Microfluidic Laser Equipment for Semiconductor Wafer Processing

Overview of Microjet Laser Technology Equipment

Microjet laser technology is an advanced, widely adopted hybrid micromachining method that couples a “hair-thin” water jet with a laser beam. Using a total internal reflection guiding mechanism similar to an optical fiber, the water jet precisely delivers the laser energy to the workpiece surface. During processing, the jet continuously cools the interaction zone and efficiently removes generated debris and powder, supporting a cleaner and more stable process.

As a cold, clean, and highly controllable laser process, microjet laser technology effectively mitigates common issues associated with dry laser machining, including heat-affected damage, contamination and redeposition, deformation, oxidation, microcracks, and kerf taper. This makes it particularly well suited for hard and brittle semiconductor materials and advanced packaging applications where yield and consistency are critical.

Basic Description of Microjet Laser Machining

1) Laser Source

• Diode-pumped solid-state (DPSS) Nd:YAG laser

• Pulse width: μs/ns options

• Wavelength: 1064 nm / 532 nm / 355 nm options

• Average power: 10–200 W (typical rated levels: 50/100/200 W)

2) Water Jet System

• Filtered deionized (DI) water, low-pressure/high-pressure supply as required

• Typical consumption: ~1 L/h (at a representative pressure of 300 bar)

• Resulting force is negligible: < 0.1 N

3) Nozzle

• Nozzle diameter range: 30–150 μm

• Nozzle materials: sapphire or diamond

4) Auxiliary Systems

• High-pressure pump module

• Water treatment and filtration system

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Technical Specifications (Two Reference Configurations)

Processing Capability (Reference)

• Surface roughness: Ra ≤ 1.6 μm (Config A) / Ra ≤ 1.2 μm (Config B)

• Drilling/opening speed: ≥ 1.25 mm/s

• Circumferential cutting speed: ≥ 6 mm/s

• Linear cutting speed: ≥ 50 mm/s

Applicable materials include gallium nitride (GaN) crystals, ultra-wide-bandgap semiconductors (e.g., diamond, gallium oxide), aerospace specialty materials, LTCC carbon-ceramic substrates, photovoltaic materials, scintillator crystals, and more.

Microjet laser processing

Applications of Microjet Laser Technology Equipment

1) Wafer Cutting (Dicing)

• Materials: silicon (Si), silicon carbide (SiC), gallium nitride (GaN), and other hard/brittle wafers

• Value: replaces diamond blade dicing and reduces chipping

  • Edge chipping: < 5 μm (blade dicing typically > 20 μm)

• Productivity: cutting speed can increase by ~30%

  • Example: SiC dicing up to 100 mm/s

• Stealth dicing: internal laser modification plus jet-assisted separation, suitable for ultra-thin wafers (< 50 μm)

2) Chip Drilling and Micro-Hole Processing

• Through-silicon via (TSV) drilling for 3D IC

• Thermal micro-hole array machining for power devices such as IGBTs

• Typical parameters:

  • Hole diameter: 10–200 μm

  • Aspect ratio: up to 10:1

  • Sidewall roughness: Ra < 0.5 μm (better than direct laser ablation, often Ra > 2 μm)

3) Advanced Packaging

• RDL window opening: laser + jet removes passivation and exposes pads

• Wafer-level packaging (WLP): epoxy molding compound (EMC) processing for Fan-Out packages

• Advantages: reduces mechanical-stress-induced warpage; yield can exceed 99.5%

4) Compound Semiconductor Processing

• Materials: GaN, SiC, and other wide-bandgap semiconductors

• Use cases:

  • Gate recess/notch processing for HEMT devices: jet-controlled energy delivery helps avoid GaN thermal decomposition

  • Laser annealing: microjet-assisted localized heating to activate ion-implanted regions (e.g., SiC MOSFET source areas)

5) Defect Repair and Fine Tuning

• Laser fusing/ablating redundant circuits in memory (DRAM/NAND)

• Microlens array trimming for optical sensors such as ToF

• Accuracy: energy control ±1%; repair position error < 0.1 μm

FAQ | Microjet (Water-Jet Guided) Laser Technology Equipment

Q1: What is microjet laser technology?
A: It is a hybrid laser micromachining process in which a thin, high-velocity water jet guides a laser beam via total internal reflection, delivering energy precisely to the workpiece while providing continuous cooling and debris removal.

Q2: What are the key advantages versus dry laser processing?
A: Reduced heat-affected damage, less contamination and redeposition, lower risk of oxidation and microcracks, minimized kerf taper, and improved edge quality on hard and brittle materials.

Q3: Which semiconductor materials are best suited for microjet laser processing?
A: Hard and brittle materials such as SiC and GaN, as well as silicon wafers. It can also be applied to ultra-wide-bandgap materials (e.g., diamond, gallium oxide) and selected advanced ceramic substrates.