Photolithography etches circuit components into a semiconductor wafer

Lasers help build the layers of circuit components in microchips

During the photolithography process, light is projected through a blueprint onto a light-sensitive chemical layer on silicon wafers, etching patterns that become transistors through a series of successive reactions. These processes require significant electricity, as only about 2% of photons reach the wafer.

Microchip fabricators create light by heating tin droplets to over 220,000 Kelvin

Every second, lasers strike 50,000 droplets moving at 250 kilometers (155 miles) per hour, vaporizing the tin in supernova-like miniature explosions that produce ultraviolet light. Knowing this light will spread via diffraction as it passes through a filter during manufacturing, designers reverse-engineer the filter design based on the required final microchip pattern.

Within fabrication plants, it takes about three months to manufacture hundreds of microchips from a single wafer of pure silicon using light and significant quantities of electricity, water, and hazardous chemicals.

Stereolithography uses light to fabricate objects in layers via chemical reactions

Specific locations in a tank of light-sensitive liquid resin are exposed to projected light, causing them to cure onto a build platform. The resulting cross-section of hardened plastic is moved slightly away from the light source, exposing it to resin once more, and the process repeats to produce successive layers.

Watch a tour of an integrated circuit fabrication plant

Explore the protocols in place to ensure clean rooms have no dust to jeopardize the integrity of silicon wafers as they are transformed into working microchips. Layering, photolithography, etching, and chemical vapor deposition are shown alongside digital visualizations.

Laser-etched electric charges guide toner during laser printing

When sending a print job, the file data generates an image that a laser maps positively charged regions onto a drum separately for each color toner. Once the negatively charged toner is applied where it was electrically attracted, heat and pressure fuse it onto the paper.

Photonic integrated circuits use light instead of electrons within circuit components

Instead of processing electric signals, photons in the visible and near-infrared serve as optical signals between chips made of electro-optical crystals. PICs can enable lower power consumption and heat generation by eliminating the friction from electrons moving along wires.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.

Silicon must be 99.9999999% pure to be used in creating microchips

After the mined quartz is processed in an electric-arc furnace to remove oxygen from the silica, it undergoes the Siemens process, where it is bathed in hydrochloric acid. The liquid produced in the reaction undergoes multiple distillations to produce ultra-pure silicon in the end.

Solar panel manufacturing begins with silicon extracted from sand

The silicon is purified and shaped into wafers less than 0.2 millimeters thick, coated and connected through a criss-cross pattern of narrow and wider metal, followed by multiple rounds of lamination before bonding to a weatherproof panel.

Chip-based 3D printers can be pocket-sized and involve no moving parts

Researchers have demonstrated a proof-of-concept version of a chip-based 3D printer that emits visible light onto light-sensitive resin to construct solid shapes. The technology may provide a portable, low-cost solution for future, small-scale fabrication needs.

Holograms are produced by shining light through recordings of interference patterns

When one half of a split laser beam that was reflected off the surface of an object recombines with its other, unreflected half, the two produce an interference pattern that becomes etched onto holographic film. When light shines through the back of the film, it reacts with the pattern to create the reflected light, projecting the original object.

Lichtenberg figures capture lightning-like patterns within insulators

When high-energy electrons from particle accelerators are fired into materials like acrylic, they form a charged plane before discharging into scarred patterns within the material. By evenly charging a cylindrical bottle through rotation during the irradiation process, a 3D figure of lightning in a bottle can be created.

How to cook food with lasers

Creative Machines Lab at Columbia Engineering have developed a system of software-controlled lasers to cook food with precision, retain moisture with the final-cooked product, brown food within its original packaging, and create an entirely new meal creation process for a consumer. Watch this three-minute video to see for yourself.

Fiber lasers used for metal engravings can’t burn your skin

These devices use diodes and mirrors to create pulses of light that vaporize metal in billionths of a second, though at wavelengths that cannot react with organic material. Pulse width, power, and speed adjustments can produce white, black, and even colored patterns through controlled heat reactions.

