Hynix - The Memory Guy Blog

3D NAND: Who Will Make It and When?

(The following is an update of a post that originally ran on 13 December 2013. It was republished in 2024 as a part of a series on The Memory Guy blog to honor the 3D NAND inventors who have received the 2024 FMS Lifetime Achievement Award.)

This series, originally run in 2013, has looked at 3D NAND technology in a good deal of technical depth. At that time, the last question to be answered centered around the players and the timing that the technology would Continue reading “3D NAND: Who Will Make It and When?”

Flash Memory Summit: Limitless Layers of 3D NAND

The single most interesting thing I learned at the 2015 Flash Memory Summit was that 3D NAND doesn’t have a natural limit, after which some other memory type will need to be adopted.

For years SanDisk has been presenting a memory roadmap (this post’s graphic is one rendition) that anticipates a move to ReRAM after 3D NAND has run through its natural life, which was expected to be as little as three generations. This has been backed by the idea that a 3D NAND stack would only be able to reach a certain number of layers before it would encounter difficulties caused by the need to etch a high aspect ratio hole through an increasing number of layers.

The aspect ratio issue is not hard to understand: Let’s assume that the hole in a 24-layer stack has an aspect ratio of 40:1, then a 32-layer hole would have an aspect ratio of about 50:1, and a 64-layer stack would be something close to 100:1. Today’s technology starts to have trouble etching holes with an aspect ratio higher than 60:1.

These high aspect ratios were thought to be the limiting factor that would prevent 3D NAND from continuing for more than three generations. 3D NAND could only have as many layers as the aspect ratio could support.

On a panel that I moderated at this year’s Flash Memory Summit one panelist, Dr. Myoung Kwan Cho of SK hynix, explained that although there is a limit Continue reading “Flash Memory Summit: Limitless Layers of 3D NAND”

DRAM Prices Down, But Not So Bad

For the past ten months DRAM prices have been undergoing a steady slide. Is the market in a crisis? Not really!

Today’s low spot price of $4.30/GB puts us on a par with February 2013, a full two years ago (see chart). DRAM makers have done a lot to reduce their production costs since that time, so their margins this quarter will be much better than they were in the first quarter of 2013.

But we are still a very long way from the bottom of the last market downturn. In late 2012 spot prices reached a low of $2.52/GB, a full 41% lower than today’s lowest spot prices.

The Memory Guy models the production costs of leading memory chips, and DRAM manufacturing costs have been decreasing for the past several years at an average annual rate of about 30%. That means that costs today are about half of what they were two years ago, and one third of their level this time in 2012.

So even though today’s Continue reading “DRAM Prices Down, But Not So Bad”

Four New Players Join 3D NAND Market

The following is excerpted from an Objective Analysis Alert sent to our clients on March 26: On March 25 SanDisk and Toshiba announced sampling of their 3D NAND flash technology, a 128Gb (gigabit) 48-layer second-generation product based on the BiCS technology that the companies pioneered in 2007. Pilot production will begin in the second half of 2015 with meaningful production targeted for 2016. This release was issued at the same time that Intel and Micron were briefing the press and analysts for their March 26 announcement of their own 3D NAND offering (pictured), which is currently sampling with select customers, and is to enter full production by year-end. The Micron-Intel chip is a 32-layer 256Gb device, which the companies proudly point out is the densest flash chip in the industry.

Similarities and Differences

These two joint ventures (Intel-Micron and SanDisk-Toshiba) are taking very different Continue reading “Four New Players Join 3D NAND Market”

Why NAND is So Difficult to Scale

NAND flash is the process leader in memory technology, and this puts it in a very challenging position: It must ramp to high volume production using techniques that have never been tried before.

The graphic for this post (click to enlarge), supplied by ASML, the semiconductor industry’s leading lithography tool supplier, illustrates the challenge of migrating from one process node to the next. Across the bottom, on the X-axis, are representative process nodes ranging from “2D-45”, or two-dimensional (planar) 45nm NAND, to “3D-5x”, or three-dimensional 5xnm NAND. Below these numbers are the year of volume production.

The vertical axis, labeled “Tolerance” represents the minimum Continue reading “Why NAND is So Difficult to Scale”

Did SK hynix Beat Samsung to the 8Gb LPDDR4?

Every so often something very strange happens that puzzles The Memory Guy. On December 29 (or Dec. 30 in Seoul) something odd occurred.

I received two e-mails, one from SK hynix at 3:55 PM Pacific Time, and one from Samsung exactly one hour later. Both were press releases.

The SK hynix release was titled: “SK Hynix Developed the World’s First Next Generation Mobile Memory LPDDR4”. It announced that the company is sampling its 20nm-class 8Gb LPDDR4 DRAM to customers.

The Samsung release was Continue reading “Did SK hynix Beat Samsung to the 8Gb LPDDR4?”

Rambus and Micron Sign License Agreement

The following is excerpted from an Objective Analysis Alert that can be downloaded from the company’s website.

Rambus and Micron announced on Tuesday that they have signed a patent cross license agreement. Micron receives rights to Rambus IC patents, including memories. Both Micron and Elpida products will be covered. The companies have thus settled all outstanding patent and antitrust claims in their 13-year court battle.

Micron will make royalty payments to Rambus of up to $10 million per quarter over the next seven years, totaling $280 million, after which Micron will receive a perpetual, paid-up license.

Rambus and Micron both have Continue reading “Rambus and Micron Sign License Agreement”

SIA: Memories Drive Record Semi Revenues

The SIA yesterday released the WSTS semiconductor sales data for September. Monthly revenues reached a record $27 billion driving third-quarter revenues to their own record of $81 billion. This was the seventh straight month of semiconductor growth, the first such run-up since 2010.

This quote, by SIA CEO Brian Toohey really caught The Memory Guy’s eye: “Sales of memory products have increased sharply compared to last year and continue to be a major driver of industry growth.”

A lot has been happening to drive this increase in memory revenues: The recent SK hynix fire increased DRAM prices, but Continue reading “SIA: Memories Drive Record Semi Revenues”

Hynix Recovery – Not so Soon?

During SK hynix’ October 29 earnings call the company further clarified the status of its Wuxi fab line that was hit by a fire on September 4. In brief, the company may miss its expected end-November date to recover to full operation.

Interestingly, although DRAM bit shipments declined by 2% because of the fire, revenues increased by 3% thanks to price increases caused by the resulting tight DRAM supply. This gave the company a revenue boost taking total semiconductor revenues from ₩3.93 trillion ($3.54B US) in the second quarter to ₩4.08 trillion ($3.66B US) in the third quarter. Not only was this revenue a record number for SK hynix, but margins also reached a record high.

All in all, it was a very good quarter, despite the fire, and perhaps because of it.

The company disclosed that restoration of the air ventilation system and the clean room have been Continue reading “Hynix Recovery – Not so Soon?”

Hynix Squeaks Out Another Update

In its own uniquely minimalistic style, Hynix has updated the status of the second line of its Wuxi fab, the one that was hit by a fire on September 4:

We would like to provide the following update on the recovery status of SK Hynix Wuxi fab that was affected by the fire on Wednesday September 4, 2013. The air ventilation system and cleanroom in the line that was affected by the fire have now been substantially restored, and we have resumed partial utilization in this line from Thursday October 10, 2013. We will gradually raise utilization and make every effort to recover normalized level of pre-fire utilization in November as planned.

This statement should put to rest Continue reading “Hynix Squeaks Out Another Update”