SBIR Phase I: SiGeC Superlattices with Direct Bandgaps for Light Emission and Absorption at 1.55 Micronn

This Small Business Innovation Research (SBIR) Phase I will investigate breakthrough concepts to overcome the limitations imposed by the fundamental physical properties of silicon that prevent it from emitting and sensing light in the infrared range of wavelengths used in telecommunications. These limitations are the most important barrier to using light, instead of electrical signals, to transmit information within a CMOS chip, and between CMOS chips. Using optical, rather than electrical, interconnects will increase performance, decrease power dissipation (heat generation), and reduce manufacturing costs. The research objectives are the identification and demonstration of a new silicon-based material, a superlattice incorporating Silicon, Germanium and Carbon atoms, whose optoelectronic properties are comparable to those of III-V semiconductors from which the LASERs and Photo-Detectors currently used in optical communications, are made. The project will begin with theoretical modeling and simulation of several superlattice compositions, in order to identify the one with the most promising properties, which will then be fabricated and characterized, both as a stand-alone film and by incorporation into a basic photo-diode. It is anticipated that a new class of Si-Ge-C superlattice materials will enable high-efficiency silicon-based devices for light-emission and light-sensing in this range of wavelengths. The broader impact/commercial potential of this project will be in the area of Silicon Photonics, which is a core technology with applications to several fields. The most important field is CMOS manufacturing, where silicon photonics can help Moore's Law maintain its trajectory, overcoming the barrier posed by the limitations of electrical interconnects by replacing them with optical interconnects, within a chip and from chip-to-chip. Optical interconnects will increase performance, improve reliability, and lower power dissipation, while reducing manufacturing costs of leading-edge CMOS technology. Other high-volume applications include fiber optics communications for Fiber-To-The-Home (FTTH) by enabling more compact equipment, capable of more functionality at lower cost, and the replacement of legacy electrical connections for Ethernet, HDMI, DisplayPort, and USB, with lower cost optical cables. By extending the functionality of CMOS to handle light efficiently, both emission and absorption across a wide range of wavelengths, new applications will open up for imaging technology and true silicon photonics.