Acorn Technologies has developed a portfolio of Semiconductor technologies. Two are being marketed at present. The first of the semiconductor inventions is a significant advance on the industry’s efforts to improve the performance of silicon that is the basis of most semiconductor products. The second invention is a new form of transistor that will support the semiconductor industry’s continuing efforts to build more powerful computer processors and other advanced digital integrated circuits.
The use of strain to enhance electron and hole mobility of silicon for transistors has been extensively explored by the semiconductor industry. Several methods have been incorporated in commercial semiconductor devices but these methods do not scale well for future devices. It is well known that increasing the lattice spacing of silicon through strain enhances electron mobility and thereby improves transistor performance. The conventional method to achieve this uses deposition of silicon on silicon germanium. However this approach inevitably creates large numbers of defects into the strained silicon, resulting in significantly reduced production yield. Acorn Technologies has developed and patented methods that overcome this problem.
The Acorn strained silicon solutions avoid defects, are additive to existing strain technologies and improve with future device scaling.
Acorn Technologies’ metal source/drain technology has been developed in response to the many problems that occur when continuing to use conventional doped source and drain as transistors scale to smaller feature sizes. These problems include source and drain resistance which is a severe performance limiter and yield issues related to device variability arising from random dopants in the channel region of a transistor. The problem with using metal for the source and drain regions has historically been the Schottky barrier, formed between metal and a semiconductor, that limits current flow in transistors. Acorn is developing manufacturable solutions to the Schottky barrier problem which counter-intuitively employ a very thin separation layer between the source or drain metal and the transistor channel. When formed using appropriate manufacturing methods, the separation layer is able to virtually eliminate the Schottky barrier and enable metal source-drain transistors to exceed the performance of equivalently sized doped transistors. Applications extend beyond silicon to semiconductors such as germanium and graphene including emerging spin injection applications. This work is protected by issued and pending patents and some aspects have been described in refereed published papers.
The Acorn solution enables metal source-drain transistors to exceed the performance of conventional doped source drain devices in future nodes, possibly replacing them and enabling the continuation of Moore’s Law scaling.