and move the machine forward and backward by the set unit movement amount <-1000μm, -100μm, -10μm, -1μ>. The clicking frequency should not be too fast. When the edge of the silicon wafer contacts the grinding wheel cutting axis 13, stop clicking the unit movement and record the movement amount.

[0014] Step 7: Close the grinding chamber door, turn on the grinding wheel cooling water, start the chamfering machine spindle rotation, select the Y-axis stepper motor movement of the grinding table and click -10μm to move it, and perform grooving and chamfering on the unnotched silicon wafer. After completing the grooving feed, turn off the chamfering machine and stop the spindle rotation.

[0015] Step 8: Select +100μm and click several times to complete the grooving and move the silicon wafer back. Then select -1000μm and click again to move the wafer until it returns to the initial position. Select <Unit Movement> and then select <Receive Position> to let the grinding table move the silicon wafer back to the initial receiving position.

[0016] Step 9: With the chamfering machine spindle rotating and the grinding wheel in a static state, open the grinding chamber door and close the grinding vacuum adsorption.

[0017] Step 10: Manually remove the grooved silicon wafer, air dry the surface moisture with an air gun, transfer it to a microscope to measure the grooving depth, and adjust the Y-axis advance of the grinding table according to the grooving depth.

[0018] Step 11: Next, place the cut silicon wafer into the chamfering machine processing station, modify the wafer receiving mode of the machine to change the groove shape, and perform coarse chamfering and fine chamfering on the silicon wafer. After the chamfering is completed, air dry and put it into the wafer cassette to complete the silicon wafer cutting process.

[0019] Preferably, the thickness of the silicon wafer is T, the diameter D of the grinding wheel cutting shaft at the lower end of the reference disk is 2000 μm, several limiting and guiding rings are provided on the grinding wheel cutting shaft, the width of the bottom of the groove between two adjacent limiting and guiding rings is W, W = T + 100 μm, and the included angle between the hypotenuse of the limiting and guiding ring and the horizontal diameter direction of the bottom of the groove is V, V = 22°.

[0020] Preferably, the diamond grit size on the grinding wheel cutting shaft is 800#.

[0021] Preferably, the set rotational speed of the main shaft of the chamfering machine is 4000 rpm, the advancing speed of the silicon wafer without a notch is 0.001 mm / s until the chamfering removal amount is 1150 μm.

[0022] Preferably, after the silicon wafer is placed in the test piece card slot, it is pulled backward to the L test piece card slot or the R test piece card slot to confirm the position, and one of the <L / R grinding tables> is selected.

[0023] Preferably, through the recording of the advancing movement amount of the grinding table, the forward movement amount of the grinding table in the Y-axis is 258.475 mm to 253.080 mm, and the total movement amount is: 4.675 mm. When splitting it into unequal parts, there are 4 <-1000 μm>, 6 <-100 μm>, and 8 <-10 μm>. When the next silicon wafer without a notch at the edge needs to be manually notched, move the coordinate position of the grinding table in the Y-axis according to this advancing amount.

[0024] Preferably, turn on the chamfering machine, rotate the main shaft, set the rotational speed to 4000 rpm, and perform rough chamfering on the silicon wafer. The rotational speed of the silicon wafer is 26 mm / s, and the single-circle chamfering removal amount is 400 μm. After one circle of rough chamfering, start to perform fine chamfering on the silicon wafer. The rotational speed of the silicon wafer is 21 mm / s, and the single-circle chamfering removal amount is 100 μm. After two circles of fine chamfering, the chamfering machine stops rotating.

[0025] The present invention can achieve the following effects:

[0026] The present invention provides an operation method for manually processing a notch on the edge of a silicon wafer. Compared with the prior art, it has the characteristics of convenient operation, time-saving and labor-saving, and good operation stability. Under the same process processing conditions, it can achieve different azimuth crystal orientations of silicon wafers and achieve various technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the laser thickness measurement device of the present invention.

[0028] Figure 2 is a schematic structural diagram of the silicon wafer test area card slot of the present invention.

