阅读说明：本技术 一种飞秒激光加工装置 (Femtosecond laser processing device ) 是由 陈洁 于 2019-03-30 设计创作，主要内容包括：本发明提供了一种飞秒激光加工装置,本发明利用第一能量激光进行分束处理,分束得到的第一中心激光穿过光闸进行对准操作,而分束得到的第一边缘激光经光闸反射进行工件切割或钻孔的边缘修复,得到较为规整的通孔侧壁或切割道侧壁。(The invention provides a femtosecond laser processing device, which utilizes first energy laser to carry out beam splitting treatment, wherein first central laser obtained by beam splitting penetrates through an optical gate to carry out alignment operation, and first edge laser obtained by beam splitting is reflected by the optical gate to carry out edge repair on workpiece cutting or drilling, so that more regular through hole side walls or cutting path side walls are obtained.)

1. A femtosecond laser processing device comprises a first laser, a second laser, a beam splitter, an optical shutter, an alignment plate and a condenser, wherein the first laser, the beam splitter, the optical shutter and the alignment plate are sequentially arranged along a first optical path, and the second laser, the optical shutter and the condenser are sequentially arranged along a second optical path; the first laser emits first energy laser along the first optical path, and the second laser is a femtosecond laser and emits second energy laser along a second optical path; wherein the first optical path is perpendicular to the second optical path;

the method is characterized in that: the optical shutter includes a central portion and an edge portion surrounding the central portion, the central portion being a light-transmitting portion, the edge portion being a light-reflecting portion; the first energy laser is divided into a first central laser and a first edge laser surrounding the first central laser by a beam splitter, and the first central laser penetrates through the central part to be used as alignment laser aligned with the alignment plate; the first edge laser is reflected by the edge part and reaches the condenser lens along a second light path, the second energy laser penetrates through the central part of the optical gate and reaches the condenser lens, the second energy laser is collected by changing the path of the condenser lens, the first edge laser is focused into second edge laser at the edge, and the second energy laser is focused into second central laser at the center.

2. The femtosecond laser processing apparatus according to claim 1, characterized in that: the laser processing device further comprises an object stage, wherein the object stage is used for bearing a workpiece to be processed, the second central laser is aligned to the central position of the workpiece to be cut or drilled, and the second edge laser surrounds the peripheral position of the central position.

3. The femtosecond laser processing apparatus according to claim 1, characterized in that: the beam splitter is a combination of a concave lens and a convex lens.

4. The femtosecond laser processing apparatus according to claim 1, characterized in that: and the included angles between the optical gate and the first light path and between the optical gate and the second light path are both 45 degrees.

5. The femtosecond laser processing apparatus according to claims 1 to 4, characterized in that: the wavelength of the first energy laser is 350nm, and the wavelength of the second energy laser is 1060 nm.

6. The femtosecond laser processing apparatus according to claim 5, characterized in that: the edge portion has a reflective film that reflects 350 nm.

7. The femtosecond laser processing apparatus according to claims 1 to 6, characterized in that: the alignment plate is a transparent substrate, and the transparent substrate is provided with a carved alignment mark.

Technical Field

The invention relates to the field of semiconductor workpiece processing, in particular to a femtosecond laser processing device.

Background

In a semiconductor process, the upper and lower interconnections between substrates or devices are often realized by through holes, and the singulation of semiconductor devices is often realized by cutting. Smaller aspect ratio (cross-sectional) vias and more irregular streets have not been able to meet the size requirements due to the shrinking dimensions. For example, in the single-beam laser drilling process, since the temperature is high at the portion where the undercut starts (the top surface of the workpiece), the undercut is too fast, and the sidewall portion of the upper portion thereof is also subjected to a continuously high temperature, if the undercut is continued as described above, the aperture at the through hole position of the top surface portion of the workpiece is much larger than the aperture at the through hole position of the bottom surface portion of the substrate, and the sidewall is uneven. This is extremely disadvantageous in practical production.

Disclosure of Invention

Based on the above problem, the present invention provides a femtosecond laser processing apparatus, including a first laser, a second laser, a beam splitter, an optical shutter, an alignment plate and a condenser, wherein the first laser, the beam splitter, the optical shutter and the alignment plate are sequentially arranged along a first optical path, and the second laser, the optical shutter and the condenser are sequentially arranged along a second optical path; the first laser emits first energy laser along the first optical path, and the second laser is a femtosecond laser and emits second energy laser along a second optical path; wherein the first optical path is perpendicular to the second optical path;

wherein: the optical shutter includes a central portion and an edge portion surrounding the central portion, the central portion being a light-transmitting portion, the edge portion being a light-reflecting portion; the first energy laser is divided into a first central laser and a first edge laser surrounding the first central laser by a beam splitter, and the first central laser penetrates through the central part to be used as alignment laser aligned with the alignment plate; the first edge laser is reflected by the edge part and reaches the condenser lens along a second light path, the second energy laser penetrates through the central part of the optical gate and reaches the condenser lens, the second energy laser is collected by changing the path of the condenser lens, the first edge laser is focused into second edge laser at the edge, and the second energy laser is focused into second central laser at the center.

