Nonvolatile memory capacity reached 64 Gb levels when NAND Flash half-pitch reached 20 nm [1]. Having reached 14 nm [2], NAND Flash half-pitch is no longer being reduced, now that it has entered the 3D era. However, recently, 3D XPoint has found applications within the Optane platform [3]. The lithography for patterning 20 nm half-pitch… Read More
EUV faces Scylla and Charybdis
It is now time for the EUV community to realize they are caught between the proverbial Scylla and Charybdis. In Greek mythology, the two monsters terrorized ships that were unlucky enough to pass between them. By avoiding one, you approached the other.
S for Scylla, or Stochastics
Scylla was a former beautiful nymph turned into
Imec Technology Forum and ASML
On Thursday July 9 Imec held a virtual technology forum. Imec is one of the premier research organizations working on semiconductor technology and their forums are always interesting. My area of interest is process technology and the following are my observation in that area from the forum.
Luc Van Den Hove
Luc Van Den Hove is the… Read More
VLSI Symposium 2020 – Imec Buried Power Rail
The 2020 VLSI Technology Symposium was held as a virtual conference from June 14th through June 19th. At the symposium Imec gave an interesting paper on Buried Power Rails (BPR) and I had a chance to interview one of the authors, Anshul Gupta.
As logic devices continue to scale down metal pitch is reaching a limit. Imec defines a pitch… Read More
Application-Specific Lithography: a 28 nm Pitch DRAM Active Area
In the recent DRAM jargon, “1X”, “1Y”, “1Z”, etc. have been used to express all the sub-20 nm process generations. It is almost possible now to match them to real numbers which are roughly the half-pitch of the DRAM active area, such as 1X=18, 1Y ~ 17, etc. At this rate, 14 nm is somewhere around
ASML More Covid Concerns and Impact
- Covid related Revenue Rec causes rev/EPS miss
- Sharp order drop reflects H2 industry uncertainty
- EUV remains solid- Memory/Logic mix is better
Results were in line after correcting Covid Caused Revenue Rec issue-
ASML reported revenues of Euro3.3B and EPS of Euro1.79 as revenues from two EUV systems was not recognized, due to … Read More
Application-Specific Lithography: The 5nm 6-Track Cell
The 5nm foundry (e.g., TSMC) node may see the introduction of 6-track cells (two double-width rails plus four minimum-width dense lines) with a minimum metal pitch in the neighborhood of 30 nm. IMEC had studied a representative case as its ‘7nm’ case [1]. TSMC had some published 5nm test structures which looked like… Read More
The Stochastic Impact of Defocus in EUV Lithography
The stochastic nature of imaging has received a great deal of attention in the area of EUV lithography. The density of EUV photons reaching the wafer is low enough [1] that the natural variation in the number of photons arriving at a given location can give rise to a relatively large standard deviation.
In recent studies [2,3], it … Read More
Can Threshold Switches Replace Transistors in the Memory Cell?
The overwhelming majority of transistors produced in the world are used in memory cells, either as the memory itself (Flash, SRAM), or as the access device (DRAM). Yet, it is not necessary to have a transistor in every memory cell. In 2015, 3D XPoint, the first major product based on transistor-less memory cells, was announced [1].
Feature-Selective Etching in SAQP for Sub-20 nm Patterning
Self-aligned quadruple patterning (SAQP) is the most widely available technology used for patterning feature pitches less than 38 nm, with a projected capability to reach 19 nm pitch. It is actually an integration of multiple process steps, already being used to pattern the fins of FinFETs [1] and 1X DRAM [2]. These steps, shown… Read More
LRCX- Mediocre, flattish, long, U shaped bottom- No recovery in sight yet-2025?