Is MLC better than TLC? What exactly are flash memory particles?

If one word is used to describe the SSD market in 2016, then flash memory particles will definitely be a key hot word that will be mentioned. In the past 2016, a series of major events have occurred around flash memory particles, including the mass production of flash memory particles causing solid-state price increases, the process problems of flash memory particles causing manufacturers to compete, and the advantages and disadvantages of MLC/TLC particles like the "Nikkei Post".

So, what exactly is a flash memory chip? What are the differences and connections between 2D NAND and 3D NAND? Let's take a look at them one by one.

What exactly are flash memory particles?

Flash memory particles, also known as flash memory, are a type of non-volatile memory, which means that the written data can still be saved in the case of power failure, and it is in fixed blocks rather than single bytes. There are many different variants of flash memory particles according to different uses and specifications. Today we mainly discuss the most commonly used NAND flash memory particles used in storage devices such as solid-state drives.

NAND flash memory particles, a member of the flash memory family, were first developed and launched into the market by Hitachi in 1989. Due to their many advantages such as lower power consumption, lower price and better performance, NAND flash memory particles have become the most important storage raw material in the storage industry.

According to the difference in density of electronic units in NAND flash memory, it can be divided into SLC (single-level cell), MLC (double-level cell) and TLC (triple-level cell). These three types of cells have obvious differences in lifespan and cost.

The Difference and Connection between 2D and 3D Flash Memory

Before explaining 3D NAND, we must first clarify what 2D NAND is and the true meaning of "2D" and "3D". First, let's talk about 2D NAND. We know that in mathematics and physics, 2D/3D both refer to directions and coordinate axes. "2D" refers to the length and width on a plane, while "3D" adds a vertical "height" concept to "2D".

Therefore, the real meaning of 2D NAND is actually a way of arranging particles inside a single die, which is to arrange flash memory particles in a traditional two-dimensional plane mode. In contrast, 3D NAND arranges particles in the vertical direction based on the two-dimensional plane, which is to innovate the original planar stacking method.

The use of new technology (i.e. 3D NAND technology) enables particles to be stacked in three dimensions, thus solving the limitation of further expanding the available capacity of a single die due to the physical limitations of the wafer. Under the condition of the same volume, the capacity volume of a single die of flash memory particles is greatly improved, further promoting the surge in the overall capacity of storage particles.

At the same time, in the industry, according to the different number of particle layers stacked in the vertical direction and the different types of particles selected, 3D NAND particles can be divided into different products of 32-layer, 48-layer or even 64-layer 3D TLC/MLC particles. This depends on the technical reserves of major original manufacturers and the actual types of particles selected.

We can use an analogy to understand the difference and connection between 2D NAND and 3D NAND technologies. 2D NAND is like a number of bungalows built on a limited plane. These bungalows are arranged neatly, but as demand continues to increase, the number of bungalows continues to increase, but eventually this limited plane can only accommodate a certain number of bungalows and cannot continue to increase;

3D NAND is like a building built on the same plane. On the same plane, the floor area ratio of the building is much higher than that of the bungalow, so it can provide more space, that is, it provides a larger storage space. 32 floors, 48 ​​floors and 64 floors are the heights of these buildings, and how many floors are stacked in total.

Although 3D NAND technology can provide more storage space in the same volume, this stacking technology is quite difficult for original equipment manufacturers to operate and requires them to have considerable technical accumulation. Therefore, there are very few original equipment companies that can master 3D NAND technology. Only a few companies such as Samsung and Micron have achieved mass production and release of 3D NAND particles.

As a winner of Toutiao's Qingyun Plan and Baijiahao's Bai+ Plan, the 2019 Baidu Digital Author of the Year, the Baijiahao's Most Popular Author in the Technology Field, the 2019 Sogou Technology and Culture Author, and the 2021 Baijiahao Quarterly Influential Creator, he has won many awards, including the 2013 Sohu Best Industry Media Person, the 2015 China New Media Entrepreneurship Competition Beijing Third Place, the 2015 Guangmang Experience Award, the 2015 China New Media Entrepreneurship Competition Finals Third Place, and the 2018 Baidu Dynamic Annual Powerful Celebrity.