TSMC Warns About Further Problems with 40nm Process Technology

TSMC’s 40nm Yield May Be Lower Than Expected

by Anton Shilov
10/29/2009 | 10:50 PM

Even though the output of wafers produced at 40nm node quadrupled at Taiwan Semiconductor Manufacturing Company in Q3 2009, actual yields of chips may be lower than back in Q2. TSMC itself considers the present yield issues “logistical problems”.


According to a news-story from DigiTimes web-site, at present 40nm yields at TSMC are at approximately 40%, down from 60%. This might be an issue with the fact that both ATI, graphics business unit of Advanced Micro Devices, Nvidia Corp. and some other customers have started to produce new designs at TSMC. However, the contract maker of chips claims that the source of the issue lies in matching the production equipment.

“Since we reported on [40nm] three months ago, we have fulfilled most of the expectations that we had at that time. However, new problems have also cropped up, but these new problems are logistical problems. They have to do with the ramp up of new production equipment. We have had to not only increase the yields, but also have had to ramp up the wafer starts on 40/45nm in the last six months and the ramp up speed has been unprecedented,” said Morris Chang, the chairman and chief executive officer of TSMC.

Even though the vast majority of chamber matching problems was resolved by late Q3, some of them still persist and will affect the company’s financial performance even in Q4 2009.

“Lots of new tools were brought in and they added a complexity to production. The problems that I have just mentioned that have cropped up recently had to do with two chamber matching. We consider these to be logistical problems and we are in the process of resolving them very quickly. […] Because of the reduction in the two chamber matching problems, the 40/45nm problem did affect the gross margin in the third quarter to the extent of about 1.5%s. Because the problems have not been completely resolved in the fourth quarter, the problem will further affect the fourth quarter gross margin to the extent of about 2%,” added Mr. Chang.

TSMC believes that 40nm wafers are on track to reach about 10% of wafer revenue in the fourth quarter of 2009.