A method is provided for the internal processing of a transparent substrate in preparation for a cleaving step. The substrate is irradiated with a focused laser beam that is comprised of pulses having an energy and pulse duration selected to produce a filament within the substrate. The substrate is translated relative to the laser beam to irradiate the substrate and produce an additional filament at one or more additional locations. The resulting filaments form an array defining an internally scribed path for cleaving said substrate. Laser beam parameters may be varied to adjust the filament length and position, and to optionally introduce V-channels or grooves, rendering bevels to the laser-cleaved edges. Preferably, the laser pulses are delivered in a burst train for lowering the energy threshold for filament formation, increasing the filament length, thermally annealing of the filament modification zone to minimize collateral damage, improving process reproducibility, and increasing the processing speed compared with the use of low repetition rate lasers.

Method of material processing by laser filamentation

Systems and methods for laser scribing provide extended depth affectation into a substrate or workpiece by focusing a laser beam such that the beam passes into the workpiece using a waveguide, self-focusing effect to cause internal crystal damage along a channel extending into the workpiece. Different optical effects may be used to facilitate the waveguide, self-focusing effect, such as multi-photon absorption in the material of the workpiece, transparency of the material of the workpiece, and aberrations of the focused laser. The laser beam may have a wavelength, pulse duration, and pulse energy, for example, to provide transmission through the material and multi-photon absorption in the material. An aberrated, focused laser beam may also be used to provide a longitudinal spherical aberration range sufficient to extend the effective depth of field (DOF) into the workpiece.

Laser scribing with extended depth affectation into a workpiece

Systems and methods are described for forming continuous curved laser filaments in transparent materials. The filaments are preferably curved and C-shaped. Filaments may employ other curved profiles (shapes). A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths in the range of 100 μm-10 mm. An aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

Method and apparatus for performing laser filamentation within transparent materials

Forming holes in a material includes focusing a pulsed laser beam into a laser beam focal line oriented along the beam propagation direction and directed into the material, the laser beam focal line generating an induced absorption within the material, the induced absorption producing a defect line along the laser beam focal line within the material, and translating the material and the laser beam relative to each other, thereby forming a plurality of defect lines in the material, and etching the material in an acid solution to produce holes greater than 1 micron in diameter by enlarging the defect lines in the material. A glass article includes a stack of glass substrates with formed holes of 1-100 micron diameter extending through the stack.

Method for rapid laser drilling of holes in glass and products made therefrom

Die singulation, also known as wafer dicing, is reviewed in terms of the brief history, critical challenges, characterization of singulation quality, different singulation technologies and underlying mechanisms, and post-singulation die strength enhancement. Mechanical blade dicing has been the workhorse of die separation in the semiconductor manufacturing process. It faces growing challenges due to the adoption of copper/low-k dielectric interconnect structures, thin and ultra-thin wafers, die attach films, narrow dicing streets, and complex stacked structures on the dicing streets. Key dicing quality characteristics are chipping, delamination, kerf geometry, die side wall damage, die surface contamination, and die strength degradation. Various die singulation technologies have been developed to address these challenges and quality issues, including dicing by thinning, laser based approaches, laser and mechanical hybrid method, and plasma dicing. Die strength is a critical parameter for thin and ultra-th...

Die singulation technologies for advanced packaging: A critical review

A laser machining system may include an opposite side camera to provide workpiece alignment from an opposite side of the system (i.e., the side opposite the laser machining process). The opposite side camera may be used with an air bearing positioning stage, and a portion of the stage and/or the opposite side camera may be moved to allow the opposite side camera to image a feature on the workpiece to be aligned. The opposite side alignment may be used with back side scribing and/or dual side scribing of a workpiece with alignment from one or both sides of the workpiece. Laser machining systems and methods may also be used to provide quasi-stealth scribing and multi-beam scribing.

Laser machining and scribing systems and methods

Laser lift off systems and methods may be used to provide monolithic laser lift off with minimal cracking by reducing the size of one or more beam spots in one or more dimensions to reduce plume pressure while maintaining sufficient energy to provide separation. By irradiating irradiation zones with various shapes and in various patterns, the laser lift off systems and methods use laser energy more efficiently, reduce cracking when separating layers, and improve productivity. Some laser lift off systems and methods described herein separate layers of material by irradiating non-contiguous irradiation zones with laser lift off zones (LOZs) that extend beyond the irradiation zones. Other laser lift off systems and methods described herein separate layers of material by shaping the irradiation zones and by controlling the overlap of the irradiation zones in a way that avoids uneven exposure of the workpiece. Consistent with at least one embodiment, a laser lift off system and method may be used to provide monolithic lift off of one or more epitaxial layers on a substrate of a semiconductor wafer.

Laser lift off systems and methods

Laser processing of hard dielectric materials may include cutting a part from a hard dielectric material using a continuous wave laser operating in a quasi-continuous wave (QCW) mode to emit consecutive laser light pulses in a wavelength range of about 1060 nm to 1070 nm. Cutting using a QCW laser may be performed with a lower duty cycle (e.g., between about 1% and 15%) and in an inert gas atmosphere. Laser processing of hard dielectric materials may further include post-cut processing the cut edges of the part cut from the dielectric material, for example, by beveling and/or polishing the edges to reduce edge defects. The post-cut processing may be performed using a laser beam with different laser parameters than the beam used for cutting, for example, by using a shorter wavelength (e.g., 193 nm excimer laser) and/or a shorter pulse width (e.g., picosecond laser).

System and method for laser beveling and/or polishing

Laser processing of sapphire is performed using a continuous wave laser operating in a quasi-continuous wave (QCW) mode to emit consecutive laser light pulses in a wavelength range of about 1060 nm to 1070 nm (hereinafter "QCW laser"). Laser processing of sapphire using a QCW laser may be performed with a lower duty cycle (e.g., between about 1% and 10%) and in an inert gas atmosphere such as argon or helium. Laser processing of sapphire using a QCW laser may further include the use of an assist laser having a shorter wavelength and/or pulse duration to modify a property of the sapphire substrate to form absorption centers, which facilitate coupling of the laser light pulses of the QCW laser into the sapphire.

Marco Mendes

Papers

Laser scribing with extended depth affectation into a workpiece

Laser machining and scribing systems and methods

Laser lift off systems and methods

System and method for laser beveling and/or polishing

Laser system and method for processing sapphire