By Dave Lammers, Contributing Writer
The flash industry, soon to be a $100 billion sector of the overall semiconductor industry, knows where it wants to go: to a petabyte of bits per wafer. But there is a fly in the ointment: rising materials costs and slowing improvements in equipment productivity over the last couple of years are imperiling flash’s steady rise, said Siva Sivaram, president of Western Digital, during a keynote speech at SEMICON West.
Opportunities beckon for continued growth. Data is being produced at a much faster pace, up 35 percent per year, though only about 10 percent of it is being analyzed and put to work. Every couple of years, flash devours another segment of the overall storage industry, with game consoles the latest example of moving to SSDs and cloud-based storage.
More Bits per Cell Do-able
Flash, unlike the logic side of the industry, has a defensible roadmap, starting with adding more layers of charge-trap bits (up from 160 layers in today’s high- volume 3D NAND devices) and increasing the number of bits-per-cell to five or more. Demand is there, the technology roadmap is in place, but the question is whether costs can be contained.
“Ninety percent of data is not stored, not adding value. That is
our opportunity. We have to make it affordable to capture and store the data so people can get more out of it,” he said.
The ability to store many more bits per wafer has been the engine of a “virtuous cycle:” lower bit costs open up new markets, which lead to growth in demand, which attracts new investments. “Reducing the costs of our technology opens up new markets. We know how well this has been working. However, this virtual cycle can quickly turn into a vicious cycle. That is what has hap- pened the last couple of years,” said Sivaram, who heads up strategy and technology at Western Digital.
Over the last seven years the number of bits on a 300mm wafer has increase by 4.5 times, and the day is not far off when a single wafer will hold a petabyte. “That is what I want to happen, so we can (after packaging in a storage system) put a petabyte in your pocket.”
Equipment and Materials Productivity
Flash is expected to become a 100-billion-dollar industry in 2025, and now accounts for about 22 percent of the semiconductor industry’s capital expenditures, even though revenues account for roughly 11 percent of chip industry revenues. That forward-looking investment strategy, which he said rivals that of a Las Vegas gambler betting on a future card, requires that all members of the value chain do their part to keep costs under control.
“What I worry about is capital efficiency. How much it takes to increase the number of bits by one percent is going through the roof. For every generation, the extra spending is so much more,” he said.
Besides what he claimed was slowing productivity of capital equipment, materials are becoming more expensive. Materials, both direct and indirect, now claim more than 26 percent of the total wafer cost. He mentioned the rising cost of gases such as xenon and krypton.
“If you spend 30 percent of revenue in capital spending, and another 26 percent of every wafer goes to materials, this is where that nice, beautiful, virtual cycle can get ugly,” Sivaram said, calling on “everyone in the this room” to work to “share value appropriately.”
“I need to get to better capital productivity for this great story to continue and for us all to be gainfully employed,” Sivaram concluded.