- Researchers find a faster way to engrave deep holes for 3D Nand
- Plasma cryo-waxing technique doubles the engraving speed, improving the efficiency
- Faster engraving could Cheaper storage, but the impact of the real world is TBD
The Flash Nand 3D memory is different from the traditional Nand with a single layer because it stacks the memory cells vertically to pile up more storage in smaller areas.
The process is to sculpt deep and deep holes in alternate 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 Boulder of the University of Colorado and the Plasma Physics Laboratory (PPPL) of the US Energy Department has developed a plasma technique that can engrave the deep holes and narrow required for the memory of Nand 3D at much faster rate, an article published in the Journal of Vacuum Science & Technology A complaints.
Will this benefit end users?
The team’s approach uses a cryogenic engraving process using hydrogen fluoride plasma rather than the traditional method.
“Cryo-waving with hydrogen fluoride plasma has shown a significant increase in the engraving rate compared to previous cryo-andc processes, where you use distinct fluorine and hydrogen sources,” said Thorsten Lill LAM research. The use of the new saw engraving method for layers go up on 310 nanometers per minute to 640 nanometers per minute – more than double efficiency.
“The quality of the engraving also seems to have improved, and that’s important,” added Lill.
Researchers also examined the impact of phosphorus trifluoride. Adding during the process has quadrupled the rate of engraving of silicon dioxide, but it had only a marginal impact on the layer of silicon nitride. They also looked at ammonium fluorosilicate, a chemical that forms during the engraving process when the silicon nitride reacts with hydrogen fluoride. This slows down the engraving process, but the addition of water turned out to be countering this.
Although the technical realization is applauded, the practical implications are less clear. Faster, better engraving rates can simplify and speed up production, but it remains to be seen that these savings have better or cheaper storage devices are visible.
“Most people know Flash Nand memory because it is the genre in memory cards for digital cameras and thumb readers. It is also used in computers and mobile phones. Make this type of memory even more dense – so that more data can be thrilled in the same footprint – will be increasingly important as our data storage needs increase due to the use of artificial intelligence ” , explained Igor Kaganovich, a principal research physicist at PPPP.
