Foundries have 28-nm yield issues, say execs

November 03, 2011 // By Peter Clarke and Dylan McGrath
Although foundry chip manufacturing will continue to grow faster than the overall chip market for the next few years, it is currently facing challenges at the leading-edge 28-nm manufacturing node, according to market analysis company Gartner and others.

In particular foundries are struggling with the introduction of 32-nm/28-nm high-K metal gate (HKMG) CMOS, according to Bob Johnson, research vice president at Gartner, speaking to a client meeting here.

"[Making] bulk silicon HKMG at 28-nm is hard. All foundries are having yield issues and defect density issues right now," he said, speaking along the same lines that executives at a couple of chip manufacturing equipment vendors had done a few days before.

In a recent conference call to discuss his company's quarterly earnings, Richard Wallace, president and CEO of semiconductor equipment maker KLA-Tencor Corp., gave the same message, saying that foundries are investing in tools for 28-nm and running into challenges with yield. "Foundry players struggling with their yield issues at 28," Wallace said.

There is also a reducing demand at 28-nm as customers push out projects because of global economic uncertainty, Gartner's Johnson said. And those designs that are going ahead are taking longer to qualify because of the customers' tightening engineering budgets, he added.

This does not fit with some of the bullish comments that have come from foundry Taiwan Semiconductor Manufacturing Co. Ltd., (TSMC). Earlier this year TSMC was claiming that its design starts at 28-nm were there times what they were at the equivalent stage in the roll out of the 40-nm manufacturing processes. However, at that time TSMC was aiming for 20 percent annual growth in 2011. For the first 9 months of 2011 TSMC's sales are 4.2 percent up on the equivalent sales in 2010. TSMC is still set to outgrow the overall chip market in 2011, but only by a few percentage points.

Johnson said that the foundries were taking the push out in demand at 28-nm as an opportunity to try and effect yield improvements. "In 2012, total 28-nm HKMG shipments will not exceed 200,000 300-mm wafers; or less than 4 percent of foundry' revenue. Shipments won't start until 2012 and