Fabrication of a GaN/diamond heterointerface is successfully achieved.
Abstract
“The direct integration of gallium nitride (GaN) and diamond holds much promise for high-power devices. However, it is a big challenge to grow GaN on diamond due to the large lattice and thermal-expansion coefficient mismatch between GaN and diamond. In this work, the fabrication of a GaN/diamond heterointerface is successfully achieved by a surface activated bonding (SAB) method at room temperature. A small compressive stress exists in the GaN/diamond heterointerface, which is significantly smaller than that of the GaN-on-diamond structure with a transition layer formed by crystal growth. A 5.3 nm-thick intermediate layer composed of amorphous carbon and diamond is formed at the as-bonded heterointerface. Ga and N atoms are distributed in the intermediate layer by diffusion during the bonding process. Both the thickness and the sp2-bonded carbon ratio of the intermediate layer decrease as the annealing temperature increases, which indicates that the amorphous carbon is directly converted into diamond after annealing. The diamond of the intermediate layer acts as a seed crystal. After annealing at 1000 °C, the thickness of the intermediate layer is decreased to approximately 1.5 nm, where lattice fringes of the diamond (220) plane are observed.”
Find the technical paper link here. Published 09/2021.
Liang, J., Kobayashi, A., Shimizu, Y., Ohno, Y., Kim, S.-W., Koyama, K., Kasu, M., Nagai, Y., Shigekawa, N., Fabrication of GaN/Diamond Heterointerface and Interfacial Chemical Bonding State for Highly Efficient Device Design. Adv. Mater. 2021, 33, 2104564. https://doi.org/10.1002/adma.202104564
Increasing complexity, disaggregation, and continued feature shrinks add to problem; oversight is scant.
Academia, industry partnerships ramp to entice undergrads into hardware engineering.
Packaging and inspection companies draw funding; 124 startups raise over $2.3 billion.
Pitches continue to decrease, but new tooling and technologies are required.
Buried features and re-entrant geometries drive application-specific metrology solutions.
While terms often are used interchangeably, they are very different technologies with different challenges.
Technology and business issues mean it won’t replace EUV, but photonics, biotech and other markets provide plenty of room for growth.
Commercial chiplet marketplaces are still on the distant horizon, but companies are getting an early start with more limited partnerships.
Existing tools can be used for RISC-V, but they may not be the most effective or efficient. What else is needed?
How customization, complexity, and geopolitical tensions are upending the global status quo.
The industry is gaining ground in understanding how aging affects reliability, but more variables make it harder to fix.
Key pivot and innovation points in semiconductor manufacturing.
Tools become more specific for Si/SiGe stacks, 3D NAND, and bonded wafer pairs.
Leave a Reply