UMC Makes 45nm SRAM
By Colleen Taylor -- EDN, November 20, 2006
Taiwan-based foundry giant United Microelectronics Corp. claims it has successfully produced functional 45nm SRAM chips that feature a bit cell size of less than 0.25 micron squared.
To make the chips, UMC said it used immersion lithography for the ICs' 12 critical layers. Immersion lithography is a resolution enhancement technique that interposes a liquid between the scanner optics and the wafer surface, replacing the traditional air gap, to ease the process of transferring smaller circuit designs. This summer, chipmaker Texas Instruments was the second company to claim to use immersion lithography at a specific node, preceded by TSMC. At that time, TI said that it had produced a 45nm test chip using immersion lithography.
UMC also incorporated technology advancements such as ultra shallow junction, mobility enhancement techniques and ultra low-k dielectrics for the 45nm SRAM chips.
According to the foundry, its 45nm process features a 30 percent design rule shrink, 50 percent 6-transistor SRAM cell size shrink, and a 30 percent device performance gain over the 65nm technology node, which is in production at UMC for several customer products. Development for the 45nm process is taking place at the foundry's 300mm Fab 12A, located in Tainan Science Park in southern Taiwan.
The company did not disclose details about when the ICs would be available on the market.
