As semiconductor devices continue to evolve toward thinner wafers, more fragile structures, and higher integration density, conventional wafer dicing technologies are increasingly challenged. MEMS devices, memory chips, power semiconductors, and ultra-thin packages demand higher chip strength, minimal contamination, and superior yield stability.

Stealth Dicing™ technology introduces a fundamentally different approach to wafer separation. Unlike blade dicing or surface laser ablation, Stealth Dicing utilizes an internal laser modification process to initiate controlled fracture within the wafer. The wafer is then separated by applying external tensile stress, eliminating surface damage, debris, and kerf loss.

This dry, non-contact process provides significant advantages in yield, strength, cleanliness, and processing efficiency, making it a key enabling technology for next-generation semiconductor manufacturing.

1. Limitations of Conventional Wafer Dicing Methods

1.1 Blade Dicing

Blade dicing uses a high-speed rotating diamond blade to physically cut through the wafer. While widely adopted in the industry, this mechanical approach presents several inherent challenges:

• Mechanical vibration introduces stress to the device

• Cooling water is required, increasing contamination risk

• Chipping occurs along cut edges

• Kerf loss reduces usable wafer area

• Debris and particles may damage fragile structures

• Yield is limited by edge quality

• Processing speed is restricted by blade wear

For advanced MEMS devices or ultra-thin wafers, these issues become even more critical.

1.2 Ablation Laser Dicing

Laser ablation dicing focuses a laser beam on the wafer surface to melt and evaporate material, forming grooves that separate the wafer.

Although it eliminates mechanical contact, it introduces thermal effects:

• Heat Affected Zone (HAZ) degrades material strength

• Surface melting can damage metal layers

• Scattered particles contaminate devices

• Additional protective coating processes may be required

• Chip strength is reduced due to thermal stress

• Throughput is limited by material removal rate

As device geometries become more delicate, surface-based removal methods present increasing risks.

2. Principle of Stealth Dicing™ Technology

Stealth Dicing operates on a completely different physical principle: internal modification instead of surface material removal.

The process consists of two main stages:

1. Laser irradiation process (SD layer formation)

2. Expansion process (controlled separation)

2.1 Laser Irradiation Process – Formation of the SD Layer

A laser beam with a wavelength capable of penetrating the wafer material is focused inside the wafer rather than on its surface.

At the focal point, a modified layer is created within the crystal structure. This internal modified region is referred to as the Stealth Dicing Layer (SD Layer).

Key characteristics:

• No surface ablation

• No material removal

• Internal micro-crack initiation

• Controlled crack propagation along planned dicing lines

Cracks extend from the SD layer toward both the top and bottom surfaces. By scanning the laser along the intended cutting path, a continuous internal fracture plane is formed.

For thick wafers or MEMS devices, multiple SD layers can be created along the thickness direction to ensure complete separation control.

2.2 Four SD Layer Modes

Depending on wafer thickness, device structure, and metal film presence, different SD layer configurations are used:

By selecting and combining these modes, optimal processing conditions can be achieved for various semiconductor structures.

2.3 Expansion Process – Stress-Induced Separation

After SD layer formation, the wafer is mounted on expansion tape. The tape is stretched radially outward.

The applied tensile stress causes the internal cracks to extend naturally to the wafer surfaces, separating individual chips.

Separation occurs through controlled crack propagation rather than material removal.

This provides several benefits:

• No mechanical impact on devices

• No thermal stress

• No chipping

• No debris generation

• No kerf loss

3. Technical Advantages of Stealth Dicing™

Stealth Dicing fundamentally resolves the problems associated with blade and ablation dicing.

3.1 Completely Dry Process

Unlike blade dicing, no cooling water is required. This eliminates:

• Water contamination

• Re-deposition of particles

• Drying processes

• Secondary cleaning steps

The process is clean and environmentally friendly.

3.2 No Kerf Loss

Traditional cutting removes material to create a dicing street. This reduces usable wafer area.

Stealth Dicing forms an internal fracture plane without removing material, meaning:

• Maximum wafer utilization

• Higher chip count per wafer

• Improved cost efficiency

3.3 No Chipping and No HAZ

Because there is no surface grinding or melting:

• No edge chipping

• No Heat Affected Zone

• No strength degradation

• Superior bending strength

This is particularly important for ultra-thin wafers below 50 μm.

3.4 Higher Chip Yield

By eliminating debris, stress, and thermal damage:

• Device reliability improves

• Yield increases

• Fragile MEMS membrane structures remain intact

• Metal and protective films are unaffected

3.5 Improved Throughput

Advanced optical systems such as Laser Beam Adjuster (LBA) enhance beam shaping and throughput.

Additionally, SDBG (Stealth Dicing Before Grinding) enables processing of ultra-thin devices by forming the SD layer prior to thinning.

These advancements significantly improve productivity for high-volume manufacturing.

4. Comparison of Dicing Technologies

5. Applications

Stealth Dicing is widely used in:

• MEMS sensors with fragile membrane structures

• NAND and DRAM memory devices

• Power semiconductor devices

• CMOS logic devices

• Optical devices

• Wafers with metal or protective films

• Ultra-thin packages (<50 μm)

The technology is especially advantageous for high-value and structurally sensitive devices.

6. Industry Trends and Future Outlook

As semiconductor manufacturing moves toward:

• Advanced packaging

• Chiplet architectures

• High-density integration

• Ultra-thin die stacking

• Wide bandgap materials (SiC, GaN)

Damage-free wafer separation becomes increasingly critical.

Stealth Dicing is positioned as a key enabling technology in next-generation semiconductor processing.

Its dry process nature also supports environmentally responsible manufacturing initiatives by reducing water usage and waste generation.

Conclusion

Stealth Dicing™ represents a paradigm shift in wafer separation technology.

By replacing mechanical cutting and surface ablation with internal laser modification and stress-controlled fracture, it eliminates chipping, debris, thermal damage, and kerf loss.

The result is:

• Higher chip strength

• Improved yield

• Cleaner processing

• Better suitability for ultra-thin and fragile devices

• Enhanced manufacturing efficiency

For semiconductor manufacturers seeking higher reliability, better performance, and improved cost efficiency, Stealth Dicing provides a powerful and future-ready solution.