Three-dimensional rolled-up inductors have a footprint more than 100 times smaller without sacrificing performance. The researchers published their new design paradigm in the journal Nano Letters.
Photo by Xiuling Li
Illinois researchers developed a new design paradigm for inductors. Processed while flat, they then roll up on their own, taking up much less space on a chip.
“It’s a new concept for old technology,” said team leader Xiuling Li, a professor of electrical and computer engineering at the University of Illinois.
Inductors, often seen as the sprawling metal spirals on computer chips, are essential components of integrated circuits. They store magnetic energy, acting as a buffer against changes in current and modulating frequency – especially important in radio-frequency wireless devices. However, they take up a lot of space. Inductance depends on the number of coils in the spiral, so engineers cannot make them smaller without losing performance.
In addition, the larger the area the inductor occupies, the more it interfaces with the substrate the chip is built on, exacerbating a hindering effect called parasitic capacitance. Researchers have developed some three-dimensional inductor structures to solve the dual problems of space and parasitic capacitance, but these methods are complex and use techniques that are difficult to scale up to manufacturing levels.
The new inductor design uses techniques Li’s group previously developed for making thin films of silicon nitrate, merely tens of nanometers in thickness, that roll themselves up into tubes. The research team used industry-standard two-dimensional processing to pattern metal lines on the film before rolling, creating a spiral inductor.
“We’re making 3-D structures with 2-D processing,” Li said. “Instead of spreading this out in a large area to increase inductance, we can have the same inductance but packed into a much smaller area.”
Using the self-rolling technique, the researchers can shrink the area needed for a radio-frequency inductor to a scant 45 microns by 16 microns – more than 100 times smaller than the area an equivalent flat spiral would require.
The design can be adjusted to fit target parameters including metal thickness and type, frequency, tube diameter and number of turns. According to Li, this technique could be used for capacitors and other integrated circuit elements as well.
Now, Li’s group is working to produce high-performance inductor prototypes, in collaboration with electrical and engineering professor Jose Schutt-Aine. Preliminary experimental data show strong correlation with the modeled designs.
“Once we have optimized this process, we should be able to make an integrated circuit with a completely different platform that could be much smaller,” Li said. “It’s an ambitious goal.”
The National Science Foundation and the Office of Naval Research supported this work. U. of I. visiting researcher Wen Huang, postdoctoral researcher Xin Yu, graduate student Paul Froeter and mechanical science and engineering professor Placid Ferreira were co-authors of this study. Li also is affiliated with the Beckman Institute for Advanced Science and Technology, the Micro and Nanotechnology Lab, and the Frederick Seitz Materials Research Lab, all at the U. of I.
Liz Ahlberg | EurekAlert!
'Super yeast' has the power to improve economics of biofuels
18.10.2016 | University of Wisconsin-Madison
Engineers reveal fabrication process for revolutionary transparent sensors
14.10.2016 | University of Wisconsin-Madison
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences