Clever Geek Handbook

Remember all. Understanding semiconductor memory

When I wrote an article “Who's Who in the World of Microelectronics” at the beginning of the year , I was surprised that in the top ten semiconductor companies, five are engaged in the production of memory, including two - only in the production of memory. The total volume of the global semiconductor memory market is estimated at $ 110 billion and is a constant headache for participants and investors, because despite the long-term growth together with the entire microelectronics industry, the local memory market is very feverish - 130 billion in 2017, 163 in 2018. 110 in 2019 and 110 are expected by the end of 2020. 





Top 10 world microelectronic companies, memory manufacturers are highlighted in red.
Top 10 world microelectronic companies, memory manufacturers are highlighted in red.

The volume of the memory market is close to a third of all microelectronics, and half of the top ten companies deal with memory. So why is semiconductor memory so special? Let's figure it out.





, . , , . , , 640 , - . , 640 . “ , ?” – . – , . , . , - , TSMC.





, , . , , , . – -, . (SRAM), (DRAM) “” (HDD SSD).





? ? , . , – . – . – . , , , , , , .





A diagram of the memory hierarchy in computing systems, with relative memory sizes and access latencies.
, .

-

– -. , , . . -, , ( , ). - , . “ ” – 6T-.





SRAM 6T Cell Wiring Diagram
6T- SRAM

– , DRAM -, , . , , . , , SRAM : – 28, 7 5 – , SRAM . , .





Different variants of the topology of a six-transistor static memory cell. Source - G. Apostolidis et. al., "Design and Simulation of 6T SRAM Cell Architectures in 32nm Technology", Journal of Engineering Science and Technology Review, 2016
. — G. Apostolidis et. al., «Design and Simulation of 6T SRAM Cell Architectures in 32nm Technology», Journal of Engineering Science and Technology Review, 2016

SRAM , , Am2900 581 . , , - , , , . - . , , , SRAM : 420 , 0.3% , . – , , , - . , SRAM – . , SRAM , . , , -, , MRAM, , , Cypress – , .





– , , . , ( ) .





Dynamic and static memory cell schemes

. DRAM (Intel 1103) 1970 1024 , 16 ! , . -, , DRAM , , .





A schematic diagram of the progress of DRAM production technology.
DRAM.

, DRAM , , .





, Intel

Intel 1968 . , . Intel , DRAM, - , DRAM, Toshiba, .





, Intel -, , Micron, , Intel Optane, .





DRAM 60-80 . NAND Flash, . DRAM – Samsung SK Hynix, Micron. – , Samsung , Micron SK Hynix , DRAM Flash. 95% , .





– , (40-50%), (15-20% ), (20-25%). , , , .





, “ ”, , HBM – high bandwidth memory. , , , , .





The insides of the AMD Fiji graphics accelerator. The central die is the actual computer, on both sides there are HBM DRAM chips packed in several layers.
AMD Fiji. – , – HBM DRAM.

, , – , . 16 , – Kingston Technology 80%, 2-3% . Kingston – Micron SK Hynix. Samsung , , , DRAM .





, Kingston

Kingston – , 1987 ,  SIMM- . , Kingston “” 1995 , , DRAM c 25% 80% , SSD, Kingston , 26% 8% 6% .





Kingston RAM module. Pay attention to the packing density of the chips on the board.
Kingston. .

Kingston - , , . , Kingston .





, DRAM Intel? 1999 Hitachi NEC Elpida, DRAM- Mitshibishi. , , , Apple. 2009 Elpida, 2012 , Micron.





DRAM flash-, .





-

SRAM, DRAM – , , . , , , - – . – . – , IBM , 2.5- HDD . , , SSD. HDD 2012, -.





Different generations of hard drives.
.

- - , , – “”. , , , , - , – ! , - – , .





Flash cell structure
-

- : , . , , – .





- , , , , , . - – NOR Flash NAND Flash, . – NAND , NOR .





Comparison of NOR Flash and NAND Flash architectures
NOR Flash NAND Flash

NOR Flash , , . NAND Flash : , , – . , - , – - ? , , , word line. NAND Flash , . , , , random-access.





, – NAND Flash NOR Flash, , : NAND – 40-60 , NOR – . ? , . NOR Flash , , NAND Flash , , , , .





, NAND Flash – , – - -. . NOR Flash – , – , , . , embedded , NOR Flash EEPROM.





: PROM

, EEPROM, – , – Read-Only Memory ROM. . ( , Intel 8086. , - - , , ? PROM (P – programmable), , , , .





– Antifuse, . : ( ), , . , , .





Memory appearance on burned-out jumpers

, , , EPROM (E – erasable) EEPROM (EE – electrically erasable). -. EEPROM NOR Flash c .





NAND Flash

NAND Flash, , , HDD , , . NAND Flash – Samsung (33% ), Kioxia ( Toshiba, 20% ), Western Digital (14%), SK Hynix (11%), Micron (10%), Intel (8%).





, , Intel, Micron -. – Western Digital, HDD, – fabless- . WD Kioxia, . WD – RISC-V, .





NAND Flash, . -, “” , , - , – , - . , - , 3D NAND , , , .





Schematic section of 2D and 3D NAND Flash memory
NAND Flash

, , , . , – , , ( , ). , , – , . , , , , 128 192 , -. - 15-20 , – 0.1-0.2 ! , GAAFET . Samsung 1 , .





, 97% . , , .





, - , , . , DRAM -, , . , , ,   EEPROM, , -.





– MRAM ( RAM), FRAM ( RAM) PCM (phase-change memory).





FRAM – . , FRAM . , MSP430, , – , 130 , – . , , FRAM, FeFET, .





MRAM , , . , – , . MRAM 2004, -. , , , MRAM , , . , , MRAM , Samsung GlobalFoundries.





PCM – , , , ( ). PCM , MRAM – , . PCM : 2012 Micron , 2014 . – Intel 2017 3D Xpoint SSD Optane (Intel) X100 (Micron). , . , SSD NAND Flash.





“ ?”

, , , . , . – , . , DRAM flash- . ?





-, - SRAM. – 16631, 16 90 , “”. , , .





-, "" 180 EEPROM, (RFID-) 16 . , , , .





EEPROM, – “-”, MRAM. – , 300 . , - , , MRAM. (, 300 ). 1 4 , 35 35/90/120/150 . MRAM, SMIC TowerJazz. , .





, – , . 122 , , – , . , , NAND flash , , . – -. , , . , , .







More articles:


All Articles