CN-122028664-A - Wafer cutting method

Abstract

A wafer dicing method includes forming a plurality of grooves by scanning a laser beam onto a front surface of a wafer, wherein the wafer includes a plurality of layers and the laser beam includes at least two beams of light, polishing a rear surface of the wafer, mounting the wafer on a dicing tape, and dicing the wafer by expanding the dicing tape, wherein the step of forming the plurality of grooves includes forming at least two grooves having different widths on at least two layers of the plurality of layers of the wafer by using the at least two beams of light.

Inventors

• DING BINGGUO
• Quan Ningzhe
• PU DONGZHU
• LI ZHONGHAO
• LIN XIANJUN
• Xu Nantai

Assignees

• 三星电子株式会社

Dates

Publication Date

20260512

Application Date

20251112

Priority Date

20241112

Claims (20)

1. 1. A wafer dicing method comprising: Forming a plurality of grooves by scanning a laser beam onto a front surface of a wafer, wherein the wafer comprises a plurality of layers and the laser beam comprises at least two beams of light; polishing the rear surface of the wafer; mounting the wafer on a dicing tape, and Dicing the wafer by expanding the dicing tape, Wherein the step of forming the plurality of grooves includes forming at least two grooves having different widths on at least two layers among the plurality of layers of the wafer by using the at least two beams of light.
2. 2. The wafer dicing method of claim 1, wherein the at least two beams of light comprise light split along a scan direction and/or a direction perpendicular to the scan direction.
3. 3. The wafer dicing method of claim 2, wherein the at least two beams of light comprise light split along a scan direction.
4. 4. A wafer dicing method according to claim 3, wherein, of the at least two light beams, a width of light at a front side in a scanning direction is larger than a width of light at a rear side in the scanning direction.
5. 5. The wafer cutting method according to claim 3, wherein the step of scanning the laser beam comprises sequentially or simultaneously irradiating the at least two beams of light onto the front surface of the wafer.
6. 6. The wafer cutting method according to claim 3, wherein the step of scanning the laser beam comprises irradiating light, which is located at the front in the scanning direction, of the at least two beams onto a first region on the front surface of the wafer, and irradiating light, which is located at the rear in the scanning direction, of the at least two beams onto a second region of the wafer that overlaps the first region.
7. 7. The wafer dicing method of claim 1, wherein the number of the plurality of layers of the wafer is the same as the number of the at least two beams of light.
8. 8. The wafer dicing method of claim 1, wherein the number of layers of a wafer is different from the number of the at least two beams of light.
9. 9. The wafer dicing method according to claim 1, wherein the wafer comprises first to nth layers sequentially stacked from an upper side of the wafer toward a lower side of the wafer, n is a natural number greater than or equal to 2, the laser beam comprises first to mth lights, m is a natural number greater than or equal to 2, and Wherein the step of forming the plurality of grooves includes forming first to mth grooves.
10. 10. The wafer dicing method according to claim 9, wherein the first layer to the n-1 th layer of the wafer are provided as element layers, and the n-th layer of the wafer is provided as a base layer.
11. 11. The wafer cutting method of claim 10, wherein forming the plurality of grooves comprises forming first through m-1 th grooves through corresponding ones of the first through n-1 th layers, respectively, and forming the m-th groove through only a portion of the n-th layer.
12. 12. The wafer dicing method of claim 11, wherein m and n are different natural numbers.
13. 13. The wafer dicing method of claim 2, wherein the at least two beams of light, when irradiated onto the wafer, differ from each other in at least one of power, pulse repetition rate, scanning speed, focus position, light shape, number of divisions, wavelength, optical axis position, and pulse width.
14. 14. The wafer cutting method according to claim 1, wherein the step of scanning the laser beam comprises sequentially or simultaneously irradiating the at least two beams of light onto the wafer, the at least two beams of light coming from a single laser cutting apparatus.
15. 15. The wafer cutting method of claim 1, wherein scanning the laser beam comprises sequentially illuminating the at least two beams of light onto the wafer, the at least two beams of light from at least two different laser cutting devices.
16. 16. The wafer dicing method according to claim 1, further comprising, before the step of polishing the rear surface of the wafer, A protective sheet is laminated on the front surface of the wafer.
17. 17. The wafer dicing method of claim 1, wherein the wafer comprises chip regions and scribe line regions disposed between the chip regions, and Wherein the step of scanning the laser beam includes irradiating the laser beam onto the wafer along the scribe line in the scribe line region.
18. 18. The wafer dicing method of claim 1, wherein the step of forming the plurality of grooves comprises: selecting one of the first mode and the second mode; Selecting based on the first mode, irradiating a first light in front of the at least two beams onto a front surface of the wafer and irradiating a second light in rear of the at least two beams onto the front surface of the wafer during a plurality of scans of the laser beam, and Based on the second mode being selected, during one scan of the laser beam, all of the at least two beams are irradiated onto the front surface of the wafer.
19. 19. A wafer dicing method comprising: Polishing a rear surface of a wafer, the wafer comprising a plurality of layers; mounting the wafer on a dicing tape; forming a plurality of grooves by scanning a laser beam onto a front surface of a wafer, the laser beam including at least two beams of light, and Dicing the wafer by expanding the dicing tape, Wherein the step of forming the plurality of grooves includes forming at least two grooves having different widths on at least two layers among the plurality of layers of the wafer by using the at least two beams of light.
20. 20. The wafer dicing method according to claim 19, further comprising, before the step of polishing the rear surface of the wafer, A protective sheet is laminated on the front surface of the wafer.