An integrated circuit combines major circuit components onto a single device

Before 1958, these components were fabricated separately before manual assembly, introducing human error, delays, and higher costs. The invention of the IC laid the foundation for automated manufacturing, miniaturization, and improvements to speed and energy efficiency.

Stimulating electrons to emit identical photons produces lasers

This effect was predicted by Albert Einstein in 1917, and requires all excited electrons in a material to exist in the same excited metastable state within their atoms. Pumping all atoms through the same mechanism, such as electricity or flash lamps, can create this environment.

Laser disc technology stores binary data in etched pits and lands

The pits are dips in the LaserDisc, CD, DVD, or Blu-ray surface that do not reflect the laser from the optical drive back to the photoelectric cell, resulting in a coded zero. Lands are reflective plateaus on the surface that code for a one.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

There is a limit to how small transistors can become because they rely on being able to allow or block the flow of electrons, but quantum effects allow electrons to leak through these barriers, generating heat, current loss, and potential data errors.

Laser technology powers communication, medical and manufacturing tools

Lasers are used when scanning groceries, printing documents or undergoing cosmetic procedures to enhance efficiency, precision and accuracy. Missile defense, targeting and optical communication systems have made using laser technology habitual in the military.

Scientists can create movies of atomic and molecular phenomena using X-ray free-electron lasers, in which images are produced by matter being struck by high-intensity light created by accelerating electrons.

In an X-ray free-electron laser, electromagnetic fields are used to accelerate and move electrons in wiggling patterns, causing them to emit synchronized, high-energy X-rays. This resulting light beam can strike targets up to 120 times per second to create movies of changing molecular structures and phenomena.

Through sonoluminescence, concentrated sound waves can produce short, high-intensity flashes of light by rapidly collapsing microscopic bubbles to temperatures up to twice that of the sun's surface.

In the photovoltaic effect, light generates electricity by creating a charge imbalance after knocking electrons out of atoms in the semiconducting materials of solar cells.

Scientists have diverted the path of lightning using lasers

A proof of concept for a laser protection system, which could be used to protect launchpads and airports in the future, was conducted on the Säntis mountain in northeastern Switzerland. Rapid laser pulses heated air molecules, creating a more conductive, 50-meter (164-foot) path for the electrical discharge to travel through.

The origin of LASIK eye surgery, from a lab incident to federal funding and widespread use

After a University of Michigan engineering student suffered retinal burns from an ultrashort pulse laser, researchers realized it could be used to reshape the cornea and improve a person's vision with greater precision than a scalpel and earlier laser technologies. Agencies, including the National Science Foundation, the National Institutes of Health, and the Department of Energy, provided funding to develop and commercialize the procedure.

Water vapor is used to manage heat in high-end smartphones

While smartphones have traditionally been cooled using a highly conductive plate that dissipates heat from the chip, vapor chambers offer a higher heat-removal capacity. This technology has been utilized in laptops for decades to absorb heat by cycling a fluid between liquid and gaseous phases.

'Magic ink' is redefining the tattoo

One University of Colorado professor has developed an ink that can be "turned on" with exposure to UV light, and "turned off" with sunlight. While the ink could help those who want to hide their body art from family members or coworkers, there are potential uses for medical procedures.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Semiconductor chips are electronic devices that store and process information

They can contain billions of microscopic switches on a chip smaller than a fingernail. An article provides a quick overview of how the devices work and how they’ve provided the backbone of the computer age.

Additive manufacturing consists of seven different process categories

Although 3D printing has become synonymous with the term, objects can be fabricated without filaments of hot plastic or light-sensitive powders. For example, during sheet lamination, ultrasonic waves—high-frequency vibrations—can join metal sheets by creating molecular bonds through friction.

Particle detection has evolved from cloud and bubble chambers to digital 3D displays

As invisible particles passed through cloud and bubble chambers, they disrupted supersaturated vapor and superheated liquid, respectively, creating trails that served as proxies for cosmic rays. The transition from photographed events to digital sensors enhanced data collection and accuracy.

Lasers can be used to reduce the motion of atoms because particles of light—photons—can collide with particles of matter, as billiard balls do, to slow them down.

Data centers can be kept cool by circulating fluid over plates atop high-temperature components or by submerging equipment in non-corrosive oil that does not conduct electricity.