[0029] Figure 3 is a schematic structural diagram of the grooving grinding wheel assembly and the silicon wafer for processing a notch of the present invention.

[0030] Figure 4 It is a schematic structural view of the slotted grinding wheel assembly of the present invention.

[0031] In the figure: laser thickness measurement bracket 1, laser thickness measurement detector 2, silicon wafer 3, measuring table sucker 4, rotating motor 5, slot detection area 6, L test piece slot 7, R test piece slot 8, test piece slot 9, slotted grinding wheel assembly 10, grinding table 11, reference disk 12, grinding wheel cutting shaft 13, limit guiding ring 14. Specific embodiments

[0032] The technical solution of the invention will be further specifically described below through embodiments in combination with the accompanying drawings.

[0033] Embodiment: As Figure 1-4 shown, a method for manually processing a notch on the edge of a silicon wafer includes the following operating steps:

[0034] The first step: When selecting a chamfer machine table, first detect the thickness of the silicon wafer 3 on a laser thickness measurement device. Place the silicon wafer 3 on the measuring table sucker 4. While the rotating motor 5 drives the silicon wafer 3 to rotate, the laser thickness measurement detector 2 on the laser thickness measurement bracket 1 melts the ultra-thick silicon wafer 3.

[0035] The second step: Select the slotted grinding wheel assembly 10 according to the thickness of the silicon wafer 3. The thickness of the silicon wafer 3 is T, the diameter D of the grinding wheel cutting shaft 13 at the lower end of the reference disk 12 is 2000 μm, there are 3 limit guiding rings 14 on the grinding wheel cutting shaft 13, and the diamond grit on the grinding wheel cutting shaft 13 is 800#. The width of the bottom of the groove between two adjacent limit guiding rings 14 is W, W = T + 100 μm, and the included angle between the hypotenuse of the limit guiding ring 14 and the horizontal diameter direction of the bottom of the groove is V, V = 22°.

[0036] The third step: After the silicon wafer 3 completes the thickness detection, enter the chamfer machining condition interface, modify the thickness of the reference wafer to the thickness of the wafer to be slotted, and at the same time modify the wafer receiving mode of the machine table to the circular shape mode.

[0037] The fourth step: Place the silicon wafer 3 without a notch in the test piece slot 9 of the slot detection area 6. After the silicon wafer 3 is in the test piece slot 9, confirm the position by pulling it back to the L test piece slot 7 or the R test piece slot 8, and select one of <L / R grinding table>. After placing the silicon wafer 3 without a notch in the slot, click <Main wafer moves to the grinding table position>, and move to the designated grinding table 11 by the action set by the chamfer for suction centering. At this time, the eccentricity in the X direction and the Y direction shall not exceed 10 μm respectively.

[0038] Step 5: Select the notch rough grinding unit to move. The notchless silicon wafer 3 is picked up on the grinding table 11. The X, Y, Z and ∅ axis routes are planned by the chamfering machine. The silicon wafer 3 is close to the grooving grinding wheel assembly 10. The position of the silicon wafer 3 at the bottom of the groove of the grooving grinding wheel assembly 10 is adjusted so that the silicon wafer 3 reaches the center position of the groove of the grooving grinding wheel assembly 10.

[0039] Step 6: Select the manual operation mode of the chamfering machine, simulate the four-way movement of the grinding table 11, select the Y-axis stepper motor movement of the grinding table 11, and move the machine forward and backward by the set unit movement amount <-1000μm, -100μm, -10μm, -1μ>. The clicking frequency should not be too fast. When the edge of the silicon wafer 3 contacts the grinding wheel cutting axis 13, stop clicking the unit movement and record the movement amount.

[0040] Step 7: Close the grinding chamber door, turn on the grinding wheel cooling water, start the chamfering machine spindle rotation, select the Y-axis stepper motor movement of the grinding table and click -10μm to move it, and perform grooving and chamfering on the silicon wafer 3 without notches. After completing the grooving feed, turn off the chamfering machine and stop the spindle rotation.

