United Microelectronics Corp. , the world's second-largest foundry, said its ramp of 28nm process technology will slow as the outlook for demand is likely to remain weak until the first half of 2016 while the chip industry works its way out of an inventory correction. The portion of total revenue for the Hsinchu, Taiwan chipmaker from its most advanced 28nm node will probably drop to about 10% during the second half of this year after peaking at 11% in the second quarter.