- Researchers discover a sooner approach to etch deep holes for 3D NAND
- Plasma-based cryo-etching approach doubles etch velocity, bettering effectivity
- Sooner etching may imply cheaper storage, however real-world affect is TBD
3D NAND flash reminiscence is totally different from conventional single-layer NAND as a result of it vertically stacks reminiscence cells to cram extra storage into smaller areas.
The method includes carving exact, deep holes into alternating layers of silicon oxide and silicon nitride, and this has at all times been a bit sluggish, till now.
A crew of researchers from Lam Analysis, the College of Colorado Boulder, and the U.S. Division of Vitality’s Princeton Plasma Physics Laboratory (PPPL) has developed a plasma-based approach that may etch the deep, slender holes required for 3D NAND reminiscence at a a lot sooner charge, a paper printed within the Journal of Vacuum Science & Know-how A claims.
Will it profit finish customers?
The crew’s strategy makes use of a cryogenic etching course of utilizing hydrogen fluoride plasma slightly than the normal technique.
“Cryo etch with the hydrogen fluoride plasma confirmed a big enhance within the etching charge in comparison with earlier cryo-etch processes, the place you might be utilizing separate fluorine and hydrogen sources,” mentioned Thorsten Lill of Lam Analysis. Utilizing the brand new technique noticed etching charges for the layers soar from 310 nanometers per minute to 640 nanometers per minute – greater than doubling the effectivity.
“The standard of the etch appears to have improved as properly, and that is vital,” Lill added.
The researchers additionally regarded on the affect of phosphorus trifluoride. Including it through the course of quadrupled the etch charge for silicon dioxide, nevertheless it solely had marginal affect on the silicon nitride layer. Additionally they checked out ammonium fluorosilicate, a chemical which kinds through the etching course of when silicon nitride reacts with hydrogen fluoride. This slows down the etching course of, however including water was discovered to counteract this.
Whereas the technical achievement is to be applauded, the sensible implications are much less clear. Sooner, higher etching charges could simplify and velocity up manufacturing, however whether or not these financial savings trickle down to higher or cheaper storage gadgets stays to be seen.
“Most individuals are conversant in NAND flash reminiscence as a result of it’s the sort that’s within the reminiscence playing cards for digital cameras and thumb drives. It’s also utilized in computer systems and cell phones. Making any such reminiscence denser nonetheless – in order that extra knowledge may be packed into the identical footprint – shall be more and more necessary as our knowledge storage wants develop because of the usage of synthetic intelligence,” defined Igor Kaganovich, a principal analysis physicist at PPPL.