Flash future
Schiltron Corporation, a 3-D Flash start up company, has partnered with Entrepix, a leading provider of CMP equipment and services for semiconductor and other advanced materials, to develop a method to manufacture 3-D Flash using existing materials, tools and processes, thus enabling a straightforward path to volume scale up. Chemical mechanical planarization (CMP) represented the most critical process step that had to be achieved to prove that Schiltron’s approach to 3-D flash was viable. The company’s joint development efforts led to the manufacture of the smallest silicon-based TFTs to date, with first silicon proving operational.
The revolutionary transistor architecture and low thermal budget process sequence allow these devices to form the basis of a monolithic 3-D Flash that is projected to gradually displace traditional NAND Flash memory in mass-storage applications such as MP3 players, digital photography and solid-state drives. Schiltron’s approach, in which achieving the CMP step proved critical, produced the smallest known silicon-based thin-film transistors with 48 nm gate length, 45 nm gate width and 35 nm channel thickness.
“The scalability of NAND Flash is coming to an end. Monolithic 3-D approaches will take over to fuel this multi-billion dollar market,” said Andrew J. Walker, Founder and President of Schiltron. “We at Schiltron wanted to show feasibility of our approach using existing materials and infrastructure. Entrepix’ foundry services, process expertise and integration know-how were key to hitting this milestone.”
One of the key goals for Schiltron was to reach proof-of-concept for its device architecture using Entrepix’ expertise in advanced CMP processes, which was leveraged at two key points in the device flow: the creation of the first gate and the formation of the ultra-thin channel, both of which are critical for device functionality.
“The novel device integration achieved in this project is a great example of the growing number of applications where CMP is the enabling process step for unique device architectures and whole new families of future products,” said Rob Rhoades, CTO of Entrepix. “The work Schiltron accomplished is a significant advancement for 3-D Flash technology, and is representative of the critical role that CMP will play in new materials and next generation devices.”
Schiltron, of Mountain View, CA, first introduced its device architecture at the most recent International Electron Devices Meeting (IEDM) in San Francisco, illustrating how the new device provides significant advantages over alternative approaches.
