TSMC CEO Morris Chang revealed that his company will initiate volume production of 20nm chips at its Fab 14/phase 5 plant in February 2014 and that additional 20nm capacity will come online at its Fab 15/phases 3 and 4 starting from May 2014. Full details at X-bit Labs.
“On 20nm [process technology], we see little competition. The risk production has started in the first quarter  and the volume production will start in early 2014 next year […] the equipment [is] already being installed, the equipment [is] streaming in and [is] being installed. […] The volume production will start in early 2014,” said Morris Chang, the head of TSMC, during quarterly conference call with financial analysts.
TSMC began to build the phase 5 of its Fab 14 in early April, 2012. The construction of the facility is now complete and the equipment has been being installed since April. It typically takes from six to twelve months to fully equip a semiconductor fab. The Fab 15/phases 3 and 4 will initiate production using 20nm process tech sometimes in May, according to Mr. Chang. Eventually, TSMC will also make chips using the 20nm technology at its fab 12/phase 6.