A UNIST analysis group has developed a brand new materials to unravel the so-called electrical arteriosclerosis phenomenon that happens as semiconductor circuit line widths lower.
The analysis group of Prof. Kim Soo-hyun from the Graduate College of Semiconductor Supplies and Parts on the Ulsan Nationwide Institute of Science and Know-how (UNIST) introduced on Dec. 18 that they’ve developed a brand new uncooked materials (precursor) for ruthenium, a next-generation semiconductor wiring materials, and an atomic layer deposition (ALD) course of making use of it.
Steel wiring is a core construction that provides energy and transmits indicators to a whole lot of thousands and thousands of transistors inside semiconductor chips. As course of miniaturization progresses, wiring widths are steadily reducing. Business copper wiring has the issue that as line width decreases, {the electrical} resistance of skinny movies will increase quickly, stopping present from flowing properly and resulting in chip efficiency degradation. In distinction, ruthenium exhibits comparatively gradual resistance enhance even when line width decreases, making it engaging as a next-generation wiring materials. Moreover, in contrast to copper, it has the benefit of not requiring a separate diffusion barrier layer, permitting for less complicated buildings.
The uncooked materials developed by the analysis group doesn’t decompose even at 400℃, enabling the formation of high-quality ruthenium wiring. Ruthenium wiring is achieved by the ALD technique, the place uncooked supplies are first adsorbed onto substrates, then response gasoline is injected to depart solely the ruthenium steel portion of the uncooked materials whereas eradicating the remainder. Whereas wiring high quality improves with increased course of temperatures, present ruthenium uncooked supplies had the issue of decomposing beneath excessive course of temperatures.
Ruthenium skinny movies deposited with this uncooked materials recorded a low resistivity of 10.6 microohms (μΩ·cm), which approaches the perfect resistivity (bulk 7.4 μΩ·cm) with out warmth remedy. Step protection additionally recorded over 95%. Which means skinny movies may be uniformly utilized to slender and deep semiconductor buildings similar to 3D NAND.
The uncooked materials used on this analysis can even scale back semiconductor course of prices and time. It’s because ruthenium is selectively deposited solely the place wiring is required and doesn’t adhere to insulators the place electrical energy shouldn’t move. Wiring adhered to insulators beforehand required elimination by separate etching processes. Moreover, a 0.13 nanometer (nm, 1.28 Å) thick ruthenium skinny movie was created in a single course of, which is roughly twice the earlier pace.
Prof. Kim acknowledged, “In a scenario the place the issue of wiring processes is growing exponentially as a result of excessive integration of semiconductor units, the importance lies in concurrently securing resistance discount in superb line widths, deposition uniformity in 3D buildings, and quick deposition pace,” including, “This may contribute to enhancing the yield and efficiency competitiveness of next-generation logic and reminiscence semiconductor mass manufacturing processes.”
This analysis was performed by worldwide joint analysis between UNIST and Tanaka Valuable Steel Applied sciences Co., a treasured steel supplies firm in Japan, and the analysis outcomes have been printed on-line within the prestigious worldwide tutorial journal Superior Science on Nov. 23.
The analysis was performed with help from the Ministry of Commerce, Business and Power (MOTIE) Know-how Innovation Undertaking.
