Manufacturing Bits: Dec. 5

Intel vs. GF; fusion power; neutrinos; dark matter.


Intel vs. GlobalFoundries
At the IEEE International Electron Devices Meeting (IEDM) this week, GlobalFoundries and Intel will square off and present papers on their new logic processes.

Intel will present more details about its previously-announced 10nm finFET technology, while GlobalFoundries will discuss its 7nm finFET process. As expected, Intel and GlobalFoundries will use 193nm immersion lithography and multi-patterning. But in a new innovation, both companies are also implementing cobalt in various portions of the process.

TSMC and Samsung are also developing 7nm processes. In simple terms, the foundry 7nm process is equivalent to Intel’s 10nm technology.

In any case, Intel’s 10nm technology represents the company’s third-generation finFET technology. The technology shows the characteristics of a steep subthreshold slope device (~70 mV/dec).

The process makes use of 193nm immersion lithography and self-aligned quadruple patterning (SAQP). As previously stated, the process includes self-aligned contact over active gate scheme. The technology features 12 metal layers with ultra-low-k dielectrics. In a first for the industry, the technology will also incorporate cobalt materials at three local interconnect layers.

Intel and other chipmakers are following the same transistor path at 10nm and 7nm–they are extending the finFET and making the fins taller and thinner, which in turn boosts the drive current. At 7nm, Intel’s transistors feature rectangular fins with 7nm fin width and 46nm fin height, according to a paper from Intel. At 10nm, Intel’s fin pitch is 34nm and the fin height is 53nm.

Using SAQP at the metal-0 and metal-1 layers, Intel achieved fin pitches down to 34nm and metal pitches of 36nm. “Scaling of density critical interconnect layers is up to 0.51x versus the traditional 0.7x,” according to Intel’s paper.

The interconnect stack has 12 layers. “Cobalt is introduced at the lowest two interconnect layers providing a 5-10x improvement in electromigration and a 2x reduction in via resistance,” according to the paper. “A cobalt cladding layer is utilized at Metal 2 – Metal 5 to improve electromigration. Low-k CDO dielectrics are used on 11 layers.”

Meanwhile, GlobalFoundries will present more details about its 7nm finFET process. Compared to 14nm, the 7nm process has a performance increase of >40% at fixed power, or power reduction of >55% at fixed frequencies, according to the company.

The technology makes use of SAQP for fin formation and SADP for the wiring schemes. Initially, GlobalFoundries won’t use extreme ultraviolet (EUV) lithography at 7nm. But the process is designed to leverage EUV when the technology is ready.

GlobalFoundries’ finFETs have a fin pitch of 30nm, a contacted gate pitch of 56nm, and a metal pitch of 40nm.

Multiple copper level stacks are offered to enable a range of SoC applications, according to GlobalFoundries. One example of a general purpose SoC is a 13-level stack. “Cobalt is introduced for contact metallization to reduce the resistance of the 7nm middle-of-line (MOL),” according to GlobalFoundries.

Fusion power problems
The International Thermonuclear Experimental Reactor (ITER) project recently gave a progress report on its oft-delayed efforts to build a system that will enable fusion power.

Fusion, the nuclear reaction that powers the sun and the stars, is a potential source of safe, non-carbon emitting energy. But developing the technology is challenging.

ITER, for example, is over a decade behind schedule. Despite ongoing delays with the project, ITER remains on track to produce “first plasma” by 2025, according to the organization. Still others have failed in the arena, including Lawrence Livermore National Laboratory.

Many others continue to develop fusion technology, such as a group from China, Lockheed Martin, MIT, TAE Technologies and several others.

Meanwhile, launched in 2006, ITER is building a tokamak, a magnetic device for use in developing fusion power.The tokamak is an experimental machine. The system produces clean energy through the fusion of atoms. This is much like how the sun produces energy.

The ITER project is under construction in Saint-Paul-lez-Durance, in the south of France. The members within ITER are China, the European Union, India, Japan, Korea, Russia and the United States. Europe is contributing almost half of the costs of the construction, while the other six members are paying the rest.

The problem is that the ITER project has been hit by delays and cost overruns, according to reports. The ITER project will operate in 2025 with plans to achieve fusion in 2035, which is 12 years later than originally planned, according to reports.

ITER fusion reactor under construction (Source: ITER)

It’s a complex technology. A tokamak is a doughnut-shaped vacuum chamber. Using heat and pressure, the system transforms gaseous hydrogen fuel into plasma. The plasma is controlled by magnetic coils placed around the vessel.

If it works, ITER could be a breakthrough in science. The world record for fusion power is held by JET, a European effort. In 1997, JET produced 16 MW of fusion power from a total input power of 24 MW, according to ITER. In comparison, ITER is designed to produce 500 MW of fusion power from 50 MW of input power.

Recently, the ITER council provided a progress report. Members vow that the project is still on track to produce fusion in 2025. In addition, the organization also adopted various metrics to measure the progress of the construction and assembly of the system. Using these metrics, the construction work for the system is 49% complete, while the component manufacturing work is 61% complete.

Neutrino watch
A group of researchers using an instrument buried deep in the ice at the South Pole have made a new discovery about neutrinos.

The IceCube Neutrino Observatory, a cubic-kilometer-sized detector sunk into the ice sheet at the South Pole, demonstrated that the Earth stops very energetic neutrinos. In other words, neutrinos do not go through everything, as previously thought.

A neutrino is a sub-atomic particle that is nearly massless. Neutrinos travel throughout the universe almost undisturbed by matter. They emanate from various parts of the universe.

They interact rarely with other matter. About 100 trillion neutrinos pass through your body every second without leaving a trace.

The IceCube Neutrino Observatory records 100,000 neutrinos each year. Some 49 institutions in 12 countries make up the IceCube Collaboration. The observatory allows researchers to see the byproducts of neutrino interactions with ice. The IceCube Neutrino Observatory has a detector. The neutrinos hit the detector, which makes use of 5,160 “basketball-sized optical sensors” encased in a cubic kilometer near the South Pole.

IceCube Neutrino Observatory

According to the IceCube Collaboration, researchers “found that there were fewer energetic neutrinos making it all the way through the Earth to the IceCube detector than from less obstructed paths, such as those coming in at near-horizontal trajectories.”

The probability of neutrinos being absorbed by the Earth is consistent with the Standard Model of particle physics. This model is how scientists explain the fundamental forces and particles in the universe.

This probability is referred to as a cross section. “This study provides the first cross-section measurements for a neutrino energy range that is up to 1,000 times higher than previous measurements at particle accelerators,” according to the IceCube Collaboration. “Most of the neutrinos selected for this study were more than a million times more energetic than the neutrinos produced by more familiar sources, like the sun or nuclear power plants.”

Darren Grant, spokesperson for the IceCube Collaboration and a professor of physics at the University of Alberta in Canada, said: “Neutrinos have quite a well-earned reputation of surprising us with their behavior. It is incredibly exciting to see this first measurement and the potential it holds for future precision tests.”

Dark matter satellite
The DArk Matter Particle Explorer (DAMPE), a satellite operated by the Chinese Academy of Sciences (CAS), may have shed light on the ongoing search for dark matter.

In its first results, the satellite has been able to measure a cosmic ray electron flux at a spectral break at ~0.9 TeV, according to CAS. Cosmic rays are high-energy radiation, which come from outside the solar system.

DAMPE has yet to detect dark matter, but the data may “shed light on the annihilation or decay of particle dark matter,” according to CAS. In theory, 4.9% of the universe consists of observable matter, such as protons, neutrons and electrons. Then, some 68.3% of the universe is dark energy, while the remaining 26.8% is dark matter. So, dark matter exists in the universe, but it is invisible to the entire electromagnetic spectrum. To date, though, researchers have failed to directly observe or detect dark matter.

There are several efforts to find dark matter. In 2015, for example, DAMPE was launched at an altitude of 500 km. The satellite’s nickname is Wukong or Monkey King. Wukong is a hero in a classic Chinese tale. Operated by the CAS, DAMPE is a collaboration between nine institutes in China, Switzerland and Italy.

The satellite is a space telescope, which detects energy gamma-rays and cosmic rays. The outside portion of the system incorporates a plastic scintillator strip detector, which is used for photon identification. This is followed by a tungsten tracker-converter, which looks for gamma rays. Inside the unit, there is an imaging calorimeter, based on bismuth germanium oxide. A layer of neutron detectors is added to the bottom of the calorimeter.

So far, DAMPE has detected 1.5 million cosmic ray electrons. It has also detected positrons above 25 GeV. More importantly, it also detected a spectral break at ~0.9 TeV, according to CAS, which says the break has spectral index changing from ~3.1 to ~3.9. “Together with data from the cosmic microwave background experiments, high energy gamma-ray measurements, and other astronomical telescopes, the DAMPE data may help to ultimately clarify the connection between the positron anomaly and the annihilation or decay of particle dark matter,” said Fan Yizhong, deputy chief designer of DAMPE’s scientific application system.

Concept image of the DAMPE satellite (Image by NSSC)