Tom Liggett, a Bournemouth University student, sent sealed photographic film into space using a helium balloon, producing photographs from cosmic rays.

How helium greatly improves the efficiency of barcode-scanning lasers

Rather than directly energizing neon atoms, electrical discharge at lower, more practical power levels can excite helium atoms to energy levels nearly equal to those in neon atoms. Within a helium-neon laser, these gases are present in a 10-to-1 ratio, enabling helium to efficiently transfer energy to neon, which is then discharged as red light.

A laser energy system has allowed scientists to achieve fusion ignition

In 2022, scientists used lasers to create a powerful implosion that bound hydrogen isotopes together, releasing more energy than was input into the system. Research is ongoing to achieve this self-sustaining reaction with larger yields and energy gains.

Lasers have been used to create natural adhesives for paper

German researchers at four Fraunhofer institutes have developed a method to seal paper packaging using a carbon monoxide laser. Without the need for glue or plastic adhesives, the Papure project is expected to improve the recyclability of paper. (Some readers may experience a paywall.)

View a timeline of 3D printing technology through 2019

The first working 3D printing device was invented in 1983 and utilized stereolithography, a process in which a laser triggers a chemical reaction that hardens liquid resin. Powder-based laser sintering technology was patented in 1987, with metal-based powders first being used for 3D printing in 1997.

Removal of different color tattoo inks may require multiple lasers

Light needs to be absorbed by ink particles to break them down into small enough pieces for the immune system to eliminate. Color ink reflects, rather than absorbs, lasers of the same color, while black ink absorbs all colored lasers.

Andy Warhol’s famous works employed a 'machine-like' technique

Warhol’s silk-screen printing style—rough, noticeably imperfect, and painterly—was the result of a refined technique in service of a grainy tabloid aesthetic.

How artificial photosynthesis can help make plastics and fuels using sunlight

These systems link a molecular light absorber to a catalyst that can synthesize fuels—such as ethanol—and ethylene, a precursor to plastics, in a carbon-neutral manner. Because these byproducts have greater energy concentrations than the carbohydrates produced by photosynthetic organisms, research is ongoing to engineer the necessary catalysts.

Photodynamic therapy is one current treatment for age-related macular degeneration.

During LASIK surgery, a laser removes microscopic amounts of tissue from the cornea

Before surgery, a patient’s vision needs are incorporated with measurements and mapping of their eye’s surface to identify corrections to refractive errors. This ensures light entering the eye correctly focuses onto the retina to produce a clear image.

Random lasers can be created from biomaterials, such as peanuts and birch leaves

Rather than creating a narrow beam of light via amplification in an optical cavity, the random laser produces a red glow by scattering photons created in the natural pores of a peanut kernel after it has been injected with a solution of light-generating carbon dots derived from birch leaves.

Flexible integrated circuits can be built from carbon nanotubes and elastic materials

Stanford researchers arranged the nanotubes in fishnet-like networks that allow deformation without loss of function. The stretchable ICs have been shown to power micro-LED displays and may be used in smart clothing.

Watch the engineering challenges overcome in turning a 3D printer into a tattoo machine

The DIY project required reprogramming the printer to operate on a curved, 2D surface rather than making flat layers in 3D, editing replacement firmware to bypass temperature safety checks, and developing a rapid system to stop the tattoo in case of an emergency. The final product printed "LEG" on a volunteer's leg.

See top-down views of Washington state's geology with cutting-edge lidar

Lidar is a revolutionary tool that creates visual models of landscapes using rapid light pulse measurements. Geologists in Washington state have deployed the technology to study the state's fault lines, landslides, tsunami inundation zones, and much more.

Some graphics processing units advertised under different product names, such as Nvidia's RTX 5070-Ti and RTX 5080, are identically manufactured microchips with different defect counts.

Photons emitted via stimulated emission have identical characteristics

When confined to a pair of mirrors, a single photon passing a region of population-inverted atoms can produce a chain reaction of monochromatic light. This chain reaction amplifies the initial photon, from which lasers get their name: light amplification by stimulated emission of radiation.