Nav: Home

Irregular silicon wafer breakage studied in real-time by direct and diffraction X-ray imaging

March 03, 2016

Fracture and breakage of single crystals, particularly of silicon wafers, are multi-scale problems: the crack tip starts propagating on an atomic scale with the breaking of chemical bonds, forms crack fronts through the crystal on the micrometre scale and ends macroscopically in catastrophic wafer shattering.

Total wafer breakage is a severe problem for the semiconductor industry not only during handling but also during temperature treatments, leading to million-dollar costs per annum in a device production line. Knowledge of the relevant dynamics governing perfect cleavage along the {111} or {110} faces, and of the deflection into higher indexed {hkl} faces of higher energy, is scarce due to the high velocity of the process. Imaging techniques are commonly limited to depicting only the state of a wafer before the crack and in the final state.

A group of researchers demonstrates, for the first time, in situ high-speed crack propagation under thermal stress, imaged simultaneously in direct transmission and diffraction X-ray imaging [Rack, Scheel and Danilewsky (2016). IUCrJ, 3, 108-114; doi:10.1107/S205225251502271X]. The scientists show how the propagating crack tip and the related strain field can be tracked in the phase-contrast and diffracted images, respectively. Movies with a time resolution of microseconds per frame reveal that the strain and crack tip do not propagate continuously or at a constant speed. Jumps in the crack tip position indicate pinning of the crack tip for about 1-2 ms followed by jumps faster than 2-6 m s-1, leading to a macroscopically observed average velocity of 0.028-0.055 m s-1. The results also give a proof of concept that the described X-ray technique is compatible with studying ultra-fast cracks up to the speed of sound.

Rack et al. comment, "We are only at the beginning of studying ultra-fast crack propagation in single-crystalline materials in real time".
-end-


International Union of Crystallography

Related Chemical Bonds Articles:

Vampire bats form deep social bonds by grooming before sharing blood
For vampire bats, sharing blood with a roostmate is the mark of a true bond.
Underestimated chemical diversity
An international team of researchers has conducted a global review of all registered industrial chemicals: some 350,000 different substances are produced and traded around the world -- well in excess of the 100,000 reached in previous estimates.
The impact of molecular rotation on a peculiar isotope effect on water hydrogen bonds
Quantum nature of hydrogen bonds in water manifests itself in peculiar physicochemical isotope effects: while deuteration often elongates and weakens hydrogen bonds of typical hydrogen-bonded systems composed of bulky constituent molecules, it elongates but strengthens hydrogen bonds of water molecular aggregates.
Chemical evolution -- One-pot wonder
Before life, there was RNA: Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich show how the four different letters of this genetic alphabet could be created from simple precursor molecules on early Earth -- under the same environmental conditions.
What happens when you explode a chemical bond?
Light-induced breakage of chemical bonds can lead to damage in the body and environment, but techniques for studying this photochemical reaction have been limited to before and after snapshots.
Fiber-optic probe can see molecular bonds
Engineers at UC Riverside have developed the world's first portable, inexpensive, optical nanoscopy tool that integrates a glass optical fiber with a silver nanowire condenser.
Chemical juggling with three particles
Chemists from the University of Bonn and their US colleagues at Columbia University in New York have discovered a novel mechanism in catalysis.
Chemical synthesis of nanotubes
For the first time, researchers used benzene -- a common hydrocarbon -- to create a novel kind of molecular nanotube, which could lead to new nanocarbon-based semiconductor applications.
Chemical catalyst turns 'trash' into 'treasure,' making inert C-H bonds reactive
The Nature paper is the latest in a series from Emory University demonstrating the ability to use a dirhodium catalyst to selectively functionalize C-H bonds in a streamlined manner, while also maintaining virtually full control of the three-dimensional shape of the molecules produced.
Carnegie Mellon researchers probe hydrogen bonds using new technique
Researchers at Carnegie Mellon University have used nuclear resonance vibrational spectroscopy to probe the hydrogen bonds that modulate the chemical reactivity of enzymes, catalysts and biomimetic complexes.
More Chemical Bonds News and Chemical Bonds Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.