According to the embodiment of the invention, the laser cutting device further comprises an object stage, wherein the object stage is used for bearing a workpiece to be processed, the second center laser is aligned to the center position of the workpiece to be cut or drilled, and the second edge laser surrounds the peripheral position of the center position.

According to an embodiment of the invention, the beam splitter is a combination of a concave lens and a convex lens.

According to an embodiment of the invention, the shutter is angled at 45 degrees to both the first and second optical paths.

According to the embodiment of the present invention, the wavelength of the first energy laser light is 350nm, and the wavelength of the second energy laser light is 1060 nm.

According to an embodiment of the present invention, the edge portion has a reflective film that reflects 350 nm.

According to an embodiment of the present invention, the alignment plate is a transparent substrate having a carved alignment mark thereon.

The invention has the following advantages: according to the invention, the first energy laser is utilized to carry out beam splitting treatment, the first central laser obtained by beam splitting penetrates through the optical gate to carry out alignment operation, and the first edge laser obtained by beam splitting is reflected by the optical gate to carry out edge repairing on workpiece cutting or drilling, so that a more regular through hole side wall or cutting channel side wall is obtained.

Drawings

FIG. 1 is a schematic view of a femtosecond laser processing apparatus according to the present invention;

fig. 2 is a schematic side view of a workpiece being laser machined according to the present invention.

Detailed Description

Referring to fig. 1 and 2, the femtosecond laser processing apparatus according to the present invention includes a first laser 20, a second laser 10, a beam splitter 3, an optical shutter 5, an alignment plate 4, and a condenser 6, wherein the first laser 20, the beam splitter 3, the optical shutter 5, and the alignment plate 4 are sequentially arranged along a first optical path, and the second laser 10, the optical shutter 5, and the condenser 6 are sequentially arranged along a second optical path; the first laser 20 emits first energy laser light 21 along the first optical path, and the second laser 10 is a femtosecond laser which emits second energy laser light 11 along a second optical path; wherein the first optical path is perpendicular to the second optical path;

wherein: the shutter 5 includes a central portion 51 and an edge portion 52 surrounding the central portion 51, the central portion 51 being a light-transmitting portion, the edge portion 52 being a light-reflecting portion; the first energy laser 21 is divided into a first center laser 23 and a first edge laser 22 surrounding the first center laser 23 by a beam splitter 3, and the first center laser 23 is used as an alignment laser aligned with the alignment plate 4 through the center part 51; the first edge laser 22 is reflected by the edge portion 52 and reaches the condenser 6 along the second optical path, the second energy laser 11 passes through the central portion 51 of the shutter 5 and reaches the condenser 6, and is collected by changing the path of the condenser 6, the first edge laser 22 is focused into the second edge laser 24 at the edge, and the second energy laser 11 is focused into the second central laser 12 at the center.

According to an embodiment of the invention, further comprising an object table (not shown) carrying a workpiece 7 to be machined, wherein the second central laser 12 is aligned with a central position 9 of the workpiece 7 to be cut or drilled and the second edge laser 24 surrounds the peripheral position 9 of the central position 8.

The beam splitter 3 is a combination of a concave lens and a convex lens, and the optical gate 5 and the first light path and the second light path are both at an included angle of 45 degrees. The wavelength of the first energy laser light 21 is 350nm, the wavelength of the second energy laser light 11 is 1060nm, and the edge portion 52 has a reflective film that reflects 350 nm.

The alignment plate 4 is a transparent substrate having an alignment mark engraved thereon. In use, the central portion of the first energy laser 21, i.e. the first central laser 23, is used to align the inscribed alignment marks in advance to complete the alignment of the lasers, wherein the first and second lasers are relatively fixed and can be adjusted through this step together. In alignment, the first edge laser 22 may be blocked by a mask disposed between the beam splitter 3 and the shutter 5.

During laser machining, the second energy laser 11 is used as a femtosecond laser to perform main central area undercutting, and the second edge laser 24 is used as a repair laser for edge areas, so that the edge laser energy is smaller, which mainly lies in repairing the side wall, thereby avoiding the risk of irregularity and collapse of the side wall.

Finally, it should be noted that: it should be understood that the above examples are only for clearly illustrating the present invention and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.