The first DRAM-Patent was granted on June 4, 1968. DRAM’s 55th anniversary is an ideal opportunity to review its evolution and take a look at its future. It took a couple of years from the filing of the patent to the first DRAM memory which was introduced in October 1970 with the Intel 1103 that had a capacity of 1024 bits * 1 (bus width). But once it took off, DRAM evolved continuously and more and more rapidly. Let’s look at the progress of DRAM since its first introduction: Capacity has reached up to 32 Gb, which means an improvement by a factor of 32 million. The cell (1 transistor and 1 capacitor) stayed the same, but technology moved from 8µm process to sub-20nm. Leading manufacturers recently unveiled the fifth generation 10nm-class DRAM that the three leading manufacturers refer to as “1b” generation. This improvement in patterning was combined with architectural changes. For the DRAM cell, the move from 8F2 to 6 F2 (F= minimum feature size) was the most important for a long ..
