by Sarah Fister Gale, contributing editor, Solid State Technology
July 14, 2008 – Despite projections about the future popularity of the “mini fab” model of ≤10,000 wafer starts/month (WSPM), what the semiconductor industry has seen is economies-of-scale pushing in the other direction, as big fab facilities with 60,000 WSPM are becoming the norm, observes Asyst Technologies CEO John Swenson. He’s got a front-row seat to this trend — the company claims to automate materials handling for >50% of all 300mm silicon wafer production, and worked directly with Toshiba on its behemoth gigafab project with Sandisk that can handle up to 200,000 WSPM.
But with scale comes a much greater order of complexity necessary to automate these massive facilities, and as fabs get bigger and the number of process steps increase there are greater risks for bottlenecks, slowdowns, and delays that can impact yield. “Some of these fabs have multi-million dollar tools that sit idle 10%-20% of the time. That’s wasted capital,” Swenson told SST, in an interview before SEMICON West.
To combat those slowdowns, Asyst has developed several solutions that can reduce process time and improve flow, which it will be showcasing at this year’s show.
The company’s newest Agile Automation family is an automated lifting load port, with the conveyor mounted on the floor under the load port shelf and a mini stocker at either end to improve throughput and reduce idle time, and added automation software that enables the stocker to load itself whenever space becomes available. When the load port needs more wafers, it can automatically lower the shelf to the ministocker and load up with more wafers on-demand without calling on the vehicle, Swenson explained.
Asyst says the system can reduce wait timed between wafer pick-up and drop-off from four minutes to 15 seconds. For short term process steps that can handle 150 wafers per hour, Swenson predicts a 30% improvement in production capability, which means 30% more throughput for those applications. “That’s based on real world simulations using actual customer data,” he said. And eliminating idle times means eliminating idle times and ultimately fewer tool investments, he added.
Asyst also is showcasing its new Visual Analysis and Optimization (VAO) software, which gives fab managers a bird’s-eye view of what’s going on in the fab even from hundreds of miles away. The software creates an animated visualization of real-time data generated from the fab (e.g., process steps and material movement) and highlights problem areas such as bottlenecks or idle tools to give viewers an instant understanding of what areas require attention.
“No-one ever knows what to do with all of the data generated from the fab each day,” noted Swenson. “This tool takes all of that information and creates a visual image of it so you can see in an instant what’s going on.” — S.F.G.
Asyst’s Agile Automation solution, demonstrated in an integrated wafer sorter application. Wafers are buffered locally in satellite stockers and shuttled to the tool through a floor-based conveyor; from which FOUPs are lifted directly by direct load lifting loadports. (Source: Business Wire)