[0041] The chamfering machine spindle is set to rotate at 4000 rpm, and the notchless silicon wafer 3 advances at a speed of 0.001 mm / s until the chamfer removal amount is 1150 μm.

[0042] Step 8: Select +100μm and click several times to complete the grooving of silicon wafer 3 and then click -1000μm to move the amount of movement until it returns to the initial position. Then select <Unit Movement> and click <Receive Position> to let the grinding table 11 move silicon wafer 3 back to the initial receiving position.

[0043] Step 9: With the chamfering machine spindle rotating and the grinding wheel in a static state, open the grinding chamber door and close the grinding vacuum adsorption.

[0044] Step 10: Manually remove the grooved silicon wafer 3, air dry the surface moisture with an air gun, transfer it to a microscope to measure the grooving depth, and adjust the Y-axis advance coordinate of the grinding table 11 according to the grooving depth.

[0045] According to the forward movement record of the grinding table 11, the forward movement of the grinding table along the Y axis is from 258.475mm to 253.080mm, and the total movement is 4.675mm. When dividing it into unequal parts, there are 4 <-1000μm>, 6 <-100μm>, and 8 <-10μm>. When the next silicon wafer 3 without an edge notch needs to be manually notched, the Y-axis coordinate position of the grinding table is moved according to this forward movement.

[0046] Step 11: Next, place the diced silicon wafer 3 into the chamfering machine processing station. Modify the wafer receiving mode of the machine to the groove shape mode. Perform coarse and fine chamfering on silicon wafer 3. Start the chamfering machine, rotate the spindle, and set the speed to 4000 rpm. Perform coarse chamfering on silicon wafer 3 at a rotation speed of 26 mm / s, with a chamfer removal of 400 μm per turn. After one round of coarse chamfering, begin fine chamfering on silicon wafer 3 at a rotation speed of 21 mm / s, with a chamfer removal of 100 μm per turn. After two rounds of fine chamfering, stop the chamfering machine. After chamfering, air dry and place in the wafer cassette, completing the wafer dicing process for silicon wafer 3.

[0047] In summary, this method for manually machining notches on the edges of silicon wafers is characterized by its ease of operation, time and labor savings, and good operational stability. It solves the problem of achieving silicon wafers with different crystal orientations under the same processing conditions, achieving multiple technical benefits.

