Technical Glossary

Blocks that are judged to be unsuitable for data storage at the manufacturing stage, or blocks that have a large number of memory cells that have been deteriorated due to an increase in the number of data writes. Because no data is stored in a bad block, the more bad blocks, the less data can be stored in the chip.

A unit of data processed by a computer. “1bit” indicates the minimum amount of data that can be expressed in binary.

Manufacturing cost per bit

Computer-aided design, a method of drawing or designing a product on a computer. The TCAD used in simulation for device and process for semiconductor devices is a type of CAD.

A logic semiconductor that plays a role in controlling NAND, DRAM, etc. Controls the reading and writing to memory, such as management of bad blocks, wear leveling, and error correction.

The unit of memory capacity. 1EB=2⁶⁰B (approximately 1billion GB)

Detect and correct errors that occur when writing data to memory or other storage media or sending or receiving data. The code used for this function is called ECC (Error Correction Code).

Removing unnecessary portions to form a circuit pattern on a wafer. There are two ways to remove: “wet etching” using chemical solutions, etc., and “dry etching” using reactive gas, etc.

KIOXIA’s personal product brand.

The process of forming a layer on the surface of a wafer as a material for semiconductor circuits, such as insulating films or metal films.

KIOXIA’s SD memory card with embedded wireless LAN function.

It is one of the non-volatile memories in which data in the memory cell remains even when the power supply is turned off, and data can be written and erased repeatedly. There are two types of flash memory: NAND type and NOR type. KIOXIA invented world's first memory in 1984.

A layer between a gate and a silicon substrate in a memory cell of flash memory. By applying voltage to the gate, it is possible to create both states; full electrons or no electrons in the floating gate.

One of the electronic components that records data. A storage device that records data by placing a magnetic head against a disk. It features a higher capacity and lower price compared to SSD. (Hard Disk Drive)

Integrating elements with multiple different functions on a silicon substrate. The integrated electronic components are called IC (Integrated Circuits), and as the degree of integration increases, they are called LSI (Large Scale Integration) and VLSI (Very Large Scale Integration).

The unit of memory capacity. 1Mbit = 2²⁰bits (approximately 1million bits)

The smallest unit of memory where information is stored in a memory chip, which itself acts like a cubicle. Data is recorded according to the amount of electrons in the memory cell (cubicle).

One of the recording media for data, which is recorded by using flash memory. It is smaller than SD memory card, and is used in small devices such as smartphones, tablets, drones, and drive recorders.

Technology that reduces the processing dimensions of elements and wiring on wafers. Miniaturization in semiconductor memory refers to a technology in which a single memory cell occupies as little space as possible and contains as many memory cells as possible in a single flash memory.

Gordon Moore, one of Intel’s founders, advocated the semiconductor integration rate law in 1965. In general, it is said that “the integration rate of semiconductors doubles in 18months.”

Units expressed “nm” representing one billionth of a meter. The minimum size of memory cells in a typical 2D NAND flash memory is about 1/4000 hair at about 15nm in recent years.

Plastic resin that protects chips equipped with electronic circuits from heat, light, shock, etc.

The unit of memory capacity. 1PB=2⁵⁰B (approximately 1million GB) 

In the lithography (exposure) process, this is the first step for transferring patterns of electronic circuits to silicon wafers. A fine circuit pattern is formed on the transparent quartz glass plate.

Data protection in case of power loss situation on SSD. Using the power charged to on-board capacitors inside of SSD, even in case of power loss situation, the recorded data can be retained and data on the cache that has just been received can also be recorded in flash memory.

Minimum unit dimensions for processing circuits and wiring when manufacturing semiconductors. It is mainly used to represent the generation of semiconductor manufacturing.

One of the data readout methods that directly links to memory performance and speed, and reads the data while skipping the order. On the other hand, the readout methods that continuously reads data in sequence are called sequential reads.

The ability of the product to meet the required specifications for a specified period of time under specified conditions. In flash memory, it is expressed as the failure rate in relation to the number of times the data can be written and the retention period. The higher the reliability, the longer the product life.

One of the recording media for data, which is recorded by using flash memory. It is larger than microSD memory card, and mainly used for digital cameras, video cameras, laptops, etc.

One of the data readout method that is directly linked to memory performance and speed, and which continuously reads data in sequence. On the other hand, reading data while skipping the order is called a random read.

A technology that increases the number of memory cells per unit area by stacking a planar structure of memory cells on top. Stacking allows for large memory capacity.

The unit of memory capacity. 1TB=2⁴⁰B (approximately 1,000GB) 

A system used in simulation for device and process for semiconductor devices. Especially in the development of advanced memory, new materials and complex three-dimensional device structures need to be developed, so TCAD is used to efficiently advance development. (Technology Computer Aided Design)

An element that controls current, such as amplification of electrical signals and ON/OFF.

Electrodes that penetrate the front and back surfaces of silicon wafers (silicon penetration electrodes). In addition, it is a technology to connect multiple chips at the shortest distance, enabling high density integration. (Through-Silicon Via)

It is a semiconductor single crystal disk that serves as the basic material for all semiconductor chips, including flash memory. In recent years, it is common to have a diameter of 300mm and a thickness of about 1mm made of silicon single crystals for memory. The silicon is purified to form a high-purity, single-crystal ingot (cylinder-shaped chunk of silicon) and thinly sliced.

Technology for preventing deterioration due to writing of data in storage media such as flash memory, and extending the product life. Prevents deterioration by controlling the writing of data so that it is evenly distributed rather than concentrated in one place.