ProMOS Technologies has reportedly entered the final phase of negotiations to sell its 12-inch fab at the Hsinchu Science Park (HSP) to Macronix International Company (MXIC) with the deal likely to top NT$8-9 billion (US$253.28-284.95 million), instead of NT$7-9 billion as previously reported.

ProMOS's sale of its HSP site will secure funds for the DRAM maker's push for technology migration, industry sources said. ProMOS is expected to move 63nm stack to mass production in the second half of 2010.

Macronix president Chih-Yuan Lu last month indicated the company was still discussing with ProMOS about buying one of its 12-inch fabs, and would use the new capacity to produce its 45nm-made ROM and 75nm NOR flash products.

ProMOS's 12-inch capacity at the HSP is estimated at 20,000 wafers a month, according to company sources. The fab also houses 8-inch production lines with monthly output capable of reaching 44,000 wafers.

After wrapping up the deal to sell its HSP facility to Macronix, ProMOS's production will be centralized at its manufacturing site at the Central Taiwan Science Park (CTSP). ProMOS only runs 12-inch lines at its CTSP facility, which now has a monthly capacity of about 60,000 wafers.

ProMOS has revealed plans to convert its production capacity from Hynix Semiconductor's 70nm process to Elpida Memory's 63nm, and diversify its business to include niche DRAM products. The company will also allocate part of its production capacity for the manufacture of Elpida's DDR3 chips in exchange for Elpida's technology.