[0048] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A method for manually machining notches on the edges of silicon wafers, characterized in that... The method comprises the following steps: First step: when selecting the chamfering machine, first detect the thickness of the silicon wafer (3) on the laser thickness measuring device, place the silicon wafer (3) on the measuring table suction disc (4), rotate the motor (5) to drive the silicon wafer (3) to rotate, and then detect the thickness of the silicon wafer (3) by the laser thickness measuring detector (2) on the laser thickness measuring support (1); Second step: select the slotting grinding wheel assembly (10) according to the thickness of the silicon wafer (3); Third step: after the thickness detection of the silicon wafer (3) is completed, enter the chamfering machine processing condition interface, modify the reference wafer thickness to the required slotting wafer thickness, and modify the silicon wafer receiving mode of the machine to a circular shape mode; Fourth step: place the silicon wafer (3) without a notch in the test piece clamping groove (9) of the clamping groove detection area (6), click <move the main wafer to the grinding table position> after placing the silicon wafer (3) without a notch, and move to the specified grinding table (11) by the action of the chamfering machine to be centered by suction, at this time, the eccentricity of the X direction and the Y direction should not exceed 10 μm respectively; Fifth step: select the notch rough grinding unit to move, the silicon wafer (3) without a notch is sucked on the grinding table (11), the X, Y, Z and ∅ axis routes are set by the chamfering machine, the silicon wafer (3) approaches the slotting grinding wheel assembly (10), the position of the silicon wafer (3) at the bottom of the slot of the slotting grinding wheel assembly (10) is adjusted, so that the silicon wafer (3) reaches the center position of the slot of the slotting grinding wheel assembly (10); Sixth step: select the manual operation mode of the chamfering machine, set the dynamic four-direction movement of the grinding table (11), select the Y-axis stepper motor movement of the grinding table (11), and move forward and backward by the set unit movement amount <-1000 μm, -100 μm, -10 μm, -1 μ> of the machine, the clicking frequency should not be too fast, when the edge of the silicon wafer (3) contacts the notch shaft 13 of the grinding wheel, stop clicking unit movement and record the movement amount; Seventh step: close the grinding chamber door, open the grinding wheel cooling water, start the main shaft rotation of the chamfering machine, select the Y-axis stepper motor movement of the grinding table, click -10 μm to move, and slot and chamfer the silicon wafer (3) without a notch, after the slotting feeding is completed, close the chamfering machine and stop the main shaft rotation; Eighth step: select to click +100 μm several times to move back after the slotting of the silicon wafer (3) is completed, select to click -1000 μm movement amount again, until it is moved back to the initial position, select to click <unit movement> and select to click <accepted position>, so that the grinding table (11) drives the silicon wafer (3) to return to the initial accepted position; Ninth step: the main shaft rotation of the chamfering machine is in a static state, open the grinding chamber door, and close the grinding vacuum suction; Tenth step: manually take down the slotted silicon wafer (3), dry the surface moisture by air gun, and transfer it to the microscope to measure the slotting notch depth, and adjust the Y-axis forward movement coordinate of the grinding table (11) according to the slotting notch depth; Eleventh step: then place the silicon wafer (3) with the completed notch into the chamfering machine processing station, modify the silicon wafer receiving mode of the machine to a groove shape mode, and coarsely chamfer and finely chamfer the silicon wafer (3), after the chamfering is completed, dry the silicon wafer (3) and place it into a wafer box, and the notch process of the silicon wafer (3) is completed.

2. The method of claim 1, wherein: The thickness of the silicon wafer (3) is T, the diameter of the grinding wheel notch shaft (13) at the lower end of the reference disc (12) is 2000 μm, the grinding wheel notch shaft (13) is provided with a plurality of limiting guide rings (14), the width of the groove bottom between two adjacent limiting guide rings (14) is W, W = T + 100 μm, the included angle between the bevel of the limiting guide ring (14) and the horizontal diameter direction of the groove bottom is V, V = 22°.

3. The method of claim 2, wherein: The diamond grit size on the grinding wheel notch shaft (13) is 800#.

4. The method of claim 1, wherein: The set rotating speed of the chamfering machine main shaft is 4000 rpm, the forward speed of the silicon wafer (3) without a notch is 0.001 mm / s, and the chamfering removal amount is 1150 μm.

5. The method of claim 1, wherein: After the silicon wafer (3) is in the test piece clamping groove (9), the position is confirmed by pulling it backward to the L test piece clamping groove (7) or the R test piece clamping groove (8), and one of the <L / R grinding table> is selected.

6. The method of claim 1, wherein: The forward movement amount of the grinding table Y axis is recorded, the forward movement amount of the grinding table Y axis is 258.475 mm to 253.080 mm, the total movement amount is 4.675 mm, the unequal parts are split into 4 <-1000 μm>, 6 <-100 μm>, and 8 <-10 μm>, and the next silicon wafer (3) without a notch needs to be manually notched, and the grinding table Y axis coordinate position is moved according to the previous forward amount.

7. The method of claim 1, wherein: The chamfering machine is started, the main shaft is rotated, the set rotating speed is 4000 rpm, the silicon wafer (3) is coarsely chamfered, the rotating speed of the silicon wafer (3) is 26 mm / s, the single-circle chamfering removal amount is 400 μm, after one circle of coarse chamfering, the silicon wafer (3) is finely chamfered, the rotating speed of the silicon wafer (3) is 21 mm / s, the single-circle chamfering removal amount is 100 μm, and the chamfering machine is stopped after two circles of fine chamfering.

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