- Scientists find a faster way to ether deep holes to 3D nand
- Plasma-based cryo-etching technique doubles the etching speed, improving efficiency
- Faster etching power Average cheaper storage but the effect in the real world is tbd
3D NAND-Flash Memory is different from traditional single-layer NAND because it stacks vertical memory cells to plug more storage into smaller spaces.
The process involves the cut of precise, deep holes in changing layers of silicon oxide and silicon nitride, and this has always been a little slow, so far.
A team of researchers from LAM Research, the University of Colorado Boulder and the US Energy Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) has developed a plasma-based technique that can see the deep, narrow holes required for 3D NAND memory On a much faster rate, a paper published in Journal of Vacuum Science & Technology A claims.
Will it benefit end users?
The team’s approach uses a cryogenic etching process using hydrogen fluoride plasma rather than the traditional method.
“Cryo etching with the hydrogen fluoride plasma showed a significant increase in the etching speed compared to previous cryo-etching processes where you use separate fluorine and hydrogen sources,” said Thorsten Lill of LAM research. Using the new method Sam etching speeds for the layers hover from 310 nanometers per day. Minute to 640 nanometers per minute. Minute – more than doubling of efficiency.
“The quality of the etching seems to have improved as well, and that’s significant,” Lill added.
The researchers also looked at the effect of phosphorusluoride. Adding it during the process four -doubled the etching speed of silicon dioxide, but it had only marginal impact on the silicon nitro layer. They also looked at ammonium fluorosilicate, a chemical formed during the etching process when silicon nitride responds with hydrogen fluoride. This slows down the etching process, but the addition of water was found to counteract this.
While the technical performance must be clapped, the practical implications are less clear. Faster, better etching speeds can simplify and speed up production, but whether these savings drip down to better or cheaper storage units to see.
“Most people are familiar with Nand Flash memory because it is the kind of memory cards for digital cameras and thumbs. It is also used in computers and mobile phones. Making this type of memory closer – so that more data can be packed in the same footprint – will be increasingly important as our data storage needs grow due to the use of artificial intelligence, ”explained Igor Kaganovich, a main research physicist at PPPL.
