28nm process changes rumoured at TSMC

Taiwan Semiconductor (TSMC,) one of the biggest chip foundry outfits in the world, is rumoured to have run into trouble with its 28nm process. As a result, claims state that it has had to temporarily cease production while it invests in a quick upgrade.

That's the claim coming from SemiAccurate, which quotes unnamed sources close to the company as revealing that TSMC ceased all 28nm production in mid-February to make as yet unknown changes to its manufacturing processes. While rumours had been spreading of yield issues for graphics giant Nvidia's 28nm chips, no other known problems were known to be affecting the company's facilities.

The news comes as a Citi report quoted by ElecroIQ suggests that TSMC is planning to increase its capital expenditure budget in order to strengthen its 28nm production facilities. In the report, Citi's Terence Whalen claims that TSMC underestimated demand for 28nm chips and was only able to provide 60 per cent of mobile chip giant Qualcomm's demand while also letting Nvidia down on the volume front.

According to Whalen, TSMC is rapidly revising its 28nm plans as its customers start to sniff around rival foundry firms. Part of that includes a volume increase from 25,000-30,000 wafer starts per month to 35,000-40,000 by the end of the year, boosted by a $1.5-$2 billion increase in capital expenditure.

TSMC's apparent failure to provide sufficient manufacturing capacity to meet demand for 28nm parts is music to its competitors' ears. AMD is believed to be talking to Samsung's foundry arm about moving some of its 28nm chip production following a deal with spin-off company GlobalFoundries to end an exclusivity agreement for accelerated processing units.

This move would be aided by AMD's announcement, reported by Electronics Weekly today, that it is to move away from silicon-on-insulator (SOI) manufacturing for its 28nm parts in favour of the more mainstream approach used by rival Intel. 'The flexibility that we gain moving in that direction, the flexibility across foundry partners, across design tools out-weigh by far the benefits of SOI,' claimed AMD's chief financial officer Thomas Seifert in an announcement on the matter.

TSMC, for its part, refused to comment on the claimed stoppages or planned changes to its 28nm production process, with a spokesperson stating that it is company policy 'not to comment on market rumours.' The spokesperson did, however, add the following: 'I want to inform you that our 28nm production is normal, and all our 28nm customers are fully aware of our production status.'