Silicon carbide & sillicon
Micro-maze ablated in silicon carbide with the Jasper X1. Channels down to 200 µm wide, with sharp edges and a clean surface. A needle tip shows the scale.
Silicon carbide (SiC, monocrystaline) and silicon (Si) are the core materials of modern semiconductors. SiC is a wide-bandgap material that is extremely hard and handles high heat and high voltage. It is used in EV inverters and fast chargers, solar power electronics and GaN-on-SiC RF chips for 5G and radar. Silicon is still the workhorse of ICs, MEMS, interposers and probe-card components. Both materials need more and more precise micro-features: through-wafer vias, cavities, grooves and functional surface textures. These features have to be made quickly and without cracks.
Key results
16.8 mm³/min SiC
ablation rate with the Jasper X1
>1000 holes/s in SiC
crack-free and chipping-free through-holes in a 130 µm wafer
>7000 holes/s in Si
through-wafer drilling of 300 µm silicon with no cracks
Challenges: hard, brittle and easy to crack
One of the hardest materials to machine. SiC is almost as hard as diamond. Mechanical tools wear out fast, run slowly and often chip the edges.
Cracks and chipping. Both SiC and Si are brittle, and too much stress during processing quickly turns into micro-cracks. The most critical place is the exit side of a through-hole in a thin wafer.
Debris around the feature. Removed material tends to land back on the surface. This debris gets in the way of later metallization and bonding steps.
Speed or quality. Laser processing usually forces a trade-off. Pushing more power to work faster costs quality, while keeping quality high makes the process too slow for production.
Our solution: femtosecond precision at production speed
At the Fluence Ultrafast Laser Application Laboratory we processed SiC and Si with the Jasper X1, using its long MHz burst mode (up to 100 pulses per burst) and High Energy Burst (HEB). Each burst splits the laser energy into a fast train of femtosecond pulses. The material is removed efficiently and gently, so the laser's full 60 W can go into the process without damaging it. The outcome is high speed and high quality in the same process.
Fast, clean ablation of SiC
With the Jasper X1 we remove up to 16.8 mm³ of SiC per minute and leave a smooth, uniform cavity floor. The Jasper X1 can switch between femtosecond and picosecond pulses, so we compared both on the same laser. Femtosecond pulses removed 4x more material in the same time.
Two channels ablated in SiC in the same time. Femtosecond pulses (left) went 100 µm deep, picosecond pulses (right) only 25 µm.
Femtosecond pulses (red) with long bursts make the most efficient use of laser energy when ablating SiC.
Crack-free holes through SiC wafers
Through-SiC vias are a key element of GaN-on-SiC RF chips and advanced SiC power modules. The Jasper X1 drills through a 130 µm SiC wafer in just 400 µs per hole, which means more than 1,000 holes per second. The holes are round and clean on both sides, with no cracks and no chipping. In High Energy Burst mode, the vias also have smooth walls and very low taper.
Through-hole in a 130 µm SiC wafer, entrance side: round and crack-free, with no chipping.
Array of through-holes in a 120 µm SiC wafer, under 0.45 ms per hole.
Hole in SiC drilled in High Energy Burst mode: smooth walls, low taper and no cracks.
7,000+ holes per second in silicon
The same approach works for silicon. The Jasper X1 drills through a 300 µm silicon wafer in only 140 µs per hole, which means more than 7,000 holes per second at just 30 W. The holes are round, with no cracks on either side and almost no recast. Silicon ablation is fast as well, at 18 mm³/min.
Through-holes in a 300 µm silicon wafer: round and crack-free.
Micro-structures made to order
For functional surfaces such as micro-pillars, textures and patterns for thermal management, sensors or bonding, we tune the process to what the customer needs most: top speed, the finest detail, or the best balance of both. The result is well-defined structures with no edge chipping and no debris.
Micro-pillars structured in SiC: a smooth floor and round pillars, with no chipping and no debris.
Laser micro-structured surface with a needle tip for scale, Si
Summary
The Jasper X1 combines femtosecond precision with production speed: fast ablation, thousands of crack-free holes per second, and clean micro-structures in both SiC and silicon. Do you have a SiC or Si part to test? Send us your samples and our application lab will develop the process with you.