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The semiconductor industry is an industry that is developed based on materials whose conductivity at room temperature lies between that of conductors and insulators. It primarily produces integrated circuit chips and various discrete devices, which are widely used in computers, mobile terminals, consumer electronics, and other fields. Semiconductors serve as the core of the information technology industry, and their development scale and technological level have become an important indicator of a country's industrial competitiveness and comprehensive national strength.

low-K Wafer Dicing

Silicon wafer — the "foundation" for manufacturing semiconductor integrated circuits. 6-inch and 8-inch wafers are being phased out, with 12-inch wafers becoming the mainstream. Larger wafer sizes lead to higher wafer utilization, lower chip production costs, and improved efficiency.

As wafer application specifications evolve, so do their processing methods. Previously, abrasive machining was used, but it suffered from low yield and unstable cutting profiles. This was later succeeded by mechanical dicing. However, directly processing low‑K wafers with mechanical dicing can cause metal chipping. Currently, laser grooving is gradually becoming the mainstream method, as it can remove the low‑K layer and relieve stress before mechanical dicing.

Comparison of Wafer Processing Methods (From Online)

Laser grooving mainly consists of three processing steps:

· Narrow Grooving: First, two fine protective grooves are cut inside the dicing street using the dual narrow laser method. This step determines whether the laser grooving process carries a risk of chipping.

· Wide Beam Grooving: The primary method for groove formation, which determines the groove profile and depth.

· After laser grooving is completed, a dicing blade is used to perform the full-cut processing.

low-k晶圆开槽加工示意图

Regarding this process, LBTEK has introduced a low‑K wafer dicing solution, which addresses key challenges encountered during processing.

Laser Grooving Optical Path for low-K Wafers

Key issues	Important matters	Measures
Laser Control Method	Power and pulse instability of long-pulse ultraviolet lasers	Under a defined laser pulse, control the laser output using an optical beam-splitting method
High-Precision Adjustable Beam Splitting Ratio	A simple polarization beam splitting crystal cannot achieve high-precision adjustability	By adding a half-wave plate and changing the polarization angle of the incident laser, high-precision adjustment of the beam splitting ratio can be achieved
Adjustable Beam Splitting Spacing	Different wafers require laser cutting of scribe lines with varying widths. The actual separation distance between the processed spots needs to range from 20 to 120 μm	By adding a wedge prism into one of the beams and controlling the deflection of light, the beam splitting spacing can be adjusted
Consistent Power of Split Beams	The adjustable beam splitting achieved through deflection can cause differences in the power of the split beams, ultimately resulting in variations in the size and shape of the spots after splitting	By adding a quarter-wave plate, linearly polarized light is converted into circularly polarized light. The electric field vector of circularly polarized light rotates uniformly, ensuring equal energy distribution in all directions
Issue of Thermal Damage During Processing	After focusing a Gaussian beam, the energy distribution of the spot is not uniform. The central region contains 86.5% of the total energy, while the remaining areas only account for 13.5% of the total energy. This leads to edge surface chipping and extensive heat-affected zones during processing	By applying beam shaping technology, the Gaussian beam spot is transformed into a flat-top beam spot. This approach, on one hand, reduces thermal damage at the edges of the scribed lines, and on the other hand, ensures better flatness at the bottom of the scribed lines
External Optical Path Alignment	Laser grooving places high demands on spot quality, with a low tolerance for alignment errors	More precise optical mounts and professional alignment techniques are employed

LBTEK offers core components for laser grooving solutions for low-k wafers, including laser control modules, beam expansion and collimation modules, optical beam splitting modules, divergence and polarization control modules, relay lens modules, focusing and protection modules, optical switches, and more. Additionally, LBTEK provides comprehensive end-to-end service support, from conceptual design to practical implementation.

Laser Annealing

Annealing is a heat treatment process that involves heating a material to a specific temperature followed by controlled cooling. Two of its most critical applications in advanced manufacturing are repairing ion implantation damage and forming ohmic contacts. Selecting an appropriate annealing method is a key step in producing high-quality ohmic contacts for materials such as silicon carbide (SiC) and gallium nitride (GaN), enabling lower contact resistance and better stability. From the perspectives of wafer protection and energy efficiency, there is a demand for a localized wafer annealing process with shallow penetration depth.

Applications of Annealing（From Internet）

Traditional annealing processes are not ideal for repairing implantation damage. Even at temperatures as high as 1150°C, defects in the ion-implanted layer cannot be completely eliminated, and secondary defects are often generated. Additionally, these processes require long heat treatment durations, and significant impurity redistribution occurs during annealing. In contrast, laser annealing has emerged as the predominant annealing method due to its ability to perform localized annealing. The spot size and spatial positioning of the laser source in laser annealing are precisely controllable, enabling localized heating of the sample. With its high energy density, laser annealing significantly reduces annealing time. Post-annealing samples exhibit larger grain sizes, fewer defects, and the resulting devices demonstrate superior electrical performance.

Optical micrographs of 4H-SiC under laser annealing at different energy densities（From Internet）

To address this process, LBTEK has introduced a laser annealing solution designed to resolve key challenges encountered during processing.

激光退火光路

Key issues	Important matters	Measures
Laser Control Method	Unstable power and pulse of pulsed ultraviolet lasers	Under a defined laser pulse, the laser output is controlled and laser monitoring is achieved using an optical beam-splitting method involving a half-wave plate and a polarizing beam splitter (PBS)
Inhomogeneous Laser Annealing Energy	The original Gaussian beam spot exhibits uneven energy distribution	A homogenizing diffractive optical element (DOE) is employed to improve the uniformity of the beam spot
Adjustable Energy Density	The energy density of the beam spot on the sample surface must reach the optimal energy density window	An energy attenuator is used to achieve precise and continuous adjustment of the pulsed laser energy
Achieving a High-Aspect-Ratio Line-Shaped Beam Spot	For large-area samples, the beam spot morphology significantly impacts processing efficiency	A linear homogenizing diffractive optical element (DOE) is used to achieve a line-shaped beam spot with an aspect ratio of 12:1

LBTEK provides core components for laser annealing solutions, including lasers, beam expansion and collimation modules, optical beam splitting modules, beam shaping modules, power detection modules, focusing and protection modules, and more. Additionally, LBTEK offers comprehensive end-to-end service support, from conceptual design to practical implementation.