Description

Wafer cutting method The present application is based on and claims priority of korean patent application No. 10-2024-0160557 filed on the korean intellectual property office at 11.12 of 2024, korean patent application No. 10-2024-0163192 filed on the korean intellectual property office at 11.15 of 2024, and korean patent application No. 10-2025-0010699 filed on the korean intellectual property office at 13 of 2025, the disclosures of which are incorporated herein by reference in their entirety. Technical Field Embodiments of the present disclosure described herein relate to methods for dicing wafers using a laser dicing apparatus. Background A plurality of semiconductor chips are formed together on a semiconductor substrate such as a wafer, and a singulation process may be performed to separate the plurality of semiconductor chips from each other. In addition, in order to improve productivity with rapid development of the electronic industry, semiconductor packages including a plurality of semiconductor chips are also formed together by using a semiconductor substrate such as a wafer, or by attaching them to a support substrate and then performing a singulation process. Recently, as the complexity of semiconductor devices has increased, singulation of various semiconductor chips has become indispensable, and a method for efficiently dicing a wafer without defects has been required. Disclosure of Invention Embodiments of the present disclosure provide a wafer dicing method using a laser dicing apparatus with high reliability. According to one aspect of an example embodiment, a wafer dicing method includes forming a plurality of grooves by scanning a laser beam onto a front surface of a wafer, wherein the wafer includes a plurality of layers and the laser beam includes at least two beams of light, polishing a rear surface of the wafer, mounting the wafer on a dicing tape, and dicing the wafer by expanding the dicing tape, wherein the step of forming the plurality of grooves includes forming at least two grooves having different widths on at least two layers of the plurality of layers of the wafer by using the at least two beams of light. According to one aspect of an example embodiment, a wafer dicing method includes polishing a rear surface of a wafer including a plurality of layers, mounting the wafer on a dicing tape, forming a plurality of grooves by scanning a laser beam onto a front surface of the wafer, the laser beam including at least two beams of light, and dicing the wafer by expanding the dicing tape, wherein the step of forming the plurality of grooves includes forming at least two grooves having different widths on at least two layers of the plurality of layers of the wafer by using the at least two beams of light. Drawings The above and other objects and features of the present disclosure will become apparent by describing in detail example embodiments thereof with reference to the accompanying drawings. Fig. 1 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 2 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 3 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 4 illustrates a process of scanning a modulated light beam in a process of cutting a wafer by using a laser cutting apparatus according to the embodiment of fig. 3. Fig. 5 is an enlarged view of a light beam corresponding to the portion P1 of fig. 4. Fig. 6 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 7A to 7C are schematic diagrams showing splitting (or referred to as "splitting", or "branching") of a light beam using a two-dimensional beam splitting optical system according to an embodiment. Fig. 8 shows an etched state of the wafer when the light beams of fig. 7C are irradiated together onto the wafer. Fig. 9A to 9C are schematic diagrams illustrating splitting of a light beam using a two-dimensional beam splitting optical system according to an embodiment. Fig. 10 shows the beam of fig. 9C, and shows the etched state of the wafer when the beam is irradiated onto the wafer together. Fig. 11 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 12 shows one of the beams of the laser cutting device of fig. 11. Fig. 13 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 14 shows one of the beams leaving the laser cutting device of fig. 13. Fig. 15 is a block diagram illustrating a laser cutting apparatus according to an embodiment of the present disclosure. Fig. 16 is a schematic diagram showing the secondary division of some of the light beams divided by the first birefringent optical system of the present disclosure. Fig. 17 is a flowchart