DRAM chipmakers currently have one to two months of wafer inventory, industry sources estimate, adding that there should be no interruptions in their supplies between March and April. But after May, whether production can run smooth will depend on the supply of wafers by major producers, the sources pointed out.
Shin-Etsu Handotai (SEH) and Sumco have to scale back their production in Japan due to rotating power cuts imposed in parts of the country, the sources observed. Meanwhile, several of their plants have remained closed since the earthquake on March 11.
Production at SEH, in particular, could be significantly affected as most of its manufacturing takes place in the earthquake-ravaged areas, the sources indicated.
According to SEH's latest update, necessary inspections are continually being carried out at its Shirakawa plant, Fukushima Prefecture. The company is still unable to confirm when normal operations at the facility can be resumed.
Sumco have disclosed that operations at its Yonezawa plant, Yamagata Prefecture, have been suspended following the earthquake. However, plants in the Kyushu region, which manufacture the same products as the Yonezawa plant, have not been affected by the quake, the company said.
SEH mainly supplies silicon wafers to Elpida Memory, Powerchip Technology and Rexchip Electronics, and also NAND flash chip vendor Toshiba, according to market observers. Sumco reportedly is the supplier for Nanya Technology and Inotera Memories, and also pure-play foundries including Taiwan Semiconductor Manufacturing Company (TSMC) and United Microelectronics Corporation (UMC).