Chipset solution vendors including Qualcomm and MediaTek have continued to seek additional 28nm capacity at United Microelectronics Corporation (UMC), Globalfoundries and, particularly, at Semiconductor Manufacturing International Corporation (SMIC) due to tight production at TSMC, according to industry sources.

Qualcomm and MediaTek have been placing 28nm wafer orders at UMC and Globalfoundries since the second half of 2013, indicated the sources. Additionally, UMC has landed more follow-up orders from the two chipset vendors recently and will ramp up its shipments starting July.

Meanwhile, Qualcomm reportedly has booked over 50% of SMIC's 28nm capacity, while MediaTek has just begun cooperating with the China-based foundry house, expecting to fabricate its dual- and quad-core solutions using 28nm process at SMIC.

Judging from Qualcomm's quarterly revenues of around US$4 billion, the US-based chipset maker needs about 150,000 28nm wafers a month, said the sources, adding that SMIC's 28m production capacity will be fully booked if Qualcomm outsources 10% of its 28nm production to the China-based foundry house.

Additional orders from MediaTek will further ramp up SMIC's total production capacity, said the sources, noting that MediaTek requires about 70,000-80,000 28nm wafers a month.

TSMC currently holds over 80% of the global 28nm process market, powered by its entry-level PolySiON process and high-end HKMG process, the sources noted.